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On April 20, 2018, the Kween District Health Office in Kween District, Uganda reported 7 suspected cases of human anthrax. A team from the Uganda Ministry of Health and partners investigated and identified 49 cases, 3 confirmed and 46 suspected; no deaths were reported. Multiple exposures from handling the carcass of a cow that had died suddenly were significantly associated with cutaneous anthrax, whereas eating meat from that cow was associated with gastrointestinal anthrax. Eating undercooked meat was significantly associated with gastrointestinal anthrax, but boiling the meat for >60 minutes was protective. We recommended providing postexposure antimicrobial prophylaxis for all exposed persons, vaccinating healthy livestock in the area, educating farmers to safely dispose of animal carcasses, and avoiding handling or eating meat from livestock that died of unknown causes.

Background On March 13, 2020, Uganda instituted COVID-19 symptom screening at its international airport, isolation and SARS-CoV-2 testing for symptomatic persons, and mandatory 14-day quarantine and testing of persons traveling through or from high-risk countries. On March 21, 2020, Uganda reported its first SARS-CoV-2 infection in a symptomatic traveler from Dubai. By April 12, 2020, 54 cases and 1257 contacts were identified. We describe the epidemiological, clinical, and transmission characteristics of these cases. Methods A confirmed case was laboratory-confirmed SARS-CoV-2 infection during March 21–April 12, 2020 in a resident of or traveler to Uganda. We reviewed case-person files and interviewed case-persons at isolation centers. We identified infected contacts from contact tracing records. Results Mean case-person age was 35 (±16) years; 34 (63%) were male. Forty-five (83%) had recently traveled internationally (‘imported cases’), five (9.3%) were known contacts of travelers, and four (7.4%) were community cases. Of the 45 imported cases, only one (2.2%) was symptomatic at entry. Among all case-persons, 29 (54%) were symptomatic at testing and five (9.3%) were pre-symptomatic. Among the 34 (63%) case-persons who were ever symptomatic, all had mild disease: 16 (47%) had fever, 13 (38%) reported headache, and 10 (29%) reported cough. Fifteen (28%) case-persons had underlying conditions, including three persons with HIV. An average of 31 contacts (range, 4–130) were identified per case-person. Five (10%) case-persons, all symptomatic, infected one contact each. Conclusion The first 54 case-persons with SARS-CoV-2 infection in Uganda primarily comprised incoming air travelers with asymptomatic or mild disease. Disease would likely not have been detected in these persons without the targeted testing interventions implemented in Uganda. Transmission was low among symptomatic persons and nonexistent from asymptomatic persons. Routine, systematic screening of travelers and at-risk persons, and thorough contact tracing will be needed for Uganda to maintain epidemic control.

