Training Report: Training of trainers and farmers’ training on validated sweetpotato silage making and use in Masaka and Kamuli districts.

European UnionInternational Fund for Agricultural Developmen

An update on the mosquito species composition and diversity in western and North Western Uganda

Although the west and north western parts of Uganda are historically known homes to a number of mosquito species and arboviruses associated with morbidity and mortality, early studies were highly focal and limited to specific collection methods. We aimed to update mosquito species composition in areas where a febrile illness study had shown evidence of arboviruses circulating. Adult mosquito sampling was done outside and inside houses using light traps baited with solid carbon dioxide and pyrethrum spray respectively. All collected mosquitoes were identified using appropriate morphological identification keys. A total of 22,455 mosquitoes from 89 species, 22 sub species and 11 genera were collected from Arua and Kasese districts. Overall abundance was found to be higher in Kasese (n=13446, 59.9%) than Arua district (n = 9009, 40.1%), though no significant differences were observed across villages in Arua and Kasese districts (Kruskal Wallis, X2 = 2, df = 3, p>0.05). Collection numbers were highest for genus Coquillettidia (n = 7942, 35.4%), followed by Culex (n = 7642, 34.03%), Mansonia (n = 3414, 15.2%), Anopheles (n = 1970, 8.8%) and Aedes (n = 1349, 6.01%). Other species were across 6 genera Eretmopodites (n = 59, 0.26%), Uranoteania (n = 36, 0.16%), Lutzia (n = 26, 0.12%), Mimomyia (n = 13, 0.06%), Aediomyia (n = 3, 0.01%) and Toxorhynchites (n = 1, 0.004%) appeared low in both districts. Species richness was comparatively higher in Kasese than Arua district, however across villages, it was evenly distributed with no significant differences observed, and species diversity was significantly higher in Arua than Kasese (Mann Whitney U test, p<0.05). A number of species identified here have been implied in arbovirus transmission. Moreover, we show the first description of Culex (Culex) litwakae Harbach mosquito in Uganda, a species previously described in the coastal regions of Kenya. The existence of a mosquito species previously not documented in Uganda suggests a likelihood of many invasive species whose potential to transmit viruses to humans and animals remains largely unknown

Identification and molecular characterization of highly divergent RNA viruses in cattle, Uganda

The risk for the emergence of novel viral zoonotic diseases in animals and humans in Uganda is high given its geographical location with high biodiversity. We aimed to identify and characterize viruses in 175 blood samples from cattle selected in Uganda using molecular approaches. We identified 8 viral species belonging to 4 families (Flaviviridae, Peribunyaviridae, Reoviridae and Rhabdoviridae) and 6 genera (Hepacivirus, Pestivirus, Orthobunya-virus, Coltivirus, Dinovernavirus and Ephemerovirus). Four viruses were highly divergent and tetantively named Zikole virus (Family: Flaviviridae), Zeboroti virus (Family: Reoviridae), Zebtine virus (Family: Rhabdoviridae) and Kokolu virus (Family: Rhabdoviridae). In addition, Bovine Hepacivirus, Obodhiang virus, Aedes pseudoscutellaris reovirus and Schmallenberg virus were identified for the first time in Ugandan cattle. We report 8 viral species belonging to 4 viral families including divergent ones in the blood of cattle in Uganda. Hence, cattle may be reservoir hosts for likely emergence of novel viruses with pathogenic potential to cause zoonotic diseases in different species with serious public health implications

Vδ2+ T cell response to malaria correlates with protection from infection but is attenuated with repeated exposure.

