Outbreak of cutaneous anthrax associated with handling meat of dead cows in Southwestern Uganda, May 2018.

BACKGROUND: Anthrax is a zoonotic infection caused by the bacteria Bacillus anthracis. Humans acquire cutaneous infection through contact with infected animals or animal products. On May 6, 2018, three cows suddenly died on a farm in Kiruhura District. Shortly afterwards, a sub-county chief in Kiruhura District received reports of humans with suspected cutaneous anthrax in the same district. The patients had reportedly participated in the butchery and consumption of meat from the dead cows. We investigated to determine the magnitude of the outbreak, identify exposures associated with illness, and suggest evidence-based control measures. METHODS: We conducted a retrospective cohort study among persons whose households received any of the cow meat. We defined a suspected human cutaneous anthrax case as new skin lesions (e.g., papule, vesicle, or eschar) in a resident of Kiruhura District from 1 to 26 May 2018. A confirmed case was a suspected case with a lesion testing positive for B. anthracis by polymerase chain reaction (PCR). We identified cases through medical record review at Engari Health Centre and active case finding in the community. RESULTS: Of the 95 persons in the cohort, 22 were case-patients (2 confirmed and 20 suspected, 0 fatal cases) and 73 were non-case household members. The epidemic curve indicated multiple point-source exposures starting on May 6, when the dead cows were butchered. Among households receiving cow meat, participating in slaughtering (RR = 5.3, 95% CI 3.2-8.3), skinning (RR = 4.7, 95% CI = 3.1-7.0), cleaning waste (RR = 4.5, 95% CI = 3.1-6.6), and carrying meat (RR = 3.9, 95% CI = 2.2-7.1) increased the risk of infection. CONCLUSIONS: This cutaneous anthrax outbreak was caused by handling infected animal carcasses. We suggested to the Ministry of Agriculture, Animal Industry and Fisheries to strengthen surveillance for possible veterinary anthrax and ensure that communities do not consume carcasses of livestock that died suddenly. We also suggested that the Ministry of Health equip health facilities with first-line antibiotics for community members during outbreaks.

Sporadic Rift Valley Fever Outbreaks in Humans and Animals in Uganda, October 2017-January 2018.

Introduction: Rift Valley fever (RVF) is a mosquito-borne viral zoonosis. The Uganda Ministry of Health received alerts of suspected viral haemorrhagic fever in humans from Kiruhura, Buikwe, Kiboga, and Mityana districts. Laboratory results from Uganda Virus Research Institute indicated that human cases were positive for Rift Valley fever virus (RVFV) by polymerase chain reaction. We investigated to determine the scope of outbreaks, identify exposure factors, and recommend evidence-based control and prevention measures. Methods: A suspected case was defined as a person with acute fever onset, negative malaria test result, and at least two of the following symptoms: headache, muscle or joint pain, bleeding, and any gastroenteritis symptom (nausea, vomiting, abdominal pain, diarrhoea) in a resident of Kiruhura, Buikwe, Mityana, and Kiboga districts from 1st October 2017 to 30th January 2018. A confirmed case was defined as a suspected case with laboratory confirmation by either detection of RVF nucleic acid by reverse-transcriptase polymerase chain reaction (RT-PCR) or demonstration of serum IgM or IgG antibodies by ELISA. Community case finding was conducted in all affected districts. In-depth interviews were conducted with human cases that were infected with RVF who included herdsmen and slaughterers/meat handlers to identify exposure factors for RVF infection. A total of 24 human and 362 animal blood samples were tested. Animal blood samples were purposively collected from farms that had reported stormy abortions in livestock and unexplained death of animals after a short illness (107 cattle, 83 goats, and 43 sheep). Convenient sampling for the wildlife (10 zebras, 1 topi, and 1 impala) was conducted to investigate infection in animals from Kiruhura, Buikwe, Mityana, and Kiboga districts. Human blood was tested for anti-RVFV IgM and IgG and animal blood for anti-RVFV IgG. Environmental assessments were conducted during the outbreaks in all the affected districts. Results: Sporadic RVF outbreaks occurred from mid-October 2017 to mid-January 2018 affecting humans, domestic animals, and wildlife. Human cases were reported from Kiruhura, Buikwe, Kiboga, and Mityana districts. Of the 24 human blood samples tested, anti-RVFV IgG was detected in 7 (29%) human samples; 1 human sample had detectable IgM only, and 6 had both IgM and IgG. Three of the seven confirmed human cases died among humans. Results from testing animal blood samples obtained from Kiruhura district indicated that 44% (64/146) cattle, 46% (35/76) goats, and 45% (9/20) sheep tested positive for RVF. Among wildlife, (1/10) zebras, (1/1) topi, and (1/1) impala tested positive for RVFV by serological tests. One blood sample from sheep in Kiboga district tested RVFV positive. All the human cases were exposed through contact or consumption of meat from infected animals. Conclusion: RVF outbreaks occurred in humans and animals in Kiruhura, Buikwe, Mityana, and Kiboga districts. Human cases were potentially infected through contact with infected animals and their products.

