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

Severe morbidity and hospital-based mortality from Rift Valley fever disease between November 2017 and March 2020 among humans in Uganda

Background: Rift Valley fever (RVF) is a zoonotic viral disease of increasing intensity among humans in Africa and the Arabian Peninsula. In Uganda, cases reported prior to 2016 were mild or not fully documented. We report in this paper on the severe morbidity and hospital-based mortality of human cases in Uganda. Methods: Between November 2017 and March 2020 human cases reported to the Uganda Virus Research Institute (UVRI) were confirmed by polymerase chain reaction (PCR). Ethical and regulatory approvals were obtained to enrol survivors into a one-year follow-up study. Data were collected on socio-demographics, medical history, laboratory tests, potential risk factors, and analysed using Stata software. Results: Overall, 40 cases were confirmed with acute RVF during this period. Cases were not geographically clustered and nearly all were male (39/40; 98%), median age 32 (range 11–63). The median definitive diagnosis time was 7 days and a delay of three days between presumptive and definitive diagnosis. Most patients (31/40; 78%) presented with fever and bleeding at case detection. Twenty-eight (70%) cases were hospitalised, out of whom 18 (64%) died. Mortality was highest among admissions in regional referral (11/16; 69%) and district (4/5; 80%) hospitals, hospitalized patients with bleeding at case detection (17/27; 63%), and patients older than 44 years (9/9; 100%). Survivors mostly manifested a mild gastro-intestinal syndrome with nausea (83%), anorexia (75%), vomiting (75%), abdominal pain (50%), and diarrhoea (42%), and prolonged symptoms of severe disease including jaundice (67%), visual difficulties (67%), epistaxis (50%), haemoptysis (42%), and dysentery (25%). Symptom duration varied between two to 120 days. Conclusion: RVF is associated with high hospital-based mortality, severe and prolonged morbidity among humans that present to the health care system and are confirmed by PCR. One-health composite interventions should be developed to improve environmental and livestock surveillance, prevent infections, promptly detect outbreaks, and improve patient outcomes

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

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

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

Ebola Hemorrhagic Fever Associated with Novel Virus Strain, Uganda, 2007–2008

Case-fatality rate is lower for this strain than for the other 3 Ebola species known to be pathogenic to humans

Undiagnosed West Nile virus lineage 2d infection in a febrile patient from South-west Uganda, 2018.

We report the retrospective identification and subsequent recovery of a near-complete West Nile Virus lineage 2 genomes from a hospitalized patient with acute febrile illness in Uganda, using a combination of degenerate primer polymerase chain reaction screening and a novel 1200bp nanopore-based whole-genome amplicon sequencing scheme. This represents the first West Nile virus genome to be recovered from a human in Uganda since its discovery in 1937. Basic molecular rather than serological surveillance methods could be more widely deployed in the region to better diagnose febrile infections

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

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