Possible Typhoon-related Melioidosis Epidemic, Taiwan, 2005

Abstract

LETTERSsequencing. This infection rate is within the range (13.5%-90%) that has been reported for R. felis infecting Ctenocephalides fl eas in Brazil and Uruguay (2,3,7). Sixteen (72.7%) cats contained R. felis-reactive antibodies; 4 of them showed titers to R. felis at least 4-fold higher than those to the other 5 rickettsial strains, fi ndings that enabled us to technically conclude that these cats were exposed to R. felis or a closely related organism (1,7,9). Our fi nding of 70% R. felis infection in fl eas infesting the cats indicates that cats acquired the infection through infected fl eas. However, the mechanism of R. felis transmission by fl eas is yet to be demonstrated under experimental conditions.To our knowledge, the presence of R. felis, or a spotted fever group Rickettsia species, has not been reported in Chile. Recent investigations have provided clinical and serologic evidence of canine (10) and human (K. Abarca and J. Lopez, unpub. data) infection by spotted fever rickettsia in Chile, confi rmed by IFA that used R. conorii commercial antigen. Since substantial serologic cross-reaction occurs between R. conorii and R. felis antigens (1), R. felis could be causing infection in dogs or humans in Chile.

The Concentrations of Ambient Burkholderia Pseudomallei during Typhoon Season in Endemic Area of Melioidosis in Taiwan

“…We found that typhoon was positively correlated with ambient B. pseudomallei . This supports conclusions from previous studies that the case clusters were associated with sudden and heavy rainfall related to cyclones and typhoons [1], [4], [6], [10], [14]–[18], [22]. Wind speed was reversely correlated with ambient B. pseudomallei .…”

“…However, pneumonia was the most common clinical presentation, which accounted for 32.6%, 51%, 45%, 42.1% and 70% of cases in India [5], northern Australia [10], Thailand [1], Malaysia [15], and Taiwan [14], respectively. In addition, epidemiological studies hypothesized that inhalation of B. pseudomallei was the mode of transmission after heavy monsoonal rains and winds [5], [6], [10], [13], [17], [20]–[22]. In this study, we successfully quantified ambient B. pseudomallei using filtration/real-time qPCR.…”

“…From 2005 to 2011, the number of melioidosis cases in Kaohsiung accounted for 70.3% cases in Taiwan and there was a hotspot of both cases and deaths in the Zoynan Region [11], [16], [22]. We chose the second floor of the elderly activity center with a distance of 11.4 meters to the Lotus Pond in the Zoynan Region in Kaohsiung, southern Taiwan, as our sampling site.…”

“…Recently, epidemiological studies support inhalation as the mode of transmission of B. pseudomallei after heavy monsoonal rains and winds [5], [6], [10], [12]–[13], [17], [21]–[22]. Animal studies also show that exhaled B. pseudomallei aerosols lead to a lower lethal dose, 50% (LD 50 ) and a shorter incubation time compared to intraperitoneal and subcutaneous injection [23]–.…”

Distribution of Melioidosis Cases and Viable Burkholderia pseudomallei in Soil: Evidence for Emerging Melioidosis in Taiwan

“…These cases were categorized as being acquired during prior travels to areas of endemicity overseas rather than by indigenous acquisition, because the confirmed cases were rare and the pathogens were never isolated from the environment. However, the number of melioidosis cases suddenly increased in the Er-Ren River Basin in southern Taiwan after a typhoon followed by a flood in 2005 (8,9). B. pseudomallei was isolated from agricultural crop soil, and the prevalence of B. pseudomallei-specific antibodies increased significantly among residents after the typhoon and flood incident (9).…”