Molecular investigation of Coxiella burnetii, Brucella spp., Ehrlichia spp., and Borrelia spp. among patients suspected of having Crimean-Congo Hemorrhagic Fever in Iran

Objectives

Crimean-Congo Hemorrhagic Fever (CCHF) is a tick-borne zoonotic viral disease that could be a public health concern. The overlapping of clinical symptoms of some acute bacterial febrile diseases with CCHF is of importance for clinical diagnosis. This study aimed to molecularly examination of Brucella, Coxiella burnetii, Borrelia, and Ehrlichia infections among individuals suspected of CCHF in Iran.

Methods

In this study, 260 serum samples of suspected cases of CCHF with definitively negative laboratory test results for CCHF virus infection, were examined for Brucella spp., Coxiella burnetii, Borrelia spp., and Ehrlichia spp. by Real-time PCR.

Results

According to the results, 3.46 % and 3.07 % of the patients were positive for brucellosis and Q fever, respectively. Notably, no cases of borreliosis or ehrlichiosis were detected. Among the positive cases for brucellosis (N = 9), three cases were identified as Brucella abortus infection. Individuals under the age of 43 displayed a significantly higher positivity rate for Q fever (p < 0.01). Furthermore, patients presenting with chills had a 5.81-fold increased likelihood of being infected with Q fever (95 % CI: 1.39–24.26) compared to those without chills. Notably, no other variables demonstrated a statistically significant association with Q fever infection.

Discussion and conclusions

The results of this study showed that bacterial infections such as Q fever and brucellosis should be considered as differential diagnoses of CCHF. It is recommended that other bacterial infections that can cause early clinical symptoms similar to CCHF should also be taken into consideration in future studies and serological and molecular investigations of these infections should be tested on a wide scale.