Seroprevalence and risk factors of Q fever in small ruminant flocks in selected States of Peninsular Malaysia

Abstract

Q fever is caused by Coxiella burnetii, an obligate intracellular parasite which causes abortion and reproductive
disorders in domestic animals and febrile illness in man. Earlier studies have detected C. burnetii, including serum
antibodies in humans, cattle, sheep and goats in Malaysia. However, the overall seroprevalence status and contributing
factors of Q fever among small ruminants in Malaysia are still unexplained. This study was therefore conducted to
investigate the seroprevalence and risk factors of Q fever among small ruminant flocks in Negeri Sembilan and
Terengganu states. To determine the seroprevalence of Q fever among small ruminants, we collected blood samples
from a total 272 sheep and goats across six smallholder farms in two states and tested all sera using commercial
Sandwich-ELISA kit with a sensitivity of 100% and specificity of 99.6% for the direct detection of specific antibody
against Coxiella burnetii. Our results revealed 12.1% (8.77-16.55) apparent prevalence and 11.8% (8.40-16.21) true
prevalence of Q fever among individual sheep and goats in the two states. Univariable analysis revealed that states (X2
=10.264: p=0.001), farms (X2 =27.32: p=0.000), gender (X2 =3.908: p=0.048), age (X2 =12.845: p=0.000), breed (X2 =13.435:
p=0.004) and production (X2 =8.992: p=0.003) of small ruminants were associated with their Q fever seropositive status.
Multivariable logistic regression further revealed 3.972, 12.455 and 11.921 times more likelihood of Q fever in the young,
the Barbados Black Belly sheep breed and the meat production animals. In conclusion, the seroprevalence Q-fever in
Terengganu and Negeri Sembilan states is associated with the age, breed and the production purpose of small
ruminants.