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Background: Malaria in northeast India affects children and adults annually. The number of malaria cases reported has declined over the past few years. Nevertheless, it is not clear whether there is an actual decline in parasitaemia or whether asymptomatic malaria infections are on the rise, especially in forested and forest-fringed areas. Asymptomatic malaria forms a parasite reservoir that acts as an epicentre for malaria spread during high-transmission season. Therefore it is important to understand the quantum of asymptomatic malaria infections among the vulnerable population., Method: Four forest fringed historically malaria endemic villages were selected for the study. A total of 133 individuals without a fever history in the past four weeks were tested for malaria parasite using rapid diagnostic test (RDT), microscopy and polymerase chain reaction (PCR) assay during January - February 2014. Indoor resting Anopheles vectors were collected, identified and tested for sporozoite using VectorTest™ panel assay during October 2013 to March 2014, which is a low transmission season for malaria. Social and demographic data were recorded during the study., Results: Mean age (± SEM) of the participants was 16.1 ± 1.2 years (95 % CI: 13.8-18.4). All participants (100 %) reported to use mosquito nets. Altogether, 43.6 % of participants had education below primary level and only 9 % reported a travel history during the past four weeks. All RDT, microscopy and PCR assays were found negative indicating no asymptomatic malaria parasitaemia. Seven known malaria vector species namely, Anopheles nivipes, An. minimus, An. annularis, An. vagus, An. aconitus, An. philippinensis and An. culicifacies, were recorded in the present study. VectorTest™ sporozoite panel assay conducted on 45 pools (N = 224) of vector mosquitoes were found negative for Plasmodium sporozoite., Discussion: Northeastern states of India report asymptomatic malaria parasitemia along with high malaria transmission. An. minimus and An. dirus are recognised as efficient vectors, but An. culicifacies, An. philippinensis and An. annularis also play role in malaria transmission. Currently all participants were found negative for asymptomatic malaria, however the small sample size may restrict the scope of present results to the population living in more remote areas., Conclusion: No cases of asymptomatic malaria infections parasitaemia was found in the present study conducted during a low transmission season indicating that asymptomatic malaria parasitaemia may not be prevalent in the region. Mosquito specimens were tested negative for the malaria sporozoites. Study findings encourage the ongoing malaria intervention efforts and recommends similar investigations in different ecological areas involving large populations.

Background: Long-lasting insecticidal nets (LLINs) are a primary method in malaria control efforts. However, a decline in the biological efficacy and physical integrity over a period of comparatively lesser time than claimed, waning of naturally acquired immunity among regular users and misuse of LLINs are serious concerns., Search and Selection of Literature: The literature for the current review was searched in PubMed, SCOPUS Database and Google using combined search strings of related key-words. Literature with sufficient data and information on the current subject was selected to reach a valid conclusion., Findings: The World Health Organization (WHO) has emphasized that LLINs should be considered a public good for people inhabiting malaria endemic settings. LLINs exhibited a cumulative effect on the vector density and may force anthropophilic mosquito vectors to find alternative animal hosts for blood meal. However, the physical integrity and biological activity of LLINs declines faster than the anticipated time due to different operational conditions and the spread of insecticide resistance. LLINs have been successful in reducing malaria incidences by either reducing or not allowing human exposure to the vector mosquitoes, but at the same time, LLINs debilitate the natural protective immunity against malaria parasite. Misuse of LLINs for deviant purposes is common and is a serious environmental concern, as people believe that traditional methods of prevention against malaria that have enabled them to survive through a long time are effective and sufficient. Moreover, people are often ill-informed regarding the toxic effects of LLINs., Conclusions: Specific criteria for determining the serviceable life and guidelines on the safe washing and disposal of LLINs need to be developed, kept well-informed and closely monitored. Malaria case management, environment management and community awareness to reduce the misuse of LLINs are crucial. Focused research on developing effective anti-malarial drugs, vaccines and new insecticides to reduce resistance is imperative to tackle malaria in the future., (Copyright © 2014 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.)

The present study evaluates the performance of OptiMAL-IT test and nested PCR assay in detection of malaria parasites. A total of 76 randomly selected blood samples collected from two malaria endemic areas were tested for malaria parasites using microscopy and OptiMAL-IT test in the field. PCR assays were performed in the laboratory using DNA extracted from blood spots of the same samples collected on the FTA classic cards. Of the total of 61 field confirmed malaria positive samples, only 58 (95%) were detected positive using microscopy in the laboratory. Sensitivity, specificity, positive predictive value, negative predictive value and false discovery rate of OptiMal-IT in comparison to the microscopy were 93%, 83%, 95%, 79% and 5%, respectively. On the other hand, the sensitivity and specificity of PCR assay were 97% and 100%, respectively, whereas positive predictive value, negative predictive value and false discovery rate were 100%, 90% and 0%, respectively. The overall performance of OptiMal-IT and PCR assays for malaria diagnosis was 76% and 97%, respectively. PCR assay enabled the identification of infection with Plasmodium malariae Laveran, 1881 in four samples misidentified by microscopy and Plasmodium-specific antigen (PAN) identified by the OptiMAL-IT test. In addition to the standard methods, such PCR assay could be useful to obtain the real incidence of each malaria parasite species for epidemiological perspectives.

