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ABSTRACT On 30 June 2021, China was certified malaria-free by the World Health Organization. In this study, the evolution, performance, outcomes, and impact of China's adaptive strategy and approach for malaria elimination from 2011 to 2020 were analysed using 10-year data. The strategy and approach focused on timely detection and rapid responses to individual cases and foci. Indigenous cases declined from 1,308 in 2011 to 36 in 2015, and the last one was reported from Yunnan Province in April 2016, although thousands of imported cases still occur annually. The "1-3-7" approach was implemented successfully between 2013 and 2020, with 100% of cases reported within 24 h, 94.5% of cases investigated within three days of case reporting, and 93.4% of foci responses performed within seven days. Additionally, 81.6% of patients attended the first healthcare visit within 1-3 days of onset and 58.4% were diagnosed as malaria within three days of onset, in 2017-2020. The adaptive strategy and approach, along with their universal implementation, are most critical in malaria elimination. In addition to strengthening surveillance on drug resistance and vectors and border malaria collaboration, a further adapted three-step strategy and the corresponding "3-3-7" model are recommended to address the risks of re-transmission and death by imported cases after elimination. China's successful practice and lessons learnt through long-term efforts provide a reference for countries moving towards elimination.

Emerging artemisinin resistance in Southeast Asia poses a significant risk to malaria control and eradication goals, including China's plan to eliminate malaria nationwide by 2020. Plasmodium falciparum was endemic in China, especially in Southern China. Parasites from this region have shown decreased susceptibility to artemisinin and delayed parasite clearance after artemisinin treatment. Understanding the genetic basis of artemisinin resistance and identifying specific genetic loci associated with this phenotype is crucial for surveillance and containment of resistance. In this study, parasites were collected from clinical patients from Yunnan province and Hainan island. The parasites were genotyped using a P. falciparum -specific single nucleotide polymorphism (SNP) microarray. The SNP profiles examined included a total of 27 validated and candidate molecular markers of drug resistance. The structure of the parasite population was evaluated by principal component analysis by using the EIGENSOFT program, and ADMIXTURE was used to calculate maximum likelihood estimates for the substructure analysis. Parasites showed a high prevalence of resistance haplotypes of pfdhfr and pfdhps and moderate prevalence of pfcrt. There was no mutation identified on pfmdr1. Candidate SNPs on chromosomes 10, 13, and 14 that were associated with delayed parasite clearance showed a low prevalence of mutants. Parasites from Southern China were clustered and separated from those from Southeast Asia. Parasites from Yunnan province were substructured from parasites from Hainan island. This study provides evidence for a genomic population with drug resistance in Southern China and also illustrates the utility of SNP microarrays for large-scale parasite molecular epidemiology., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Huang, Jacob, Takala-Harrison, Adams, Yang, Liu, Xia, Zhou, Tang and Plowe.)

Background: The emergence and spread of artemisinin resistance in Plasmodium falciparum poses a threat to malaria eradication, including China's plan to eliminate malaria by 2020. Piperaquine (PPQ) resistance has emerged in Cambodia, compromising an important partner drug that is widely used in China in the form of dihydroartemisinin (DHA)-PPQ. Several mutations in a P. falciparum gene encoding a kelch protein on chromosome 13 (k13) are associated with artemisinin resistance and have arisen spread in the Great Mekong subregion, including the China-Myanmar border. Multiple copies of the plasmepsin II/III (pm2/3) genes, located on chromosome 14, have been shown to be associated with PPQ resistance., Methods: The therapeutic efficacy of DHA-PPQ for the treatment of uncomplicated P. falciparum was evaluated along the China-Myanmar border from 2010 to 2014. The dry blood spots samples collected in the efficacy study prior DHA-PPQ treatment and from the local hospital by passive detection were used to amplify k13 and pm2. Polymorphisms within k13 were genotyped by capillary sequencing and pm2 copy number was quantified by relative-quantitative real-time polymerase chain reaction. Treatment outcome was evaluated with the World Health Organization protocol. A linear regression model was used to estimate the association between the day 3 positive rate and k13 mutation and the relationship of the pm2 copy number variants and k13 mutations., Results: DHA-PPQ was effective for uncomplicated P. falciparum infection in Yunnan Province with cure rates > 95%. Twelve non synonymous mutations in the k13 domain were observed among the 268 samples with the prevalence of 44.0% and the predominant mutation was F446I with a prevalence of 32.8%. Only one sample was observed with multi-copies of pm2, including parasites with and without k13 mutations. The therapeutic efficacy of DHA-PPQ was > 95% along the China-Myanmar border, consistent with the lack of amplification of pm2., Conclusion: DHA-PPQ for uncomplicated P. falciparum infection still showed efficacy in an area with artemisinin-resistant malaria along the China-Myanmar border. There was no evidence to show PPQ resistance by clinical study and molecular markers survey. Continued monitoring of the parasite population using molecular markers will be important to track emergence and spread of resistance in this region.

Coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused great public concern worldwide due to its high rates of infectivity and pathogenicity. The Chinese government responded in a timely manner, alleviated the dilemma, achieved a huge victory and lockdown has now been lifted in Wuhan. However, the outbreak has occurred in more than 200 other countries. Globally, as of 9:56 am CEST on 19 May 2020, there have been 4,696,849 confirmed cases of COVID-19, including 315,131 deaths, reported to Word Health Organization (WHO). The spread of COVID-19 overwhelmed the healthcare systems of many countries and even crashed the fragile healthcare systems of some. Although the situation in each country is different, health workers play a critical role in the fight against COVID-19. In this review, we highlight the status of health worker infections in China and other countries, especially the causes of infection in China and the standardised protocol to protect health workers from the perspective of an anaesthesiologist, in the hope of providing references to reduce medical infections and contain the COVID-19 epidemic., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2020 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.)

Background: China is facing challenges of the shifting presentation of tuberculosis (TB) from younger to elderly due to an ageing population, longer life expectancy and reactivation disease. However, the burden of elderly TB and influence factors are not yet clear. To fill the gap, we generated a cohort study to measure the magnitude of TB incidence and associated factors among the elderly population aged 65 years and above in China., Methods: In this cohort established in 2013 through a prevalence survey conducted in selected sites, a total of 34 076 elderlies without TB were enrolled into two-year follow-up. We used both active and passive case findings to find out all TB patients among them. The person-year (PY) incidence rates for both bacteriologically positive TB and active TB were calculated. Cox proportional regression model was performed to test effect of risk factors, and the population attributable fraction (PAF) of each risk factor contributing to incident TB among elderlies was calculated., Results: Over the two-year follow-up period, a total of 215 incident active TB were identified, 62 of which were bacteriologically positive. The incidence rates for active TB and bacteriologically positive TB were 481.8 per 100 000 PY (95% CI: 417.4-546.2 per 100 000 PY) and 138.9 per 100 000 PY (95% CI: 104.4-173.5 per 100 000 PY), respectively. Incident cases detected by active case finding were significantly higher (P < 0.001). Male, non-Han nationality, previously treated TB, ex/current smoker and body mass index (BMI) < 18.5 presented as independent predictors for developing TB disease. For developing bacteriologically positive TB, the biggest contribution was from self-reported ex or current smoker (18.06%). And, for developing active TB, the biggest contribution was from non-Han nationality (35.40%), followed by male (26.80%) and age at 75 years and above (10.85%)., Conclusions: Ageing population in China had a high TB incidence rate and risk to develop TB disease, implying that National TB Program (NTP) needs to prioritize for elderly. Active case finding should be applied capture more active TB cases among this particular population, especially for male, non-Han nationality, and those with identified risk factors.

