Malaria is an infectious disease that is widespread in tropical and subtropical regions. The malaria parasite is able to skip the host immunity and thus maintains not only persistent but also repeated infections. There are a number of multigene families in Plasmodium that code for the variant antigens and are targets for protective immunity. In this article, we summarize the virulence genes of P. falciparum (var genes) and P. vivax (vir genes) which play key roles in disease pathogenesis by evading elimination by the host immune system. These genes occurring within the parasite population are mostly present in the subtelomeric regions of the chromosome.

DENVirDB is a web portal that provides the sequence information and computationally curated information of dengue viral proteins. The advent of genomic technology has increased the sequences available in the public databases. In order to create relevant concise information on Dengue Virus (DENV), the genomic sequences were collected, analysed with the bioinformatics tools and presented as DENVirDB. It provides the comprehensive information of complete genome sequences of dengue virus isolates of Southeast Asia, viz. India, Bangladesh, Sri Lanka, East Timor, Philippines, Malaysia, Papua New Guinea, Brunei and China. DENVirDB also includes the structural and non-structural protein sequences of DENV. It intends to provide the integrated information on the physicochemical properties, topology, secondary structure, domain and structural properties for each protein sequences. It contains over 99 entries in complete genome sequences and 990 entries in protein sequences, respectively. Therefore, DENVirDB could serve as a user friendly database for researchers in acquiring sequences and proteomic information in one platform.

Background & objectives: An entomological study using CDC miniature light-traps was performed in El Hanchane locality, where cutaneous leishmaniasis (CL) was emerging during the summer of 2011. The aim of this study is to identify the vectors of Leishmania and of phleboviruses. Methods: In the field, a total of 643 sandfly specimens were collected, identified by morphological keys and categorized by sex and species. A total of nine distinct species were morphologically identified where seven belonged to the Phlebotomus genus and two species to the Sergentomyia genus. Phlebotomus sergenti was the most abundant species (76%). Phleboviruses were detected by nested RT-PCR using 30 pooled sandflies while P. sergenti females were tested individually for infections of Leishmania species. Results: By using ITS1-PCR-RFLP approach, Leishmania tropica DNA was detected in 10 females, caught in this emerging focus, and provide additional evidence in favour of the role of P. sergenti as vector of L. tropica in Morocco. Real-time PCR screening for phlebovirus RNA, using an assay targeting the polymerase gene, showed positive result in one pool of male P. sergenti. Interpretation & conclusion: In this study, P. sergenti were infected by L. tropica and Toscana virus. To our knowledge, actually this is the first time that Toscana virus has been detected in P. sergenti.

Background & objectives: Dengue fever (DF) is a major vector-borne disease in Malaysia. The incidences of DF in Malaysia are caused by viruses transmitted through the bites of infected female Aedes albopictus and Ae. aegypti mosquitoes. This study aims to establish the spatial density of mosquito population or breteau index (BI) in the areas of Kuala Lumpur using geographic information system (GIS), remote sensing (RS) and spatial statistical tools. Method: The 2010 weekly report data of BI obtained from the Ministry of Health (MoH) and the 2010 monthly rainfall data obtained from Malaysia Meteorological Services Department were analyzed using RS and spatial statistical tools to show the spatial correlation of dengue in each zone in Kuala Lumpur. The Kernel density was implemented to identify the better dengue hotspot localities. Results: Results indicated a strong significant positive relationship between the number of localities with high BI and monthly rainfall (r = 0.64; p = 0.024). In addition, types of landuse did not appear to influence the mosquito's population (Built-up: r = 0.16, p = 0.118; Cleared area: r = – 0.107, p = 0.304; Vegetation dense: r = – 0.206, p = 0.046; Vegetation sparse: r = 0.023, p = 0.823; and Water: r = 0.246, p = 0.016). Interpretation & conclusion: In the present study, several hotspots identified will be beneficial to assist the local health authorities to reduce and eradicate mosquitoes in these areas. These results will provide valuable information through the application of advanced tools in combating Aedes mosquitoes.

