Ahmad Raeisi

Malaria is the most important mosquito-borne disease, which is transmitted by Anopheles species. According to the recent report of World Health Organization, there were an estimated 229 million malaria cases in 2019 in 87 malaria endemic countries. There are several vector control method specially using pesticides. The aim of this study was to collect all the data about insecticide resistant of malaria vectors in the Eastern Mediterranean region countries. In this study, all the published papers related to insecticide resistance of malaria vectors in the region were collected and resistant status of vectors in the countries was mapped. Resistance to different insecticide classes such as pyrethroids, organophosphate, organochlorine and carbamates were evaluated using World Health Organization guidelines. Results showed a wide variety of susceptibility/resistance status to these chemicals according to the location, historical context of pesticide used, genetic background of vectors, age and abdominal conditions of adults may play a role in the susceptibility status of these species to different insecticides. The results of this study is providing a guideline for countries to manage their vector control activities against insecticide resistance of malaria vectors and provide novel approaches such as male sterility, using Wolbachia, using new insecticide with new mode of action.

Iran has achieved a substantial decline in malaria incidence over the past decades. A common feature of malaria-endemic settings is the requirement for more sensitive techniques to describe levels of low transmission. In this study, serological and parasitological methods were used to measure transmission levels of Plasmodium falciparum and Plasmodium vivax during an elimination programme (2012) in Chabahar District, Sistan and Baluchistan Province, south-eastern Iran. Participants were randomly selected from 64 different geographical clusters in Chabahar city and surrounding villages. Antibody responses to P. falciparum and P. vivax blood-stage antigens were assessed by ELISA, while microscopy and molecular testing were used to determine parasite carriage by species. Age-adjusted antibody responses were analysed using a reversible catalytic model to calculate seroconversion rates (SCR). There was no evidence of recent transmission in the study areas, indicated by an absence of parasite infections in all ages and low or absent serological responses to either species in young children. The best model for age P. falciparum seroconversion was one with a change in exposure 21 years before sampling was done in Chabahar city (P = 0.018) and 4 years in the villages (P = 0.039). There was a higher level of recent P. vivax transmission compared to P. falciparum, based on the SCRs, in both the city and village settings. Serological analysis identified a decline in P. falciparum transmission in the urban areas of Chabahar, consistent with a previously described decrease in malaria in the early 1990s, demonstrating the utility of this approach to reconstruct exposure history. At present, it remains unclear whether the P. vivax antibody responses reflect active transmission due to new infections or relapse infections. The absence of parasitological and serological evidence of recent malaria transmission in Chabahar District is viable evidence for certification of elimination.

Due to the effect of midgut bacteria on proliferation of parasites and their potential as paratransgenesis tools, their identification in malaria vector mosquitoes is important. Anopheles culicifacies s.l. is one of the main malaria vectors in Asia; however, its midgut microbiota remains un-studied. This work was primarily designed to isolate potential candidates for use in a paratransgenesis approach, but also to give a picture of the midgut microbiota of wild-caught An. culicifacies larvae and adults from the southeast corner of Iran, which has the highest malaria endemicity in the country. A total of 68 larvae and 34 adult females (newly eclosed and older) from three different biotopes in Iran were analyzed for their midgut microflora. The mosquitoes had their midgut bacterial contents plated on three different culture media (brain heart agar, nutrient agar and blood agar) yielding 57 bacterial isolates. The 16S rRNA genes of the isolates were sequence analyzed for species designation, which then was confirmed by biochemical analysis. A total of twelve bacterial genera were identified: Acinetobacter, Aeromonas, Bacillus, Chryseobacterium, Delftia, Exiguobacterium, Kurthia, Microbacterium, Pseudomonas, Staphylococcus, Thorsellia and Variovorax. In older females, only Gram-negative bacteria were found, whereas larvae and newly-eclosed adults also harbored Gram-positive bacteria. The diversity of isolates also varied between sampling sites and mosquito stages, with the largest number of genera found in the Anguri district and in larvae, respectively. Pseudomonas was the most common genus retrieved from all sampling sites, and in both larvae and adults, suggesting a potential transstadial passage of these bacteria. Interestingly, identical 16S sequences of Pseudomonas were found in mosquitoes originating from different habitats at least 45 km apart, which could suggest that these bacteria have been adapted to the mosquitoes. The study of vector mosquito microbiota has recently gathered increased interest because of the potential influence on vector competence. By adding data from a hitherto uncharacterized malaria mosquito, a better picture of gut flora in vector mosquitoes was obtained. Furthermore, some species of the predominant genus Pseudomonas will be evaluated for the selection of a paratransgenesis candidate.

Malaria continues to be a global public health challenge, particularly in developing countries. Delivery of prompt and effective diagnosis and treatment of malaria cases, detection of malaria epidemics within one week of onset and control them in less than a month, regular disease monitoring and operational classification of malaria are among the major responsibilities of the national malaria programme. The study was conducted to determine these indicators at the different level of primary health care facilities in malaria-affected provinces of Iran

Malaria is one of the leading causes of sickness and death in the developing world, causing more than a million deaths and around 250 million new cases annually worldwide. The aim of this comprehensive survey was to provide information on malaria indicators at household level in high-risk malaria areas in Iran.

This work was carried out to assess the patterns and prevalence of resistance to chloroquine (CQ) and sulphadoxine-pyrimethamine (SP) in Iran.

Between 2002 and 2004, the standardized 28-day protocol recently developed by the World Health Organization was used to explore the efficacy of chloroquine, in the treatment of uncomplicated, Plasmodium falciparum malaria, in five sentinel sites in southern Iran. All but 14 of the 158 patients enrolled (128, 28 and two from the provinces of Sistan-Baluchestan, Hormozgan and Kerman, respectively) were successfully followed-up. The overall frequency of treatment failure by day 28 was 78.5%, with 17.4% of the patients being classed as early treatment failures, 34.7% as late clinical failures, and 26.4% as late parasitological failures. There appeared to be no significant change in the frequency of treatment failure between the 2002-2003 and 2003-2004 transmission seasons, nor any significant between-site variation in the efficacy of chloroquine. Given these observations, the replacement of chloroquine, as the first-line drug for the treatment of uncomplicated, P. falciparum malaria in Iran, was inevitable. Artesunate-sulfadoxine-pyrimethamine is now the recommended first-line treatment, with artemether-lumefantrine used for second-line treatment. The efficacies of these combination therapies are currently being evaluated and monitored.