Background: Orang Primary Health Centre (OPHC) and Balipara Primary Health Centre (BPHC) of Assam (India) report mosquito borne diseases annually. Current study was performed to ascertain the prevalence of known malaria and Japanese Encephalitis (JE) vectors and their possible role in disease transmission. Methods: Malaria epidemiological data for 2006-2010 and JE data for 2008-2013 of Assam, India were obtained from the health authority. Mosquitoes were collected using CDC light traps and identified morpho-taxonomically. Results: Plasmodium falciparum cases (81.5%, 95% CI= 72.0-91.1) were statistically higher in OPHC (P< 0.0001, t= 8.0) during the recent years. There was 4.4 folds rise in the confirmed acute encephalitis syndrome (AES) and 3.2 folds increase in the confirmed JE cases during 2013 as compared to 2008. Altogether 9,218 mosquito specimens (PTND= 153.6), comprising of 44.1% anophelines (PTND= 67.7), 42.3% culicines (PTND= 65.0) and 9.5% manso- nia (PTND= 14.6) were recorded. In BPHC, Anopheles vagus was recorded in high density (P< 0.0001), whereas Culex quinquefasciatus was the predominant JE vector (P= 0.04). In OPHC, among the known malaria vectors, the density of Anopheles annularis was significantly high (P< 0.0001). However Culex bitaeniorhynchus was the predominant known JE vector (P< 0.0001) followed by Cx. quinquefasciatus. Conclusion: Even in the absence of known efficient vectors, many Anopheles species are still involved in malaria transmission. There was disappearance of Anopheles minimus and Anopheles dirus and establishment of An. annularis, An. vagus and An. philippinensis/nivipes mosquitoes in study area. [ABSTRACT FROM AUTHOR]

Background: The malaria vector Anopheles culicifacies (sensu lato) is an important malaria vector in Southeast Asia which comprises of five sibling species namely A, B, C, D and E. However, only a few forms have been identified as malaria vectors in various endemic countries. Currently, for the first time egg morphometry and morphology has been used to differentiate the three known vector sibling species of Anopheles culicifacies collected from malaria endemic Madhya Pradesh state of central India. Methods: The adult An. culicifacies (s.l.) was collected from five districts using standard mosquito collection methods. Adult female mosquitoes were allowed to lay eggs individually. The emerged mosquitoes were identified using allele specific polymerase chain reaction (AS-PCR) to sibling species. Eggs of sibling species A, D and E were studied using scanning electron microscopy (SEM) for morphometric and morphological characteristics. Results: Currently AS-PCR identified four known sibling species (B, C, D and E) of An. culicifacies in the study area. The surface morphology and morphometric attributes of the sibling species A, D and E eggs considerably differed from each other. An. culicifacies E had a narrow deck as compared to A and D, while An. culicifacies A had a bigger micropyle with 6-7 sectors as compared to D and E that had 6 sectors. An. culicifacies D had the smallest float (the structure present on sides of the egg surface in which air is filled that help in floating) and the number of ribs was also fewer than for An. culicifacies A and E. Conclusions: The present study provides the first evidence that in addition to PCR assay, sibling species of An. culicifacies can also be differentiated using morphological and morphometric characteristics of the egg stage. The results also advocate that the sibling species of An. culicifacies are morphologically dissimilar and can be resolved using advanced microscopy. [ABSTRACT FROM AUTHOR]

Background: Anopheles culicifacies s.l. is one of the primary vectors of malaria in India responsible for the highest number of malaria cases. This vector is resistant to DDT in most parts of the country with indication of emerging resistance to pyrethroids. Since knockdown resistance (kdr) is known to confer cross-resistance between DDT and pyrethroids owing to a common target site of action, knowledge of prevalence of knockdown resistance (kdr) alleles is important from insecticide resistance management point of view. Methods: Nine populations of An. culicifacies belonging to five states of India, representing northern, western and central-east India, were screened for the presence of two alternative kdr mutations L1014F and L1014S using PCR-based assays. Dead and alive mosquitoes, following WHO standard insecticide susceptibility test against deltamethrin and DDT, were tested for allelic association. Results: L1014F mutation was recorded in all populations studied except from Haryana and Rajasthan states in northern India, with low frequencies ranging between 0.012 and 0.076; whereas presence of L1014S mutation was recorded in five populations only belonging to central-east India, with allelic frequencies ranging between 0.010 and 0.046. Both the kdr mutant alleles were found mostly in heterozygous condition without deviating from Hardy-Weinberg equilibrium. Both mutations showed protection against deltamethrin whereas only L1014S mutation showed protection against DDT when tested using additive model. Conclusions: The two L1014-kdr mutations, L1014F and L1014S, co-occurred in five populations belonging to Chhattisgarh and Odisha states of India whereas L1014F was present in all populations studied except populations from northern states. Both kdr mutations were found with very low allelic frequencies mostly in heterozygous condition and exhibited protection against deltamethrin. [ABSTRACT FROM AUTHOR]

