Serological tests
Serological tests such as indirect haemagglutination assay (IHA) have been used to detect the presence of antibodies against B. pseudomallei. However, different groups of people have widely different levels of antibodies, so interpretation of these tests depends on location. In Australia, less than 5% of people have B. pseudomallei antibodies, so the presence of even relatively low amounts of antibody is unusual and could suggest melioidosis. In Thailand, many people have antibodies against B. pseudomallei so the diagnosis of melioidosis should not be reliant entirely on the serological tests done in endemic areas. Indirect immunofluorescent test (IFAT) uses either B. pseudomallei or B. thailandensis antigens to look for the total number of antibodies in human serum. Using IFAT is labour intensive and is not used in large scale investigations.Antigen detect tests allow rapid detection of melioidosis. Examples of antigen detection tests are: latex agglutination test and ELISA. Latex agglutination uses antibodies coated on latex beads to detect B. pseudomallei antigens in solid or liquid media, although not all the assays can detect different species of Burkholderia. Latex agglutination is useful in screening for suspected B. pseudomallei colonies. IgG and IgM ELISAs has been used to detect lipopolysaccharide (LPS) antigens of B. pseudomallei, but plagued with low sensitivity. Commercial ELISA kits for melioidosis no longer available in the market due to low sensitivity to human antibodies detection. Nevertheless, antigen detection tests may be useful in severely ill patients because the bacterial load is high enough for detection.
Melioidosis is an infectious disease caused by a gram-negative bacterium called Burkholderia pseudomallei. Most people exposed to B. pseudomallei experience no symptoms; however, those who do experience symptoms have signs and symptoms that range from mild such as fever and skin changes, to severe with pneumonia, abscesses, and septic shock that could cause death. Approximately 10% of people with melioidosis develop symptoms that last longer than two months, termed "chronic melioidosis".Humans are infected with B. pseudomallei by contact with contaminated soil or water. The bacteria enter the body through wounds, inhalation, or ingestion. Person-to-person or animal-to-human transmission is extremely rare. The infection is constantly present in Southeast Asia particularly in northeast Thailand and northern Australia. In temperate countries such as Europe and the United States, melioidosis cases are usually imported from countries where melioidosis is endemic. The signs and symptoms of melioidosis resemble tuberculosis and misdiagnosis is common. Diagnosis is usually confirmed by the growth of B. pseudomallei from an infected persons blood or other bodily fluid such as pus, sputum, and urine. Those with melioidosis are treated first with an "intensive phase" course of intravenous antibiotics (most commonly ceftazidime) followed by a several-months treatment course of co-trimoxazole. In countries with the advanced healthcare system, approximately 10% of people with melioidosis die from the disease. In less developed countries, the death rate could reach 40%.Efforts to prevent melioidosis include: wearing protective gear while handling contaminated water or soil, practising hand hygiene, drinking boiled water, and avoiding direct contact with soil, water, or heavy rain.