Hamid Reza Basseri

Background: Notwithstanding progress in recent years, a safe, an effective and affordable malaria vaccine is not available yet. Ookinete-secreted protein, Plasmodium vivax von Willebrand factor A domain-related protein (PvWARP), is a candidate for malaria transmission-blocking vaccines (TBVs). Methods: The PvWARP was expressed in Escherichia coli BL21 using the pET-23a vector and was purified using Ni-NTA affinity chromatography from a soluble fraction. Polyclonal antibody was raised against rPvWARP and transmission blocking activity was carried out in an Anopheles stephensi-P. vivax model. Results: Expression of full length of PvWARP (minus signal peptide) expression showed a 35-kDa protein. The purified protein was recognized by mouse polyclonal antibody directed against rPvWARP. Sera from the animals displayed significantly a blocking activity in the membrane feeding assay of An. stephensi mysorensis. Conclusions: This is the first report on P. vivax WARP expression in E. coli that provides an essential base for development of the malaria TBV against P. vivax. This may greatly assist in malaria elimination, especially in the oriental corner of WHO Eastern Mediterranean Regional Office (WHO/EMRO) including Afghanistan, Iran and Pakistan.

Each year, 24–36% of malaria cases in Beluchestan (area) occur among Afghani refugees. Knowledge about malaria transmission and protection are important for these refugees to enable local Health Services to manage malaria control in the area. Our objective was to explore and investigate knowledge, attitude and practices of Afghan refugees and Iranian residents with respect to malaria transmission and protection. A cross-sectional study was performed and 10% of target groups were selected by systematic random sampling and then interviewed. In this study, 385 Iranian and 390 Afghani refugees participated in the survey. Respondents answered questions about demographic characters, cause and transmission of malaria, belief about severity and complications of malaria, malaria mobility and health care-seeking behavior, perceived control of malaria prevention, beliefs about utility of bed nets, perceived susceptibility to malaria, and whether they use window-screens and bed nets. The majority of Iranians (76.6%) and Afghanis (60.1%) were familiar with typical symptoms of the malaria disease, but about 50% of each group did not know malaria transmission occurs by mosquito bites. About 90% of Afghanis stated they do not use personal protection against mosquito bites over night, while 60% of Iranians used bed net. Only one third of Afghani refugees use local Health Center services. Conclusion: The cross-border traffic of Afghanis is an important factor for persistence of malaria in Baluchestan but based on our data, life style and protective behavior of refugees with regard to malaria protection are also important factors, particularly because they do not use local Health Services. Therefore, it is important to implement prevention education programs specifics to target Afghani refugees and to employ Afghani public health professionals to asset with elimination and treatment. Chaque année, 24 à 36% des cas de paludisme dans la région du Baloutchistan surviennent chez des réfugiés afghans. Il est important que ces réfugiés connaissent les mécanismes de transmission du paludisme et les moyens de protection, pour permettre aux services sanitaires locaux de combattre cette maladie dans la région. Notre objectif était d’examiner et d’analyser les connaissances, les attitudes et les pratiques des réfugiés afghans et des résidants iraniens concernant la transmission du paludisme et les moyens de protection. Une étude transversale a été conduite, et 10 % des groupes cibles ont été sélectionnés par échantillonnage aléatoire systématique, puis interrogés. Dans cette étude, 385 Iraniens et 390 réfugiés afghans ont participé à l’enquête. Les sujets ont répondu à des questions d’ordre démographique et sur la cause et la transmission du paludisme, les croyances sur la gravité et les complications du paludisme, la mobilité du paludisme et la recherche de soins, la façon dont est perçue la prévention du paludisme, les croyances sur l’utilité des moustiquaires, la sensibilité subjective au paludisme et l’utilisation ou non de volets et de moustiquaires. La majorité des Iraniens (76,6 %) et des Afghans (60,1 %) connaissaient les symptômes typiques du paludisme, mais environ 50 % dans chaque groupe ignoraient que le paludisme se transmet par des piqûres de moustique. Environ, 90 % des Afghans ont déclaré ne pas utiliser de protection personnelle contre les piqûres de moustique pendant la nuit, tandis que 60 % des Iraniens utilisaient des moustiquaires. Seul un tiers des réfugiés afghans avaient recours aux services sanitaires locaux. Conclusion Le trafic transfrontalier des Afghans est un important facteur de persistance du paludisme au Baloutchistan, mais, d’après nos données, le mode de vie et le comportement des réfugiés en ce qui concerne la protection antipaludique sont également des facteurs importants, en particulier parce qu’ils n’utilisent pas les services sanitaires locaux. Il est donc important de mettre en œuvre des programmes spécifiques d’éducation à la prévention visant les réfugiés afghans, et d’employer des professionnels de santé publique afghans pour favoriser le traitement et l’éradication.

Background: The identification of key molecules is crucial for designing transmission-blocking vaccines (TBVs), among those ookinete micronemal proteins are candidate as a general class of malaria transmission-blocking targets. Here, the sequence analysis of an extra-cellular malaria protein expressed in ookinetes, named von Willebrand factor A domain-related protein (WARP), is reported in 91Plasmodium vivaxisolates circulating in different regions of Iran.Methods: Clinical isolates were collected from north temperate and southern tropical regions in Iran. Primers have been designed based onP. vivaxsequence (ctg_6991) which amplified a fragment of about 1044 bp with no size variation. Direct sequencing of PCR products was used to determine polymorphism and further bioinformatics analysis inP. vivaxsexual stage antigen,pvwarp.Results: Amplifiedpvwarpgene showed 886 bp in size, with no intron. BLAST analysis showed a similarity of 98–100% toP. vivaxSal-I strain; however, Iranian isolates had 2 bp mismatches in 247 and 531 positions that were non-synonymous substitution [T (ACT) to A (GCT) and R (AGA) to S (AGT)] in comparison with the Sal-I sequence.Conclusion: This study presents the first large-scale survey onpvwarppolymorphism in the world, which provides baseline data for developing WARP-based TBV against both temperate and tropicalP. vivaxisolates.

Despite the abundance of studies conducted on the role of mosquitoes in malaria transmission, the biology and interaction of Plasmodium with its insect host still holds many mysteries. This paper provides the first study to follow the sporogonic cycle of Plasmodium vivax in a wild insecticide-resistant mysorensis strain of Anopheles stephensi, a major vector of vivax malaria in south-eastern Iran. The study subsequently demonstrates that host-parasite sugar binding interactions are critical to the development of this parasite in the salivary glands of its mosquito host. The identity of the receptors or sugars involved was revealed by a receptor "pre-saturation" strategy in which sugars fed to the mosquitoes inhibited normal host-parasite interactions.