Over the past decade, global malaria-related mortality has declined dramatically because of combined international actions that have defined and prioritized national and regional efforts to reduce the incidence of malaria, with the ultimate goal of eradication. Vector control strategies using insecticide-treated nets (ITNs) and indoor residual spraying (IRS) in African countries have contributed significantly to the declining incidence of malaria. However, the effectiveness of malaria control is threatened by increasing insecticide resistance and behavioral changes in Anopheles vectors. Thus, there is an urgent need to ensure that future programmes are designed to address these threats and protect the progress made so far in controlling malaria. This review summarizes the current malaria vector control tools and discusses about the critical threats to vector control programme and vector management.

Glossina swynnertoni is a savannah tsetse that is largely confined to the Serengeti-Mara [a very small part of East Africa covering northern Tanzania (Arusha and Manyara regions and parts of Shinyanga and Mara regions) extending to Maasai Mara ecosystem in southwestern Kenya]. Nevertheless, it is of great concern to human and animal health and is one of the top target tsetse species for eradication. To achieve this eradication objective, it is important to know about its behaviour so that the appropriate tools/measures especially the right traps can be applied against it. In this paper G. swynnertoni is reviewed in terms of its behaviour, and development of traps for its survey and control. Glossina swynnertoni control is of paramount importance in Tanzania tourism industry and country’s income. Since, G. swynnertoni is also distributed in national parks, control is vital as it might reduce tourists excursion/movement, by transmitting the African trypanosomiasis among travelers. Different literature search engines such as Google Scholar and PubMed were deployed for literature search. It was found that the behaviour of G. swynnertoni is relatively similar but unique from other tsetse flies. Its feeding cycle is 2½-3 days as opposed to 3–1 days observed in other tsetse species. The flight activity pattern varied between sex, with male having their peak at 1100-1200 hrs and females 1400-1600 hrs. The activity in both sexes decline rapidly towards the dusk (1700-1800 hrs). It was further depicted that host odours, relatively smaller and vertically oriented devices, as well as host movement are the main attractive factors to this tsetse species, which can be exploited to design efficient artificial devices for control of G. swynnertoni. Therefore, due to its restricted distribution and threat it poses on tourism industry, deliberate efforts need to be made against G. swynnertoni as a next candidate to be eradicated using artificial bait technology.

Background & objectives: Knowledge on prevalence of malaria vector species of a certain area provides important information for implementation of appropriate control strategies. The present study describes a rapid method for screening of major Anopheline vector species and at the same time detection of Plasmodium falciparum sporozoite infection and blood meal preferences/trophic preferences. Methods: The study was carried from February 2012 to March 2013 in three seasons, i.e. rainy, winter and summer in Jhumpura PHC of Keonjhar district, Odisha, India. Processing of mosquitoes was carried out in two different methods, viz. mosquito pool (P1) and mosquito DNA pool (P2). Pool size for both the methods was standardized for DNA isolation and multiplex PCR assay. This PCR based assay was employed to screen the major vector composition in three different seasons of four different ecotypes of Keonjhar district. Pearson’s correlation coefficient was determined for a comparative analysis of the morphological identification with the pool prevalence assay for each ecotype. Results: A pool size of 10 was standardized for DNA isolation as well as PCR. PCR assay revealed that the average pool prevalence for all ecotypes was highest for An. annularis in winter and summer whereas for An. culicifacies it was rainy season. Foothill and plain ecotypes contributed to highest and lowest vectorial abundance respectively. The results of the prevalence of vector species in pool from PCR based assay were found to be highly correlated with that of the results of morphological identification. Interpretation & conclusion: Screening by pool based PCR assay is relatively rapid as compared to conventional morphological identification and can be employed as an important tool in malaria control programmes.

Background & objectives: Chikungunya virus (CHIKV) infection has recently witnessed re-emergence, affecting rural areas of India with high morbidity rates. This prospective study was conducted to evaluate seroprevalence and clinical manifestation in targeted villages reporting cases of CHIKV infection. Methods: A total of482 patients were recruited from Kalmana and Kothari villages of Ballarpur; Chandrapur district of Maharashtra state, India during CHIKV outbreaks in 2011–12. The serum samples from infected CHIKV patients were simultaneously screened through ELISA for detection of antigen and antibodies (IgM and IgG). Chi-square analysis was used to evaluate differences in seropositivity between age, gender and clinical manifestations of CHIKV. Results: Out of 482 enrolled participants, 197 (41%) males and 285 (59%) females were aged between 5 and 92 yr. The clinical manifestations such as small joint pain (80%), neck stiffness (75%), fever (49%) and large joint pain (47%) were observed amongst CHIKV infected subjects. Mucocutaneous rashes (91%) on knees (71%), feet (56%), fingers and palms (54%) were also observed. Overall, seroprevalence of CHIKV infection was found to be 46% in infected participants during the epidemic period. Among risk factors, ageing and female gender was strongly associated with a raised seroprevalence of CHIKV infection along with symptoms such as rashes, small joints pain and neck stiffness. Interpretation & conclusion: This study reported high seroprevalence rates of CHIKV infection in targeted populations, suggesting its re-emergence in rural India. Proper surveillance is, therefore, necessary to minimize re-emergence and in controlling these impending and sporadic outbreaks.

