History and epidemiology of foot-and-mouth disease in Afghanistan: a retrospective study

Foot-and-mouth disease virus dynamics in border areas of Pakistan with Afghanistan

BACKGROUND

Foot and mouth disease (FMD) is a highly contagious disease that impacts cloven-hoofed animals globally. The illegal trade of livestock between the border regions of Pakistan and Afghanistan can contribute to the spread of this disease. This study focuses on investigating the outbreaks of FMD that occurred in this area from June 2020 to May 2021.

METHODS

RESULTS: A total of 233 epithelial tissue samples were collected, and 77% were found positive for FMDV through an antigen-detection by ELISA and molecular conformation through RT-PCR. The study found three serotypes of FMDV dominating in the border area of Pakistan with Afghanistan: O, A, and Asia-1. The outbreak activity was peaked between August/September followed by July/October 2020. Phylogenetic analysis conducted using the VP1 region sequence showed that serotype O isolates belonged to the Middle East-South Asia (ME-SA) topotype, PanAsia-2 lineage, and ANT-10 sub-lineage, while serotype Asia-1 isolates belonged to a novel lineage BD-18.The highest prevalence of serotype O of FMDV was found in cattle and buffalo of 1-2 year age group, while the highest outbreak ratio of serotype O was recorded in goats of 0-1 year age group and sheep of > 2 year age group. The serotype O was more prevalent in male than female sheep. The type A was more prevalent in females of sheep and goats than their corresponding males. The serotype Asia-1 was more prevalent in females of cattle and sheep than their corresponding males. The outbreak epidemiology of FMD varied significantly between various regions, months of study, animal species, age groups, and gender.

CONCLUSIONS

The study found that FMD outbreaks in the border area of Pakistan and Afghanistan were diverse and complicated, and that different types of FMDV were circulating. The study recommended effective actions to stop FMD transmission in this area.

Epidemiological and genetic characteristics of foot-and-mouth disease virus in China from 2010 to 2022

Foot-and-mouth disease virus (FMDV) is a highly contagious picornavirus that can infect cloven-hoofed animals of significant agricultural importance. In China, foot-and-mouth disease (FMD) epidemics occur annually, resulting in localized outbreaks or sporadic epidemics that cause significant economic losses. This study summarized 123 cases of FMD reported in China between 2010 and 2022, using data from the official website of the Chinese Center for Animal Disease Control and Prevention. The epidemic situation and genetic characteristics of FMDV in China were studied through phylogenetic analysis, amino acid variation analysis of antigenic epitopes, and genetic recombination analysis. The findings provide important references for predicting the FMDV epidemic situation in China, developing vaccines, and effectively preventing and controlling FMD.

The prevalence of foot-and-mouth disease in Asia

Foot-and-mouth disease (FMD) is listed among the highly contagious diseases in animals and is endemic throughout the Asian continent. The disease is caused by the Foot-and-mouth disease virus (FMDV) and affects a wide variety of domesticated animals as well as wild ungulates. Clinically, the disease is described as a vesicular lesion on the tongue, muzzle, lips, gum, dental pad, interdigital cleft, coronary band, and heel of the foot. Sometimes these lesions give rise to lameness. Mastitis is also caused due to teat lesions. A biochemical test reveals that during FMD infection, there are elevated levels of interleukin-1 (IL-1), tumor necrosis factor-alpha, interferon-gamma (IFN-γ), interleukin-6, serum amyloid A protein, lactoferrin, mannose-binding lectin, and monocytes chemo-attractant protein-1 in the serum of infected animals. There is no specific treatment for FMD although some antivirals are given as prophylaxis and antibiotics are given to prevent secondary bacterial infection. This review presents comprehensive data on the prevalence of FMD and serotypes of FMDV that are attributable to the cause of FMD from a regional point of view. It also explains the worldwide dynamics of the seven serotypes of FMD and tries to identify epidemiological clusters of FMD in various geographical areas. Furthermore, the pathology associated with the foot and mouth disease virus along with the pathophysiology is discussed. The continent-wide prevalence and diversity patterns of FMD suggest that there is a need for stringent policies and legislation implementation regarding research and development aimed at manufacturing strain-specific vaccination, infection prevention, and control of the disease.

