MELIOIDOSIS OUTBREAK IN BAKUN, SARAWAK

Several cases of melioidosis were detected in Bakun area, Belaga District, Sarawak, Malaysia. According to the Sarawak Environment and Public Health Minister Dato Sri Wong Soon Koh, until August 3, this year, 35 cases of melioidosis were recorded so far. Most cases are reported in the districts of Kapit (15) and Belaga (12). Last year, 17 deaths from this disease were reported, compared with five deaths this year. However, none of victims this year are locals from Bakun.

In most of the cases, the predisposing factor was related to working condition, which involved contact with soil. Bakun is classified as an endemic area for melioidosis that first occurred in 2006 when three foreign workers at the Bakun HEP died from this disease. In 2007 and 2008, two foreigners working there have suffered from the disease but fortunately they survived.

Melioidosis is an infectious disease caused by a Gram-negative bacterium, Burkholderia pseudomallei, found in soil and water. It is a recognized disease in animals, including cats, goats, sheep, and horses. Cattle, water buffalo, and crocodiles are considered to be relatively resistant to melioidosis despite their constant exposure to mud. Melioidosis is endemic in parts of southeast Asia (including Thailand, Laos and southern China, Singapore, Malaysia, Burma and Vietnam), Taiwan and northern Australia. There is a clear association with increased rainfall: with the number (and severity) of cases increasing following increased precipitation.

Person-to-person transmission is exceedingly unusual; and patients with melioidosis should not be considered contagious and be quarantined. In endemic areas, people (rice-paddy farmers in particular) are warned to avoid contact with soil, mud and surface water where possible. Case clusters have been described following flooding and cyclones and probably relate to exposure. Other case clusters have related to contamination of drinking water supplies. Populations at risk include patients with diabetes mellitus, chronic renal failure, chronic lung disease or patients with an immune deficiency of any kind. The effectiveness of measures to reduce exposure to the causative organism has not been established. A vaccine is not yet available. There has been interest in melioidosis because it has the potential to be developed as a biological weapon.

Melioidosis outbreak that confined only to Bakun areas may be considered related to HEP projects that are currently developed there. These projects involved extensive exposure by stripping off the soil and flooding the catchment area will mobilize the bacteria to the downstream areas coupled with some heavy downfalls. Increasing number (and severity) of cases ever since the Bakun HEP Project indicates some clear association with increased disturbance and exposure of the land surface by stripping of soil and flooding.

Perhaps there is a good basis that local people believe melioidosis outbreak in Bakun was curse of the angry spirits in the area and they should perform some form of offering ceremonies to appease the spirits of the graveyards and gods in the area. But Health Department confirmed that the fatalities were caused by melioidosis and leptospirosis. The locals believe the diseases were brought about by angry gods of the area and spirits of their ancestors. Rituals to appease the spirits of their ancestors had not been done and thus incurred their wrath. The fact is local people have been in contact with it ever since it was detected but they suffer no ill effects of it while the foreigners probably had not developed any kind of immunity to it.