Search

Background: Scrub typhus (ST) is a life-threatening infectious disease if appropriate treatment is unavailable. Large discrepancy of clinical severity of ST patients was reported among age groups, and the underlying risk factors for severe disease are unclear. Methods: Clinical and epidemiological data of ST patients were collected in 55 surveillance hospitals located in Guangzhou City, China, from 2012 to 2018. Severe prognosis and related factors were determined and compared between pediatric and elderly patients. Results: A total of 2,074 ST patients including 209 pediatric patients and 1,865 elderly patients were included, with a comparable disease severity rate of 11.0% (95% CI 7.1%–16.1%) and 10.3% (95% CI 9.0%–11.8%). Different frequencies of clinical characteristics including lymphadenopathy, skin rash, enlarged tonsils, etc. were observed between pediatric and elderly patients. Presence of peripheral edema and decreased hemoglobin were the most important predictors of severe illness in pediatric patients with adjusted ORs by 38.99 (9.96–152.67, p<0.001) and 13.22 (1.54–113.50, p = 0.019), respectively, while presence of dyspnea and increased total bilirubin were the potential determinants of severe disease in elderly patients with adjusted ORs by 11.69 (7.33–18.64, p<0.001) and 3.17 (1.97–5.11, p<0.001), respectively. Compared with pediatric patients, elderly patients were more likely to receive doxycycline (64.8% v.s 9.9%, p<0.001), while less likely to receive azithromycin therapy (5.0% v.s 41.1%, p<0.001). Conclusion: The disease severity rate is comparable between pediatric and elderly ST patients, while different clinical features and laboratory indicators were associated with development of severe complications for pediatric and elderly patients, which is helpful for diagnosis and progress assessment of disease for ST patients. Author summary: The study investigated different clinical features and risk factors for severe disease between pediatric and elderly patients with scrub typhus. We found that significantly higher frequencies of lymphadenopathy, skin rash, enlarged tonsils, etc. were observed in pediatric patients than elderly patients. Other non-specific signs, subjective complaints, and chest radiographic abnormality were overpresented in elderly patients. Risk factors for severe disease between pediatric and elderly patients with scrub typhus were different. Presence of peripheral edema and decreased hemoglobin were the most important factors for pediatric patients, while presence of dyspnea and increased total bilirubin for elderly patients. These findings reminded medical workers to acknowledge this important difference and to adopt an age specific method in the differential diagnosis and risk assessment for scrub typhus. [ABSTRACT FROM AUTHOR]

Background: Tick-borne bacteria and protozoa can cause a variety of human and animal diseases in China. It is of great importance to monitor the prevalence and dynamic variation of these pathogens in ticks in ever-changing natural and social environment. Materials and Methods: Ticks were collected from Heilongjiang and Jilin provinces of northeastern China during 2018–2019 followed by morphological identification. The presence of Rickettsia spp., Anaplasma spp., Ehrlichia spp., Borrelia spp., Babesia spp., and Theileria spp. was examined by PCR and Sanger sequencing. The obtained sequences were subjected to phylogenetic analysis through Mega 7.0. Statistical analysis was performed using SPSS 24.0. Results: A total of 250 ticks from 5 species of 3 genera were collected. Ixodes and Haemaphysalis ticks carried more species of pathogens than Dermacentor, and the pathogens detected in Haemaphysalis japonica varied significantly among different sampling sites. The infection rates of Rickettsia spp., Anaplasma spp., Ehrlichia spp., Borrelia spp., Babesia spp., and Theileria spp. were 41.2%, 0, 2.0%, 7.2%, 1.2%, and 7.2%, respectively. Twelve pathogens were identified, among which Rickettsia raoultii (29.6%), Candidatus Rickettsia tarasevichiae (9.2%), and Theileria equi (4.4%) were the three most common ones. Rickettsia had its dominant vector, that is, R. raoultii had high infection rates in Dermacentor nuttalli and Dermacentor silvarum, Ca. R. tarasevichiae in Ixodes persulcatus, and Rickettsia heilongjiangensis in H. japonica. Interestingly, unclassified species were observed, including a Rickettsia sp., an Ehrlichia sp., a Borrelia sp., and a Babesia sp. Coinfections with different pathogens were identified in 9.2% of all tested ticks, with I. persulcatus most likely to be coinfected (23.8%) and Rickettsia spp. and Borrelia spp. as the most common combination (16.7%). Conclusions: The results of this study reflect high diversity and complexity of pathogens in ticks, which are useful for designing more targeted and effective control measures for tick-borne diseases in China. [ABSTRACT FROM AUTHOR]