Cutaneous anthrax associated with handling carcasses of animals that died suddenly of unknown cause: Arua District, Uganda, January 2015-August 2017.

BACKGROUND: Anthrax is a zoonotic disease that can be transmitted to humans from infected animals. During May-June 2017, three persons with probable cutaneous anthrax were reported in Arua District, Uganda; one died. All had recently handled carcasses of livestock that died suddenly and a skin lesion from a deceased person tested positive by PCR for Bacillus anthracis. During July, a bull in the same community died suddenly and the blood sample tested positive by PCR for Bacillus anthracis. The aim of this investigation was to establish the scope of the problem, identify exposures associated with illness, and recommend evidence-based control measures. METHODS: A probable case was defined as acute onset of a papulo-vesicular skin lesion subsequently forming an eschar in a resident of Arua District during January 2015-August 2017. A confirmed case was a probable case with a skin sample testing positive by polymerase chain reaction (PCR) for B. anthracis. Cases were identified by medical record review and active community search. In a case-control study, exposures between case-patients and frequency- and village-matched asymptomatic controls were compared. Key animal health staff were interviewed to learn about livestock deaths. RESULTS: There were 68 case-patients (67 probable, 1 confirmed), and 2 deaths identified. Cases occurred throughout the three-year period, peaking during dry seasons. All cases occurred following sudden livestock deaths in the villages. Case-patients came from two neighboring sub-counties: Rigbo (attack rate (AR) = 21.9/10,000 population) and Rhino Camp (AR = 1.9/10,000). Males (AR = 24.9/10,000) were more affected than females (AR = 0.7/10,000). Persons aged 30-39 years (AR = 40.1/10,000 population) were most affected. Among all cases and 136 controls, skinning (ORM-H = 5.0, 95%CI: 2.3-11), butchering (ORM-H = 22, 95%CI: 5.5-89), and carrying the carcass of livestock that died suddenly (ORM-H = 6.9, 95%CI: 3.0-16) were associated with illness. CONCLUSIONS: Exposure to carcasses of animals that died suddenly was a likely risk factor for cutaneous anthrax in Arua District during 2015-2017. The recommendations are investigation of anthrax burden in livestock, prevention of animal infections through vaccinations, safe disposal of the carcasses, public education on risk factors for infection and prompt treatment of illness following exposure to animals that died suddenly.

Trends and spatial distribution of animal bites and vaccination status among victims and the animal population, Uganda: A veterinary surveillance system analysis, 2013-2017.

