Malaria Vector Surveillance in Ganghwa-do, a Malaria-Endemic Area in the Republic of Korea

Abstract

We investigated the seasonality of Anopheles mosquitoes, including its species composition, density, parity, and population densities of mosquitoes infected with the parasite in Ganghwa-do (Island), a vivax malaria endemic area in the Republic of Korea. Mosquitoes were collected periodically with a dry-ice-tent trap and a blacklight trap during the mosquito season (April-October) in 2008. Anopheles sinensis (94.9%) was the most abundant species collected, followed by Anopheles belenrae (3.8%), Anopheles pullus (1.2%), and Anopheles lesteri (0.1%). Hibernating Anopheles mosquitoes were also collected from December 2007 to March 2008. An. pullus (72.1%) was the most frequently collected, followed by An. sinensis (18.4%) and An. belenrae (9.5%). The composition of Anopheles species differed between the mosquito season and hibernation seasons. The parous rate fluctuated from 0% to 92.9%, and the highest rate was recorded on 10 September 2008. Sporozoite infections were detected by PCR in the head and thorax of female Anopheles mosquitoes. The annual sporozoite rate of mosquitoes was 0.11% (2 of 1,845 mosquitoes). The 2 mosquitoes that tested positive for sporozoites were An. sinensis. Malarial infections in anopheline mosquitoes from a population pool were also tried irrespective of the mosquito species. Nine of 2,331 pools of Anopheles mosquitoes were positive. From our study, it can be concluded that An. sinensis, which was the predominant vector species and confirmed as sporozoite-infected, plays an important role in malaria transmission in Ganghwa-do.

Seasonal dynamics ofAnophelesspecies at three locations in the Republic of Korea

“…Anopheles sinensis Wiedemann sensu stricto (s.s.) has been implicated as a malaria vector and is the predominant Anopheles spp. collected south of Gyeonggi and Gangwon provinces in the ROK (Lee et al , Oh et al , Rueda et al , b). There is increased support for An.…”

“…Studies of the seasonal abundance of vector populations in the ROK are important prerequisites for identifying potential malaria high‐risk areas (Kim et al , , Shim and Kim , Strickman et al , Shin et al , Jeong et al , Oh et al ). According to Ree (), females of the first generation of An.…”

Mosquito Species Composition andPlasmodium vivaxInfection Rates on Baengnyeong-do (Island), Republic of Korea

“…For example, relative species abundance and demographic factors, such as longevity, which may predispose mosquitoes for the growth of sporozoites, varies throughout the mosquito season in the ROK [8] (unpublished data). Also, the presence of sporozoites, while necessary for infection of humans, may not translate to new cases, if the number of sporozoites is low [22].…”

Malaria dynamics with long latent period in hosts

“…The death function described in Figure 2.9 matches with the empirical observation of the mosquito survival rate increasing during August and September [47].…”

“…Those factors are highly seasonal dependent. For example, the parous rate fluctuated from 0.0% to 92.9% during summer season [47]. For simplicity, we consider a Gaussian type birth function 70) with the position of the center of the peak δ to be less than ν considering a maturation time.…”