Seropositivity of brucellosis in human and livestock in Tribal-Kurram Agency of Pakistan indicates cross circulation

Abstract

Brucellosis is an endemic disease in Pakistan, yet an overall systemic surveillance data of the country is missing. This study aims to determine seroprevalence in domestic livestock population and high and low risk-associated humans of tribal Kurram Agency, Pakistan. A total of 567 random animal blood samples (148 cattle, 105 buffaloes, 154 sheep, and 160 goats), 197 human serum samples (n= 83 from low risk population n= 114 from high risk individuals) and ,in order to establish association between abortion and brucellosis, additional 395 animals with maximum of 4 weeks of foetal-birth history with or without abortion were initially screened by rose bengal plate test (RBPT) and further confirmed by indirect enzyme linked immunosorbant assay (I-ELISA). Our results indicated an overall seroprevalence of 4.73% in cattle, 4.76% in buffaloes, 1.95% in sheep, and 3.13% in goats. Interestingly, seroprevalence of brucellosis in males of cattle, sheep and goats was found higher as compared to females, while, it was found higher in male buffaloes as compared to female buffaloes. Furthermore, there was a statistically significant relationship between occurrence of brucellosis and abortion (Chi-square test, p<0.05). The overall seropositivity in individuals at high risk (those with close and physical contacts with animals) was found 4.39% as compared to 1.20% seropositivity of low risk (people with no obvious close physical contacts with animals) general population. Interestingly, seroprevalence of human brucellosis was relatively higher in human females as compared to males. Overall, these results indicate a higher seroprevalence of brucellosis in human and their livestock animals.