Comments
INITIAL SYMPTOMS:
Pneumonia (from mild to fulminant septic shock); Chronic lung infection (mimicking tuberculosis); Skin ulcers & abscesses; Suppurative parotitis in children in Thailand; [PPID] Acute to chronic & localized to disseminated infections; [Guerrant]
EPIDEMIOLOGY:
Infection occurs through contact with contaminated water or soil through breaks in the skin, inhalation, or ingestion. Rice farmers in Thailand are at risk for this disease. Some chronic diseases (diabetes, cirrhosis, alcoholism, renal failure, COPD, thalassemia, malignancy) increase the risk of contracting the disease. The mortality rate ranges from 15 to 40%. Horses are the primary reservoir; also sheep, goats, swine, monkeys and rodents; [CCDM, p. 397-400] Risk factors include diabetes, alcoholism, chronic renal disease, COPD, thalassemia, and malignancy. [CDC Travel, p. 260]
FINDINGS
These saprophytic bacteria may infect humans and other animals. About 50% of patients present with acute pneumonia. Some patients develop rapidly fatal septicemia. The disease may be confused with typhoid fever or tuberculosis. Findings may include pulmonary cavitation, empyema, chronic abscesses, and osteomyelitis. In 5% of cases in northern Australia, patients have meningoencephalitis with paralysis and weakness. [CCDM, p. 397-8] A petechial or purpuric rash may occur. Jaundice may occur in septicemic melioidosis. Leukopenia, lack of fever, azotemia, and abnormal liver function tests are poor prognostic indicators. Empyema and purulent pericarditis are complications. [Guerrant, p. 220, 956]
The disease may present as sepsis and "overwhelming necrotizing pneumonia." Other findings may include pleuritic chest pain, normal or elevated WBC count, arthritis, meningitis, septic shock, abdominal pain, diarrhea, pharyngitis, skin pustules, lymphadenitis, cyanosis, myalgias, and abnormal liver function tests. Chest x-ray findings may include pleural effusions, nodular infiltrates, cavitation, and consolidation. [Merck Manual, p. 1254] Liver and spleen abscesses are common in patients with septicemic melioidosis. Unlike TB, hilar adenopathy is not usually found in pulmonary infections caused by B. pseudomallei. Acute suppurative parotitis caused by B. pseudomallei occurs in about 1/3 of pediatric cases of melioidosis in Thailand. [Guerrant, p. 220-1] Presentations of 363 cases in Northern Australia were pneumonia (81), genitourinary (21), skin abscesses (45), soft tissue abscesses (11), neurologic (12), and osteomyelitis/septic arthritis (5). Mortality was 5% in pneumonia cases and 25% in neurologic cases. Genitourinary diseases include prostate abscesses and orchitis. Neurologic diseases include encephalomyelitis, cranial nerve palsies, brain abscesses, motor weakness, and paralysis. 12% of patients presented with chronic symptoms similar to tuberculosis (fever, weight loss, and productive cough). [PPID, p. 2544-8] 1/4 of Thai patients have urinary symptoms including hematuria. [Cohen, p. 1214] Chronic pulmonary disease may mimic tuberculosis. Regional lymphadenopathy may accompany skin lesions. [Harrison ID, p. 564]
For updated text and symptoms of infectious diseases, see iddx.com.