Rift Valley fever virus exposure amongst farmers, farm workers, and veterinary professionals in central South Africa

Rift Valley fever (RVF) is a re-emerging arboviral disease of public health and veterinary importance in Africa and the Arabian Peninsula. Major RVF epidemics were documented in South Africa in 1950–1951, 1974–1975, and 2010–2011. The number of individuals infected during these outbreaks has, however, not been accurately estimated. A total of 823 people in close occupational contact with livestock were interviewed and sampled over a six-month period in 2015–2016 within a 40,000 km2 study area encompassing parts of the Free State and Northern Cape provinces that were affected during the 2010–2011 outbreak. Seroprevalence of RVF virus (RVFV) was 9.1% (95% Confidence Interval (CI95%): 7.2–11.5%) in people working or residing on livestock or game farms and 8.0% in veterinary professionals. The highest seroprevalence (SP = 15.4%; CI95%: 11.4–20.3%) was detected in older age groups ( 40 years old) that had experienced more than one known large epidemic compared to the younger participants (SP = 4.3%; CI95%: 2.6–7.3%). The highest seroprevalence was in addition found in people who injected animals, collected blood samples (Odds ratio (OR) = 2.3; CI95%: 1.0–5.3), slaughtered animals (OR = 3.9; CI95%: 1.2–12.9) and consumed meat from an animal found dead (OR = 3.1; CI95%: 1.5–6.6), or worked on farms with dams for water storage (OR = 2.7; CI95%: 1.0–6.9). We estimated the number of historical RVFV infections of farm staff in the study area to be most likely 3849 and 95% credible interval between 2635 and 5374 based on seroprevalence of 9.1% and national census data. We conclude that human RVF cases were highly underdiagnosed and heterogeneously distributed. Improving precautions during injection, sample collection, slaughtering, and meat processing for consumption, and using personal protective equipment during outbreaks, could lower the risk of RVFV infection.U.S. Department of Defense, Defense Threat Reduction Agencyhttps://www.mdpi.com/journal/virusespm2020Animal and Wildlife Science

Rift Valley fever virus seroprevalence among humans, Northern KwaZulu-Natal Province, South Africa, 2018-2019

We detected Rift Valley fever virus (RVFV) IgM and IgG in human serum samples collected during 2018–2019 in northern KwaZulu-Natal Province, South Africa. Our results show recent RVFV circulation and likely RVFV endemicity in this tropical coastal plain region of South Africa in the absence of apparent clinical disease.The Division of Global Migration and Quarantine, National Center for Emerging and Zoonotic Infectious Diseases, US Centers for Disease Control and Prevention Division .http://www.cdc.gov/eidam2022Medical Virolog

Human rabies associated with domestic cat exposures in South Africa, 1983–2018

Rabies is a fatal encephalitic disease caused by lyssaviruses belonging to the family Rhabdoviridae. At the time of this report, a total of 16 species of lyssaviruses, which included the prototype rabies virus (RABV), and 2 related but unclassified bat lyssaviruses, Taiwan and Kothalati, had been recognised by the International Committee on Taxonomy of Viruses (ICTV 2019). Globally RABV, also referred to as ‘classic rabies’, circulates in natural transmission cycles involving domestic dogs and various wildlife species. In the Americas, RABV is found in certain insectivorous and haematophagous bat species (Banyard et al. 2013). The public health burden of rabies is, however, very closely related to the occurrence of the disease in domestic dogs; thus, human cases of rabies are mostly reported from areas where dog rabies is uncontrolled (Hampson et al. 2015). An annual estimation of 59 000 human deaths occur worldwide with 95% of rabies cases occurring in Africa and Asia (Hampson et al. 2015). In South Africa, RABV circulates both in domestic animals and wildlife cycles, involving the canid and mongoose variants of the virus (Nel, Thomson & Von Teichman 1993). The urban cycle involves domestic dogs reported from various locations in the country, but particularly from the KwaZulu-Natal, Eastern Cape, Limpopo and Mpumalanga provinces (Cohen et al. 2007; Zulu, Sabeta & Nel 2009). Sylvatic cycles of the canid variant RABV in bat-eared foxes and black-backed jackal (Zulu et al. 2009) and the mongoose variant RABV in certain species of mongoose occur in South Africa (Van Zyl, Markotter & Nel 2010). Apart from the reservoir species, canid and mongoose RABV infections are reported in an array of domestic and wildlife species in the country, with these animals primarily serving as dead-end hosts (Sabeta et al. 2018). Laboratory-confirmed human rabies cases in South Africa are predominantly dogmediated, and seven cases of rabies linked to other domestic species and wildlife have been reported (Weyer et al. 2011).http://www.jsava.co.zaam2020Medical VirologyVeterinary Tropical Disease

