Household and animal factors associated with sheeppox and goatpox sero-prevalence and identification of high-risk areas in selected States of northern Nigeria

Abstract

Sheeppox and goatpox (SGP) are transboundary, highly contagious diseases affecting sheep and goats with characteristic clinical signs. SGP affect populations of small ruminants in Africa, Asia and the Middle East and, as a result, threaten farmers’ livelihoods. Despite their importance, studies looking at factors that increase the risk of sheeppox-virus (SPPV) and goatpox-virus (GTPV) exposure and infection are limited. A cross-sectional study was conducted in three states of Northern Nigeria (Bauchi, Kaduna and Plateau) to determine the sero-prevalence and spatial patterns of SGP, and identify risk factors for SPPV/GTPV exposure at animal and household level. Sera samples were collected from 1,800 small ruminants from 300 households. Data on putative risk factors were collected using a standardised questionnaire. Twenty-nine small ruminants were sero-positive to SGP - apparent weighted sero-prevalence 2.0 %; 95 % C.I. 1.1–.3.0 %. Sero-positive animals came from 19 (6.3 %) households. Analysis of the questionnaire showed that a fifth (20.3 %) of farmers claimed to have experienced SGP outbreaks previously in their flocks, with 33 (1.8 %) of the individual animals sampled in this study reported to have had clinical signs. At animal level, the odds of being sero-positive were higher in older animals (>24months; OR = 8.0, p = 0.008 vs ≤24 months) and small ruminants with a history of clinical SGP (OR = 16.9, p = 0.01). Bringing new small ruminants into the household and having a history of SGP in the flock were the main factors identified at household level. Households were less likely to be sero-positive if the time between bringing animals into the household and sampling was over a year (PR = 0.31, p = 0.05), while households with a history of SGP were more likely to be sero-positive regardless of the timeframe. Important spatial heterogeneity was found. The Bayes smooth rate ranged from 0.06 to 4.10 % across local government areas (LGA), with LGA in the north-east or north-west of the study area identified as hot-spots for SGP exposure. Results from this study shed new light on the understanding of SGP epidemiology and provide key inputs to design risk-based surveillance and intervention programmes in the area.

Spatio-temporal analysis of sheep and goat pox outbreaks in Uganda during 2011–2022

“…We observed poor biosecurity measures at outbreak farms including poor carcass disposal, mixing of sick and apparently healthy animals, uncontrolled movement of animals and people on farms, limited disease knowledge, lack of disinfection and no record of screening animals for SGP before purchase. Consistent with previous reports, these practices were positively correlated with SGP seropositivity on investigated cases [ 27 ]. The farmers managed clinical cases with a broad range of antibiotics such as [Oxytetracycline Penicillin and multivitamins] consistent with previous report [ 9 ].…”

“…We were unable to determine the actual time when SGP clinical signs were first observed in investigated flocks because none of the flocks was managed by a professional veterinarian and relied on farmers recall capacity in absence of records. It is therefore likely that we took samples outside the SGP optimal sampling time a period when, detectable neutralizing antibodies are low, explaining low levels [27%] of seroconversion rates in the investigated outbreak small ruminant herds [ 27 ]. Additionally, panic sales that are triggered by suspected SGP outbreaks could have contributed to low seropositivity in investigated outbreak flocks as it was unlikely to find index cases at the farm.…”

Development and Optimization of Indirect ELISAs for the Detection of Anti-Capripoxvirus Antibodies in Cattle, Sheep, and Goat Sera

“…The A34 protein is a glycoprotein present in the outer membrane of the extracellular enveloped virion of poxviruses, involved in cell-to-cell transmission [ 43 ]. Previous studies on the antigenicity of vaccinia’s A34 protein showed its potential as a target candidate to develop an ELISA [ 44 , 45 ].…”

Financial impact of sheeppox and goatpox and estimated profitability of vaccination for subsistence farmers in selected northern states of Nigeria

“…Participants were identified via convenience sampling. Primary data from a survey conducted in 2019 involving 300 randomly selected sedentary herds in Bauchi, Kaduna and Plateau, 100 in each state, was used to obtain herd demographic data and SGP prevalence from the number of households reporting SGP clinical signs ( Adedeji et al, 2021 ). Finally, values missing after literature review, focus group discussion and the survey were obtained from authors who have field and laboratory knowledge and experience in virology, vaccinology, SGP epidemiology, small ruminant husbandry, and animal health programmes within Northern Nigeria.…”

“…Based on data from the survey in the study area, 97.5 % of young animals were older than 3 months at time of survey. Therefore, 100 % of the reproductive herd and 97.5 % of the young herd are eligible so will be vaccinated ( Adedeji et al, 2021 )…”