Anthrax bio-surveillance of livestock in Arua District, Uganda, 2017-2018.

Anthrax, caused by Bacillus anthracis, is a widespread zoonotic disease with many human cases, especially in developing countries. Even with its global distribution, anthrax is a neglected disease with scarce information about its actual impact on the community level. Due to the ecological dynamics of anthrax transmission at the wildlife-livestock interface, the Sub-Saharan Africa region becomes a high-risk zone for maintaining and acquiring the disease. In this regard, some subregions of Uganda are endemic to anthrax with regular seasonal trends. However, there is scarce data about anthrax outbreaks in Uganda. Here, we confirmed the presence of B. anthracis in several livestock samples after a suspected anthrax outbreak among livestock and humans in Arua District. Additionally, we explored the potential risk factors of anthrax through a survey within the community kraals. We provide evidence that the most affected livestock species during the Arua outbreak were cattle (86%) compared to the rest of the livestock species present in the area. Moreover, the farmers' education level and the presence of people's anthrax cases were the most critical factors determining the disease's knowledge and awareness. Consequently, the lack of understanding of the ecology of anthrax may contribute to the spread of the infection between livestock and humans, and it is critical to reducing the presence and persistence of the B. anthracis spores in the environment. Finally, we discuss the increasingly recognized necessity to strengthen global capacity using a One Health approach to prevent, detect, control, and respond to public threats in Uganda.

Risk factors for Crimean-Congo Haemorrhagic Fever (CCHF) virus exposure in farming communities in Uganda.

BACKGROUND: Crimean-Congo Haemorrhagic Fever (CCHF) is an emerging human-health threat causing sporadic outbreaks in livestock farming communities. However, the full extent and the risks associated with exposure of such communities has not previously been well-described. METHODS: We collected blood samples from 800 humans, 666 cattle, 549 goats and 32 dogs in districts within and outside Ugandan cattle corridor in a cross-sectional survey, and tested for CCHFV-specific IgG antibodies using Enzyme-Linked Immunosorbent Assays. Sociodemographic and epidemiological data were recorded using structured questionnaire. Ticks were collected to identify circulating nairoviruses by metagenomic sequencing. RESULTS: CCHFV seropositivity was in 221/800 (27·6%) in humans, 612/666 (91·8%) in cattle, 413/549 (75·2%) in goats and 18/32 (56·2%) in dogs. Human seropositivity was associated with livestock farming (AOR=5·68, p<0·0001), age (AOR=2·99, p=0·002) and collecting/eating engorged ticks (AOR=2·13, p=0·004). In animals, seropositivity was higher in cattle versus goats (AOR=2·58, p<0·0001), female sex (AOR=2·13, p=0·002) and heavy tick infestation (>50 ticks: AOR=3·52, p=0·004). CCHFV was identified in multiple tick pools of Rhipicephalus appendiculatus. INTERPRETATION: The very high CCHF seropositivity especially among livestock farmers and multiple regional risk factors associated exposures, including collecting/eating engorged ticks previously unrecognised, highlights need for further surveillance and sensitisation and control policies against the disease.

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.

Overcoming the challenges of pen-side molecular diagnosis of African swine fever to support outbreak investigations under field conditions.

African swine fever (ASF) is a devastating disease of pigs. Without a vaccine, early detection and rapid diagnosis of ASF is a crucial step towards effective disease control. In many countries where ASF is endemic, laboratory infrastructure including sampling and sample shipment is inadequate, and a rapid laboratory confirmation would require that the diagnosis is performed at regional laboratories close to the pig farms of concern, or even at the farm-side. This study intended to evaluate measures including sample preparation methods, a dried-down assay, and a portable, battery-powered real-time PCR instrument, to improve molecular diagnosis under field conditions. A simple dilution of blood samples, either in Phosphate-buffered saline or a commercial buffer, worked similarly to beads-based nucleic acid extraction using a magnet as the core equipment; the latter method did work as well for those samples with low viral load or high Ct values. The real-time PCR assay using a Universal ProbeLibrary (UPL) probe tolerated suspected inhibitory substances present in the prepared samples better, whereas the dried-down assay had a higher diagnostic sensitivity. Additionally, an inhibition control assay proved to be helpful in avoiding false negative results when interpreting negative results of samples that might be of low quality or with inadequate reduction in inhibitory substances. When tested with synthetic DNA standards, the portable instrument performed at a level approaching stationary thermocyclers. In summary, the developments of suitable sample preparation methods, robust and thermal-stable real-time PCR assays with inhibition control, and battery-powered portable thermocyclers with middle-throughput offer one way forward to provide rapid, reliable molecular diagnosis under challenging field conditions.

Low topotype diversity of recent foot-and-mouth disease virus serotypes O and A from districts located along the Uganda and Tanzania border

Foot-and-mouth disease (FMD) is one of the most important livestock diseases in East Africa with outbreaks reported annually that cause severe economic losses. It is possible to control disease using vaccination, but antigenic matching of the vaccine to circulating strains is critical. To determine the relationship between foot-and-mouth disease viruses circulating in districts along the Uganda and Tanzanian border between 2016 and 2017 and currently used vaccines, phylogenetic analysis of the full VP1 virus sequences was carried out on samples collected from both sides of the border. A total of 43 clinical samples were collected from animals exhibiting signs of FMD and VP1 sequences generated from 11 of them. Eight out of the 11 sequences obtained belonged to serotype O and three belonged to serotype A. The serotype O sequences obtained showed limited nucleotide divergence (average of 4.9%) and belonged to topotype East Africa-2, whereas the most common O-type vaccine strain used in the region (O/KEN/77/78) belonged to East Africa-1. The serotype A viruses belonged to topotype Africa-G1 (average nucleotide divergence 7.4%), as did vaccine strain K5/1980. However, vaccine strain K35/1980 belonged to Africa G VII with an average sequence divergence of 20.5% from the study sequences. The genetic distances between current vaccine strains and circulating field strains underscores the crucial need for regular vaccine matching and the importance of collaborative efforts for better control of FMD along this border area.