Q Fever in U.S. Soldiers Deployed to Iraq

Abstract & Commentary

By Dean L. Winslow, MD, FACP, FIDSA, Chief, Division of AIDS Medicine, Santa Clara Valley Medical Center; Clinical Professor of Medicine, Stanford University School of Medicine, Section Editor, HIV, is Associate Editor for Infectious Disease Alert.

Dr. Winslow serves as a consultant to Siemens Diagnostics and is on the Speakers Bureaus of Boehringer-Ingelheim and GSK.

Synopsis: Three soldiers who were recently or currently deployed to Iraq are described. All presented with various combinations of fever, abdominal pain, pneumonia, and liver function abnormalities. Two had clinical and radiographic evidence of acalculous cholecystitis. Treatment with doxycycline may shorten the duration of symptoms and prevent chronic disease.

Source: Hartzell JD, et al. Atypical Q Fever in US Soldiers. CDC Emerg Infect Dis. 2007 Aug. Available from www.cdc.gov

This interesting report written by an ID Fellow at Walter Reed Army Medical Center (WRAMC) describes 3 cases of Q fever in deployed (or recently redeployed) soldiers serving in Iraq.

The first patient was a 22-year-old male Army National Guard member who presented to a New Hampshire ER 7 days after returning from Iraq with flu-like symptoms, fever, leukopenia, a normal chest X-ray and modestly elevated serum transaminases. He was empirically treated with azithromycin and ceftriaxone. While his fever decreased he developed abdominal pain, dyspnea, and worsening transaminases with his ALT reaching 993 U/L and alkaline phosphatase 269 U/L. After transfer to WRAMC chest and abdominal CT scans showed bilateral ground glass pulmonary infitrates and gallbladder wall thickening without evidence of ductal dilatation. He was treated with doxycycline and his signs and symptoms resolved. Diagnosis of Q fever was made serologically by demonstrating both IgM antibodies to Coxiella burnettii present at 1: 256 and IgG antibodies at 1:128 in convalescent sera and negative antibodies in acute sera.

The second patient was 24-year-old male Army National Guard soldier who was admitted to the 28th Combat Support Hospital (CSH) in Baghdad with flu-like symptoms, nausea and a dry cough. He was febrile to 40.2 deg C. Mild epigastric tenderness was present and the patient had mild leukopenia, platelets 130,000, and markedly elevated ALT and AST (approx. 800 U/L for both). Abdominal CT scan showed gallbladder wall thickening and enhancement. Q fever was considered in the differential diagnosis and the patient received doxycycline and metronidazole. His fever decreased, metronidazole was discontinued but doxycycline was continued for a 14-day course and he was transferred to Landstuhl Regional Medical Center (LRMC). Serologic studies demonstrated high titer IgM antibodies to C. burnetii (1:2048) in both acute and convalescent phase sera. He made a complete recovery and was returned to duty.

The last patient was a 34-year-old female active duty soldier with a history of asthma who presented to one of the Baghdad area Troop Medical Clinics with flu-like symptoms. She was initially treated symptomatically but returned with altered mental status, dyspnea and abdominal pain. Chest CT scan showed a left lower lobe infiltrate. Abdominal ultrasound was normal. She was transferred to the 10th CSH in Baghdad. She remained febrile to 39.8 deg C and was tachycardic. Mild increases in serum transaminases were observed. She was treated with levofloxacin but respiratory failure requiring intubation and mechanical ventilation developed. She was evacuated initially to LRMC where bronchoscopy was performed. Follow up chest X-rays showed evidence of ARDS. Doxycycline was given and the patient was transferred to WRAMC. By the time she arrived in Washington, DC, she was afebrile and her respiratory status rapidly improved and she was extubated. She completed a 14-day course of doxycycline and recovered completely.

Commentary

Acute Q fever often presents with fever, pneumonia, and/or hepatitis but other manifestations can include meningoencephalitis and myopericarditis.1,2 Chronic infection may manifest as culture-negative endocarditis. Only about 12 cases of acute cholecystitis due to Q fever have been described.3 Interestingly, none of the 3 soldiers described in this paper reported typical zoonotic exposures.

This series of patients reminds us of the protean manifestations of Q fever and of the importance of including Q fever in the differential diagnosis of fever, pneumonia, and hepatitis in soldiers deployed (or recently returned from deployment) to Southwest Asia. Doxycycline remains the antimicrobial of choice for this infection and likely shortens the duration of acute illness and prevents chronic disease (endocarditis) from developing.

References:

  1. Parker NR, et al. Q fever. Lancet 2006;367:679-688.
  2. Raoult D, et al. Q fever 1985-1998: clinical and epidemiological features of 1,383 infections. Medicine 2000;79:109-123.
  3. Reina-Serrano S, et al. Q fever-related cholecystitis: a missed entity? Lancet Infect Dis 2005;5:734-735.