Peniterester (1), a new tricyclic sesquiterpene, together with 6 known compounds (2-7) were isolated from the secondary metabolites of an artificial mutant Penicillium sp. T2-M20 which was obtained from the parental strain Penicillium sp. T2-8 via UV irradiation as well as nitrosoguanidine (NTG) induction. Peniterester was only produced by the mutant T2-M20 on the basis of LC-MS analysis. Meanwhile, the results of in vitro bioactivities screening indicated that peniterester owned obvious antibacterial activities against Bacillus subtilis, Escherichia coli and Staphylococcus aureus with MICs of 8.0, 8.0 and 4.0 μg/mL, respectively., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Background: To estimate the prevalence of elevated blood glucose level (EBG, including type 2 diabetes mellitus and impaired fasting glucose), and its association with non-valvular atrial fibrillation (NVAF) in Guangzhou, China., Methods: The population-based follow-up Guangzhou Heart Study collected baseline data from July 2015 to August 2017 among 12,013 permanent residents aged > 35 from 4 Guangzhou districts. Two streets (Dadong and Baiyun) in the Yuexiu District, and one street (Xiaoguwei) and two towns (Xinzao and Nancun) in the Panyu District were chosen as representative of urban and rural areas, respectively. Each participant completed a comprehensive questionnaire, and underwent physical examination, blood sample collection for laboratory testing, electrocardiography, and other evaluations. Multivariable logistic regression analyses were used to estimate the independent association between hyperglycemia and NVAF prevalence., Results: The prevalence of EBG in overall study population was 29.9%. Compared with residents without EBG, the odds ratio (OR) for AF among residents with EBG was significantly higher (1.94, 95% confidence interval [CI]: 1.40-2.70, P <  0.001), even after multivariate adjustment for metabolic abnormalities (OR = 1.60, 95% CI: 1.14-2.25, P = 0.007), and driven by women (OR = 1.80, 95% CI: 1.12-2.91, P = 0.016)., Conclusions: In Guangzhou, China, prevalence of EBG is high among residents aged > 35 years and associated with a multivariate adjusted increase in prevalence of NVAF overall and in women.

Background: Malaria reduction and future elimination in China is made more difficult by the importation of cases from neighboring endemic countries, particularly Myanmar, Laos, and Vietnam, and increased travel to Africa by Chinese nationals. The increasing prevalence of artemisinin resistant parasites across Southeast Asia highlights the importance of monitoring the parasite importation into China. Artemisinin resistance in the Mekong region is associated with variants of genes encoding the K13 kelch domain protein (pf13k), found in specific genetic backgrounds, including certain alleles of genes encoding the chloroquine resistance transporter (pfcrt) and multidrug resistance transporter PgH1 (pfmdr1)., Methods: In this study we investigated the prevalence of drug resistance markers in 72 P. falciparum samples from uncomplicated malaria infections in Tengchong and Yingjiang, counties on the Yunnan-Myanmar border. Variants of pf13k, pfcrt and pfmdr1 are described., Results: Almost all parasites harboured chloroquine-resistant alleles of pfcrt, whereas pfmdr1 was more diverse. Major mutations in the K13 propeller domain associated with artemisinin resistance in the Mekong region (C580Y, R539T and Y493H) were absent, but F446I and two previously undescribed mutations (V603E and V454I) were identified. Protein structural modelling was carried out in silico on each of these K13 variants, based on recently published crystal structures for the K13 propeller domain. Whereas F446I was predicted to elicit a moderate destabilisation of the propeller structure, the V603E substitution is likely to lead to relatively high protein instability. We plotted these stability estimates, and those for all previously described variants, against published values for in vivo parasitaemia half-life, and found that quadratic regression generates a useful predictive algorithm., Conclusion: This study provides a baseline of P. falciparum resistance-associated mutations prevalent at the China-Myanmar border. We also show that protein modelling can be used to generate testable predictions as to the impact of pfk13 mutations on in vivo (and potentially in vitro) artemisinin susceptibility., Competing Interests: The authors have declared that no competing interests exist.

Large numbers of DNA sequences deposited in the International Nucleotide Sequence Databases (INSD) are erroneously annotated. The erroneous information may lead to misleading conclusions or cause great economic losses to farmers. Lentinus edodes (= Lentinula edodes (Berk.) Pegler) is one of the most important and popular culinary-medicinal mushrooms with a high nutritional value. In this study, experimental and in silico methods were used to correct the sequences annotated as L. edodes in the INSD. A total of 3,426 nucleotide entries were retrieved from public databases, including 140 different types of genetic sequences. Excluding 1,893 genome sequences, the most abundant signatures represented by ITS (258) and IGS1 (259) sequences accounted for 33.23% of the total entries. A total of 3,058 sequences were annotated correctly, 350 were indeterminate, and 18 were annotated erroneously based on the two methods. Correction of sequences will be beneficial for species identification and annotation. Phylogenic analysis based on ITS sequences suggested that L. edodes segregate in four clades in the tree based on ITS sequences. The isolates from China were distributed into two clades. In L. edodes, the intraspecific variation of the ITS2 sequences was much higher than that of the ITS1 sequences. In addition, the genetic diversity of the L. edodes sequences from China was much higher than that of any other regions included in this study. The northwest and southwest regions of China were L. edodes diversity centers.

Background: Recent gains in reducing the global burden of malaria are threatened by the emergence of Plasmodium falciparum resistance to artemisinins. The discovery that mutations in portions of a P. falciparum gene encoding kelch (K13)-propeller domains are the major determinant of resistance has provided opportunities for monitoring such resistance on a global scale., Methods: We analyzed the K13-propeller sequence polymorphism in 14,037 samples collected in 59 countries in which malaria is endemic. Most of the samples (84.5%) were obtained from patients who were treated at sentinel sites used for nationwide surveillance of antimalarial resistance. We evaluated the emergence and dissemination of mutations by haplotyping neighboring loci., Results: We identified 108 nonsynonymous K13 mutations, which showed marked geographic disparity in their frequency and distribution. In Asia, 36.5% of the K13 mutations were distributed within two areas--one in Cambodia, Vietnam, and Laos and the other in western Thailand, Myanmar, and China--with no overlap. In Africa, we observed a broad array of rare nonsynonymous mutations that were not associated with delayed parasite clearance. The gene-edited Dd2 transgenic line with the A578S mutation, which expresses the most frequently observed African allele, was found to be susceptible to artemisinin in vitro on a ring-stage survival assay., Conclusions: No evidence of artemisinin resistance was found outside Southeast Asia and China, where resistance-associated K13 mutations were confined. The common African A578S allele was not associated with clinical or in vitro resistance to artemisinin, and many African mutations appear to be neutral. (Funded by Institut Pasteur Paris and others.).

Like other developing countries, China was reported to have a relatively high seroprevalence of anti-hepatitis A antibodies (anti-HAV). However, no studies have evaluated the prevalence of anti-HAV and HAV RNA among voluntary blood donors with or without elevated serum alanine transaminase (ALT) levels. Anti-HAV antibodies were detected using an enzyme-linked immunosorbent assay, and reverse transcription quantitative polymerase chain reaction was carried out for detection of HAV RNA. In the current study, we analyzed a total of 450 serum samples with elevated ALT levels (≥40 U/L) and 278 serum samples with non-elevated ALT levels. Seroprevalence rates of anti-HAV were 51.6% in donors with elevated ALT and 41.4% in donors with non-elevated ALT; however, none of the samples was positive for HAV RNA. The results of our study showed lower seroprevalence rates of anti-HAV in blood donors (irrespective of ALT levels) than those in published data on Chinese populations. Although donors with elevated ALT had statistically higher prevalence rates of anti- HAV than did those with non-elevated ALT, none of the serum samples had detectable levels of the active virus. In conclusion, our results demonstrate that the transmission of hepatitis A by blood transfusion will occur rarely.