Background & objectives: Many essential oils have been reported as natural sources of insect repellents; however, due to high volatility, they present low repellent effect. Formulation technique by using microencapsulation enables to control the volatility of essential oil and thereby extends the duration of repellency. In this study, the effectiveness of microencapsulated essential oils of Alpinia galanga, Citrus grandis and C. aurantifolia in the lotion formulations were evaluated against mosquito bites. Methods: Essential oils and W,W-Diethyl-3-methylbenzamide (DEET) were encapsulated by using interfacial precipitation techniques before incorporation into lotion base to form microencapsulated (ME) formulation. The pure essential oil and DEET were also prepared into lotion base to produce non-encapsulated (NE) formulation. All the prepared formulations were assessed for their repellent activity against Culex quinquefasciatus under laboratory condition. Field evaluations also were conducted in three different study sites in Peninsular Malaysia. In addition, Citriodiol® (Mosiquard®) and citronella-based repellents (KAPS®, MozAway® and BioZ Natural®) were also included for comparison. Results: In laboratory conditions, the ME formulations of the essential oils showed no significant difference with regard to the duration of repellent effect compared to the microencapsulated DEET used at the highest concentration (20%). It exhibited >98% repellent effect for duration of 4 h (p = 0.06). In the field conditions, these formulations demonstrated comparable repellent effect (100% for a duration of 3 h) to Citriodiol® based repellent (Mosiguard®) (p = 0.07). In both test conditions, the ME formulations of the essential oils presented longer duration of 100% repellent effect (between 1 and 2 h) compared to NE formulations. Interpretation & conclusion: The findings of the study demonstrate that the application of the microencapsulation technique during the preparation of the formulations significantly increases the duration of the repellent effect of the essential oils, suggesting that the ME formulation of essential oils have potential to be commercialized as an alternative plant-based repellent in the market against the mosquitoes.

Background & objectives: Loop-mediated isothermal amplification (LAMP) is an emerging nucleic acid based diagnostic approach that is easily adaptable to the field settings with limited technical resources. This study was aimed to evaluate the LAMP assay for the detection and identification of Plasmodium falciparum and P. vivax infection in malaria suspected cases using genus and species-specific assay. Methods: The 18S rRNA-based LAMP assay was evaluated for diagnosis of genus Plasmodium, and species-specific diagnosis of P. falciparum and P. vivax, infection employing 317 malaria suspected cases, and the results were compared with those obtained by 18S nested PCR (n-PCR). All the samples were confirmed by microscopy for the presence of Plasmodium parasite. Results: The n-PCR was positive in all Plasmodium-infected cases (n=257; P. falciparum=133; P. vivax=124) and negative in microscopy negative cases (n=58) except for two cases which were positive for P. vivax, giving a sensitivity of 100% (95% CI: 97.04-100%) and a specificity of 100% (95% CI: 88.45-99.5%). Genus-specific LAMP assay missed 11 (3.2%) microscopy and n-PCR confirmed vivax malaria cases. Considering PCR results as a reference, LAMP was 100% sensitive and specific for P. falciparum, whereas it exhibited 95.16% sensitivity and 96.7% specificity for P. vivax. The n-PCR assay detected 10 mixed infection cases while species-specific LAMP detected five mixed infection cases of P. vivax and P. falciparum, which were not detected by microscopy. Interpretation & conclusion: Genus-specific LAMP assay displayed low sensitivity. Falciparum specific LAMP assay displayed high sensitivity whereas vivax specific LAMP assay displayed low sensitivity. Failed detection of vivax cases otherwise confirmed by the n-PCR assay indicates exploitation of new targets and improved detection methods to attain 100% results for P. vivax detection.