Vδ2+ γδ T cells are semi-innate T cells that expand markedly following P. falciparum (Pf) infection in naïve adults, but are lost and become dysfunctional among children repeatedly exposed to malaria. The role of these cells in mediating clinical immunity (i.e. protection against symptoms) to malaria remains unclear. We measured Vδ2+ T cell absolute counts at acute and convalescent malaria timepoints (n = 43), and Vδ2+ counts, cellular phenotype, and cytokine production following in vitro stimulation at asymptomatic visits (n = 377), among children aged 6 months to 10 years living in Uganda. Increasing age was associated with diminished in vivo expansion following malaria, and lower Vδ2 absolute counts overall, among children living in a high transmission setting. Microscopic parasitemia and expression of the immunoregulatory markers Tim-3 and CD57 were associated with diminished Vδ2+ T cell pro-inflammatory cytokine production. Higher Vδ2 pro-inflammatory cytokine production was associated with protection from subsequent Pf infection, but also with an increased odds of symptoms once infected. Vδ2+ T cells may play a role in preventing malaria infection in children living in endemic settings; progressive loss and dysfunction of these cells may represent a disease tolerance mechanism that contributes to the development of clinical immunity to malaria

Historical environmental change in Africa drives divergence and admixture of Aedes aegypti mosquitoes: a precursor to successful worldwide colonization?

Article PurchasedIncreasing globalization has promoted the spread of exotic species, including disease vectors. Understanding the evolutionary processes involved in such colonizations is both of intrinsic biological interest and important to predict and mitigate future disease risks. The Aedes aegypti mosquito is a major vector of dengue, chikungunya and Zika, the worldwide spread of which has been facilitated by Ae. aegypti's adaption to human-modified environments. Understanding the evolutionary processes involved in this invasion requires characterization of the genetic make-up of the source population(s). The application of approximate Bayesian computation (ABC) to sequence data from four nuclear and one mitochondrial marker revealed that African populations of Ae. aegypti best fit a demographic model of lineage diversification, historical admixture and recent population structuring. As ancestral Ae. aegypti were dependent on forests, this population history is consistent with the effects of forest fragmentation and expansion driven by Pleistocene climatic change. Alternatively, or additionally, historical human movement across the continent may have facilitated their recent spread and mixing. ABC analysis and haplotype networks support earlier inferences of a single out-of-Africa colonization event, while a cline of decreasing genetic diversity indicates that Ae. aegypti moved first from Africa to the Americas and then to Asia. ABC analysis was unable to verify this colonization route, possibly because the genetic signal of admixture obscures the true colonization pathway. By increasing genetic diversity and forming novel allelic combinations, divergence and historical admixture within Africa could have provided the adaptive potential needed for the successful worldwide spread of Ae. aegypti

Arbovirus circulation, epidemiology and spatiotemporal distribution in Uganda

BackgroundArboviruses are endemic in Uganda; however, little is known about their epidemiology, seasonality, and spatiotemporal distribution. This study sought to provide information on arbovirus outbreaks from acute clinical presentations.MethodsA retrospective analysis of IgM and confirmatory Plaque Reduction Neutralization Test (PRNT)and results for arbovirus diagnosis of samples collected from 2016 to 2019 was carried out. Demographic data were used to determine the epidemiology and spatiotemporal distribution of arboviruses using the SaTScan and SPSS software.ResultsArbovirus activity peaked consistently during March-May rainy seasons. The overall arbovirus seroprevalence was 9·5% (137/1441). Of the 137 IgM positives, 72 (52·6%) were confirmed by PRNT, of which the central region (53/72; 73·6%) and YFV (20/72; 27·8%) had the highest prevalence. The 5-14 age group were four times more likely to be infected with an arbovirus p=0·003, 4·1 (1·3- 12·3 CI). Significant arboviral activity was observed among indoor (p=0·003) and outdoor (p=0·05) patients. Spatiotemporal analysis indicated arboviral activity in 23 districts with five distinct clusters in 6 districts. Masaka, in the Central region, was the most affected among the districts, with a significant YFV cluster (p˂0·001) from March to May 2016.InterpretationThis study shows that arbovirus activity peak 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

Outbreak of Marburg hemorrhagic fever among miners in Kamwenge and Ibanda Districts, Uganda, 2007

Marburg hemorrhagic fever was detected among 4 miners in Ibanda District, Uganda, from June through September, 2007. Infection was likely acquired through exposure to bats or bat secretions in a mine in Kamwenge District, Uganda, and possibly human-to-human transmission between some patients. We describe the epidemiologic investigation and the health education response

Assessment of core capacities for the International Health Regulations (IHR[2005]) – Uganda, 2009