Background: To date, there have been few investigations on Candidatus Rickettsia tarasevichiae in rodents carried out in China. In this study, we conducted surveillance for Candidatus R. tarasevichiae infection in rodents. A total of 463 rodents were captured at five survey sites in Mudanjiang, Heilongjiang province, where Candidatus R. tarasevichiae patients have been reported. PCR targeting citrate synthase and outer membrane protein genes was performed and positive amplicons were sequenced. Result:Candidatus R. tarasevichiae was detected in 1.29% of the 463 rodents sampled from the five survey sites in Mudanjiang, Heilongjiang province. Only 2 out of 13 (15.38%) Rattus norvegicus and 4 out of 80 (5%) Clethrionomys rufocanus collected from Dashigou forestry were positive for the gltA and ompA genes of Candidatus R. tarasevichiae DNA. The detected Candidatus R. tarasevichiae was in the same clade of sequences from patients in Mudanjiang based on phylogenetic analysis. Conclusion: Rodents are major host of ticks and also serve as reservoirs of spotted fever group (SFG) Rickettsia. Although this is the first confirmation of Candidatus R. tarasevichiae detected in rodents in China, further investigations are needed to clarify the distribution of Candidatus R. tarasevichiae in rodents elsewhere and what role they play as reservoirs. [ABSTRACT FROM AUTHOR]

Background: Outbreaks of monkeypox have been ongoing in non-endemic countries since May 2022. A thorough assessment of its global zoonotic niche and potential transmission risk is lacking. Methods: We established an integrated database on global monkeypox virus (MPXV) occurrence during 1958 − 2022. Phylogenetic analysis was performed to examine the evolution of MPXV and effective reproductive number (Rt) was estimated over time to examine the dynamic of MPXV transmissibility. The potential ecological drivers of zoonotic transmission and inter-regional transmission risks of MPXV were examined. Results: As of 24 July 2022, a total of 49 432 human patients with MPXV infections have been reported in 78 countries. Based on 525 whole genome sequences, two main clades of MPXV were formed, of which Congo Basin clade has a higher transmissibility than West African clade before the 2022-monkeypox, estimated by the overall Rt (0.81 vs. 0.56), and the latter significantly increased in the recent decade. Rt of 2022-monkeypox varied from 1.14 to 4.24 among the 15 continuously epidemic countries outside Africa, with the top three as Peru (4.24, 95% CI: 2.89–6.71), Brazil (3.45, 95% CI: 1.62–7.00) and the United States (2.44, 95% CI: 1.62–3.60). The zoonotic niche of MPXV was associated with the distributions of Graphiurus lorraineus and Graphiurus crassicaudatus, the richness of Rodentia, and four ecoclimatic indicators. Besides endemic areas in Africa, more areas of South America, the Caribbean States, and Southeast and South Asia are ecologically suitable for the occurrence of MPXV once the virus has invaded. Most of Western Europe has a high-imported risk of monkeypox from Western Africa, whereas France and the United Kingdom have a potential imported risk of Congo Basin clade MPXV from Central Africa. Eleven of the top 15 countries with a high risk of MPXV importation from the main countries of 2022-monkeypox outbreaks are located at Europe with the highest risk in Italy, Ireland and Poland. Conclusions: The suitable ecological niche for MPXV is not limited to Africa, and the transmissibility of MPXV was significantly increased during the 2022-monkeypox outbreaks. The imported risk is higher in Europe, both from endemic areas and currently epidemic countries. Future surveillance and targeted intervention programs are needed in its high-risk areas informed by updated prediction. [ABSTRACT FROM AUTHOR]

Background: Babesia, usually found in wild and domestic mammals worldwide, have recently been responsible for emerging malaria-like zoonosis in infected patients. Human B. microti infection has been identified in China, primarily in the Southwest along the Myanmar border but little direct surveillance of B. microti infection in rodents has been carried out here (Yunnan province). In this region, a diverse topographic range combined with tropical moisture sustains a high biodiversity of small mammals, which might play important role on Babesia transmission. Methods: Small mammals were captured in 141 sample locations from 18 counties located Yunnan Province, and screened for B. microti-like parasites infection by a nested PCR to target 18S rRNA gene of Babesia, plus directly sequencing for positive samples. Univariate and multivariate forward stepwise logistic regression analysis was used to access the association between infections and some related risk factors. Results: Infection with Babesia microti was confirmed in 2.4% (53/ 2204) of small mammals. Significant differences in prevalence rates of B. microti were observed based on variations in forest, agricultural, and residential landscapes. Furthermore, adult small mammals had higher prevalence rates than younger, pubertal mammals. The near full-length 18S rRNA gene revealed that there were two types of B. microti, Kobe and Otsu, which demonstrate the genetic diversity and regional distribution. Conclusions: There exists a wide distribution and genetic diversity of endemic B. microti in Southwestern China, warranting further investigations and monitoring of clinical disease in individuals presenting with Babesia like symptoms in these areas. [ABSTRACT FROM AUTHOR]