Background & objectives: Interest in insect glutathione s-transferases (GSTs) has primarily focused on their role in insecticide resistance. These play an important role in biotransformation and detoxification of many different xenobiotic and endogenous substances including insecticides. The GST activity among 10 laboratory selected insecticide resistant and susceptible/control strains of Anopheles stephensi was compared using the substrates 1-chloro-2,4-dinitrobenzene (CDNB). The difference in the GST activities of different life stages of diverse insecticide resistant strains was compared and presented. Methods: About 100 larvae, pupae, adult males, adult females and eggs (100 μg in total weight) were collected and used for the experiment. The extracts were prepared from each of the insecticide-resistant strains and control. Protein contents of the enzyme homogenate and GST activities were determined. Results: Deltamethrin and cyfluthrin-resistant strains of An. stephensi showed significantly higher GST activity. Larvae and pupae of DDT-resistant strain showed peak GST activity followed by the propoxur-resistant strain. On contrary, the GST activity was found in reduced quantity in alphamethrin, bifenthrin, carbofuran and chloropyrifos resistant strains. Adults of either sexes showed higher GST activity in mosquito strain resistant to organophosphate group of insecticides namely, temephos and chloropyrifos. Interpretation & conclusion: The GST activity was closely associated with almost all of the insecticides used in the study, strengthening the fact that one of the mechanisms associated with resistance includes an increase of GST activity. This comparative data on GST activity in An. stephensi can be useful database to identify possible underlying mechanisms governing insecticide-resistance by GSTs.

Background & objectives: Mosquito control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin could serve as potential alternatives in future. Larvicidal efficacies of different parts of mangrove plants belonging to Rhizophoraceae family were tested against the late IV instar larvae of dengue vector, Aedes aegypti. Methods: Different plant parts (leaf, bark, root, stilt root, hypocotyl and flower) of Rhizophoraceae family mangrove plants (Bruguiera cylindrica, Ceriops decandra, Rhizophora mucronata and R. apiculata) were collected from Karangadu southeast coast of India. The larval mortality was observed after 24 h exposure. Repellency bioassays were carried out in a 10 Χ 10 Χ 3 m room at 27– 35°C and 60– 80% RH. The bark (A3 and E1) and stilt root (A3 and E4) fractions of R. mucronata with different concentrations (0.25, 0.50, 0.75, 1, 2 and 4 mg/cm) were applied on one arm. Results: The stilt root crude extract of R. mucronata showed maximum larvicidal activity (LC50 value 0.0275 ± 0.0066 μg/ml and LC90 = 0.0695 ± 0.156 μg/ml) followed by the bark extract (LC50 value of 0.03 ± 0.0076 μg/ml and LC90 = 0.0915 ± 0.156 μg/ml). Column chromatographic fractions of R. mucronata bark extracts (E1) showed maximum larvicidal activity (LC50 = 0.0496 ± 0.0085 μg/ml and LC90 = 0.1264 ± 0.052 μg/ml) followed by the acetone extract (LC50 = 0.0564 ± 0.0069 μg/ml and LC90 = 0.1187 ± 0.05 μg/ml). Ethanolic fraction (E4) of R. mucronata stilt root extracts showed maximum larvicidal activity (LC50 = 0.0484 ± 0.0078 μg/ml and LC90 = 0.1191 ± 0.025 μg/ml) followed by acetone fraction (A3) (LC50 = 0.0419 ± 0.0059 μg/ml and LC90 = 0.0955 ± 0.069 μg/ml). Repellent activity of R. mucronata stilt root and bark extracts (A3) showed maximum percentage of protection (97.5%) with 9.1 h protection time at 4 mg concentration of the stilt root extract. Moreover, ethanolic fraction of the stilt root (E4) extract showed maximum percentage of protection (100%) with 10 h protection time at 4 mg concentration. GC-MS analysis revealed that R. mucronata possesses variety of biopesticidal compounds. Interpretation & conclusion: The results as well as the significance of this preliminary investigation highlight the importance of R. mucronata as a novel source for natural insecticidal products.

