Peste Des Petits Ruminants in Atypical Hosts and Wildlife: Systematic Review and Meta-Analysis of the Prevalence between 2001 and 2021

Abstract

Peste des petits ruminants (PPR) or goat plague is considered a leading, highly contagious, and most lethal infectious viral disease of small ruminants affecting the worldwide livestock economy and international animal trade. Although sheep and goats are the primarily affected, the PPR Virus (PPRV) host range has expanded to other livestock (large ruminants) and wildlife animals over the last few decades, resulting in serious concern to the ongoing PPR global eradication program, which is primarily optimized, designed, and targeted towards accessible sheep and goat population. A systematic review and meta-analysis study was conducted to estimate the prevalence and spill-over infection of PPRV in large ruminants (bovine and camel) and wildlife. Published articles from 2001 to October 2021 on the "PPR" were searched in four electronic databases of PubMed, Scopus, Science direct, and Google Scholars. The articles were then selected using inclusion criteria (detection/prevalence of PPRV in bovine, camel, and wildlife population), exclusion criteria (only sheep or goats, lack of prevalence data, experimental trial, test evaluation, and reviews written in other languages or published before 2001), and the prevalence was estimated by random effect meta-analysis model. In the current study, all published articles belonged to Africa and Asia. The overall pooled prevalence of PPR estimates was 24% (95% CI: 15-33), with 30% in Asia (95% CI: 14-49) and 20% in Africa (95% CI: 11-30). The overall estimated pooled prevalence at an Africa-Asia level in bovine and camel was 13% (95% CI: 8-19), and in wildlife, it was 52% (95% CI: 30-74) with significant heterogeneity (I² = 97%) in most pooled estimates with a high prevalence in atypical hosts and wildlife across Asia and Africa. Over the last two decades, the host range has increased drastically in the wildlife population, even for prevalent PPR in the unnatural hosts only for a short time, contributing to virus persistence in multi-host systems with an impact on PPR control and eradication program. This observation on the epidemiology of the PPRV in unnatural hosts demands appropriate intervention strategies, particularly at the livestock-wildlife interface.

Keywords: Bovine; Camel; Meta-analysis, Prevalence; PPR; Systemic Review; Wildlife.

Figure 1

PRISMA checklist flow diagram of the selection of eligible studies for inclusion in the meta-analysis

Figure 2

Funnel plot for the examination of publication bias of the prevalence estimates of PPR in bovine, camel, and wildlife during 2001-2021

Figure 3

Forest plot of the subgroup and sensitivity analysis of PPR in bovine, camel and wildlife during 2001-2021

Figure 4

A. PPR affected countries in Asia and Africa to bovine, camel, and wildlife animals and animal species distribution. B. Graph depicting the number of species described in the year-wise publication, and the frequency of new or unique species described for the first time.

Figure 5

Forest plot of the prevalence estimates of PPR in bovine, camel, and wildlife during 2001-2021

Figure 6

A. Estimated pooled prevalence of PPR in studied animals in Asia and Africa B. Showing reported countries for PPR in sheep and goats (as per OIE 2018), bovine, camel, and wildlife

Figure 7

Forest plot subgroup analysis of prevalence estimates of PPR in bovine, camel, and wildlife

Figure 8

Cumulative reported countries for PPR in atypical hosts -bovine and camel- for the period 2001-2005, 2001-2010, 2001-2015 and 2001-2021 (A), in wildlife for the period 2001-2005, 2001-2010, 2001-2015 and 2001-2021 (B)