Background: Human adenovirus (HAdV) is a major pathogen that causes acute respiratory tract infections (ARTI) and is frequently associated with outbreaks. The HAdV prevalence and the predominant types responsible for ARTI outbreaks remains obscure in China. Methods: A systematic review was performed to retrieve literature that reported outbreaks or etiological surveillance of HAdV among ARTI patients in China from 2009 to 2020. Patient information was extracted from the literature to explore the epidemiological characteristics and clinical manifestations of the infection of various HAdV types. The study is registered with PROSPERO, CRD42022303015. Results: A total of 950 articles (91 about outbreaks and 859 about etiological surveillance) meeting the selection criteria were included. Predominant HAdV types from etiological surveillance studies differed from those in outbreak events. Among 859 hospital-based etiological surveillance studies, positive detection rates of HAdV-3 (32.73%) and HAdV-7 (27.48%) were significantly higher than other virus types. While nearly half (45.71%) of outbreaks were caused by HAdV-7 with an overall attack rate of 22.32% among the 70 outbreaks for which the HAdVs were typed by the meta-analysis. Military camp and school were main outbreak settings with significantly different seasonal pattern and attack rate, where HAdV-55 and HAdV-7 were identified as the leading type, respectively. Clinical manifestations mainly depended on the HAdV types and patient's age. HAdV-55 infection tends to develop into pneumonia with poorer prognosis, especially in children <5 years old. Conclusions: This study improves the understanding of epidemiological and clinical features of HAdV infections and outbreaks with different virus types, and helps to inform future surveillance and control efforts in different settings. Author summary: In this systematic review, we made an exhaustive search of published literature that reported outbreaks or etiological surveillance of HAdV among ARTI patients in China from 2009 to 2020. A total of 950 studies were included in this study, and we explored the epidemiological characteristics and clinical manifestations of the infection of various HAdV types. Positive detection rates of HAdV-3 (32.73%) and HAdV-7 (27.48%) were significantly higher than other virus types according to the hospital-based etiological surveillance studies. Nearly half (45.71%) of outbreaks were caused by HAdV-7 with an overall attack rate of 22.32% among the 70 outbreaks for which the HAdVs were typed by the meta-analysis. Military camp and school were main outbreak settings with significantly different seasonal pattern and attack rate, where HAdV-55 and HAdV-7 were identified as the leading type, respectively. Clinical manifestations mainly depended on the HAdV types and patient's age. HAdV-55 infection tends to develop into pneumonia with poorer prognosis, especially in children <5 years old. This study will help improve the epidemiological and clinical understanding of different HAdV types of human infections and thus will promote the targeted surveillance and measures to control and prevent HAdV infection. [ABSTRACT FROM AUTHOR]

