Blood meal profile and positivity rate with malaria parasites among different malaria vectors in Sudan

Abstract

Background Malaria is a life-threatening public health problem globally with particularly heavy burden in the sub-Saharan Africa including Sudan. The understanding of feeding preference of malaria vectors on different hosts is a major challenge for hindering the transmission cycle of malaria. In this study, blood meals taken by blood-fed Anopheles mosquitoes collected from the field in malaria endemic areas of Sudan were analysed for source of blood meal and malaria parasite presence. Methods Anopheles mosquitoes were collected from different regions in Sudan: Khartoum state, Sennar state, Northern state, and El Gedarif state between September 2020 and February 2021. Anopheles mosquitoes were collected using the standard pyrethrum spray catch and back-pack aspirator. Mosquito samples were sorted and morphologically identified to species level using international identification keys. Morphologically identified mosquito species were also confirmed using PCR. Genomic DNA was extracted from mosquitoes for molecular identification of blood meal source and parasite detection. The presence of Plasmodium species DNA in each mosquito sample was investigated using semi-nested PCR. Frequency of each blood meal source, Anopheles mosquito vector, and malaria parasite detected was calculated. Positivity rate of each fed female Anopheles mosquito was calculated for each species. Results A total of 2132 Anopheles mosquitoes were collected. 571 (26.8%) were males and 1561 (73.2%) were females classified based on their abdominal status into 1048 (67.1%) gravid, 274 (17.6%) fed, and 239 (15.3%) unfed females. Among the blood fed Anopheles mosquitoes, 263 (96.0%) were morphologically identified and confirmed using PCR to Anopheles arabiensis, 9 (3.3%) to Anopheles stephensi, and 2 (0.7%) to Anopheles rufipes. Of 274 blood-fed An. arabiensis, 68 (25.9%) fed on mixed blood meals from human and cattle, 8 (3.0%) fed on cattle and goat, and 13 (4.8%) fed on human, cattle and goat. For single blood meal sources, 70 (26.6%) fed on human, 95 (36.1%) fed on cattle, 8 (3.0%) fed on goat, and 1 (0.4%) fed on dog. While An. rufipes and An. stephensi fed on dog (2; 0.75%) and cattle (9; 3.3%), respectively. Plasmodium parasite detection in the blood meals showed that 25/274 (9.1%) An. arabiensis meals were positive for Plasmodium vivax and 19/274 (6.9%) An. arabiensis meals were positive for Plasmodium falciparum. The rate of positivity of An. arabiensis with any Plasmodium species was 16.7%. However, the positivity rate with P. falciparum only was 7.2%, while P. vivax was 9.5%. Both An. rufipes and An. stephensi were having positivity rates of 0.0% each. Conclusions This study which was mainly on blood-fed Anopheles mosquitoes showed a diversity in the type of diet from human, cattle, and goat. Anopheles mosquitoes especially An. arabiensis in Sudan, are opportunistic blood feeders and can feed broadly on both human and cattle. The application of blood meal identification is not only important in malaria vector epidemiological surveillance but also is very useful in areas where arthropods exhibit zoophilic feeding behaviour for mammals.

Changing epidemiology of Plasmodium vivax malaria in Nouakchott, Mauritania: a six-year (2015–2020) prospective study

“…In Nouakchott, until proven otherwise, malaria parasites are transmitted exclusively by An. arabiensis, which can transmit both P. vivax and P. falciparum, as demonstrated in other African countries where P. vivax and P. falciparum are sympatric [43][44][45]. It is therefore not easy to understand why P. falciparum has been responsible for only a minority of malaria infections in Nouakchott until present.…”

Bridging the Knowledge Gap: Associations between malaria infections, personally used prevention measures, and risk factors in Al Gezira State, Sudan

“…This study revealed a slightly higher proportion of females who tested positive for malaria in comparison to males. While similar ndings have been reported earlier [31], this may be due to more complex behaviours, such as sleeping indoors, which may offer to some extent protection against outdoor vector biting [4,27]. Generally, one who spent time outside are more susceptible to malaria infection than their counterparts [32].…”

“…This con rms the heterogeneity of malaria transmission in Sudan. This heterogeneity is mainly in uenced by the proportional distribution of the risk factors such as climate, geography, and socio-economic status, as well as environmental conditions, abundance of the various vectors, as well as socioeconomic characteristics, local risky behaviours and practices [10,27,33]. Several studies have also reported similar variations in malaria prevalence across the different regions in Sudan [34,35].…”

“…Identifying risk factors associated with malaria infection locally is essential for successfully controlling and eventually eliminating malaria. Several well-known risk factors such as wide spectrum of endemic vectors [27], invasive competent vectors [20,28], climate change [3,10] and the rapidly spreading insecticides resistance are hindering the global efforts to eliminate malaria [29]. Nevertheless, several anthropological factors related to human behaviours and practices have a substantial in uence on increasing malaria transmission [4,5].…”

Cattle feeding tendency of Anopheles mosquitoes and their infection rates in Aradum village, North Wollo, Ethiopia: an implication for animal-based malaria control strategies

“…Interestingly, a substantial number of the origins of Anopheles blood meals were not identified using human and bovine antibodies. This may indicate that different blood meal sources exist for malaria mosquitoes as documented in Sudan [ 36 ]. As a result, considering all wild animals, including cattle, could have provided a better understanding of the sources of Anopheles blood meals in the study area.…”