Sero-Epidemiology and Associated Risk Factors of Foot-and-Mouth Disease (FMD) in the Northern Border Regions of Pakistan

The present cross-sectional survey was carried out to investigate the distribution and risk factors of FMD in Pakistan's northern border regions. About 385 serum samples were compiled from small ruminants (239) and large ruminants (146) and tested using 3ABC-Mab-bELISA. An overall apparent seroprevalence of 67.0% was documented. The highest seroprevalence of 81.1% was reported in the Swat, followed by 76.6% in Mohmand, 72.7% in Gilgit, 65.6% in Shangla, 63.4% in Bajaur, 46.6% in Chitral and lowest 46.5% in Khyber region. Statistically significant variations in seroprevalence of 51.5%, 71.8%, 58.3%, and 74.4% were recorded in sheep, goats, cattle, and buffaloes, respectively. From the different risk factors investigated, age, sex, species of animal, seasons, flock/herd size, farming methods, outbreak location, and nomadic animal movement were found to be significantly associated (p < 0.05) with the seroprevalence of FMD. It was concluded that proper epidemiological study, risk-based FMD surveillance in small ruminants, vaccination strategy, control measures for transboundary animal movement, collaborations, and awareness programs need to be practiced in the study regions to investigate the newly circulating virus strains in large and small ruminants and associated factors for the wide seroprevalence to plan proper control policies to bound the consequence of FMD in the region.

Knowledge, Attitudes, and Practices (KAPs) of Farmers on Foot and Mouth Disease in Cattle in Baghlan Province, Afghanistan: A Descriptive Study

Simple Summary

Foot and mouth disease (FMD) affects the productivity and health of several animals species, including cattle. In Afghanistan, cattle represent a valuable source of food security and play a vital role in the rural economy. Using a questionnaire-based approach, we evaluated the self-reported knowledge, attitudes, and practices of various stakeholders involved in the cattle industry and veterinary management of animal health in a northern province of Afghanistan. The study pointed to several aspects that could be translated into practical management options to add value to FMD management in the cattle industry in Afghanistan.

Abstract

This study was performed to investigate the knowledge, attitudes, and practices (KAPs) of farmers, animal traders, and veterinary professionals on FMD in Baghlan province, Afghanistan. Four structured questionnaires were administered to the respondents. Almost half (48.5%) of the farmers had heard of the occurrence of FMD in their neighbourhood or knew the name of the disease. The majority of farmers could recognise the clinical signs of FMD in their animals (salivation, 85.9%; tongue ulcers, 78.8%; gum lesions, 78.2%; hoof lesions, 76.8%). Most farmers stated that the “introduction of new animals” was the primary cause of FMD appearing on their farms and to control the spread of the disease, over half of the farmers (56%) preferred not to buy cattle from unknown or potentially infected sources. Animal traders’ knowledge was limited to recognising some clinical signs of the disease such as: salivation, and lesions in the mouth and on the feet. No animals were directly imported by the traders from outside Afghanistan. Over half of the local veterinary professionals (65%) kept record books of the animal diseases seen and/or treatment plans undertaken, and 80% of them reported the occurrence of FMD to the provincial, regional, and central veterinary authorities. No regular vaccination programme against FMD was implemented in the province. Poor import controls and quarantine were considered to be the main barriers to the control of FMD in the study area and the surrounding provinces. It can be concluded that, despite relatively good knowledge about FMD in the study area, there are gaps in farmers’ and traders’ knowledge that need to be addressed to overcome the burden of the disease in the province. These should focus on strengthening interprovincial quarantine measures and implementation of regular vaccination campaigns against the circulating FMDV within the area.

Seroprevalence and risk factors for foot-and-mouth disease in cattle in Baghlan Province, Afghanistan

A serological study of 376 cattle from 198 herds and a concurrent survey of farmers were undertaken in 53 villages in Khinjan, Doshi and Puli Khumri districts of Baghlan province, Afghanistan to determine the seroprevalence of Foot and Mouth Disease (FMD) and to identify risk factors for seropositive herds. A total of 419 cases of FMD were reported by the farmers in the year preceding the survey. The animal-level population seroprevalence was estimated at 42.0% (95% CI, 37.0-47.2). The seroprevalence increased with age in the sampled cattle (<2 years - 30.4%, 2-6 years - 40.3% and >6 years - 52.2%). Herds were more likely to be seropositive if the farmers: had purchased cattle in the year prior to the survey (OR = 2.6; 95% CI, 1.37-4.97); purchased ruminants from unknown (potentially risky) sources (OR = 2.13; 95% CI, 1.13-4.03); and sold milk to the market (OR = 1.99; 95% CI, 1.09-3.63). Herds that had been vaccinated had a lower odds of being seropositive (OR = 0.33; 95% CI, 0.68-0.66). This was the first epidemiological study of FMD in Baghlan province and the findings provide valuable direction for disease control on FMD in this and other provinces in Afghanistan.

