Transmission Modes of Melioidosis in Taiwan

Abstract

In Taiwan, melioidosis is an emerging disease that suddenly increased in the Er-Ren River Basin, beginning in 2005 and in the Zoynan region during 2008–2012, following a typhoon. Additionally, the disease sporadically increased in a geography-dependent manner in 2016. Subcutaneous inoculation, ingestion, and the inhalation of soil or water contaminated with Burkholderia pseudomallei are recognized as the transmission modes of melioidosis. The appearance of environmental B. pseudomallei positivity in northern, central and southern Taiwan is associated with disease prevalence (cases/population: 0.03/100,000 in the northern region, 0.29/100,000 in the central region and 1.98/100,000 in the southern region). However, melioidosis-clustered areas are confined to 5 to 7.5 km2 hot spots containing high-density populations, but B. pseudomallei-contaminated environments are located >5 km northwestern of the periphery of these hot spots. The observation that the concentration of B. pseudomallei-specific DNA in aerosols was positively correlated with the incidence of melioidosis and the appearance of a northwesterly wind in a hot spot indicated that airborne transmission had occurred in Taiwan. Moreover, the isolation rate in the superficial layers of a contaminated crop field in the northwest was correlated with PCR positivity in aerosols collected from the southeast over a two-year period. The genotype ST58 was identified by multilocus sequence typing in human and aerosol isolates. The genotype ST1001 has increased in prevalence but has been sporadically distributed elsewhere since 2016. These data indicate the transmission modes and environmental foci that support the dissemination of melioidosis are changing in Taiwan.

Burkholderia pseudomallei presenting with appendicular abscess: A great mimicker

“…3,4 Risk factors for infection are diabetes mellitus, heavy alcohol consumption, renal disease, chronic lung disease, thalassemia and immunocompromised patients on chemotherapy or prolonged corticosteroid used. 3,4 Risk factors for our patient were occupation as a farmer and diabetes mellitus. We believe that the most probable mode of transmission in our patient was hematogenous dissemination, which can be either from ingestion, inoculation or inhalation.…”

“…2 People working in the agricultural field, especially farmers, are at a higher risk of being infected, as the bacteria is commonly found on the surface of water and soil. 3,4 Risk factors for infection are diabetes mellitus, heavy alcohol consumption, renal disease, chronic lung disease, thalassemia and immunocompromised patients on chemotherapy or prolonged corticosteroid used. 3,4 Risk factors for our patient were occupation as a farmer and diabetes mellitus.…”

Melioidosis: A Neglected Cause of Community-Acquired Pneumonia

“…66 More recently in Taiwan, as mentioned above, the appearance of a northwesterly wind in a hot spot indicated that airborne transmission had occurred. 67 Exposure to soil or water, particularly during the monsoon season, has been well established to correlate with increased cases of melioidosis. 63 Although melioidosis is not contagious, with human-tohuman transmission rarely reported, 68,69 outbreaks have been linked to unchlorinated water supplies in Australia 70 and from drinking water in rural areas of south/southeast Asia.…”

Neurological melioidosis complicated by cerebral venous sinus thrombosis

“…Melioidosis is an infectious disease caused by a Gram-negative bacterium, Burkholderia pseudomallei, found in soil and water. 1 Three forms of infection have been documented; subclinical, acute and chronic. 2 Acute melioidosis is defined as an illness with symptoms lasting less than two months.…”