Melioidosis: A Widely-endemic Disease

What is Melioidosis?

Melioidosis is a highly contagious disease primarily infecting people in areas with agriculture and farming. Classified as a bioterrorism agent by the Centers for Disease Control and Prevention (CDC), Burkholderia pseudomallei, the bacteria that causes Melioidosis (or Whitmore's disease), was first discovered in 1911 by pathologist Alfred Whitmore and his assistant.

This "glanders-like" disease was first discovered in morphia addicts, according to a clinical review from the American Society for Microbiology. B. pseudomallei can infect both humans and animals, both agricultural animals as well as domesticated pets. These bacteria are found in soil and water, primarily in agriculturally rich areas. Humans contract this infection by skin inoculation, ingestion, or inhalation. Individuals can become infected with the bacterium primarily through direct contact with contaminated soil or water. Person to person transmission is rare.

Symptoms of Melioidosis

Melioidosis has a vast range of symptoms and may be mistaken for tuberculosis or pneumonia. There are four types of infections associated with melioidosis: localized infection, pulmonary infection, bloodstream infection and disseminated infection. The most common risks associated with melioidosis infection include diabetes, liver disease, renal disease, thalassemia, immunocompromising conditions such as cancer or HIV, and chronic lung disease.

Patients with pulmonary, bloodstream, or disseminated infection show symptoms consisting of headaches, chest pain, anorexia, joint pain, stomach or chest pain, seizures, weight loss, abdominal discomfort, respiratory distress, and disorientation. Symptom onset can range from one day after exposure, to many yeares. Most symptoms appear between two to four weeks after exposure. If caught early, the chance of survival is greater. Treatment options include medication, intravenous therapy, and oral antimicrobial therapy. Treatment begins with intravenous therapy for 10 to 14 days and then oral antimicrobial therapy for three to six months.

Melioidosis in Thailand

Although Melioidosis is endemic in Southeast Asia and northern Australia, additional cases have been frequently reported in northeastern Thailand, Singapore, and northern Australia according to the CDC. Cases are thought to frequently occur in Papua New Guinea, India, Southern China, Taiwan, and Vietnam among others, though under-reported in these regions.

According to data from a study published in The American Journal of Tropical Medicine and Hygiene, Melioidosis is the third most common cause of death relating to infectious disease in Thailand, coming up under HIV/AIDS and tuberculosis.

Over 1,000 people die of culture-confirmed Melioidosis on a yearly basis, and approximately 40% of the roughly 2,500 cases in Thailand die each year from this infection. The economic burden of this fatality on Thailand is at least $14.5 million annually, according to the Melioidosis information report.

Research conducted by the Mahidol Oxford Tropical Medicine Research Unit (MORU) in Bangkok suggests that the increase in incidences of Melioidosis among adults in northeastern Thailand exceeds that of malaria, diarrheal illnesses, and measles combined.

Melioidosis in US Marines

Infection with this disease was diagnosed in United States marines during the Vietnam war era. Out of 34 previously unexposed US marines, 13 had positive serology after two weeks in Thailand and one developed acute disseminated disease according to a study published in The American Journal of Tropical Medicine and Hygiene.

CDC Recommendations

The CDC recommends travelers going to melioidosis-endemic countries exercise caution and use protective equipment such as waterproof boots and gloves to shield from contaminated soil and water. Travelers are also advised to thoroughly clean skin or abrasions that have been exposed to soil or surface water.