Distribution and breeding sites of Aedes aegypti and Aedes albopictus in 32 urban/peri-urban districts of Mozambique: implication for assessing the risk of arbovirus outbreaks

Abstract

BackgroundAedes-borne arboviruses have emerged as an important public health problem worldwide and, in Mozambique, the number of cases and its geographical spread have been growing. However, information on the occurrence, distribution and ecology of Aedes aegypti and Ae. albopictus mosquitoes remain poorly known in the country.MethodsBetween March and April 2016, a cross-sectional study was conducted in 32 districts in Mozambique to determine the distribution and breeding sites of Ae. aegypti and Ae. albopictus. Larvae and pupae were collected from a total of 2,807 water-holding containers using pipette, dipper, funnel and sweeping procedures, depending on the container type and location. Both outdoor and indoor water-holding containers were inspected. The immature forms were reared to adults and the identifications of the mosquito species was carried out with a stereomicroscope using a taxonomic key.ResultsAedes aegypti was found in every district sampled, while Ae. albopictus was only found in Moatize district, situated in Tete Province in the central part of the country. Six hundred and twenty-eight of 2,807 (22.4%) containers were positive for Ae. aegypti but only one (0.03%) was positive for Ae. albopictus. The Container Index (CI) of Aedes was highest in densely populated suburban areas of the central region (260/604; 43.0%), followed by suburban areas in northern areas (228/617; 36.9%) whilst the lowest proportion was found in urbanized southern areas (140/1586; 8.8%). The highest CI of Aedes was found in used tires (448/1268; 35.3%), cement tanks (20/62; 32.3%) and drums (21/95; 22.1%).ConclusionData from our study showed that Ae. aegypti is present nation-wide, since it occurred in every sampled district, whilst Ae. albopictus had a limited distribution. Therefore, the risk of transmission of dengue and chikungunya is likely to have been underestimated in Mozambique. This study highlights the need for the establishment of a national entomological surveillance program for Aedes spp. in Mozambique in order to gain a better understanding about vector bionomics and to support the development of informed effective vector control strategies.

Detection of Transovarial Transmission on Aedes sp. in Gombong Kebumen Central Java

“…Aedes aegypti mosquitoes usually prefer to lay eggs indoor while the Aedes albopictus mosquito prefers to lay eggs outdoors. 16 However, unfortunately, this cannot be confirmed in this study because no eggs were identified. The implication of the information from the results of this study is the awareness of used goods such as used tires, buckets, bottles or cans that are left around the house which are left unchecked.…”

Important Aedes Spp. Infestation Levels In Kinshasa, Democratic Republic Of Congo

“…The larval indices are remarkable high for a place without important endemicity of arboviruses and only sporadical reporting of cases of dengue (14)(12)(15)(13), outbreaks of chikungunya (11)(9) and yellow fever (31). The level of infestation is on the higher end of what has been published in other African settings: in south-eastern Tanzania with HI of 4.9-6.6, CI of 14.6-18.9 (32); in Burkina Faso with HI of 70, CI of 35 and BI of 10 (33); in north-west Ethiopia with HI of 25.5, CI of 32.9 and BI of 48.4 (34); in Mozambique with CI of 22 (35); and in Angola with HI of 4.3-27.9, CI of 2.1-9.3 and BI of 5.8-42.2 (36). But the Breteau Index in Kinshasa was much lower than the one observed in Kenya during a dengue outbreak in 2013-14, where BI reached a value of 270/100 houses (37).…”

“…Used car tires, water storage containers and arti cial breeding sites (type trash) were the main containers chosen by Aedes mosquitoes for the oviposition coinciding with other studies conducted in several countries of the African continent (33)(34)(35)(36)(37)39) (40). The water storage containers were also found to be the most productive for Aedes pupae, which is a stage in the mosquito cycle which does not need nutrients and which is just before the adult stage of the mosquito.…”

Research agenda for preventing mosquito-transmitted diseases through improving the built environment in sub-Saharan Africa

“…aegypti, is common in African towns and cities (Agha et al 2017). As urban areas expand it is highly likely that Aedes-borne diseases will become more common in SSA, unless action is taken to reduce the aquatic habitats of the immature mosquitoes (Abílio et al 2018) and reduce the number of adult biting mosquitoes, since there is no dengue vaccine suitable for programmatic use or any specific treatment.…”