• There is a higher incidence of severe fever with thrombocytopenia syndrome (SFTS) in selenium-deficient areas. • Mortality of SFTS is higher in severe selenium-deficient areas. • Insufficient serum selenium in humans is associated with poor prognosis in SFTS. Selenium deficiency can be associated with increased susceptibility to some viral infections and even more severe diseases. In this study, we aimed to examine whether this association applies to severe fever with thrombocytopenia syndrome (SFTS). An observational study was conducted based on the data of 13,305 human SFTS cases reported in mainland China from 2010 to 2020. The associations among incidence, case fatality rate of SFTS, and crop selenium concentration at the county level were explored. The selenium level in a cohort of patients with SFTS was tested, and its relationship with clinical outcomes was evaluated. The association between selenium-deficient crops and the incidence rate of SFTS was confirmed by multivariate Poisson analysis, with an estimated incidence rate ratio (IRR, 95% confidence interval [CI]) of 4.549 (4.215−4.916) for moderate selenium-deficient counties and 16.002 (14.706−17.431) for severe selenium-deficient counties. In addition, a higher mortality rate was also observed in severe selenium-deficient counties with an IRR of 1.409 (95% CI: 1.061−1.909). A clinical study on 120 patients with SFTS showed an association between serum selenium deficiency and severe SFTS (odds ratio, OR: 2.94; 95% CI: 1.00–8.67) or fatal SFTS (OR: 7.55; 95% CI: 1.14–50.16). Selenium deficiency is associated with increased susceptibility to SFTS and poor clinical outcomes. This is special type of abstract that is so short and could be inserted after main abstract of article, as a blurb or inserted as annotations into a Table of contents [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Viral pathogens belonging to the order Bunyavirales pose a continuous background threat to global health, but the fact remains that they are usually neglected and their distribution is still ambiguously known. We aim to map the geographical distribution of Bunyavirales viruses and assess the environmental suitability and transmission risk of major Bunyavirales viruses in China. Methods: We assembled data on all Bunyavirales viruses detected in humans, animals and vectors from multiple sources, to update distribution maps of them across China. In addition, we predicted environmental suitability at the 10 km × 10 km pixel level by applying boosted regression tree models for two important Bunyavirales viruses, including Crimean-Congo hemorrhagic fever virus (CCHFV) and Rift Valley fever virus (RVFV). Based on model-projected risks and air travel volume, the imported risk of RVFV was also estimated from its endemic areas to the cities in China. Results: Here we mapped all 89 species of Bunyavirales viruses in China from January 1951 to June 2021. Nineteen viruses were shown to infect humans, including ten species first reported as human infections. A total of 447,848 cases infected with Bunyavirales viruses were reported, and hantaviruses, Dabie bandavirus and Crimean-Congo hemorrhagic fever virus (CCHFV) had the severest disease burden. Model-predicted maps showed that Xinjiang and southwestern Yunnan had the highest environmental suitability for CCHFV occurrence, mainly related to Hyalomma asiaticum presence, while southern China had the highest environmental suitability for Rift Valley fever virus (RVFV) transmission all year round, mainly driven by livestock density, mean precipitation in the previous month. We further identified three cities including Guangzhou, Beijing and Shanghai, with the highest imported risk of RVFV potentially from Egypt, South Africa, Saudi Arabia and Kenya. Conclusions: A variety of Bunyavirales viruses are widely distributed in China, and the two major neglected Bunyavirales viruses including CCHFV and RVFV, both have the potential for outbreaks in local areas of China. Our study can help to promote the understanding of risk distribution and disease burden of Bunyavirales viruses in China, and the risk maps of CCHFV and RVFV occurrence are crucial to the targeted surveillance and control, especially in seasons and locations at high risk. [ABSTRACT FROM AUTHOR]

Background To combat the coronavirus disease 2019 (COVID-19) pandemic, nonpharmaceutical interventions (NPIs) were implemented worldwide, which impacted a broad spectrum of acute respiratory infections (ARIs). Methods Etiologically diagnostic data from 142 559 cases with ARIs, who were tested for 8 viral pathogens (influenza virus [IFV], respiratory syncytial virus [RSV], human parainfluenza virus [HPIV], human adenovirus [HAdV], human metapneumovirus [HMPV], human coronavirus [HCoV], human bocavirus [HBoV], and human rhinovirus [HRV]) between 2012 and 2021, were analyzed to assess the changes in respiratory infections in China during the first COVID-19 pandemic year compared with pre-pandemic years. Results Test-positive rates of all respiratory viruses decreased during 2020, compared to the average levels during 2012–2019, with changes ranging from −17.2% for RSV to −87.6% for IFV. Sharp decreases mostly occurred between February and August when massive NPIs remained active, although HRV rebounded to the historical level during the summer. While IFV and HMPV were consistently suppressed year-round, RSV, HPIV, HCoV, HRV, and HBoV resurged and went beyond historical levels during September 2020–January 2021, after NPIs were largely relaxed and schools reopened. Resurgence was more prominent among children <18 years and in northern China. These observations remain valid after accounting for seasonality and long-term trend of each virus. Conclusions Activities of respiratory viral infections were reduced substantially in the early phases of the COVID-19 pandemic, and massive NPIs were likely the main driver. Lifting of NPIs can lead to resurgence of viral infections, particularly in children. [ABSTRACT FROM AUTHOR]