Rabies is a vaccine-preventable fatal zoonotic disease. Uganda, through the veterinary surveillance system at National Animal Disease Diagnostics and Epidemiology Centre (NADDEC), captures animal bites (a proxy for rabies) on a monthly basis from districts. We established trends of incidence of animal bites and corresponding post-exposure prophylactic anti-rabies vaccination in humans (PEP), associated mortality rates in humans, spatial distribution of animal bites, and pets vaccinated during 2013-2017. We reviewed rabies surveillance data at NADDEC from 2013-2017. The surveillance system captures persons reporting bites by a suspected rabid dog/cat/wild animal, human deaths due to suspected rabies, humans vaccinated against rabies, and pets vaccinated. Number of total pets was obtained from the Uganda Bureau of Statistics. We computed incidence of animal bites and corresponding PEP in humans, and analyzed overall trends, 2013-2017. We also examined human mortality rates and spatial distribution of animal bites/rabies and pets vaccinated against rabies. We identified 8,240 persons reporting animal bites in Uganda during 2013-2017; overall incidence of 25 bites/ 100,000population. The incidence significantly decreased from 9.2/100,000 in 2013 to 1.3/100,000 in 2017 (OR = 0.62, p = 0.0046). Of the 8,240 persons with animal bites, 6,799 (82.5%) received PEP, decreasing from 94% in 2013 to 71% in 2017 (OR = 0.65, p<0.001). Among 1441 victims, who reportedly never received PEP, 156 (11%) died. Western region had a higher incidence of animal bites (37/100,000) compared to other regions. Only 5.6% (124,555/2,240,000) of all pets in Uganda were vaccinated. There was a decline in the reporting rate (percentage of annual district veterinary surveillance reports submitted monthly to Commissioner Animal Health by districts) of animal bites. While reported animal bites by districts decreased in Uganda, so did PEP among humans. Very few pets received anti-rabies vaccine. Evaluation of barriers to complete reporting may facilitate interventions to enhance surveillance quality. We recommended improved vaccination of pets against rabies, and immediate administration of exposed humans with PEP.

Rabies in Uganda: rabies knowledge, attitude and practice and molecular characterization of circulating virus strains.

BACKGROUND: Rabies is a deadly preventable viral disease that affects all warm-blooded animals and widespread in many regions including Africa. The disease remains of major public health importance in Uganda. The purpose of this study was to establish Knowledge, Attitude, Practice (KAP) of Rabies in Moyo and Ntoroko districts and to characterize Rabies virus (RABV) strains from seven districts of Uganda with consistent prevalence of rabies. METHODS: KAP survey data were collected based on animal biting history by interviewing the head of the veterinary departments, the medical centers and selected households from the study sites. Data were obtained from 84 households in Ntoroko and Moyo districts. Thirty-five (35) brain samples were collected from bovine, dogs, goats, foxes, jackals ad sheep between 2011 and 2013. Samples were tested using fluorescent antibody test (FAT), One step RT-PCR (following RNA extraction) and partial RABV N gene was sequenced by Sanger method before phylogenetic and phylogeographic analyses of sequences. RESULTS: Scarcity of post-exposure prophylaxis services in the health centers was noted. Poor attitude of wound washing and deficiency of knowledge on how to handle wounds related to dog bites and the significance among household participants lacked. There is a high risk of rabies infection due to a limited dog's vaccination. Dog biting episodes in humans were of 75.00 and 62.50% in Moyo and Ntoroko districts respectively. Twenty-seven (27) samples tested positive for rabies by FAT and PCR. Ugandan sequences were closely related (97% nucleotide id) to the rabies virus sequences from Tanzania, Rwanda, Burundi, Nigeria, Central African Republic and Sudan with both the "Africa 1A" and "Africa 1B" RABV clades represented. A putative new clade 1D was also detected. CONCLUSIONS: Rabies remains a public health hazard in Uganda. There is urgent need to establish advocacy programs in both schools and communities to curtail the spread of rabies. Increasing the knowledge regarding wound washing, post-exposure prophylaxis and dogs vaccination would enhance prevention of rabies. A strong collaboration between medical and veterinary sectors under a one health platform is required to ensure sufficient preventative services to the communities.

Disentangling the role of Africa in the global spread of H5 highly pathogenic avian influenza.

The role of Africa in the dynamics of the global spread of a zoonotic and economically-important virus, such as the highly pathogenic avian influenza (HPAI) H5Nx of the Gs/GD lineage, remains unexplored. Here we characterise the spatiotemporal patterns of virus diffusion during three HPAI H5Nx intercontinental epidemic waves and demonstrate that Africa mainly acted as an ecological sink of the HPAI H5Nx viruses. A joint analysis of host dynamics and continuous spatial diffusion indicates that poultry trade as well as wild bird migrations have contributed to the virus spreading into Africa, with West Africa acting as a crucial hotspot for virus introduction and dissemination into the continent. We demonstrate varying paths of avian influenza incursions into Africa as well as virus spread within Africa over time, which reveal that virus expansion is a complex phenomenon, shaped by an intricate interplay between avian host ecology, virus characteristics and environmental variables.