Background: Artemisinin-based combination therapy (ACT) is the recommended first-line treatment of falciparum malaria in all endemic countries. Artemisinin resistance in Plasmodium falciparum has been confirmed in the Greater Mekong subregion (GMS). Dihydroartemisinin-piperaquine (DAPQ) is the most commonly used ACT in China. To understand the DAPQ sensitivity of P. falciparum, DAPQ resistance was monitored in vivo along the China-Myanmar border from 2007 to 2013., Methods: Eligible patients with mono-infections of P. falciparum were recruited to this study after obtaining full informed consent. DAPQ tablets for different categories of kg body weight ranges were given once a day for three days. Patients were followed up for 42 days. Polymerase chain reaction (PCR) was conducted to distinguish between re-infection and recrudescence, to confirm the Plasmodium species. The data were entered and analysed by the Kaplan-Meier method. Treatment outcome was assessed according to the WHO recommended standards., Results: 243 patients were completed valid follow-up. The fever clearance time (FCT) and asexual parasite clearance times (APCT) were, respectively, 36.5 ± 10.9 and 43.5 ± 11.8 hours, and there was an increasing trend of both FCT (F = 268.41, P < 0.0001) and APCT (F = 88.6, P < 0.0001) from 2007 to 2013. Eight (3.3%, 95% confidence interval, 1.4-6.4%) patients present parasitaemia on day three after medication; however they were spontaneous cure on day four. 241 (99.2%; 95% CI, 97.1-99.9%) of the patients were adequate clinical and parasitological response (ACPR) and the proportions of ACPR had not changed significantly from 2007 to 2013 (X(2) = 2.81, P = 0.7288)., Conclusion: In terms of efficacy, DAPQ is still an effective treatment for falciparum malaria. DAPQ sensitivity in P. falciparum had not significantly changed along the China-Myanmar border of Yunnan Province, China. However more attentions should be given to becoming slower fever and parasite clearance.

Background: Plasmodium vivax is the most widespread of the malaria parasites infecting human hosts. In malaria-eliminating settings, both imported and local malaria predominantly occurs in border areas, and most of them are P. vivax. Chloroquine (CQ) is the first-line drug for P. vivax treatment in China. To understand CQ sensitivity in P. vivax, in vivo monitoring of CQ resistance was conducted along the China-Myanmar border from 2008 to 2013., Methods: Eligible patients with mono-infections of P. vivax were recruited to this study after obtaining full informed consent. CQ tablets for different categories of kg body weight ranges were given once a day for three days. Patients were followed up for 28 days. PCR was conducted to distinguish between re-infection and recrudescence, to confirm the Plasmodium species. The data were entered and analysed by the Kaplan-Meier method. Treatment outcome and sensitivity were classified according to the WHO recommended standards., Results: 603 patients were completed valid follow-up. The fever clearance time and asexual parasite clearance times were, respectively, 22.2 ± 10.2 and 38.1 ± 12.6 hours. 594 (98.5%) patients were adequate clinical and parasitological response (ACPR), and nine (1.5%) patients, who were late clinical failure (LCF) or resistant response level I (RI), were imported from the neighbouring districts of Myanmar., Conclusion: In terms of efficacy, CQ is still effective for vivax malaria treatment. Plasmodium vivax CQ sensitivity had not significantly changed along the China-Myanmar border of Yunnan Province, China.

Reduction patterns of Plasmodium falciparum and P. vivax malaria transmission and the role of an integrated strategy of case management and vector control are compared between different ecological zones. The epidemiology of malaria in Hainan and Yunnan provinces was disparate, even though distinct malaria control strategies have been adapted to different situations based on risk group, vector behaviours, local health infrastructure, and environmental conditions. The island Hainan appears to be victorious in eliminating malaria. However, there is still a long way to go to prevent the reintroduction of malaria in Hainan province and eliminating malaria in the border areas of Yunnan province. This review of the experiences and challenges from malaria control to elimination in Hainan and Yunnan provinces of southern China will provide a basis for the future elimination of malaria in the whole country., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The Global Fund to Fight AIDS, Tuberculosis and Malaria (GFATM) supported a project on the control and elimination of malaria in People's Republic of China which was one of the biggest-scale international cooperation programmes to control malaria in the country during the past 10 years. The project promoted the effective implementation of the Chinese national malaria control programme. On the basis of epidemiologic data, an overview of the project activities and key performance indicators, the overall impact of the GFATM project was evaluated. We also reviewed relevant programme features including technological and management approaches, with a focus on best practice, innovations in implementation and the introduction of international standards. Last, we summarised the multi-stakeholder cooperation mechanism and comments on its sustainability in the post-GFATM period. Recommendations for the future management of the Chinese national malaria elimination programme are put forward after considering the challenges, shortcomings and lessons learnt during the implementation of the GFATM project in China to sustain past achievements and foster the attainment of the ultimate goal of malaria elimination for the country., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

The Malaria Elimination Action Plan has been launched in China since 2010, to pursue the goal of national wide malaria elimination by 2020. To ensure the achievement of the goal, the strategy and interventions should be transited from control to elimination, based on the better understanding of malaria elimination. In this article, we delineate the difference between malaria control and elimination phase, and explain the importance of transition of the goal, strategy and interventions from control to elimination, also decrypt the background, definition, critical points and challenges of China's current malaria elimination strategy and interventions, to improve health workers' understanding and implementation of national elimination program at different levels, and eventually impact the progress of national elimination program.

Objective: To apply moving percentile method on surveillance and early-warning on visceral leishmaniasis in Kashgar Region and evaluate its effect., Methods: Incidence data of visceral leishmaniasis in Kashgar Region were collected from the National Web-based Infectious Diseases Report System. Monthly detection was carried out by using moving percentile method. The 50th percentile (P50), 70th percentile (P70) and 90th percentile (P90) of historical baseline data were calculated for drawing a control chart, and P70 was adopted as the warning threshold to determine whether an epidemic would appear. If the number of cases in one month is higher than the corresponding P70 of historical baseline data, the warning signal will be generated. The sensitivity, specificity and positive predictive value were calculated for the evaluation of early-warning effect., Results: During the study period, 61.0% cases were reported in the year of 2008 and 2009, the incidence peak was from September to December, accounting for 51.9%, and infants under 3 years old were the population most threatened by visceral leishmaniasis, accounting for 62.7%. A total of 58 detections were performed, and 17 warning signals were generated by the threshold on P70. Among them, the numbers of cases in 9 detections were higher than the corresponding P90 of historical-baseline data. Based on the actually epidemic status of visceral leishmaniasis in study period, according to the threshold on P70, a total of 10 warning signals of 11 epidemics were detected, and the sensitivity of the warning model was 90.9% (10/11). 7 wrongly signals of 47 non-epidemics were detected, and the specificity was 85.1% (40/47). 10 of 17 signals were proved to be correct, and the positive predictive value was 58.8% (10/17)., Conclusion: The moving percentile method can effectively perform surveillance and early-warning on visceral leishmaniasis in Kashgar Region.