Background: Jingmen tick virus (JMTV) has attracted great attention due to its potential pathogenicity in humans and its transmission by ticks. Dermacentor silvarum (D. silvarum) is one of the dominant tick species in northeastern China, and can transmit many pathogens to humans and animals. However, there have been no report of transmission of JMTV by D. silvarum. Materials and Methods: Ticks were collected from vegetation at the Aershan Port in Inner Mongolia in April 2019. And we do attempt to infect D. silvarum with JMTV by the immersion technique in laboratory conditions. The transmission of JMTV was examined by reverse transcriptase PCR, fluorescence in situ hybridization, and indirect immunofluorescence assay. Statistical analysis was performed using SPSS 24.0. Results: We found that JMTV may only be maintained in the tick without replication, and could not be transmitted to a host following transstadial transmission. Moreover, no virus colonization was found in the midgut or salivary glands of unfed D. silvarum; therefore, D. silvarum may not be susceptible to JMTV infection and therefore unlikely to carry and transmit JMTV. Conclusion: Our study has to some extent filled the knowledge gap regarding the possibility of JMTV transmission by a medically important tick vector, D. silvarum. [ABSTRACT FROM AUTHOR]

The geographic expansion of mosquitos is associated with a rising frequency of outbreaks of mosquito-borne diseases (MBD) worldwide. We collected occurrence locations and times of mosquito species, mosquito-borne arboviruses, and MBDs in the mainland of China in 1954−2020. We mapped the spatial distributions of mosquitoes and arboviruses at the county level, and we used machine learning algorithms to assess contributions of ecoclimatic, socioenvironmental, and biological factors to the spatial distributions of 26 predominant mosquito species and two MBDs associated with high disease burden. Altogether, 339 mosquito species and 35 arboviruses were mapped at the county level. Culex tritaeniorhynchus is found to harbor the highest variety of arboviruses (19 species), followed by Anopheles sinensis (11) and Culex pipiens quinquefasciatus (9). Temperature seasonality, annual precipitation, and mammalian richness were the three most important contributors to the spatial distributions of most of the 26 predominant mosquito species. The model-predicted suitable habitats are 60–664% larger in size than what have been observed, indicating the possibility of severe under-detection. The spatial distribution of major mosquito species in China is likely to be under-estimated by current field observations. More active surveillance is needed to investigate the mosquito species in specific areas where investigation is missing but model-predicted probability is high. [ABSTRACT FROM AUTHOR]

As one of the important tick-borne zoonotic pathogens, Anaplasma has both veterinary and public health significance. Here, we performed a survey of Anaplasma infection in the goats from a farm in Beijing, China, and found 44.6% (41/92) were infected with Anaplasma capra, and 22.8% (21/92) were infected with Anaplasma sp. This Anaplasma sp. bacterium was close to a recently emerging Anaplasma platys strain based on gltA and groEL gene phylogenetic analysis. As to further understand the characteristics of Anaplasma sp., we raised a couple of positive goats (n = 2) in the laboratory with tick-free settings. We observed inappetence, vomiting, high fever, and weakness of limbs in the goat's offspring (n = 3). In addition, the blood samples from all offspring were all positive of this Anaplasma spp. We did not see any intracellular morulae in neutrophils, monocytes, and erythrocytes, but we identified some in the platelets of the blood smears from the positive goats by light microscopy. We named it A. platys-like and suggested it may infect platelets and be transmitted vertically through the placenta of goats. These findings deserve further evaluation. [ABSTRACT FROM AUTHOR]

Background Human babesiosis is an emerging health problem in China. Methods Babesia were identified in ticks, sheep, and humans in northeastern China using polymerase chain reaction (PCR) followed by genetic sequencing. We enrolled residents who experienced a viral-like illness after recent tick bite or were healthy residents. We defined a case using the definition for babesiosis developed by the US Centers for Disease Control and Prevention. Results A Babesia crassa –like agent was identified in Ixodes persulcatus and Haemaphysalis concinna ticks using PCR followed by sequencing. The agent was characterized through phylogenetic analyses of the 18S rRNA gene, the β-tubulin gene, and the internal transcribed spacer region. We tested sheep as a possible reservoir and found that 1.1% were infected with the B. crassa –like agent. We screened 1125 human participants following tick bites using B. crassa –specific PCR and identified 31 confirmed and 27 suspected cases. All the patients were previously healthy except for 1 with an ovarian tumor. Headache (74%), nausea or vomiting (52%), and fever (48%) were the most common clinical manifestations of confirmed cases. Six of 10 cases remained PCR positive for B. crassa –like infection 9 months after initial diagnosis. Asymptomatic infections were detected in 7.5% of 160 local residents. Conclusions We identified B. crassa –like infection in people in northeastern China that caused mild to moderate symptoms. The possibility of more severe disease in immunocompromised patients and of transmission through the blood supply due to asymptomatic infections justifies further investigation of this reported infection. [ABSTRACT FROM AUTHOR]