Background & objectives: Aedes aegypti mosquito is the principal vector of the viruses responsible for urban yellow fever, dengue, dengue haemorrhagic fever, as well as Zika and chikungunya in Brazil. The present study was aimed to investigate the insecticidal potential of the extract and fractions of Ottonia anisum, along with special metabolites isolated from it, as natural alternatives against larvae (L3) of Ae. aegypti, vector of potentially deadly tropical infections in Brazil. Methods: The plant species O. anisum was collected in March 2015, at Xerém area, in Rio de Janeiro City, Brazil. Crude extracts and the isolated pure compounds were screened for toxicity against Ae. aegypti larvae (L3). Bioassays were performed on 20 larvae (L3) of Ae. aegypti in triplicate. The samples were dissolved in a mixture of acetone and DMSO at final concentrations of 1-200 μg/ml. The toxicity of the solutions was evaluated towards the growth and development of Ae. aegypti larvae till emergence of adults. Results: The crude hexane extract showed 100% larval mortality 24 h after treatment at a concentration of 200 μg/ ml. The bioassays using 1-butyl-3,4-methylenedioxybenzene revealed 100% mortality among L3 larvae, 24 h after the treatment at a concentration of 30 μg/ml, the LC₅₀ recorded was 1.6 μg/ml. At concentration of 10 μg/ml, the L3 larval mortality recorded was 92%. Interpretation & conclusion: The metabolite 1-butyl-3,4-methylenedioxybenzene showed potent toxicity against Ae. aegypti larvae. This arylbutanoid agent could be used as a natural alternative adjuvant pesticide, in new compositions that would be environmentally safer.

Background & objectives: Culex tritaeniorhynchus is the primary vector of Japanese encephalitis virus (JEV) which is a major threat to animals and humans health. This virus has been reported earlier from low altitude regions of Tibet, in mosquitoes, Tibetan pigs and local Tibetans, but no reports are available for the probable propagation of JE to high altitude regions (3100 m) of Tibet. This study aimed to find the evidence of JEV in Cx. tritaeniorhynchus and pigs from high altitude regions of Tibet, China. Methods: In total, 102 porcine serum samples and eight pools of Cx. tritaeniorhynchus were subjected to real-time PCR (RT-PCR) for the amplification of a fragment (~ 420 bp) of the NS1 gene. The resultant amplicons of the genes were subsequently analyzed and sequenced. Results: Overall seroprevalence of JE in Tibetan pigs was 6.86%, while five pools of Cx. tritaeniorhynchus were found positive for JEV. Results showed genotype III as the most prevalent (100%) among JEV positive isolates. Furthermore, phylogenetic analysis of the JEV positive strains showed 98.8-99% similarity to four reference strains from China (JEV-Hubei, Whe, HYZ and CQ11-66). Interpretation & conclusion: The present study revealed that JEV has extended its geographic range to high altitude regions of Tibet. The factors like increased tourism and transportation might play key role in the transmission of JE that comprises a potential health risk for humans and animals.

Background & objectives: Many host genetic factors are associated with the disease severity and fatal outcome of falciparum malaria. CD40L gene has been found to be one of the most important factors associated with malaria in African countries. This study was aimed to investigate the possible association of CD40L gene polymorphism in severe falciparum malaria in Indian adults. Methods: One hundred fifteen adult cases with severe falciparum malaria were included in the study. Two single-nucleotide polymorphisms (SNPs) of CD40L gene, CD40L-726(C/T) and CD40L+220(C/T) were investigated, and the possible association with different clinical sub-phenotypes of severe falciparum malaria were analyzed. Results: Statistically no significant difference was observed in the incidence of CD40L–726C between the patients and control group. The incidence of CD40L+220C allele was found to be significantly higher (OR, 2.25; p = 0.03) in male patients compared to controls but no significant difference was observed in females. Haplotype data showed the susceptibility of –726T/+220C haplotype to severe malaria whereas –726C/+220T was associated with protection against severe malaria. CD40L+220C allele was associated with severe malarial anaemia in males (×^[2] = 6.60; p = 0.01). Interpretation & conclusion: CD40L gene polymorphism was found to be associated with severe falciparum malaria in Indian population especially in severe malarial anaemia. CD40L may be considered as a factor of immunity in understanding the pathophysiology of falciparum malaria.