Background: Visceral leishmaniasis (VL) was once a severe parasitic disease in China. Thanks to the great efforts of integrated control, VL was eliminated in most epidemic areas, except for certain western provinces (autonomous region) at the end of 1950s. From then on, VL gained less attention and has seemed to spread, especially in the last 15 years. Infants are the most important population threatened by VL. However, there have been few studies on the endemic characteristics of infantile VL in China., Methods: Infantile VL cases were collected from the online National Infectious Diseases Reporting System (NIDRS). Statistical description and inference was used to reveal the endemic characteristics in gender, age group, time and regionalism. Spatial analysis was carried out to explore the high risk area for infantile VL in China., Results: A total of 1093 infantile VL cases were reported from 2006 to 2012. There was no statistically significant difference in gender over time. The minimum, maximum and mean age of these cases was 1.1, 35.9 and 13.8 months, respectively. Among them 86.92% were under 2 years of age, and there was a statistically significant difference among age groups over time. An incidence peak appeared in 2008-2009, most cases were distributed in the months September to December, and there was a tail-raising effect in the coming two months of the next year. More than 98% of cases were reported in Xinjiang Uygur Autonomous Region, Gansu Province and Sichuan Province, accounting for 61.02%, 32.75% and 4.57%, respectively. A total of 56 counties reported infantile VL cases, with the cumulative incidence ranging from 0.02 to 24.57%. There were two main zones of high endemicity for infantile VL in China. The monthly incidence clearly coincides with the number of towns where infantile VL cases were reported. Three fatalities were reported during the study period, the case fatality rate was 2.75‰., Conclusions: The endemic situation of infantile VL is serious, and there are several active foci of infantile VL prevalence in China. VL has emerged as a severe threat to infants of endemic regions in China.

Objective: To define and evaluate the malaria transmission potential in the Yangtze River, following construction of the Three Gorges Reservoir., Methods: Six villages, namely, Kaixian, Fengjie, Wanzhou, Fuling, Yubei, and Zigui were selected for investigating the malaria transmission potential in the reservoir. Transmission potential was estimated by mathematical modeling and evaluation of the local malaria situation. Factors that influenced the transmission potential were analyzed using Poisson regression analysis in combination with Grey Systematic Theory (based on evaluation by the Delphi method)., Results: Indirect fluorescent antibody data and the incidence of malaria in the local population were consistent with the malaria transmission potential calculated for the area. Multivariate Poisson regression analysis showed a statistically significant association between the riparian zone and the man-biting rate., Conclusion: The risk of a malaria epidemic can be forecasted using the malaria transmission potential parameters investigated here which was closely correlated with the riparian zone., (Copyright © 2013 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.)

Objective: Our objective was to systematically evaluate chemotherapy-based control of ascariasis and hookworm infection and make predictions of the effectiveness of repeated mass treatment at different levels of coverage in highly endemic areas of China., Methods: Field surveys were carried out to acquire the ascariasis and hookworm prevalence and intensity (mean worm burden) at baseline, one month and one year later. We calculated model parameters based on the survey data, then incorporated them into a quantitative framework to predict the prevalence and intensity one year later. Sensitivity analyses were performed to assess the influence of the chemotherapy measures on prevalence and intensity, and model simulations were performed to evaluate the feasibility of achieving the proposed transmission control criteria under different chemotherapy measures., Results: The predicted prevalence and intensity one year from baseline were within the 95% confidence interval of actual values. As treatment frequency or coverage increased, the prevalence and intensity decreased. Model simulations show that many rounds of treatment are needed to maintain the prevalence at a low level in highly endemic areas of China., Conclusion: We should select different combinations of treatment frequency, coverage and drug efficacy according to available resources and practical attainable conditions. Mathematical modeling could be used to help optimize the chemotherapeutic scheme aiming at specific parasitic species and areas, and to direct the establishment of soil-transmitted helminthiasis control criteria in China., (Copyright © 2012 The Editorial Board of Biomedical and Environmental Sciences. Published by Elsevier B.V. All rights reserved.)

Objectives: To study the major ecologic factors influencing the re-emergence of malaria in the areas along the Yellow River and Huai River by analyzing the relationship between the malaria incidence and the land use and cover change (LUCC)., Methods: The data of annual parasite incidence (API) and LUCC in the counties of Huaiyuan, Yongcheng and Tong ai in 1990-2006 were collected retrospectively. Considering the hysteresis effect of LUCC played on malaria transmission, analysis of LUCC in these counties were conducted based on the data of 1990-1995 and 1996-2000, while the API data in 1996-2000 and 2001-2005 were used to analyze the trends and changes of malaria incidence. The correlation and trend analyses were conducted between LUCC and malaria incidence change in the periods., Results: The LUCC in 1990-1995 in Tongbai County was significant, being 3 265.79% in the farmland and -90.42% in paddy field. The increase of malaria incidence in Tongbai was also significant in 1996-2000, the change rate was 2 799.70%, showing a positive correlation. The LUCC of other 2 counties in 1990-1995 was -0.27% and -0.78%, respectively, while the rate of malaria incidence change in 1996-2000 was 206.25% and 0.00%. The LUCC of the 2 counties in 1996-2000 was -0.08% and -0.50%, while the rate of malaria incidence change in 2001-2005 was 153.22% and 2 500.00%, respectively. It indicated that there was no significant relationship between malaria re-emergence and LUCC in Huaiyuan and Yongcheng Counties., Conclusion: It seems that the LUCC shows no significant impact on malaria re-emergence in areas along the Yellow River and Huai River since 2001, though there was a positive correlation between the two in Tonghai County in the late 1990s.

Objective: To investigate the status of controllable risk factors of cardiovascular disease in Chinese pilots., Methods: Pilots in seven regions of China were selected with cluster sampling. The rates of hypertension, diabetes mellitus,smoking and abnormal body mass index (BMI) as well as levels of total cholesterol, triglyceride and high density lipoprotein-cholesterol were obtained., Results: (1) A total of 5012 pilots were selected and 4684 pilots whose data were effective were studied. (2) The prevalence rates of hypertension, high total cholesterol, triglyceride, low high density lipoprotein-cholesterol and diabetes mellitus were 8.07%, 7.47%, 14. 45%, 27.63% and 0.43%, respectively. The rate of smoking was 66.45%. The rat of increased BMI was 49.64%. (3) Significant difference existed on the rates of hypertension, total cholesterol, triglyceride, low high density lipoprotein-cholesterol, smoking and abnormal BMI among pilots from different regions (all P < 0.01). There was also a significant difference between the rates of hypertension, total cholesterol, triglyceride, smoking and abnormal BMI in different age groups (all P < 0.01). The rate of low high density lipoprotein-cholesterol was similar in different age groups (P > 0.05). (4) 88.96% of the participants had at least one controllable risk factor. 54.46% of the participants had at least two controllable risk factors. None of the participants had more than seven risk factors. There was a significant difference between the rates of pilots who have more than two controllable risk factors in different regions (P < 0.01). There was a significant difference between the rates of pilots who have more than two risk factors in different age groups (P < 0.01)., Conclusions: There was high prevalence of controllable cardiovascular risk factors in Chinese pilots. Active intervention targeting these cardiovascular disease risk factors needs to be considered to reduce the risk of developing cardiovascular disease in Chinese pilots.

