Case Presentation: 19-year-old slaughterhouse worker from Pennsylvania presented to the hospital with recurrent episodes of fever, myalgias, dysphagia, headache, and diarrhea. He denied recent travel, tick bites and sick contacts. He was febrile at 102.6F with the pulse rate of 102bpm. Physical examination was benign without lymphadenopathies, organomegaly, meningeal signs and neurological deficits. Labs were remarkable for WBC 17,700/µl with 87% neutrophils, hemoglobin 12.4g/dl and platelets 267,000/uL with lactate 2.4meq/L, ESR 89 mm/hr and CRP 19.12 mg/dl. Mild elevation of liver enzymes with AST 98, ALT 218 IU/L noted. Strep A throat culture, hepatitis panel, CMV antibody, Lyme and HIV serologies were negative. Blood and stool cultures, Clostridium difficile toxin, stool ova-parasite and blood parasite smear were unrevealing. The cerebrospinal-fluid study, MRSA and respiratory pathogen panel by PCR for unremitting fever also failed to give any clues. Imaging studies and echocardiogram could not isolate any source. Coxiella/Brucella antibodies, rocky mountain spotted fever titer, blood smear for Babesia and serum Ehrlichia/anaplasma were checked meanwhile being treated with piperacillin-tazobactam. The patient had an overall improvement of health condition with remission of fever on completion of the seventh day of antibiotic and was discharged home. On a one-month visit, he again complained of myalgia and generalized weakness; elevated titers of Coxiella Burnetii sent during hospitalization was found with phase II IgG at 1:512, phase I IgG <1:16 and negative IgM titers. Repeat IgM titer sent was elevated at 1:32. With elevated phase II IgG and IgM titer, he was diagnosed with acute Q fever and was started on Doxycycline. He continues to work at the slaughterhouse, despite counseling provided for the possible source of illness and remains in a close follow up at infectious disease clinic.
Discussion: Q-fever or “Query” fever is a zoonosis historically discovered after an outbreak of a mysterious febrile illness among slaughterhouse workers. The causative agent, Coxiella burnetii, an obligate intracellular gram-negative bacterium, although a worldwide zoonotic pathogen, is uncommon in USA and thus has been a nationally notifiable disease since 1999. Certain professions such as veterinarians, meat processing plant workers, sheep and dairy workers, livestock farmers and researchers dealing with parturient livestock are at high risk for developing Q-fever infection through aerosol inhalation and ingestion from contaminated dairy products. Although once regarded a rare disease, increasing trend of Q fever in USA have been anticipated with 146 cases reported by CDC in 2014.
Conclusions: Q fever is a substantially underreported zoonosis because of its nonspecific clinical signs and the necessity of confirming infection through serologic testing. Physicians should be aware of this rare diagnosis and should consider it as a differential in patients presenting with fever and livestock exposure.