Background: Rare investigation on tick-borne pathogens was carried out in Yunnan, China. In this study, we did a survey on Ehrlichia infection in small mammals and ticks. A total of 40 small mammals and 49 ticks were collected from Tengchong, Yunnan province. PCR targeting 16S ribosomal RNA (rRNA), citrate synthase, GroEL heat-shock protein operon, and major outer membrane protein genes was performed and positive amplicons were sequenced. Results: The 40 small mammals were identified as 10 species, 2 (5.0%) of which were infected with Ehrlichia, 4 (10.0%) were infected with Anaplasma phagocytophilum and another 2 (5.0%) were infected with Candidatus Neoehrlichia mikurensis. Six (12.2%) ticks were positive for Ehrlichia and another two (4.1%) were infected with A. phagocytophilum. Neither small mammals nor ticks had coinfection. The detected Ehrlichia was named as Ehrlichia sp. YN04, which was in the same clade of Ehrlichia sp. 360 by phylogenetic analysis. The sequences of the pathogen recovered from small mammals and ticks were identical with each other. Conclusion: The study reports one Ehrlichia species first detected from small mammals and ticks in mainland China. As Yunnan is a famous "Global Biodiversity Hotspot" in the world, we may expect much more tick-borne infectious pathogens existing and declare more public health attention in this region. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 55-year-old female patient who was admitted to the hospital for tick-borne diseases with complaints of dizziness, gait disturbance and headache. Topics discussed include the cerebrospinal fluid (CSF) tests performed on the patient; the administration of the doxycycline drug for the patient; and diagnosis of a tick-borne Colpodella species parasite infection in the patient.

• All individual complications including shock, ARDS, meningitis and acute kidney injury were found to be significantly associated with treatment failure and time to defervescence, after adjusting for the effects of age, sex, initial antibiotic type, and interval from symptom onset to start of antibiotic treatment. • Treatment failure risk was higher for azithromycin than doxycycline for patients with meningitis; and treatment failure risk was higher for chloramphenicol than doxycycline for patients with acute kidney injury, pneumonia or shock. • Antibiotic resistance occurred in 2.4% of doxycycline group, 6.3% of azithromycin group and 10.4% of chloramphenicol group. Deaths occurred in 29.4% (5/17), 0% (0/5) and 10.0% (1/10) of patients, respectively, with no significant differences between groups (P =0.232). Previous studies have evaluated treatment efficacy of various antibiotics for patients with mild-to-moderate scrub typhus (ST). However, the efficacy of different antibiotics for treating severe ST remains uncertain. A retrospective study of patients with severe ST was undertaken in China. The treatment efficacy rates of doxycycline, azithromycin and chloramphenicol were compared, using treatment failure and time to defervescence as primary outcomes. In total, 876 patients with severe ST who initially received doxycycline, azithromycin or chloramphenicol were recruited. The treatment failure rate did not differ significantly between patients receiving doxycycline and patients receiving azithromycin (6.0% vs 11.4%; P =0.109). However, a higher treatment failure rate was observed for chloramphenicol compared with doxycycline (14.6% vs 6.0%; P =0.004). No significant difference in time to defervescence was observed between patients receiving doxycycline, azithromycin or chloramphenicol. Further subgroup analysis revealed a higher risk of treatment failure for chloramphenicol compared with doxycycline in patients with acute kidney injury, pneumonia and shock; and a higher risk of treatment failure for azithromycin compared with doxycycline in patients with meningitis. Significant correlation was found between azithromycin resistance and meningitis (P =0.009), and between chloramphenicol resistance and acute respiratory distress syndrome (ARDS) (P <0.001) using Cramer's V correlation coefficient. Multi-variate Cox regression analysis revealed significant associations between time to defervescence and presence of ARDS, shock, myocarditis, meningitis and acute kidney injury. Azithromycin and doxycycline were found to have significant therapeutic effects in patients with severe ST. In contast, chloramphenicol was less efficacious for the treatment of these patients. [ABSTRACT FROM AUTHOR]