A case of human survival of rabies, South Africa

Human survival from rabies is exceptionally rare. We report a case of human survival (with severe neurological sequelae) in a child from South Africa. The patient was exposed to rabid dogs on two separate occasions and subjected to incomplete post-exposure prophylaxis for rabies.http://www.tandfonline.com/loi/ojid20am2017Microbiology and Plant Patholog

Tanapox, South Africa, 2022

Tanapox is a rarely diagnosed zoonosis known to be endemic to equatorial Africa. All previously reported human cases were acquired within 10° north or south of the Equator, most recently 19 years ago. We describe a human case of tanapox in South Africa (24° south of the Equator). Expanded surveillance for this pathogen is warranted.https://wwwnc.cdc.gov/eid/am2024Veterinary Tropical DiseasesSDG-03:Good heatlh and well-bein

Factors affecting the use of biosecurity measures for the protection of ruminant livestock and farm workers against infectious diseases in central South Africa

Biosecurity measures have been introduced to limit economic losses and zoonotic exposures to humans by preventing and controlling animal diseases. However, they are implemented on individual farms with varying frequency. The goal of this study was to evaluate which biosecurity measures were used by farmers to prevent infectious diseases in ruminant livestock and to identify factors that influenced these decisions. We conducted a survey in 264 ruminant livestock farmers in a 40,000 km2 area in the Free State and Northern Cape provinces of South Africa. We used descriptive statistics, to characterize biosecurity measures and farm attributes, then multivariable binomial regression to assess the strength of the association between the attributes and the implementation of biosecurity measures including property fencing, separate equipment use on different species, separate rearing of species, isolation of sick animals, isolation of pregnant animals, quarantine of new animals, animal transport cleaning, vaccination, tick control and insect control. Ninety-nine percent of farmers reported using at least one of the 10 biosecurity measures investigated (median [M]: 6; range: 0–10). The most frequently used biosecurity measures were tick control (81%, 214 out of 264), vaccination (80%, 211 out of 264) and isolation of sick animals (72%, 190 out of 264). More biosecurity measures were used on farms with 65–282 animals (M: 6; odds ratio [OR]: 1.52) or farms with 283–12,030 animals (M: 7; OR: 1.87) than on farms with fewer than 65 animals (M: 4). Furthermore, farmers who kept two animal species (M: 7; OR: 1.41) or three or more species (M: 7) used more biosecurity measures than single-species operations (M: 4). Farmers with privately owned land used more biosecurity measures (M: 6; OR: 1.51) than those grazing their animals on communal land (M: 3.5). Farms that reported previous Rift Valley fever (RVF) outbreaks used more biosecurity measures (M: 7; OR: 1.25) compared with farms without RVF reports (M: 6) and those that purchased animals in the 12 months prior to the survey (M: 7; OR: 1.19) compared with those that did not (M: 6). When introducing new animals into their herds (n = 122), most farmers used fewer biosecurity measures than they did for their existing herd: 34% (41 out of 122) used multiple biosecurity measures like those of vaccination, tick control, quarantine or antibiotic use, whereas 36% (44 out of 122) used only one and 30% (37 out of 122) used none. Certain farm features, primarily those related to size and commercialization, were associated with more frequent use of biosecurity measures. Given the variation in the application of biosecurity measures, more awareness and technical assistance are needed to support the implementation of a biosecurity management plan appropriate for the type of farm operation and available resources.DATA AVAILABILITY STATEMENT : The data that support the study's findings and that can be disclosed per IRB protocol are available upon request from EcoHealth Alliance, 520 Eighth Ave Ste 1200, New York, NY 10018, from Melinda K. Rostal ([email protected]).The project depicted is sponsored by the U.S. Department of Defense, Defense Threat Reduction Agency.http://wileyonlinelibrary.com/journal/tbedhj2022Production Animal Studie

Large-scale international validation of an indirect ELISA based on recombinant nucleocapsid protein of rift valley fever virus for the detection of IgG antibody in domestic ruminants