Background: Malaria transmission is perennial in the Assam-Arunachal Pradesh interstate border areas in the Sonitpur district of Assam, India. A yearlong study was carried out on the incidence of symptomatic and asymptomatic malaria and the role of asymptomatic malaria carriers in persistent transmission of the disease. The relationships between malaria incidence and weather parameters were also investigated. Methods: Active and mass blood surveys were conducted on a monthly basis in Bengenajuli, Sapairaumari Pathar, and Nigam villages near the Assam-Arunachal Pradesh border. Epidemiological indices were estimated for malaria-positive cases. Multiple linear regression between monthly malaria incidence and monthly average temperature, and relative humidity along with monthly total rainfall was carried out. The known malaria vectors collected in CDC light traps were identified and recorded. Results: Slide positivity rate (SPR) and Plasmodium falciparum percent (Pf %) for symptomatic malaria were 26.1 and 79.8, respectively. Prevalence of malaria vectors was observed throughout the year with varying density. Anopheles philippinensis/nivipes and A. annularis were predominant among the seven known vector species recorded currently. Asymptomatic parasitemiawas detected throughout the year with SPR ranging from 4.8 to 5.3. Monthly rainfall with 1-month lag had the highest correlation (r=0.92) with SPR. The relationship between SPR and weather factors was established as SPR=-114.22+0.58 Tmin+1.38 RH+0.03 RF (R2=0.89; p=0.00). Conclusion: Low and relatively constant levels of asymptomatic parasitemia was present in the study area. High malaria vector density and presence of asymptomatic malaria parasite carriers were responsible for persistent malaria transmission in the region. This study concludes that passive detection and prompt treatment of asymptomatic carriers is essential for preventing persistent disease transmission. Rainfall along with some other weather variables may be used for predicting the malaria epidemics in the region. The predictive information could be useful to target resources more effectively. [ABSTRACT FROM AUTHOR]

Background: Anopheles culicifacies is an important vector of malaria in Southeast Asia, contributing to almost 70% of malaria cases in India. It exists as a complex of five morphologically indistinguishable species A, B, C, D and E with varied geographical distribution patterns. In India, 8% of the total population of Madhya Pradesh (Central India) contributes about 30% of total malaria cases, 60% of total falciparum cases and 50% of malaria deaths. An. culicifacies is the major malaria vector in this state. Vector control mainly relies on the proper identification and distribution of vector species exists in a particular area. The present study was carried out to identify the distribution of An. culicifacies sibling species in certain endemic district of Central India, Madhya Pradesh. Methods: The An. culicifacies mosquitoes collected from the study districts were identified morphologically. The genomic DNA was isolated from the mosquitoes and subjected to Allele specific PCR targeting D3 domain of 28S ribosomal DNA. Results: The mean prevalence of An. culicifacies during the study period was in the range of 8-120 per man per hour (PMH). From the study areas species B was identified from Jabalpur, Chindwara and Hoshangabad, Species C from Hoshangabad only, Species D from Narsinghpur and Khandwa and sibling species E from Mandla, Chindwara and Hoshangabad respectively. Conclusion: This is the first report to detect species E from Madhya Pradesh region which necessitate for reconsideration of species distribution of each An. culicifacies sibling species that would enable to develop required vector control strategies. [ABSTRACT FROM AUTHOR]

Abstract: India reports the highest number of malaria cases in Southeast Asia, of which Plasmodium falciparum contribute more than half of the cases every year. North eastern states of India contribute only 3.96% of country's population but account for >10% of total reported malaria cases, 11% of Plasmodium falciparum cases and 20% of malaria related deaths annually. In India, chloroquine resistance was reported for the first time from northeast region and since then chloroquine treatment failure is being reported from many parts of the region. Increased chloroquine treatment failure has led to change of the drug policy to artemisinin combination therapy as first line of malaria treatment in the region. However, replacing chloroquine to artemisinin combination therapy has not shown significant difference in the overall malaria incidence in the region. The present review addresses the current malaria situation of northeastern region of India in the light of antimalarials drug resistance. [Copyright &y& Elsevier]

The article information on a study conducted by The Gambia National Malaria Control Programme (NMCP) and The Gambia Bureau of Statistics (GboS) which examines the association between malaria and poverty in Gambia. It mentions that wealth quintiles and laboratory-confirmed malaria were used to evaluate the association between malaria infection and socio-economic status (SES) in general population and children. It shows that poor wall housing materials were linked to higher malaria prevalence.