Background & objectives: Vivax malaria has long been considered a benign entity. However, an increasing number of reports are highlighting that it may no longer be so. An investigation was carried out to study the profile of malarial admissions in a tertiary care pediatric hospital and to analyse the burden of vivax-related complications. Methods: It is a retrospective observational study. The medical case records of all the patients admitted in the year 2011 with the clinical diagnosis of malaria and laboratory evidence in the form of positive peripheral smear and/or rapid malarial antigen test were retrieved and retrospectively analysed. Results: Overall, 198 cases were included, 128 (64.6%) were due to Plasmodium vivax, 66 (33.3%) due to P. falciparum and 4 (2%) had evidence of mixed infection of Pv + Pf. The clinical features on admission were similar in all the groups. In total, 64/128 (50%) patients with vivax infection had one or more complications with severe anemia in 33 (26%) and cerebral malaria in 16 (12.5%). Six deaths were reported in P. vivax cases. In the falciparum group, 52 (78.8%) had one or more complications with severe anemia in 37 (56.1%) and cerebral malaria in 24 (36.4%). Four deaths were reported in P. falciparum cases. Interpretation & conclusion: Overall because of their larger numbers, vivax patients outnumbered other groups, with regards to severe complications and deaths. It was concluded that vivax malaria is emerging as an important cause of malaria-related complications in children.

Background & objectives: Malaria is the leading cause of death in children under 5-yr of age in the Republic of Guinea. This study aimed at investigating the knowledge, attitudes and practices of malaria control in urban and rural communities in Guinea in order to better target future health interventions. Methods: A cross-sectional survey of 200 randomly selected households was conducted in an urban site and in three rural villages within the health district of Forιcariah using two semi-structured questionnaires. Results: Only 18.5% of the respondents were aware of the role of mosquitoes in the transmission of malaria in both urban and rural households. Mosquito nets were identified as a malaria prevention method by 11.5% of the participants and only 8.5% of the respondents mentioned stagnant water as a potential mosquito breeding site. Households' heads were more aware of mosquito control methods, with 56 and 42% of the respondents recognizing that bednets or insecticidal coils can protect from mosquitoes, respectively. Despite the limited knowledge of malaria transmission and prevention, 55% of the households owned at least one long-lasting insecticide-treated net (LLIN) and 79% of the net-owning households slept under a net/LLIN the night before the survey. Interpretation & conclusion: In order to maximize the benefits of malaria control strategies, health education should be implemented, building on the higher awareness of mosquito control methods and stressing the role of vectors in transmitting the disease.

Background & objectives: In malaria endemic areas, continuous exposure to Plasmodium parasites leads to asymptomatic carriers that provide a reservoir, contributing to the persistence of malaria transmission. Thus, a study of the degree of prevalence of asymptomatic parasitaemias will help in assessing the level of reservoir of infection. Methods: All the consented participants without any signs and symptoms, suggestive of malaria were interviewed and thick blood smears were made to detect malaria parasites. The children presenting with malaria or any other severe illness, and those declining to give consent were excluded from the study. Results: A total of 118 (59.6%) children out of 198 apparently healthy children were positive for malaria parasites while 80 (40.4%) children were negative for malaria parasites. Prevalence of asymptomatic malaria was higher in males 75 (63.6%) compared to females 43 (36.4%), but the difference was not statistically significant. Incidence of asymptomatic malaria was highest with 76.1% in the children aged 6– 10 yr. There was statistically significant association of the use of bednet on prevalence of asymptomatic malaria. Interpretation & conclusion: High prevalence of asymptomatic malaria detected in this study is a big challenge and can be a threat to the present malaria control programme. Thus, it should be considered in assessing and reorganising more effective malaria elimination strategies to achieve the desired goal of malaria control.