Serological and Molecular Investigation of Brucellosis in Breeding Equids in Pakistani Punjab.

Amjad Hussain,Muhammad Hammad Hussain,Mudassar Iqbal,Riaz Hussain,Waqas Ahmad,Muhammad Saqib,Heinrich Neubauer,Tariq Jamil,Iahtasham Khan,Ali Zohaib,Falk Melzer,Abdul Malik Tareen

doi:10.3390/pathogens9090673

Abstract

Brucellosis is an important zoonosis worldwide. Equines are susceptible to the infection when in close contact with infected animals. The objective of our study was to update the existing knowledge and detect and differentiate the causative agent of brucellosis in breeding equines in Punjab, Pakistan. A cross-sectional study was designed to evaluate the occurrence and etiology of the infection in the equine population in three districts. A total of 448 equine sera were collected from three prefectures viz. Sahiwal, Khanewal, and Okara of the Punjab Province of Pakistan. Ninety-six (21.4%) samples were found positive by RBPT, 3.56% (16/448) by iELISA, and 4.24% (19/448) by CFT. Real-time PCR demonstrated the presence of Brucella abortus-DNA in sero-positive samples. Age and location were found as risk factors. The study concludes equine brucellosis seroprevalence in the country where Brucella abortus as the main etiology. Fistulous withers and poll evil cases should be treated with care as they could be hazardous and a source of zoonotic transmission. Routine screening at an early age, vaccination in ruminants, and consumption of pasteurized dairy milk in humans is recommended for prevention of the infection. Specific tests need to be standardized and validated.

Highlights

Brucellosis is an abortive bacterial zoonosis primarily seen in ruminants and is caused by Brucella (B.) abortus and B. melitensis [1,2,3]
Owing to unavailability of prevalence estimates of equine brucellosis in the study locales, an expected prevalence of 50% with a 95% confidence interval (CI) and 5% desired absolute precision was taken for sample size estimation [20]
Our study has demonstrated the occurrence of B. abortus as the prevailing cause of brucellosis in the tested equines

Summary

Introduction

Brucellosis is an abortive bacterial zoonosis primarily seen in ruminants and is caused by Brucella (B.) abortus and B. melitensis [1,2,3]. Transmission occurs via direct contact with infected animals or indirectly via the contaminated environment. “Nonpreferred” hosts (e.g., equids) are susceptible when in close contact with the infected “preferred” hosts [5,6,7,8]. Abortion storms during the last trimester, hyperthermia, and retention of fetal membranes and intermittent fever, arthralgia, and myalgia in acute cases and neurologic disorders in chronic cases in humans are characteristic signs [9]. The bursal fluid from such equids may be a source of infection in humans. In Pakistan, brucellosis has been reported in ruminant herds caused by both B. abortus and B. melitensis [1,5]. Occupational exposure to the infected animals has been associated with transmission of the infection in the country [14,15,16]

Objectives

Methods

Results

Discussion

Conclusion