Diagnostic performance of an indirect enzyme-linked immunosorbent assay (I-ELISA) based on a recombinant nucleocapsid protein (rNP) of the Rift Valley fever virus (RVFV) was validated for the detection of the IgG antibody in sheep (n = 3367), goat (n = 2632), and cattle (n = 3819) sera. Validation data sets were dichotomized according to the results of a virus neutralization test in sera obtained from RVF-endemic (Burkina Faso, Democratic Republic of Congo, Mozambique, Senegal, Uganda, and Yemen) and RVF-free countries (France, Poland, and the USA). Cut-off values were defined using the two-graph receiver operating characteristic analysis. Estimates of the diagnostic specificity of the RVFV rNP I-ELISA in animals from RVF-endemic countries ranged from 98.6% (cattle) to 99.5% (sheep) while in those originating from RVF-free countries, they ranged from 97.7% (sheep) to 98.1% (goats). Estimates of the diagnostic sensitivity in ruminants from RVF-endemic countries ranged from 90.7% (cattle) to 100% (goats). The results of this large-scale international validation study demonstrate the high diagnostic accuracy of the RVFV rNP I-ELISA. Standard incubation and inactivation procedures evaluated did not have an adverse effect on the detectable levels of the anti-RVFV IgG in ruminant sera and thus, together with recombinant antigen-based I-ELISA, provide a simple, safe, and robust diagnostic platform that can be automated and carried out outside expensive bio-containment facilities. These advantages are particularly important for less-resourced countries where there is a need to accelerate and improve RVF surveillance and research on epidemiology as well as to advance disease control measures.The International Atomic Energy Agencyhttp://www.mdpi.com/journal/virusespm2021Medical Virolog

Adult male circumcision as an intervention against HIV: An operational study of uptake in a South African community (ANRS 12126)

<p>Abstract</p> <p>Background</p> <p>To evaluate the knowledge, attitudes and beliefs about adult male circumcision (AMC), assess the association of AMC with HIV incidence and prevalence, and estimate AMC uptake in a Southern African community.</p> <p>Methods</p> <p>A cross-sectional biomedical survey (ANRS-12126) conducted in 2007-2008 among a random sample of 1198 men aged 15 to 49 from Orange Farm (South Africa). Face-to-face interviews were conducted by structured questionnaire. Recent HIV infections were evaluated using the BED incidence assay. Circumcision status was self-reported and clinically assessed. Adjusted HIV incidence rate ratios (aIRR) and prevalence ratios (aPR) were calculated using Poisson regression.</p> <p>Results</p> <p>The response rate was 73.9%. Most respondents agreed that circumcised men could become HIV infected and needed to use condoms, although 19.3% (95%CI: 17.1% to 21.6%) asserted that AMC protected fully against HIV. Among self-reported circumcised men, 44.9% (95%CI: 39.6% to 50.3%) had intact foreskins. Men without foreskins had lower HIV incidence and prevalence than men with foreskins (aIRR = 0.35; 95%CI: 0.14 to 0.88; aPR = 0.45, 95%CI: 0.26 to 0.79). No significant difference was found between self-reported circumcised men with foreskins and other uncircumcised men. Intention to undergo AMC was associated with ethnic group and partner and family support of AMC. Uptake of AMC was 58.8% (95%CI: 55.4% to 62.0%).</p> <p>Conclusions</p> <p>AMC uptake in this community is high but communication and counseling should emphasize what clinical AMC is and its effect on HIV acquisition. These findings suggest that AMC roll-out is promising but requires careful implementation strategies to be successful against the African HIV epidemic.</p

Trends in the prevalence of microscopically-confirmed schistosomiasis in the South African public health sector, 2011–2018

Background Schistosomiasis, also known as bilharzia, is a chronic parasitic blood fluke infection acquired through contact with contaminated surface water. The illness may be mild or can cause significant morbidity with potentially serious complications. Children and those living in rural areas with limited access to piped water and services for healthcare are the most commonly infected. To address the prevalence of the disease in parts of South Africa (SA) effective national control measures are planned, but have not yet been implemented. This study aimed to estimate the prevalence and trends of public sector laboratory-confirmed schistosomiasis cases in SA over an eight-year (2011–2018) period, to inform future control measures. Methodology &amp; principal findings This is a descriptive analysis of secondary data from the National Health Laboratory Service (NHLS). The study included all records of patients for whom microscopic examination detected Schistosoma species eggs in urine or stool specimens from January 2011 to December 2018. Crude estimates of the prevalence were calculated using national census mid-year provincial population estimates as denominators, and simple linear regression was used to analyse prevalence trends. A test rate ratio was developed to describe variations in testing volumes among different groups and to adjust prevalence estimates for testing variations. A total number of 135 627 schistosomiasis cases was analysed with the highest prevalence observed among males and individuals aged 5–19 years. We describe ongoing endemicity in the Eastern Cape Province, and indicate important differences in the testing between population groups. Conclusion While there was no overall change in the prevalence of schistosomiasis during the analysis period, an average of 36 people per 100 000 was infected annually. As such, this represents an opportunity to control the disease and improve quality of life of affected people. Laboratory-based surveillance is a useful method for reporting occurrence and evaluating future intervention programs where resources to implement active surveillance are limited. </jats:sec