Risk Factors of African Swine Fever in Domestic Pigs of the Samara Region, Russian Federation

Abstract

African swine fever (ASF) is an incurable viral disease of domestic and wild pigs. A large-scale spread of ASF began in Eurasia in 2007 and has affected territories from Belgium to the Far East, occurring as both local- and regional-level epidemics. In 2020, a massive ASF epidemic emerged in the southeastern region of European Russia in the Samara Oblast and included 41 outbreaks of ASF in domestic pigs and 40 cases in wild boar. The Samara Oblast is characterized by a relatively low density of wild boar (0.04–0.05 head/km2) and domestic pigs (1.1–1.3 head/km2), with a high prevalence of small-scale productions (household farms). This study aims to understand the driving forces of the disease and perform a risk assessment for this region using complex epidemiological analyses. The socioeconomic and environmental factors of the ASF outbreak were explored using Generalized Linear Logistic Regression, where ASF infection status of the Samara Oblast districts was treated as a response variable. Presence of the virus in a district was found to be most significantly (p < 0.05) associated with the importation of live pigs from ASF-affected regions of Russia (OR = 371.52; 95% CI: 1.58–87290.57), less significantly (p < 0.1) associated with the density of smallholder farms (OR = 2.94; 0.82–10.59), volume of pork products' importation from ASF-affected regions of Russia (OR = 1.01; 1.00–1.02), summary pig population (OR = 1.01; 0.99–1.02), and insignificantly (p > 0.1) associated with presence of a common border with an ASF-affected region (OR = 89.2; 0.07–11208.64). No associations were found with the densities of pig and wild boar populations. The colocation analysis revealed no significant concentration of outbreaks in domestic pigs near cases in wild boar or vice versa. These results suggest that outbreaks notified in low biosecurity household farms were mainly associated with the transportation and trade of pigs and pork products from ASF-affected regions of Russia. The findings underline the importance of taking into account animal transportation data while conducting future studies to develop a risk map for the region and the rest of European Russia.

Direct and indirect pathways for the spread of African swine fever and other porcine infectious diseases: An application of the mental models approac

“…Our study reiterates the central role of direct pig trade in the spread of infectious diseases, which has been previously illustrated for all the diseases investigated here: ASF, PRRS, and EP (Gao et al, 2021;Glazunova et al, 2021;Hege et al, 2002;Kwong et al, 2013;Mortensen et al, 2002). In addition, studies of pig trade networks in different countries highlighted that accounting for trade-related indirect pathways significantly increased infectious disease spread potential (Porphyre et al, 2020;Salines et al, 2017;Sterchi et al, 2019;Thakur et al, 2015).…”

Analisis Sebaran Kasus African Swine Fever pada Babi Di Provinsi Sumatera Utara Tahun 2019–2020

“…Lalu lintas hewan merupakan salah satu faktor utama dalam penyebaran ASF pada babi. Penelitian di Rusia menyebutkan bahwa rute transportasi dalam perdagangan babi dan produk babi serta kepadatan populasi babi secara simultan dapat mempengaruhi sebaran kasus ASF (Gulenkin et al, 2011;Glazunova et al, 2021). Transportasi merupakan faktor penting dalam menghubungkan wilayah satu dengan wilayah yang lain.…”

African swine fever in wild pigs in the Asia and the Pacific Region

“…Generalised comments on the role of wild pigs in ASF are often inferred from the role of wild boar in the pandemic in other geographical regions of the world. Much more is known about the epidemiology of ASF in wild pigs in areas of Europe, where more surveillance, research and epidemiological analyses have been conducted (European Food Safety Authority Boklund et al, 2020;Dixon et al, 2020;Glazunova et al, 2021).…”

“…In general, with the exception of Western Europe, the ASF pandemic appears to be driven by domestic production cycles, with wild boar being of secondary importance to transmission although they undergo regular spillover events and sometimes transmit infection. For example, in the Russian Federation and Caucuses, transmission is associated with movement of live domestic pigs and pork products or with poor biosecurity of smallholder pig production (Glazunova et al, 2021). It appears that where wild boar outbreaks occur, transmission is more commonly from domestic pigs to wild boar.…”