Objective: To investigate the intelligence level and characteristics of cognitive structure of school-age children infected with soil-transmitted helminthes (STH) (hookworm, Ascaris lumbricoides and Trichuris trichiura)., Methods: 1 031 children of 9 to 12 years old from Baishui village of Guangxi, Longzhou and Xinzhu villages of Hainan were selected for the survey. Stool samples from children were collected and examined by modified Kato-Katz method. 77 children infected with only one species (hookworm, A. lumbricoides, or T. trichiura) were used as case group and 39 healthy children as control. The cognitive ability for children were assessed by WISC-LV., Results: A total of 378 cases with STH infection was found from 1 031 children, and the overall prevalence of STH infection was 36.7%. The prevalence of moderate and heavy STH infections was 16.8% (173/1 031). The verbal comprehension (VCI), working memory (WMI), processing speed (PSI) and full scale IQ (FSIQ) indices of case group were lower than those of control group (P < 0.05). The VCI (97.2), WMI (84.6), PSI (91.1) and FSIQ (95.4) indices in moderate/heavy infection group were lower than those in light infection group (99.2, 103.3, 88.3 and 99.1, respectively) and control group (102.0, 104.2, 91.9 and 100.1, respectively) (P < 0.05). The WMI index in hookworm infection group (83.7) was lower than that in A. lumbricoides (87.6) or T. trichiura (88.3) infection groups (P < 0.05). The PSI index of T. trichiura infection group (92.8) was lower than that of A. lumbricoides (97.3) or hookworm (94.4) infection groups (P < 0.05)., Conclusion: The total intelligence level of STH infection children is in a normal range, or on borderline. The low VCI, WMI, PSI indices have been found in moderate/heavy STH infection children.

Background: Malaria still represents a significant public health problem in China, and the cases dramatically increased in the areas along the Huang-Huai River of central China after 2001. Considering spatial aggregation of malaria cases and specific vectors, the geographical, meteorological and vectorial factors were analysed to determine the key factors related to malaria re-emergence in these particular areas., Methods: The geographic information of 357 malaria cases and 603 water bodies in 113 villages were collected to analyse the relationship between the residence of malaria cases and water body. Spearman rank correlation, multiple regression, curve fitting and trend analysis were used to explain the relationship between the meteorological factors and malaria incidence. Entomological investigation was conducted in two sites to get the vectorial capacity and the basic reproductive rate to determine whether the effect of vector lead to malaria re-emergence., Results: The distances from household of cases to the nearest water-body was positive-skew distributed, the median was 60.9 m and 74% malaria cases were inhabited in the extent of 60 m near the water body, and the risk rate of people live there attacked by malaria was higher than others(OR = 1.6, 95%CI (1.042, 2.463), P < 0.05). The annual average temperature and rainfall may have close relationship with annual incidence. The average monthly temperature and rainfall were the key factors, and the correlation coefficients are 0.501 and 0.304(P < 0.01), respectively. Moreover, 75.3% changes of monthly malaria incidence contributed to the average monthly temperature (T(mean)), the average temperature of last two months(T(mean₀₁)) and the average rainfall of current month (R(mean)) and the regression equation was Y = -2.085 + 0.839I₁ + 0.998T(mean₀) - 0.86T(mean₀₁) + 0.16R(mean₀). All the collected mosquitoes were Anopheles sinensis. The vectorial capacity and the basic reproductive rate of An. sinensis in two sites were 0.6969, 0.4983 and 2.1604, 1.5447, respectively., Conclusion: The spatial distribution between malaria cases and water-body, the changing of meteorological factors, and increasing vectorial capacity and basic reproductive rate of An. sinensis leaded to malaria re-emergence in these areas.

On July 29, 2007, a severe coalmine-flooded disaster occurred in central China and 69 miners were trapped in an about 1400 m underground coal pit. Fortunately, all of them were rescued after 75 h of the ordeal. At 3 and 6 months after the disaster, psychopathological profiles, plasma levels of cortisol and adrenocorticotropic hormone (ACTH) were evaluated in 48 survivors for posttraumatic stress disorder (PTSD) and comorbid symptoms. Magnetic resonance imaging (MRI) study was performed at 6 months. The prevalence of PTSD was 35.4% (17/48) at 3 months and 31.3% (15/48) at 6 months post-disaster, with high rates of comorbid symptoms. Risk factors for PTSD included previous traumatic experience, less than 5 years of being a miner, in an extremely exhausted or sick during the disaster, poor interpersonal relationship and poor sleep quality experienced before the disaster. Mean plasma cortisol levels at 6 months, but not at 3 months, were significantly higher in PTSD-positive subjects than the negative, and positively correlated with the severity of several comorbid symptoms. Either whole or regional brain volumes of PTSD-positive subjects were not significantly different from PTSD-negative subjects, but PTSD subjects had significantly reduced fractional anisotropy values in the right posterior cingulum and bilateral hippocampal body compared to subjects without PTSD. These results suggest that traumatic exposure in severe coalmining disasters results in considerable psychological consequences, with highly prevalent PTSD and comorbid symptoms, which are associated with previous traumatic experience, shorter-length underground services, and poor interpersonal relationships and sleep quality experienced before the disaster. Baseline cortisol level may be a useful biological predictor for different phases of the development of PTSD. The aberrant connectivity of the hippocampus and the cingulum may represent an early pathological response to trauma exposure., (Copyright 2009 Elsevier Ltd. All rights reserved.)

Objective: To evaluate a gold-immunochromatographic assay (GICA) for malaria diagnosis in an endemic area of vivax malaria., Methods: Blood samples were collected from febrile patients in 5 township-hospitals of Mengcheng County, Anhui Province, between September and October 2008. The samples were examined by GICA and microscopy under double blind condition and the results were compared., Results: Among 292 blood samples, 181 were found P. vivax-positive by microscopy, and 163 were positive by GICA. Altogether, the coincidence of the two methods stood for 92.8% (271/292), including 108 negatives and 163 positives. 21 samples with discrepancy covered 18 microscopy positive but GICA negative, 3 microscopy negative but GICA positive. The GICA positive rate in patients with a parasitaemia of > 1,000 parasites/microl, 100-1,000 parasites/microl, and < 100 parasites/microl was 93.5% (115/123), 86.0% (43/50), and 62.5% (5/8), respectively., Conclusion: GICA is a useful diagnosis method for endemic area of vivax malaria.

Objective: In China, Chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) were abandoned for the treatment of falciparum malaria 20 years ago due to resistance. Subsequent field studies showed a trend of declining CQ and SP resistance in the country. The main purpose of this study was to analyse the molecular markers of antimalarial resistance and thereby to assess the possibility of reintroduction of CQ or SP for falciparum malaria treatment., Methods: Plasmodium falciparum field isolates were collected in 2006-2007 from Hainan and Yunnan provinces, China. Nested PCR-sequencing assays were applied to analyse the SNPs in four genes: P. falciparum chloroquine resistance transporter (pfcrt) gene, multi-drug resistance 1 (pfmdr1) gene, dihydrofolate reductase (dhfr) gene and dihydropteroate synthetase (dhps) gene., Results: We found the widespread presence of point mutations in the dhfr and dhps genes which are associated with SP treatment failure. The molecular analyses also showed the fairly high prevalence of point mutation in the pfcrt gene which is linked to CQ resistance., Conclusion: The results of the present study indicate that CQ and SP should not be reintroduced for falciparum malaria treatment in the near future in China.

Rhesus macaques (Macaca mulatta) serve as important animal models for human disease and vaccine research. Although Chinese rhesus macaques are the same species as those of Indian origin, they are from a geographically separated population and possess divergent major histocompatibility complex (MHC) class I A alleles. In an analysis of 65 Chinese rhesus macaques, 17 novel Mamu-A alleles were identified and deposited under the following accession numbers: EU252155-158, EU262737-741, EU418504-505, EU422996, EU418506, EU753185-187, and EU828528. The discovery of these additional MHC class I A sequences indicates a greater diversity and polymorphism of Chinese rhesus macaques in different geographic locations. As the set of Mamu-A alleles in Chinese rhesus macaques differs from the alleles of Indian animals, more work still needs to be carried out to identify these new allele-restricted immune responses with regard to vaccine studies.

