Suspected Meningococcal Meningitis on an Aircraft Carrier

Military Medicine, Sep 2004 by Farr, R Wesley, Gonzalez, Michele J, Garbauskas, Heather, Zinderman, Craig E, LaMar, James E II

A suspected case of meningococcal meningitis was diagnosed in a 24-year-old sailor onboard an aircraft carrier at sea in 2003. He was immediately confined to the ship's hospital ward under respiratory isolation precautions and was treated with intravenously administered antibiotics. His illness resolved without sequelae. A total of 99 close contacts from the ship were identified and given antibiotic prophylaxis, with directly observed therapy. British public health authorities were contacted to trace and treat persons identified as close contacts during a port call a few days before presentation. Managing a communicable disease such as meningococcal meningitis in the austere shipboard environment represents a unique challenge to military medical personnel. Successful management is possible through prompt treatment, respiratory isolation, and open communication between primary health care providers and public health officials. The identification of shipboard close contacts and other infection control procedures used by the ship's medical department are reviewed.

Introduction

Military personnel living in close quarters constitute a population at particularly high risk for developing bacterial meningitis caused by Neisseria meningitidis. Although rare, it is a significant source of morbidity and death among young adults. A case of suspected meningococcal meningitis that occurred in May 2003 in a young, active duty male sailor aboard a deployed U.S. Navy ship, its management, and the strategies used by the ship's medical department to diagnose, treat, and contain the illness are described.

Case Report

While the aircraft carrier was in the mid-Atlantic Ocean returning from deployment, shipboard medical personnel were called to evaluate a 24-year-old male in his berthing area. He was found to have a blood pressure of 86/52 mm Hg and a pulse of 130 beats per minute and was transported immediately to the ship's medical department. He reported symptoms of a common cold for the previous 4 to 7 days and complained of headache and photophobia. His medical history was unremarkable. The patient had received the meningococcal vaccine during recruit training 3 years previously. Recent immunizations were the influenza vaccine and Vi capsular polysaccharide typhoid vaccine that were administered 26 days before admission. The only medication the patient had been taking long term was multivltamins. He had received acetaminophen, pseudoephedrine, guaifenesin, and anesthetic throat lozenges for his cold symptoms 4 days before admission. He denied taking dietary supplements and ibuprofen or other nonsteroidal anti-inflammatory drugs. He did not smoke. His temperature was 101�F, with physical examination findings notable for petechial rash (Figs. 1 and 2), meningismus, and positive Kernig's and Brudzinski's signs. A presumptive diagnosis of bacterial meningitis was made on the basis of these findings.

Intravenous fluid hydration with normal saline was initiated, with respiratory droplet isolation. Within 1 hour after the patient's initial presentation, ceftriaxone (2 g) was administered intravenously and a lumbar puncture was completed. C�r�brospinal fluid (CSF) analysis showed cloudy fluid with many neutrophils and no organisms with Gram stain. The white blood cell count was 28,500 cells//j,L. Intravenously administered vancomycin was added to the antibiotic regimen approximately 3 hours after presentation, because the Gram stain did not establish JV. memngitidis as the etiological agent. Twenty-four hours later, the patient was afebrile, with normal blood pressure. The CSF culture showed no growth after 24 hours. Intravenous administration of ceftriaxone and vancomycin was continued, and respiratory droplet isolation was discontinued. Forty-eight hours after presentation, the patient's meningismus had almost completely resolved and he remained afebrile. The CSF culture grew a possible colony, which was subplated; however, the Gram stain results were nondiagnostic. Three days after presentation, the patient was afebrile and ambulatory and had experienced complete resolution of his meningismus, and his antibiotic regimen was changed to a daily dose of penicillin G (24 million units). CSF showed no growth on the original culture plate or the subplate after 96 hours. Six days after presentation, the patient continued to be afebrile and asymptomatic. He completed a total 6-day course of antibiotics and was discharged from the ship's medical department after administration of a 500-mg dose of ciprofloxacin to eradicate possible meningococcal nasal colonization. All patient care was provided aboard ship.

After the ship returned to port, the original CSF sample was sent to a tertiary care hospital for additional studies. A repeat Gram stain analysis showed no organisms, and the culture showed no growth. Bacterial antigens, as determined with latex agglutination, were negative for JV. memngitidis, Haemophilus influenza type B, Streptococcus pnewnoniae, and Streptococcus agalactiae.