Rift Valley fever (RVF) is caused by RVF virus (RVFV), a single-stranded RNA virus in the Bunyavirales order, Phenuiviridae family, and Phlebovirus genus. It is an emerging epidemic disease of humans and livestock and an important endemic problem in sub-Saharan Africa.1 Rift Valley fever virus is transmitted to livestock and humans by the bite of infected mosquitoes or exposure to tissues or blood of infected animals.2 Interepidemic virus maintenance is thought to occur either transovarially in Aedes species mosquitoes or through cycling of low-level transmission between domestic livestock or wild ungulates and mosquitoes.3 After periods of heavy rainfall, Aedes mosquitoes rapidly emerge, resulting in extensive amplification of the virus through infection of livestock.2 Presentation of RVF in animals can vary among species with a range of clinical severity. Livestock, particularly cattle, sheep, and goats are highly susceptible to RVFV and present with symptoms of fever, loss of appetite, weakness, low milk production, nasal discharge, vomiting, and diarrhea. During large epizootics, “abortion storms,” particularly in sheep and cattle, have been identified. High newborn mortality (80–100%) and adult mortality (5–20%) may also be observed.3 Humans infected with RVFV typically have mild, self-limited febrile illness, but can present in a small number of cases (< 8%) with severe jaundice, rhinitis, encephalitis, and hemorrhagic manifestations. Retinal degeneration (5–10% of cases), hemorrhagic fever (< 1%), or encephalitis (< 1%) may also develop.4,5 Outbreaks of RVF have been reported most frequently in East Africa, especially Kenya, Somalia, and Tanzania, with the last major outbreak in the region recorded in 1997–1998. However, outbreaks have also been reported in other African countries, including Egypt, South Africa, Madagascar, and Senegal.6 In 2000, the first RVF outbreak outside of Africa was reported in Saudi Arabia and Yemen.5,7 More recently, Kenya and Tanzania experienced a large epizootic of RVFV in 2006–2007 and Sudan in 2010.6 The emergence of RVFV in East Africa resulted in widespread livestock morbidity and mortality, with hundreds of laboratory-confirmed human cases, and likely thousands of asymptomatic or mild RVFV human infections going undetected.8,9 Rift Valley fever virus in Uganda was first detected in mosquitos collected in Semliki forest, Western Uganda, in 1944,10 and has since been detected several times by the East African Virus Research Institute (EAVRI), now the Uganda Virus Research Institute (UVRI). Human cases were recorded during outbreaks occurring near Entebbe in 1960 and 1962.11,12 Since then, serological evidence of human and livestock RVFV infections in Uganda have been intermittently reported,13,14 but the last published description of acute human RVFV infection was seven cases occurring near Entebbe in 1968.15 On March 10, 2016, UVRI and the Uganda Ministry of Health (MOH) received a report of a suspected viral hemorrhagic fever (VHF) case presenting to Kabale Regional Referral Hospital (KRRH) in Kabale district in southwestern Uganda. The initial case was of a 48-year-old male butcher who had been working in a local abattoir, where livestock were brought for slaughter. The patient presented with a history of fever, vomiting, diarrhea, headache, and hemorrhagic symptoms (bleeding gums, epistaxis, bloody urine, and stools). A blood sample was taken and sent to the UVRI VHF laboratory for testing. On March 11, a second suspected VHF case presented to KRRH with similar symptoms; a blood sample was collected for testing. This patient was a 16-year-old male student first reported by Kabale District Health Office from the Uganda–Rwanda border village of Katuna. Both samples were tested for hemorrhagic fever viruses, including Ebola viruses, Marburg virus, Crimean–Congo hemorrhagic fever virus, and RVFV. Both specimens were found to be positive for RVFV by reverse transcriptase polymerase chain reaction (RT-PCR) and IgM serology.

Background: Crimean–Congo hemorrhagic fever (CCHF) is the most geographically widespread tick-borne viral infection. Outbreaks of CCHF in sub-Saharan Africa are largely undetected and thus under-reported. On November 9, 2015, the National Viral Hemorrhagic Fever Laboratory at the Uganda Virus Research Institute received an alert for a suspect VHF case in a 33-year-old male who presented with VHF compatible signs and symptoms at Mengo Hospital in Kampala. Methods: A blood sample from the suspect patient was tested by RT-PCR for CCHF and found positive. Serological testing on sequential blood specimens collected from this patient showed increasing anti-CCHFV IgM antibody titers, confirming recent infection. Repeat sampling of the confirmed case post recovery showed high titers for anti-CCHFV-specific IgG. An epidemiological outbreak investigation was initiated following the initial RT-PCR positive detection to identify any additional suspect cases. Results: Only a single acute case of CCHF was detected from this outbreak. No additional acute CCHF cases were identified following field investigations. Environmental investigations collected 53 tick samples, with only 1, a Boophilus decoloratus, having detectable CCHFV RNA by RT-PCR. Full-length genomic sequencing on a viral isolate from the index human case showed the virus to be related to the DRC (Africa 2) lineage. Conclusions: This is the fourth confirmed CCHF outbreak in Uganda within 2 years after more than 50 years of no reported human CCHF cases in this country. Our investigations reaffirm the endemicity of CCHFV in Uganda, and show that exposure to ticks poses a significant risk for human infection. These findings also reflect the importance of having an established national VHF surveillance system and diagnostic capacity in a developing country like Uganda, in order to identify the first cases of VHF outbreaks and rapidly respond to reduce secondary cases. Additional efforts should focus on implementing effective tick control methods and investigating the circulation of CCHFV throughout the country. Keywords: Crimean–Congo hemorrhagic fever, Uganda, Outbreak, CCHF