Summary Background Anaplasma phagocytophilum and Anaplasma ovis cause human infections. We investigated the potential for human pathogenicity of a newly discovered Anaplasma species infecting goats in China. Methods We collected blood samples from patients with a history of tick bite in the preceding 2 months at Mudanjiang Forestry Central Hospital of Heilongjiang Province from May 1, to June 10, 2014, to detect the novel Anaplasma species by PCR. We inoculated positive samples into cell cultures. We characterised the isolated pathogen by morphological and phylogenetic analyses. We tested serum antibodies by indirect immunofluorescence assay. Findings 28 (6%) of 477 patients assessed were infected with the novel Anaplasma species according to PCR and sequencing. We isolated the pathogen in vitro from three patients. Phylogenetic analyses of rrs, gltA, groEL, msp2 , and msp4 showed that the pathogen was distinct from all known Anaplasma species. We provisionally nominate it “ Anaplasma capra ”. 22 (92%) of 24 patients with data available had seroconversion or a four-fold increase in antibody titres. All 28 patients developed non-specific febrile manifestations, including fever in 23 (82%), headache in 14 (50%), malaise in 13 (46%), dizziness in nine (32%), myalgia in four (14%), and chills in four (14%). Additionally, ten (36%) of 28 patients had rash or eschar, eight (29%) had lymphadenopathy, eight (29%) had gastrointestinal symptoms, and three (11%) had stiff neck. Five patients were admitted to hospital because of severe disease. Six (35%) of 17 patients with data available had high hepatic aminotransferase concentrations. Interpretation The emergence of “ A capra ” as a cause of human disease suggests that individuals living in or travelling to endemic regions in northern China should take precautions to reduce their risk of exposure to this novel tick-borne pathogen. Funding Natural Science Foundation of China and the US National Institutes of Health. [ABSTRACT FROM AUTHOR]

Background: Human babesiosis is an emerging zoonosis. "Babesia venatorum" has been identified in only four asplenic men and a child so far. We aimed to describe the epidemiological, clinical, and laboratory characteristics of a series of cases with "B venatorum" infection identified in a sentinel hospital in China.Methods: We recruited participants with a recent tick bite at Mudanjiang Forestry Central Hospital, Heilongjiang province, China. Cases were diagnosed through PCR followed by sequencing, microscopic identification, or isolation by animal inoculation, or both.Findings: 48 individuals (30 women or girls; median age 45 years, range 7 months to 75 years) with "B venatorum" infection were identified. 32 of these individuals were confirmed cases and 16 were probable cases. None of the 48 cases had received a blood transfusion or had a splenectomy. Geographically, cases were distributed diffusely throughout the hospital catchment area. Of the 32 confirmed cases, 21 (66%) presented with a fever, 13 (41%) with a headache, 12 (38%) with myalgia or arthralgia, and three (9%) with chills. 14 (44%) patients had fatigue, eight (25%) had dizziness, and eight (25%) had hypersomnia. Six (19%) patients had an erythematous non-pruritic rash around the tick-bite site and two (6%) had lymphadenopathy. Seven (22%) and four (13%) patients had anaemia and thrombocytopenia, respectively, and seven (50%) of 14 patients with confirmed infection had increased hepatic transaminase concentrations. In the confirmed cases, concentrations of intercellular adhesion molecule 3 (p<0·001), P-selectin (p<0·05), and platelet endothelial cell adhesion molecule 1 (p<0·001) were significantly reduced, whereas tumour necrosis factor α (p<0·01) and vascular cell adhesion molecule 1 (p<0·001) were significantly increased.Interpretation: "B venatorum" infection should be included in the differential diagnosis of patients with a tick-exposure history in areas where this pathogen has previously been identified in ticks or people.Funding: Natural Science Foundation of China and Mega-Project for Infectious Diseases. [ABSTRACT FROM AUTHOR]