Objective: To carry out national surveys for ascertaining the current status and trends of soil-transmitted nematode infections in China, providing scientific basis for further developing control strategies., Methods: In 1988-1992 (hereinafter abbreriated as "survey in 1990"), a stratified cluster random sampling method was used in the survey. In 2001-2004 (hereinafter abbreriated as "survey in 2003"), in order to compare with the survey in 1990, two-characteristic stratified cluster random sampling method was used and 687 investigation spots were sampled from the 2848 spots selected in the survey in 1990. Kato-Katz thick smear method was used to examine the eggs of soil-transmitted nematodes in fecal samples., Results: The prevalence rates were 53.6% and 19.6% for soil-transmitted nematodes, 14.6% and 6.120% for hookworms, 44.6% and 12.7% for Ascaris lumbricoides, 17.4% and 4.630% for Trichuris trichiura in survey 1990 and survey 2003, respectively. The prevalence rates of soil-transmitted nematodes were higher in 13 provinces than the average level in China in the survey in 1990, and higher in 8 provinces than the average level in the survey in 2003. The prevalence of hookworms, Ascaris lumbricoides, Trichuris trichiura and the overall prevalence of soil-transmitted nematodes were higher in females than in males. It is estimated from the results of survey in 2003 that the number of persons with soil-transmitted nematode infections in the country is about 129 million, less than that in the survey in 1990., Conclusion: The prevalence of soil-transmitted nematodes has declined considerably but is still relatively high in some provinces and autonomous regions. Control activities and socioeconomic development may have contributed to the decreased prevalence.

Objective: To study the morphology and ecological habits of An. anthropophagus and its role in malaria transmission in Hengqin Island of Zhuhai City, Guangdong Province., Methods: Mosquitoes were captured through overnight/semi-overnight trapping with human and cattle baits as well as lamp-trapping. The specimens were morphologically identified through describing the adult mosquitoes, eggs and pupae. The relevant parameters were collected to calculate the vectorial capacity of both An. anthropophagus and An. sinensis., Results: There is no morphological difference between the isolate of An. aothropophagus from Hengqin Island and that from Jiangsu Province. Its human blood preference ratio and human blood index was 0.94 and 0.75 respectively, and the vectorial capacity of An. anthropophagus was 7.36 times higher than that of An.sinensis (5.1914/0.7052)., Conclusion: The isolate of An. anthropophagus from Hengqin Island belongs same species to that from the mainland, which prefers to human blood and shows higher malaria transmission potential.

Objective: To explore the feasibility of using the capture-recapture method (CRM) for national malaria sentinel surveillance program and to evaluate the malaria prevalence at those points., Methods: By CRM to compare data on malaria cases reported from national sentinel surveillance program and those from the registration of case report system (CRS). Analysis was made to express the difference regarding the number of cases in order to get the estimates and the incidence rate., Results: The incidence in the relative higher epidemic area, unstable epidemic area and relative lower epidemic area were 1247.30/100000, 171.50/100000 and 46.10/100000, respectively. The rate of miss-reporting malaria cases in these areas were 65.20% ,45.32% and 66.67%, respectively., Conclusion: The situation of the malaria cases in the national sentinel surveillance points could be estimated,using the CRM.

In order to detect the nucleic acid of Puumala hantavirus, RNA was extracted from lungs of bank voles captured in Northeast China, and partial S and M genome segments of Puumala virus were amplified by RT-PCR and sequenced. Phylogenetic analysis suggested that Chinese Puumala virus had diverged from the common node of PUUV, with accumulating nucleotide substitutions and formed a distinct lineage from other Puumala viruses. Newly found Puumala virus was most closely related to the Kamiiso-8Cr-95 and Tobetsu-60Cr-93 strains which came from Japan and the muju strains which came from South Korea. By analysis of S and M genome segments of Puumala virus, we deduced a new Puumala virus subtype did exist in Northeast China.

Objective: To explore the application of seasonal time series ARIMA model in prediction of malaria incidence in an unstable malaria area., Methods: SPSS13.0 software was used to construct the ARIMA model based on the monthly malaria incidence of Huaiyuan and Tongbai counties in Huaihe River Valley, from Jan. 1998 to Dec. 2005, with consideration of residual un-correlation and conclusion. Akaike's information criterion (AIC) and Bayesian information criterion (BIC) were used to confirm the fitness of model. The constructed model was then applied to predict the monthly malaria incidence in 2006 and the incidence from ARIMA model was compared with the actual incidence, so as to evaluate the model's validity. Malaria incidence of 2007 was predicted by ARIMA model based on malaria incidence from 1998 to 2006., Results: Statistics assisted estimation of the significance of the fitted autoregressive and seasonal moving average coefficients (AR1=0.512, SMA1=0.609, P<0.01). ARIMA (1,0,0)(0,1,1)12 model, with AIC=67.01, BIC= 71.87 and white noise for predicting error, exactly fitted the incidence of the previous monthly incidence from Jan. 1998 to Dec. 2005, and the predicted monthly incidence in 2006 by the model was consistent with the actual incidence. Malaria incidence of 2007 would be 106.50/100 000, with a peak incidence during July and October., Conclusion: The model of ARIMA seems to be an appropriate model to fit exactly the changes of malaria incidence and to predict the future incidence trend, with a high prediction precision of short term time series.

Objective: To make a field investigation on the affecting factors of malaria outbreak in a village of Congjiang County, Guizhou Province., Methods: The investigation was made in August, 2006. Filter paper dry blood samples were taken for indirect fluorescent antibody test (IFAT) from all the 495 residents above 1 year-old in the village where an outbreak of malaria was reported. Questionnairing was conducted in 423 villagers over 10 years-old, covering malaria history in the past 2 years, knowledge on malaria and its control, use of mosquito nets, and out-door sleeping habit. Data on febrile outpatients were collected from the records of the township health center for analyzing the compliance of the patients in seeking medical services. Mosquito collecting by human-bait before mid-night, and in mosquito nets and cattle pens in early morning was performed for mosquito composition and man-biting rate., Results: Re-examination of the 42 positive blood smears confirmed 12 positives of P. vivax infection. The malaria incidence in 18 d was 2.1%, including 4 cases clinically diagnosed. The antibody positive rate of IFAT in the population was 8.7% (43/495) with a positive GMRT of 20.6, overall GMRT of 10.6; the IFAT positive rate in the age group of under 5 was 7.5% (3/40) with a GMRT of 25.1. The rate of seeking medical advice among febrile patients was 81.3% (118/145), 78.8% (93/118) of which being in the village clinic. The average time of going to a doctor after fever was 3.9 days, 37.4% (195/521) and 3.3% (17/521) were in 4-6 days and over 10 days respectively, with the longest 26 days. The average knowledge rate on malaria was 25.5% (108/423), with 17.1%, 29.2% and 40.0% in the groups of illiteracy, primary school and high school education respectively. A statistical significance was found between primary school/high school education and the illiteracy (P<0.01). The average rate of using mosquito nets was 31.0% (131/423), out-door sleeping rate was40.7% (172/423). The radical cure rate in 2004 and 2005 was 68.2% (15/22) and 48.3% (14/29) respectively. In addition to Anopheles sinensis, An. anthropophagus and An. minimus also existed in rooms and nets with a man-biting rate of 0.0566 and 0.0755 respectively., Conclusions: Three species of anopheline mosquitoes are the important transmitting vectors. Poor self-protection, outdoor sleeping habit, delayed examination and treatment, and irregular chemotherapy among the residents are the main factors resulting malaria outbreak.

