Zoning of the republic of Kazakhstan as to the risk of natural focal diseases in animals: the case of rabies and anthrax

Abstract

Rabies and anthrax, being natural focal diseases, are characterized by the ability to persist in areas with a certain combination of environmental factors without human intervention. These infections annually cause sporadic outbreaks in domestic, livestock and wild animals in the Republic of Kazakhstan (RK) receiving close attention of the veterinary service. In particular, targeted mass vaccination and surveillance are conducted, which requires zoning of the country according to the exposure to the diseases.This paper presents a zoning approach based on the estimation of suitability to the study diseases using the Environmental Niche Modelling method. Retrospective data on animal rabies outbreaks in the RK for 2003-2014, as well as data on anthrax burial sites for 1933-2014 were used. The following environmental factors were treated as potential explanatory variables: 1) a set of climate data derived variables BIOCLIM; 2) altitude above the sea level; 3) land cover type; 4) the maximum green vegetation fraction and 5) soil type.The modelling outcomes for both diseases indicate elevated risks along the northern and southeastern borders of the RK that not only follows the distribution of historic disease cases, but also accounts for potentially suitable environmental conditions. To comply with the requirements of the veterinary service, gridded risk maps were converted into categorical maps by averaging risk values within municipal districts and ranking according to four categories: low, medium, high, and very high.The maps obtained may be used as recommendations to the veterinary service as a basis for developing regionspecific anti-epizootic measures.

Rabies in the Republic of Kazakhstan: spatial and temporal characteristics of disease spread over one decade (2013–2022)

“…Most (725/1,119) animal cases reported between 1996 and 2004 in Kazakhstan affected cattle, causing far-reaching economic losses (12, 13). However, because of interspecies transmission, prevention measures targeting only domestic animals are insufficient to eradicate rabies and protect the human population, leaving different parts of the country vulnerable to the disease (14)(15)(16). Key measures taken to control the disease in Kazakhstan include (1) strategic oral vaccination of wild animals during outbreaks and in areas of potential disease spread; (2) compulsory and prophylactic vaccination of prone domestic animals;…”

“…(3) registration of susceptible domestic animals, and (4) public education and outreach (16,17). The specifications of the vaccination campaign, including the number of vaccine doses and vaccine type used, depend on the total number of susceptible livestock and the epidemiological situation of the district (16)(17)(18)(19).…”

“…(3) registration of susceptible domestic animals, and (4) public education and outreach (16,17). The specifications of the vaccination campaign, including the number of vaccine doses and vaccine type used, depend on the total number of susceptible livestock and the epidemiological situation of the district (16)(17)(18)(19). Briefly, all susceptible livestock, dogs, and cats are vaccinated, and the oral vaccine is distributed for wild animals, in high-risk districts, whereas vaccination and surveillance activities are selectively applied in districts classified as mid, low, or negligible risk (18-21).…”

“…However, because of inter-species transmission, prevention measures targeting only domestic animals are insufficient to eradicate rabies and protect the human population, leaving different parts of the country vulnerable to the disease ( 14 – 16 ). Key measures taken to control the disease in Kazakhstan include (1) strategic oral vaccination of wild animals during outbreaks and in areas of potential disease spread; (2) compulsory and prophylactic vaccination of prone domestic animals; (3) registration of susceptible domestic animals, and (4) public education and outreach ( 16 , 17 ). The specifications of the vaccination campaign, including the number of vaccine doses and vaccine type used, depend on the total number of susceptible livestock and the epidemiological situation of the district ( 16 – 19 ).…”

“…A retrospective analysis of data provided by the National Veterinary Services, resulted in the identification of significant spatial and temporal clusters, and zoning and regionalization strategies were subsequently recommended ( 19 ). Although the frequency of cases per susceptible species in Kazakhstan seems to also vary across regions ( 10 , 17 , 19 ), species-specific clusters of disease, and their relation with demographic and environmental factors, are yet to be elucidated.…”