Prediction of arboviral disease outbreaks and planning for appropriate control interventions require knowledge of the mosquito vectors involved. Although mosquito surveys have been conducted in different regions of Uganda since the mid 30's such studies have not been carried out in Mpigi District. In October 2011, we conducted mosquito collections in Mpigi district to determine species composition and relative abundance of the different species. The survey was conducted in four villages, Njeru, Ddela, Kiwumu and Nsumbain Kammengo sub-county, Mpigi district, Uganda. CDC light traps baited with dry ice (carbon dioxide) were used to capture adult mosquitoes. A total of 54,878 mosquitoes comprising 46 species from eight genera were collected. The dominant species at all sites was Coquilletidia (Coquilletidia) fuscopennata Theobald (n=38,059, 69%), followed by Coquillettidia (Coquillettidia) metallica Theobald (n=4,265, 7.8%). The number of species collected varied from 17 in the genus Culex to 1 in the genus Lutzia. Of the 46 species identified, arboviruses had previously been isolated from 28 (60.9%) suggesting a high potential for arboviral transmission and/or maintenance in Mpigi District.

https://www.entomoljournal.com/archives/2014/vol2issue5/PartE/61-901.pdf

Studies on the Species Composition and Relative Abundance of Mosquitoes of Mpigi District, Central Uganda

Arboviruses are endemic in Uganda; however, little is known about their epidemiology, seasonality and spatiotemporal distribution. Our study sought to provide information on arbovirus outbreaks from acute clinical presentations.Immunoglobulin M (IgM) and confirmatory Plaque Reduction Neutralisation Test (PRNT) results for arbovirus diagnosis of samples collected from patients attending sentinel sites from 2016-19 were analysed retrospectively. Demographic data were analysed with SaTScan and SPSS software to determine the epidemiology and spatiotemporal distribution of arboviruses.Arbovirus activity peaked consistently during March-May rainy seasons. Overall, arbovirus seroprevalence was 9.5%. Of 137 IgM positives, 52.6% were confirmed by PRNT, of which 73.6% cases were observed in central Uganda with Yellow Fever Virus had the highest prevalence (27.8%). The 5-14 age group were four times more likely to be infected with an arbovirus p=0.003, 4.1 (95% CI 1.3-12.3). Significant arboviral activity was observed among outdoor workers(p=0.05) . Spatiotemporal analysis indicated arboviral activity in 23 of the 85 districts analysed..Our study shows that arbovirus activity peaks during the March-May rainy season and highlights the need for YFV mass vaccination to reduce the clinical burden of arboviruses transmitted within the region. 

https://doi.org/10.1016/j.ijregi.2023.01.013

Arbovirus circulation, epidemiology and spatiotemporal distribution in Uganda

Background: Arboviruses research in Uganda dates before the 1930s. More than 38 arboviruses and over 224 mosquito species together with many other insect vectors are documented to occur in Uganda. However, arboviruses research activities came to a virtual standstill in the 1980s. Surveillance for arboviruses was reinstated in 2007 through the Uganda Arbovirus Program 2007 to collect new information on arbovruses in Uganda.

/pdf/uganda-arboviruses-surveillance-activities-8lezbs8b9z.pdf

Julius J Lutwama

Papers

Uganda Arboviruses Surveillance Activities