A Survey of Acute Q Fever among Patients with Brucellosis-Like and Atypical Pneumonia Symptoms Who Are Referred to Qaemshahr Razi Hospital in Northern Iran (2014-2015)
Authors: Ghasemian Roya , Mostafavi Ehsan , Esmaeili Saber , Najafi Narges , Arabsheybani Sara 
Published: August 2016

<p><strong>INTRODUCTION</strong><strong>:</strong> Coxiella burnetii is the etiologic agent of the zoonotic disease of Q fever which causes lots of morbidities and mortalities every year. The main route of human infection is inhalation of contaminated aerosols; however, consumption of contaminated dairy products is the second cause. Mazandaran province is one of the main livestock centers of the country and consumption of raw dairy in the region is quite common. There isn’t any data about Q fever incidence in this region. It seems that most cases are undiagnosed. Our main target is to prove existence of Q fever human cases in Mazandaran province. We evaluated suspect Q fever cases to demonstrate its incidence and identify the risk factors.</p><p><strong>MATERIAL </strong><strong>&amp; METHODS</strong>: In this cross-sectional study, 56 Patients including 36 patients with brucellosis-like systemic symptoms identified by negative Wright, Coomb's Wright and 2-mercaptoethanol tests as well as 20 patients with symptoms of atypical pneumonia who did not respond to conventional therapy were enrolled. At the beginning of hospitalization and 3-4 weeks later, 10cc blood was obtained from each of 56 patients who referred for a second blood sampling. Demographic, epidemiological, and clinical manifestations of Q fever and clinical changes were completed for each patient. The samples were evaluated quantitatively in terms of the presence of phase II IgG antibodies against Coxiella burnetii by ELISA method. Acute Q fever was confirmed by line-sero conversion (change of antibody from negative to positive) or fourfold antibody rising titer in each patient. The presence of primary and secondary seropositive samples and absence of line-sero conversion (change of antibody from negative to positive) or fourfold increase in antibody titer was considered as previous infection.</p><p><strong>RESULTS</strong><strong>:</strong> The prevalence rate of acute Q fever in 56 patients with 2nd blood sample was 5.3%. There was no history of tick bite, while in 100% of cases there were risk factors such as a history of residence near animal care centers as well as a history of consumption of raw dairy products (P = 0/001). 23.2% had a previous history of Q fever infection, out of which 25.8% lived in rural areas. Among people with risk factors of keeping domestic animals, living close to animal care centers and animal abortion, the prevalence rate of previous infection was higher compared to those who did not have these risk factors.</p><p><strong>CONCLUSION</strong><strong>: </strong>Since most of the patients with acute Q fever have no specific symptom, health care providers do not suspect acute Q fever disease. In this study, it was demonstrated that infection is either directly or indirectly associated with increase in environmental risk factors including contact with livestock and its products. Our study proved that Q fever is endemic in Mazandaran province. In order to have an accurate diagnosis and proper management, clinicians should be aware of existence of this disease in the region. Because of the climate of northern Iran and easy transportation of contaminated particles, appropriate measures should be taken to control and prevent this disease.</p>