The Hyrcanus group of Anopheles consists of many related species, of which An. sinensis, An. lesteri, and An. anthropophagus are known as malaria vector species. It is not possible to identify these species morphologically in the adult and larval stages. Nucleotide sequence alignment of 2nd internal transcribed spacer (ITS2) regions from 4 specimens of An. lesteri collected in Japan, 2 specimens of An. anthropophagus collected in China, and 1 specimen of An. sinensis collected in Korea were sequenced and compared. Sequences of ITS2 regions varied only at 4 sites between An. lesteri and An. anthropophagus, and individual variations among each An. lesteri and An. anthropophagus were found at 5 and 7 sites, respectively, whereas sequences varied at 161 sites between An. lesteri and An. sinensis. This molecular evidence strongly supports that An. lesteri from Japan and An. anthropophagus from China are the same species.

In 2004, 38,972 malaria cases and 106,704 suspected cases with 31 deaths were reported by the annual case reporting system in 1,005 counties of 23 Provinces/Municipality/Autonomous Region (P/ M/A) and the annual incidence was 0.38/10 000, a decrease of 4.2% than that of the last year, which is the year that the disease was slightly rolled back after consecutively increased since 2001. As an important development of the case reporting system, the internet reporting system started in 2004, majority of the malaria cases (38 254) were reported through internet from 1,074 counties of all the 30 P/M/A except Qinghai Province. Among the 1,005 counties with reported malaria cases, 32 counties were with an incidence of more than 10/10,000 distributing in Yunnan (19 counties), Hainan (10) and Anhui (3). There were 61 counties in which the malaria incidence was between 1/10,000 and 10/10,000. The number of Plasmodium falciparum malaria cases was 4,891, accounting for 12.6% of the total cases, of which 35.0% (1,714) were imported cases reported in 174 counties/cities of 18 P/M/A. Indigenous falciparum malaria was found in 45 counties/ cities of Yunnan and Hainan Provinces, of which 29 counties/cities were in Yunnan, decreased by 35, 16 were in Hainan, increased by 2 compared to that of 2003. Yunnan and Hainan Provinces are still the relatively high transmission areas. Yunnan has ranked No. 1 in the country in terms of the number of cases while Hainan ranked No. 1 by malaria incidence in recent years. 22 247 malaria cases were reported from the two provinces in 2004, accounting for 57.1% of the total reported cases in the country. There were 12,865 cases with 25 deaths reported from Yunnan, and the incidence was 3.09/10,000, a decrease of 16.6% than that in the last year. Among the reported cases, 3,251 were falciparum malaria, decreased by 7.9% in comparison to 2003. The number of reported cases in Hainan was 9 832, with an incidence of 11.64/10 000, 46.6% increase than the last year. In central China, the re-emergence of malaria was considerable in provinces along the Huai River, especially in Anhui Province. The case number in Anhui has been the second or third largest in the country since 2001. 8909 malaria cases and 14,542 suspected cases were reported from the Province in 2004, accounting for 22.9% of the total cases in the country, with an incidence of 1. 38/10,000 increased by 9.8% than that in 2003. Hubei reported 2,714 malaria cases with an incidence of 0.47/10,000, decreased by 60.8%. The number of reported cases in Henan was 2,211, decreased by 43.1%. 676 cases were reported from Jiangsu, almost the same as that in 2003. Focal outbreaks occurred in 109 villages of 13 counties in Anhui, Hubei and Jiangsu, where Anopheles sinensis is the principal transmission vector. Malaria cases reported from the above 4 provinces accounted for 37.2% of the national figure. Cases reported from Guizhou, Sichuan, Guangxi, Guangdong, Zhejiang, Shanghai and Hunan in southeast China occupied about 5% of the total cases, over 50% of which were imported cases. Less than 100 cases were reported from each of Fujian, Chongqing, Shandong, Jiangxi, Liaoning, Shaanxi, Shanxi, Gansu, Xinjiang and Heilongjiang Provinces in the year. In summary, although malaria cases slightly decreased after several years' consecutive increase, malaria is still an important problem of public health in China, especially in the southern and central parts. Yunnan and Hainan still face a critical situation of malaria endemics with the spread of P.falciparum, especially in the 25 border counties in Yunnan. In central parts of the country, especially in Anhui, malaria prevalence was highly unstable with frequent focal outbreaks in areas along the Huai River, which reveals new challenges to the national malaria control program.

Total 40,681 malaria cases and 129,147 suspected cases with 52 deaths were reported by the case reporting system in 910 counties of 21 Provinces/Municipality/Autonomous Region (P/M/A) in 2003, and the annual incidence was 0.39/10000, an increase of 15.3% than that of the last year, which is the third year that malaria incidence consecutively increased since 2001. Based on a baseline survey in the project funded by the Global Fund to Fight AIDS, Tuberculosis and Malaria (GFATM), the estimated number of malaria cases was about 740,000 in 2003, 18 times more than reported. Among the 910 counties with reported malaria cases, 29 counties with an incidence more than 10/10000 distributed in Yunnan (17 counties), Hainan (9), Anhui (1), Hubei (1) and Henan (1). There were 69 counties in which the malaria incidence was between 1/10000 and 10/10000. The number of Plasmodium falciparum malaria cases was 4727, accounting for 11.6% of the total cases, of which 13.1% (621) were imported cases reported in 107 counties/cities of 16 P/M/A. Indigenous falciparum malaria was found in 78 counties/cities of Yunnan and Hainan Provinces, of which 64 counties/cities were in Yunnan, increased by 22, 14 counties/cities were in Hainan, decreased by 2 compared to that of 2002. Yunnan and Hainan are stil the relatively high transmission areas. Yunnan has ranked No. 1 in the country in terms of the number of cases while Hainan ranked No. 1 by malaria incidence in recent years. 21,788 malaria cases were reported from the two provinces in 2003, accounting for 53.6% of the total reported cases in the country. There were 15 431 cases with 43 deaths reported from Yunnan, the incidence was 4.24/10000, with an increase of 26.3% than that in the last year. Among the reported cases, 3529 were falciparum malaria, increased by 22.9% in comparison to 2002. The number of reported cases in Hainan was 6357, with an incidence of 7.94/10000, 19.6% increase than the last year. In central China, the re-emergence of malaria was considerable in provinces along the Huai River, especially in Anhui Province. It should be stressed that the proportion of malaria cases was increasing in Anopheles sinensis transmitted areas where malaria was almost under control in the 1990s. The number of malaria cases in Anhui has been the second largest in the country since 2001. 8025 malaria cases and 18533 suspected cases were reported from Anhui in 2003, accounting for 19.7% of the total cases in the country, with an incidence of 1.53/10000 increased by 59.4% than that in 2002. Hubei Province reported 5 334 malaria cases with an incidence of 1.2/10000, increased by 33.3%. The number of reported cases in Henan and Jiangsu Provinces was 2 448 and 638 and the incidence decreased by 24.1% and 12.7% respectively. Focal outbreaks occurred in 222 villages of 9 counties in Anhui, Hubei and Jiangsu, where Anopheles sinensis is the principal transmission vector. Malaria cases reported from the above 4 provinces accounted for over 40% of the national figure. Cases reported from other P/M/A in the South and East China occupied about 6% of the total with certain degree of decrease, several hundreds from each of Guizhou, Guangxi, Sichuan, Guangdong, Fujian, Chongqing, Zhejiang, Shanghai and Hunan, more than 50% of which were imported cases. Less than 100 cases were reported from each of Shandong, Jiangxi, Liaoning, Shaanxi, Shanxi and Gansu Provinces in 2003. In summary, malaria is still an important problem of public health in China, especially in the southern and central parts where the incidence has been increasing since 2001. Yunnan and Hainan still faced critical situation of malaria endemics with a spread of Plasmodium falciparum, especially in the 25 border counties in Yunnan. In the central part of the country including Anhui, Hubei, Henan and Jiangsu, where Anopheles sinensis was the principal vector, the malaria prevalence was highly unstable with frequent focal outbreaks in areas along the Huai River, which revealed new challenges to the malaria control program in China. Meanwhile, opportunities also exist with the support of the GFATM and the government, the latter paid much closer attention recently to issues in relation to public health.