<p>Abstract</p> <p>Background</p> <p>Uganda is currently implementing the International Health Regulations (IHR[2005]) within the context of Integrated Disease Surveillance and Response (IDSR). The IHR(2005) require countries to assess the ability of their national structures, capacities, and resources to meet the minimum requirements for surveillance and response. This report describes the results of the assessment undertaken in Uganda.</p> <p>Methods</p> <p>We conducted a descriptive cross-sectional assessment using the protocol developed by the World Health Organisation (WHO). The data collection tools were adapted locally and administered to a convenience sample of HR(2005) stakeholders, and frequency analyses were performed.</p> <p>Results</p> <p>Ugandan national laws relevant to the IHR(2005) existed, but they did not adequately support the full implementation of the IHR(2005). Correspondingly, there was a designated IHR National Focal Point (NFP), but surveillance activities and operational communications were limited to the health sector. All the districts (13/13) had designated disease surveillance offices, most had IDSR technical guidelines (92%, or 12/13), and all (13/13) had case definitions for infectious and zoonotic diseases surveillance. Surveillance guidelines were available at 57% (35/61) of the health facilities, while case definitions were available at 66% (40/61) of the health facilities. The priority diseases list, surveillance guidelines, case definitions and reporting tools were based on the IDSR strategy and hence lacked information on the IHR(2005). The rapid response teams at national and district levels lacked food safety, chemical and radio-nuclear experts. Similarly, there were no guidelines on the outbreak response to food, chemical and radio-nuclear hazards. Comprehensive preparedness plans incorporating IHR(2005) were lacking at national and district levels. A national laboratory policy existed and the strategic plan was being drafted. However, there were critical gaps hampering the efficient functioning of the national laboratory network. Finally, the points of entry for IHR(2005) implementation had not been designated.</p> <p>Conclusions</p> <p>The assessment highlighted critical gaps to guide the IHR(2005) planning process. The IHR(2005) action plan should therefore be developed to foster national and international public health security.</p

Discovery and Characterization of Bukakata orbivirus (\u3ci\u3eReoviridae:Orbivirus\u3c/i\u3e), a Novel Virus from a Ugandan Bat

While serological and virological evidence documents the exposure of bats to medically important arboviruses, their role as reservoirs or amplifying hosts is less well-characterized. We describe a novel orbivirus (Reoviridae:Orbivirus) isolated from an Egyptian fruit bat (Rousettus aegyptiacus leachii) trapped in 2013 in Uganda and named Bukakata orbivirus. This is the fifth orbivirus isolated from a bat, however genetic information had previously only been available for one bat-associated orbivirus. We performed whole-genome sequencing on Bukakata orbivirus and three other bat-associated orbiviruses (Fomede, Ife, and Japanaut) to assess their phylogenetic relationship within the genus Orbivirus and develop hypotheses regarding potential arthropod vectors. Replication kinetics were assessed for Bukakata orbivirus in three different vertebrate cell lines. Lastly, qRT-PCR and nested PCR were used to determine the prevalence of Bukakata orbivirus RNA in archived samples from three populations of Egyptian fruit bats and one population of cave-associated soft ticks in Uganda. Complete coding sequences were obtained for all ten segments of Fomede, Ife, and Japanaut orbiviruses and for nine of the ten segments for Bukakata orbivirus. Phylogenetic analysis placed Bukakata and Fomede in the tick-borne orbivirus clade and Ife and Japanaut within the Culicoides/phlebotomine sandfly orbivirus clade. Further, Bukakata and Fomede appear to be serotypes of the Chobar Gorge virus species. Bukakata orbivirus replicated to high titers (106–107 PFU/mL) in Vero, BHK-21 [C-13], and R06E (Egyptian fruit bat) cells. Preliminary screening of archived bat and tick samples do not support Bukakata orbivirus presence in these collections, however additional testing is warranted given the phylogenetic associations observed. This study provided complete coding sequence for several bat-associated orbiviruses and in vitro characterization of a bat-associated orbivirus. Our results indicate that bats may play an important role in the epidemiology of viruses in the genus Orbivirus and further investigation is warranted into vector-host associations and ongoing surveillance efforts