Discussion:
Brucellosis infects people of all age groups who consume raw dairy products or have close contact with infected animals [8, 6]. This zoonotic disease is an important socioeconomic problem and public health issue worldwide especially in developing countries [6].
The incidence of brucellosis is varied in different parts of Iran (average 114 per 100,000 populations) [7]. Our patient had main ailments including shortness of breath, fever and was hospitalized in the COVID-19 department. Because of the COVID-19 pandemic, and the risk of spreading the virus, taking a detailed history of his brucellosis and a positive serology test for Brucella was delayed. The patient had consumed unpasteurized milk and dairy products. The symptoms of fatigue, joint pains extreme weight loss, and drenching sweating are typical in brucellosis [5]. Thoracic CT imaging in our patient showed no symptoms of pulmonary brucellosis or other pulmonary disorders such as pneumonia and abscess of lungs empyema that are common in endemic countries such as Iran [1,6, 9]. Other clinical studies showed that in patients with mild to moderate COVID-19 a shared variety of clinical and laboratory features can be found in other diseases including Dengue and Malta fever [3, 6]. Other pathogens including influenza, legionnaire illness, dengue virus, and mycoplasma pneumonia are infections widely happening with SARS-CoV-2 infection [5, 10, 11, 12, 13]. The co-infection of brucellosis and SARS-CoV-2 is not generally reported [14]. It is the first report of Brucella and COVID-19 co-infection in our region. COVID-19 could mimic or unknown other febrile diseases therefore a positive test for SARS-CoV-2, is not an indication of the absence of other infections especially when the manifestation is uncharacteristic [5, 15].
In conclusion: brucellosis is an endemic disease in our country and, physicians should be overlooked other endemic diseases in COVID-19 patients based on the history of admitted patients.