Background & objectives: Black flies (Diptera: Simuliidae) are ecologically and medically important insects. Female adults of black flies are the solitary vectors of river blindness (onchocerciasis) and their larvae play a vital role in stream ecosystem. This study examined the distribution of black flies in the Oriental region and analyzed the phylogenetic relationship of the subgenus Gomphostilbia members based on two molecular loci. Methods: The distribution data of black fly species in different countries of Oriental region were obtained from world black flies geographic inventory. The two gene sequences, COI and ITS1 were used to study the phylogenetic relationships of the members of subgenus Gomphostilbia members. Results: The distribution analysis revealed that out of the 16 subgenera in the genus Simulium Latreille s., the species-level diversity of three subgenera (Gomphostilbia, Nevermannia and Simulium) contributes about thrice of total black fly species diversity. The highest diversity of species was found in the subgenus Simulium. The strict consensus of Tree analysis using New Technology (TNT) and Maximum Likelihood (ML) recovered similar topologies for Gomphostilbia members and they formed as monophyly. The overall sequence identities of the 19 species of subgenus Gomphostilbia were high and shared 55–60% similarity. Interpretation & conclusion: Results of this study highlighted that eight subgenera of Simulium Latreille s. str are commonly distributed in different parts of Oriental region. Among these the subgenera of Simulium, Gomphostilbia and Nevermannia are most common with high diversity in China, Pakistan, Thailand and Vietnam. The phylogenetic analysis of Gomphostilbia members demonstrates the inter-specific divergence, indicating the centre of origin (India) or the recipient of ancestral migrant lineages in Oriental region.

Background & objectives: Ecoepidemiological studies of cutaneous leishmaniasis and regular monitoring of Lutzomyia species have generated a knowledge base that can be used for control and prevention strategies targeted at the disease transmission dynamics in focal areas of Colombia. In this study, the presence and spatial distribution of phlebotomines of medical importance in the municipalities of Tierralta (El Loro and Tuis Tuis villages) and Valencia (Guadua and Mieles villages) were determined. Methods: Entomological surveys were performed in 2015 (months of June, September and November) and samples were collected via CDC-traps located in intradomicilary and peridomiciliary areas in the municipalities of Tierralta and Valencia (Department of Córdoba, Colombia). Active searches were also carried out with a mouth aspirator to collect adult phlebotomines from resting sites. ANOVA and Kruskal-Wallis tests were performed to assess if the differences between the communities of phlebotomines. Spatial distribution maps of the Lutzomyia species were generated. Results: A high species diversity of Lutzomyia was observed with a total of 1677 Lutzomyia individuals belonging to 12 species. Among these species, Lu. panamensis was the most abundant (80.18%). The composition of the intradomicilary and peridomiciliary phlebotomines varied significantly (F = 0.9962; df = 1; p = 0.02895). Species like Lu. carpenteri, Lu. camposi, Lu. dysponeta, Lu. atroclavata and Lu. yuilli yuilli were recorded for the first time in the Department of Córdoba, Colombia. Interpretation & conclusion: The spatial distribution shows that Lu. panamensis and Lu. gomezi are predominant and present in areas with high concentration of houses. This study provides basic information on new records of phlebotomines in the Department of Córdoba. The results suggest that greater vector-human contact occurs in the peridomiciliary environment and that a high number of Lutzomyia species associated with the transmission of leishmaniasis are present in Colombia.

Background & objectives: Visceral leishmaniasis (VL) is a fatal zoonotic disease in tropical and sub-tropical countries including Iran. Dogs constitute the main domestic reservoir for VL (kala-azar) in Iran but incidence of the disease in cats from Fars and East Azerbaijan provinces has led to propose them as secondary reservoirs, and possible expansion of the feline role in the transmission of disease. The aim of this study was to evaluate the prevalence of Leishmania infantum infection in stray cats in Kerman City by ELISA and PCR methods. Methods: In this cross-sectional descriptive study, 60 stray cats were randomly live trapped from different parts of Kerman City during a six month period between March and September 2014. About 3 ml blood samples were drawn from jugular vein of captured cats and a detailed questionnaire about demographic characteristics and clinical status of each cat was recorded by attending veterinarian. The complete blood counts and biochemistry analysis were performed for all cats. Finally collected sera samples were tested by an indirect enzyme-linked immunosorbent assay (ELISA) kit and PCR amplification method. Results: Prevalence of Leishmania infantum infection was 6.7 and 16.7% by ELISA and PCR assays, respectively. Infection rate was significantly higher in leukopenic cats, which were older than 3 yr. Interpretation & conclusion: The results of the study indicate that stray cats are at risk of L. infantum infection in Kerman City. Further, studies are required to elucidate the role of cats as potential reservoir host in the epidemiology of VL in endemic regions.