Introduction In October 2017, a blood sample from a resident of Kween District, Eastern Uganda, tested positive for Marburg virus. Within 24 hour of confirmation, a rapid outbreak response was initiated. Here, we present results of epidemiological and laboratory investigations. Methods A district task force was activated consisting of specialised teams to conduct case finding, case management and isolation, contact listing and follow up, sample collection and testing, and community engagement. An ecological investigation was also carried out to identify the potential source of infection. Virus isolation and Next Generation sequencing were performed to identify the strain of Marburg virus. Results Seventy individuals (34 MVD suspected cases and 36 close contacts of confirmed cases) were epidemiologically investigated, with blood samples tested for MVD. Only four cases met the MVD case definition; one was categorized as a probable case while the other three were confirmed cases. A total of 299 contacts were identified; during follow- up, two were confirmed as MVD. Of the four confirmed and probable MVD cases, three died, yielding a case fatality rate of 75%. All four cases belonged to a single family and 50% (2/4) of the MVD cases were female. All confirmed cases had clinical symptoms of fever, vomiting, abdominal pain and bleeding from body orifices. Viral sequences indicated that the Marburg virus strain responsible for this outbreak was closely related to virus strains previously shown to be circulating in Uganda. Conclusion This outbreak of MVD occurred as a family cluster with no additional transmission outside of the four related cases. Rapid case detection, prompt laboratory testing at the Uganda National VHF Reference Laboratory and presence of pre-trained, well-prepared national and district rapid response teams facilitated the containment and control of this outbreak within one month, preventing nationwide and global transmission of the disease., Author summary Marburg virus disease (MVD) is caused by the virus that belongs to the same family as that of Ebola Virus disease. The disease is characterized by severe clinical symptoms such as high fever, diarrhoea and vomiting, and severe bleeding from most body openings. On average, 54% of the people who get infected with Marburg virus die from it [1]. In October 2017, Uganda reported an outbreak of MVD in the eastern district of Kween that borders Kenya in the Mount Elgon plains. This was the first time MVD was being detected in this part of the country since previous MVD outbreaks had been reported in the western part of Uganda. The Ministry of Health together with partners instituted rapid outbreak response for control. Investigations revealed a cluster of one family involving four cases whereby only one survived. The outbreak was traced back into bat caves in Kween district. Rock salt mining in the cave led to a spill-over of the virus into the human population with the subsequent person-to-person transmission. Through contact tracing and isolation of the infected people among other approaches, the outbreak was brought under control as explained in this article.

Background On 28 March, 2016, the Ministry of Health received a report on three deaths from an unknown disease characterized by fever, jaundice, and hemorrhage which occurred within a one-month period in the same family in central Uganda. We started an investigation to determine its nature and scope, identify risk factors, and to recommend eventually control measures for future prevention. Methods We defined a probable case as onset of unexplained fever plus ≥1 of the following unexplained symptoms: jaundice, unexplained bleeding, or liver function abnormalities. A confirmed case was a probable case with IgM or PCR positivity for yellow fever. We reviewed medical records and conducted active community case-finding. In a case-control study, we compared risk factors between case-patients and asymptomatic control-persons, frequency-matched by age, sex, and village. We used multivariate conditional logistic regression to evaluate risk factors. We also conducted entomological studies and environmental assessments. Results From February to May, we identified 42 case-persons (35 probable and seven confirmed), of whom 14 (33%) died. The attack rate (AR) was 2.6/100,000 for all affected districts, and highest in Masaka District (AR = 6.0/100,000). Men (AR = 4.0/100,000) were more affected than women (AR = 1.1/100,000) (p = 0.00016). Persons aged 30–39 years (AR = 14/100,000) were the most affected. Only 32 case-patients and 128 controls were used in the case control study. Twenty three case-persons (72%) and 32 control-persons (25%) farmed in swampy areas (ORadj = 7.5; 95%CI = 2.3–24); 20 case-patients (63%) and 32 control-persons (25%) who farmed reported presence of monkeys in agriculture fields (ORadj = 3.1, 95%CI = 1.1–8.6); and 20 case-patients (63%) and 35 control-persons (27%) farmed in forest areas (ORadj = 3.2; 95%CI = 0.93–11). No study participants reported yellow fever vaccination. Sylvatic monkeys and Aedes mosquitoes were identified in the nearby forest areas. Conclusion This yellow fever outbreak was likely sylvatic and transmitted to a susceptible population probably by mosquito bites during farming in forest and swampy areas. A reactive vaccination campaign was conducted in the affected districts after the outbreak. We recommended introduction of yellow fever vaccine into the routine Uganda National Expanded Program on Immunization and enhanced yellow fever surveillance.