Objective: To establish Anopheles minimus density evaluation model based on climate, environmental and remote sensing data., Methods: 27 townships in 10 counties of Yunnan Province were chosen as field spots. Data on climate, environment, remote sensing and An. minimus density were collected from 1984 to 1993. Grey correlation analysis was carried out to study the relationship of 18 indices with An. minimus density. E variable was developed and its relation to the An. minimus density was analyzed to establish an evaluation model., Results: Eight indices were selected based on a grey threshold 0.70: Dry season average temperature > dry season temperature(min) > wet season temperature(min) > wet season NDVI > wet season average temperature > the ratio of paddy field in total arable land > dry season temperature(max) > wet sea son temperature(max). The An. minimus density evaluation model was derived as follows: [formula: see text] The correct rate of evaluation by the model was 92.0%. e0.5 = 18%, with an average relative error of 21%., Conclusion: A quasi-evaluation on the An. minimus density can be made by applying the grey model.

Objective: To compare the difference of resting habitat between Anopheles minimus A and An. minimus C in Yunnan Province., Methods: A village was selected in Mengla and Yuanjiang County respectively to collect mosquitoes by hanging ultraviolet lamps inside the cattle pen and human dwellings. The samples were identified by multiplex-PCR after morphological examination. Suspicious An. minimus A/C hybrid samples were identified by PCR-ASA, PCR-RFLP and D3 region sequence., Results: In human dwellings, the proportion of An. minimus A and C was 21.35% and 78.65%, and in cattle pen, 28.54% and 71.46% respectively. As for the An. minimus A/C hybrid, the result of PCR-ASA and PCR-RFLP displayed the pattern of both An. minimus A and An. minimus C (PCR-ASA: 376, 294 and 112 bp, PCR-RFLP:108, 268 and 376 bp), the D3 sequence displayed heterozygosis in the variation place of An. minimus A and An. minimus C, which means that the hybrid possesses the signal of both An. minimus A and An. minimus C., Conclusion: There is no resting habit difference between An. minimus A and An. minimus C in Yunnan Province. In Mengla County, 5 An. minimus A/C hybrids have been found for the first time.

Objective: To explore the epidemic regularity of malaria and encephalitis B by using the data of remote sensing (Rs) in flood area., Methods: The demarcation standards in counties with flood disaster were formed depending on the descriptive analysis results of remote sensing data and combined with that of field survey. Three indicators were used to analyze the epidemic situation of malaria and encephalitis B in Jiangxi Province during a heavy flooding in 1998: the increasing percentage of incidence in 1998 comparing with the median of past five years (1993-1997), the increasing percentage of incidence in 1998 comparing with that of 1997, the increasing percentage of incidence in 1999 comparing with that of 1998., Results: The demarcation standards of flooding counties were defined as follows: by Rs, a county with a flood area of over 100 thousand mu was classified into group one, a county with a flood area under 100 thousand mu was classified into group two, a county with reported flood but not identified by RS was classified into group three, the other counties in the province were classified into group four. The malaria incidence in the province in 1998 was at an average historical level. Compared with 1997, malaria incidence in each group increased in 1998 by 111.61% in group one, 97.50% in group two, 43.63% in group three. So there is an evident correlation between the flood area by Rs and the increasing of malaria incidence (Rs = 0.893, P < 0.05). Malaria incidence in 1999 in non-flood area increased by 83.39% in comparison with that of 1998. The encephalitis B incidence increased by 252.03% in 1998 in group four compared with that of 1997; while the incidence increased in all the four groups in 1999 than that of in 1998., Conclusion: The remote sensing data on flood can help fully analyze the epidemic situation of malaria and encephalitis B.

Objective: To study the thresholds and potential of malaria transmission by Anopheles anthropophagus in Hubei Province and provide indicators for the disease surveillance, early warning, prevention and control in the locality., Methods: From July to August 2001, field investigations on vectors and malaria situation were carried out in the village of Yanjiafan, Suizhou City, where the malaria incidence was high. The entomological investigations included the man-biting rate, the proportion of parous anophelines, the human blood index and the blood preference. The others included malaria incidence and parasite rate in human population, the intervals from episode to treatment of the cases, and collection of data on the mean temperature in the area. Based on the formula of basic reproductive rate, the critical man-biting rate was estimated., Results: 92.6% (63/68) of An. anthropophagus were found to have human blood meals, it occupied 91.5% (97/106) of the mosquitoes in human dwellings, its human blood index and vectorial capacity were 12.5 times (0.50/0.04) and 6.5 times (0.9448/0.1449) higher than those of An. sinensis. The critical man-biting rate was 0.2823 and the adjusted man-biting rate was 3.5 times of its critical man-biting rate (0.9892/0.2823). The malaria incidence was 0.65% (12/1844) and the parasite rate in pupils was 0.51%(1/198)., Conclusion: A reduction of the adjusted man-biting rate of An. anthropophagus by 71.5% is needed for interrupting malaria transmission by this vector in the study area.

Objective: To study the role of Anopheles anthropophagus in malaria transmission and transmission threshold so as to provide basis for vector surveillance and malaria control strategy., Methods: Parasitological and entomological methods were used in the investigation at 5 villages of Xinyang City, Henan Province., Results: From July to August, 1999, 74 febrile cases (10.9% of the total population) were examined. Among them 50 were infected, the incidence in the population of surveyed spots was 7.4%. Active detection was made in another randomly selected two villages and found that the parasite rate in the inhabitants was 2.0%, and the positive rate of IFA was 8.4%. Only vivax malaria was detected. An. anthropophagus and An. sinensis were collected, with An. anthropophagus as the predominant one in human dwellings. The estimated man-biting rate and the human blood index were 4.9388 and 0.7858 respectively. The vectorial capacity of An. anthropophagus was 5.5296. The critical man-biting rate of An. anthropophagus was 0.2407 as calculated by the formula (ma = -rlnP/abPh) according to Macdonald's model. The local man-biting rate was 20 times higher than that of the critical man-biting rate., Conclusion: The results demonstrated that An. anthropophagus is the principal vector in malaria transmission in the area. The findings imply that the critical man-biting rate is of practicable importance in vector surveillance.

Objective: To compare the practicability of IFAT in different malarious areas using Plasmodium cynomolgi(P.c.) and Plasmodium falciparum(P.f.) antigens., Methods: This survey was carried out in Yaliang Township of Sanya City, Hainan Province, where a mixed malaria is endemic, and in Tongbo County, Henan Province where only vivax malaria is endemic, and in Weihui City, Henan Province where vivax malaria has been under effective control since 1994-1998., Results: In Yaliang Township, 310 blood samples were examined, the antibody positive rates with P.c. and P.f. were 37.4% and 31.3%, respectively, the rate of coincidence being 83.9%. In Tongbo County, 300 blood samples were examined. The antibody positive rates with P.c. and P.f. were 23.0% and 9.7%, respectively (P < 0.01). Another 245 blood samples from children were examined in Weihui City and the antibody positive rates were below 1% with two antigens, while the positive antibody rate was 3.3% with P.f. antigen., Conclusion: Both P.f. and P.c. antigens could be used in malaria antibody surveillance in mixted endemic areas, while in vivax malaria endemic areas, P.c. antigen was recommended.