Seroprevalance to Coxiella burnetti in the Ramu Valley of Papua New Guinea

Background: In Papua New Guinea (PNG) most febrile illnesses are attributed to malaria. However, recent studies have confirmed the presence of other fever producing illness like dengue and rickettsia. The purpose of this study was to establish serological evidence to C. burnetii the causative bacteria of Q fever, another fever producing illness in the human population of PNG in the Ramu Valley. Methods: 327 blood samples were sent to the Australian Rickettsial Reference Laboratory in Geelong, Australia, for serology and PCR testing. Results: There was only phase II positive serological results, none of the samples had phase I reactivity. This study considered a cut off of phase II titer of ≥50 of either IgA, IgM or IgG as seropositive. The seroprevalence of Q fever in the Ramu Valley was 4.9% (16/327). The proportion of females (62%) was higher than males (38%). In age distribution, the largest proportion 7.2% (7/97×100) of seropositive was in the 21–30 year age group. Residential areas and cattle exposure were found to be the main risk factors associated with exposure to C. burnetii. All PCR results were negative. Conclusion: There is serological evidence of exposure to C. burnetii in the Ramu Valley of PNG. Health workers can consider Q fever as a differential diagnosis in patients with fever, generalised body aches, malaise and a suggestive history.