Outbreak investigation of foot and mouth disease in Nangarhar province of war-torn Afghanistan, 2014

Afghanistan has long history of ongoing conflicts, resulting in massive destruction of the country's infrastructure. Illegal trade of livestock between Afghanistan and Pakistan boosted the spread of Foot & Mouth Disease (FMD). Current study was conducted to investigate outbreaks of FMD occurred between April-August 2014 in Nangarhar, Afghanistan. Descriptive data about suspected FMD cases were collected from the Civil Veterinary Hospital, Nangarhar to analyze spatio-temporal pattern of FMD. Case farms (n = 137) were selected from list of clinically confirmed FMD outbreaks available in the hospital. Control farms (n = 137) were enrolled from neighboring premises of case farms. The epidemic curve showed that the virus is continuously circulating among susceptible population. The mean age of the oldest lesion was 2.8 days. Foot & Mouth Disease was more likely to occur in female animals compared to male animals (p < 0.001). Farmers having no ability to clinically recognize FMD (OR 5.8, 95% CI 1.4-23.8); previously having any FMD case in herd (OR 11.8, 95% CI 3.0-45.8), farms where animals leave shed during day (OR 15.4, 95% CI 5.6-42.0), and farms, where neighboring farmers used to visit the premises (OR 3.5, 95% CI 1.2-9.9) were identified as risk factors. Current findings may be used to create awareness of concerned veterinary health authorities about FMD control.

Antigenic properties of a novel vaccine strain for type Asia1 foot-and-mouth disease in pigs

Newly developed vaccine strains to prevent foot-and-mouth disease caused by the emerging serotype Asia1 virus were evaluated. To protect against the group (G)-VIII strain, which occurred recently, we produced an infectious cDNA clone of Asia1 Shamir cDNA (Asia1 Shamir-R). In addition, by adding a site 1 epitope of VP1 of the G-VIII lineage virus to this virus, we produced a new virus (Sham GVIII- EPI), and another virus(Sham GVIII-VP1) was replaced with that of G-VIII lineage in the VP1 region of Shamir. Test vaccines were produced using these three types of vaccine virus, and their immunogenicity and protection capabilities were evaluated in mice. Immunized mice were challenged with the Asia1 Shamir or G-VIII virus, and the results show that all the vaccines have similar protective effects. As they showed similar antigenicity, we chose the Shamir-R vaccine. Pigs maintained relatively high neutralizing antibody levels against homologous viruses of the Shamir and G-VII or G-VIII lineage three to four weeks after immunization. However, they formed relatively low levels of antibodies to G-IV and G-V viruses. In conclusion, we produced a vaccine candidate capable of protection against the G-VIII virus in the vaccine experiment for the type Asia1 serotype vaccine. This Shamir-R vaccine virus was found to protect against the viruses of the Asia1 genotype G-VII and G-VIII lineages, which occurred recently in Asia.

History and epidemiology of foot-and-mouth disease in Afghanistan: a retrospective study

BACKGROUND

Foot and mouth disease (FMD) is endemic in Afghanistan with serotypes O, A and Asia 1 being prevalent. A retrospective study of data collected through passive surveillance of outbreaks of FMD in Afghanistan from 1995 to 2016 was undertaken to determine the temporal and spatial distribution of FMD in the country.

RESULTS

A total of 4171 outbreaks were reported between 1995 and 2008 with a strong correlation between the number of outbreaks and the number of provinces (r = 0.85, s = 68.2, p < 0.001); and between the number of outbreaks and the number of districts containing infected animals (r = 0.68, s = 147.8, p = 0.008). Of 7558 samples collected from livestock originating from 34 provinces in 2009, 2011 and 2013-2015, 54.1% were test positive (FMDV 3ABC-trapping ELISA) and the prevalence varied significantly between years (χ2 = 263.98, df = 4, P < 0.001). Clinically suspected cases were reported in 2016 with a substantial positive correlation (r = 0.70, P < 0.001) between the number of districts with cases and the number of reported cases. Serotype O was the predominant serotype detected during the study period, although serotypes A and Asia1 were also detected. Cattle were involved in all outbreaks in the study period and infections were detected in all years of the study in Hirat province in the north-west (bordering Iran), Nangarhar province in the east (bordering Pakistan) and Kabul province in the centre of the country.

CONCLUSIONS

The current paper was the first analysis of existing data focusing on the spatiotemporal distribution of FMD in Afghanistan. The findings from this study provide valuable direction for further research to understand the epidemiology of FMD and its control in Afghanistan.