Clinical Features

Both glanders and melioidosis may occur in an acute localized form, as an acute pulmonary infection, or as an acute rapidly fatal, bacterial infection. Combinations of these syndromes may occur in human cases.

Melioidosis may remain asymptomatic after initial acquisition, and remain latent for decades. Patients may appear with active melioidosis years later, often associated with an immune-compromising state.

Aerosol infection produced by a bioterrorism weapon containing either B. mallei or B. pseudomallei could produce any of these syndromes. The incubation period ranges from 10-14 days, depending on the inhaled dose and agent virulence.

The bacterial infection form begins suddenly with fever, rigors, sweats, muscle aches, chest pain, chronic inflammatory lesion, generalized reddening of the skin, jaundice, sensitivity to light, tearing, and diarrhea.

Physical examination may reveal fever, rapid heartbeat (100 or more beats per minute), glandular disease and mild enlarged liver or spleen. Blood cultures are usually negative until the patient is dying. A mild elevation of the white blood count with a shift to an abnormal decrease in the number of white blood cells can occur. The pulmonary form may follow inhalation or contact with infected blood. Chest radiographs may show small lesions and/or a bilateral bronchopneumonia, lobar pneumonia, lung lesions.

Both glanders and melioidosis can cause an acute infection of the nose, throat, and/or eyes. This is indicated by blood streaked mucus discharge from the nose, and nasal ulcerations. If systemic infection occurs from mucous membrane or skin lesions then a pustular rash may occur that can be mistaken for smallpox (another possible bioterrorism agent). Evidence of infection includes the presence of skin pustules; abscesses of internal organs, such as liver and spleen; and multiple pulmonary lesions. These forms of glanders and melioidosis carries a high mortality rate, and most patients develop rapidly progressive septic shock.

The chronic form, characterized by skin and intramuscular abscesses on the legs and arms, is unlikely to be present within 14 days after a bioterrorism aerosol attack. These lesions are associated with enlargement and hardening of the regional lymph channels and nodes. The chronic form may be asymptomatic, especially with melioidosis. There have been cases associated with the development of bone inflammation, brain abscess, and meningitis.

Diagnosis

The occurrence of glanders and melioidosisin the absence of animal contact and/or in an epidemic is presumptive evidence of a bioterrorism attack. Mortality will be high despite antibiotic use.

Medical Management

Standard Precautions should be used to prevent person-to-person transmission in proven or suspected cases. The recommended therapy will vary with the type and severity of the clinical presentation.

The following oral regimens have been suggested for localized disease:

• Amoxicillin/clavulanate 60 mg/kg/day in three divided doses;
• Tetracycline 40 mg/kg/day in three divided doses;
• Trimethoprim/sulfa (TMP 4 mg/kg/day-sulfa 20 mg/kg/day) in two divided doses;
• The duration of treatment should be for 60 - 150 days.

If the patient has localized disease with signs of mild toxicity, then a combination of two of the oral regimens is recommended for a duration of 30 days, followed by monotherapy with either amoxicillin / clavulanate or TMP / sulfa for 60 - 150 days. If extrapulmonary suppurative disease is present, then therapy should continue for 6-12 months. Surgical drainage of abscesses may be required.

For severe disease, preventative therapy with Ceftazidime 120 mg/kg/day in three divided doses combined with TMP/sulfa (TMP 8 mg/kg/day - sulfa 40 mg/kg/day) in four divided doses for 2 weeks, followed by oral therapy for 6 months.

Other antibiotics that have been effective in experimental infection in hamsters include doxycycline, rifampin, and ciprofloxacin. The limited number of infections in humans has precluded therapeutic evaluation of most of the antibiotic agents; therefore, most antibiotic sensitivities are based on animal and in vitro studies. Various isolates have markedly different antibiotic sensitivities; therefore, each isolate should be tested for its own resistance pattern.

Preventative Measures

None