Summary Background Human babesiosis is an emerging zoonosis. “ Babesia venatorum ” has been identified in only four asplenic men and a child so far. We aimed to describe the epidemiological, clinical, and laboratory characteristics of a series of cases with “ B venatorum ” infection identified in a sentinel hospital in China. Methods We recruited participants with a recent tick bite at Mudanjiang Forestry Central Hospital, Heilongjiang province, China. Cases were diagnosed through PCR followed by sequencing, microscopic identification, or isolation by animal inoculation, or both. Findings 48 individuals (30 women or girls; median age 45 years, range 7 months to 75 years) with “ B venatorum ” infection were identified. 32 of these individuals were confirmed cases and 16 were probable cases. None of the 48 cases had received a blood transfusion or had a splenectomy. Geographically, cases were distributed diffusely throughout the hospital catchment area. Of the 32 confirmed cases, 21 (66%) presented with a fever, 13 (41%) with a headache, 12 (38%) with myalgia or arthralgia, and three (9%) with chills. 14 (44%) patients had fatigue, eight (25%) had dizziness, and eight (25%) had hypersomnia. Six (19%) patients had an erythematous non-pruritic rash around the tick-bite site and two (6%) had lymphadenopathy. Seven (22%) and four (13%) patients had anaemia and thrombocytopenia, respectively, and seven (50%) of 14 patients with confirmed infection had increased hepatic transaminase concentrations. In the confirmed cases, concentrations of intercellular adhesion molecule 3 (p<0·001), P-selectin (p<0·05), and platelet endothelial cell adhesion molecule 1 (p<0·001) were significantly reduced, whereas tumour necrosis factor α (p<0·01) and vascular cell adhesion molecule 1 (p<0·001) were significantly increased. Interpretation “ B venatorum ” infection should be included in the differential diagnosis of patients with a tick-exposure history in areas where this pathogen has previously been identified in ticks or people. Funding Natural Science Foundation of China and Mega-Project for Infectious Diseases. [ABSTRACT FROM AUTHOR]

Salp15, a 15-kDa tick salivary gland protein, is both essential for ticks to successfully obtain host blood and also facilitates transmission of Lyme borreliosis. To determine whether the Salp15 gene is expressed in Ixodes persulcatus and Ixodes sinensis, principle vectors of Lyme borreliosis in China, we studied transcriptions of this gene in semi-engorged larvae, nymph and adults of these two species. A total of eight Salp15 homologues, five in I. persulcatus and three in I. sinensis, were identified by reverse transcriptase–polymerase chain reaction (RT-PCR). Interestingly, the intra-species similarity of Salp15 is approximately equal to its interspecies similarity and more than one Salp15 protein is expressed in a certain tick developmental stage. Comparison of DNA and proteins with other available tick Salp15 homologues suggests that the Salp15 superfamily is genetically conserved and diverse in the Ixodes ricinus complex. These findings indicate that Salp15 proteins in the I. ricinus complex may play an essential role in interacting with the host immune system and transmission of Borrelia genospecies. [ABSTRACT FROM AUTHOR]

A total of 705 rodents from 6 provinces and autonomous regions of mainland People's Republic of China were tested by PCRs for tick-borne agents (Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato, spotted fever group rickettsiae, and Francisella tularensis). Infection rates were 5.5%, 6.7%, 9.1% and 5.0%, respectively. Eighteen (2.6%) rodents of 10 species were positive for 2 or 3 agents. Sequence analysis of PCR products confirmed the presence and genotypes of detected agents. These findings demonstrate that these tick-borne agents cocirculate and that a variety of rodent species may be involved in their enzootic maintenance. [ABSTRACT FROM AUTHOR]

Among arthropod vectors, ticks transmit the most diverse human and animal pathogens, leading to an increasing number of new challenges worldwide. Here we sequenced and assembled high-quality genomes of six ixodid tick species and further resequenced 678 tick specimens to understand three key aspects of ticks: genetic diversity, population structure, and pathogen distribution. We explored the genetic basis common to ticks, including heme and hemoglobin digestion, iron metabolism, and reactive oxygen species, and unveiled for the first time that genetic structure and pathogen composition in different tick species are mainly shaped by ecological and geographic factors. We further identified species-specific determinants associated with different host ranges, life cycles, and distributions. The findings of this study are an invaluable resource for research and control of ticks and tick-borne diseases. • Six high-quality ixodid tick genomes and 678 re-sequenced tick specimens • Insights into the genetic basis of tick hematophagy and related phenotypes • Population structure and genetic diversity of six tick species • Tick-borne pathogen composition and distribution by metagenome analyses The high-quality genomes of six ixodid tick species and resequencing of 678 tick specimens are a resource to understand the genetic diversity, population structure, and pathogen distribution of ticks with implications for control of ticks and tick-borne diseases. [ABSTRACT FROM AUTHOR]

Abstract: A total of 54 wild rabbits captured from southeastern China were examined for Anaplasma phagocytophilum and Borrelia burgdorferi sensu lato by polymerase chain reaction (PCR) assays. One and three samples were positive for A. phagocytophilum and B. burgdorferi, respectively. Sequence analyses of PCR products identified a variant of A. phagocytophilum and a B. garinii genotype. This is the first detection of the two tick-borne agents in Chinese rabbits, the role of which in the maintenance of the agents deserve further investigations. [Copyright &y& Elsevier]