[Epidemiology of melioidosis in China].

The research highlights the geographic distribution and incidence rates of melioidosis, a disease caused by the bacterium P. pseudomallei, in China from 1975 to 1989, with a special focus on the provinces of Qiong, Yue, Gui and Xiang. Additionally, the study discusses the potential public health risk posed by infected animals and misdiagnosed cases of melioidosis.

Distribution of P. pseudomallei

• The study identified a significant correlation between the geographic distribution of P. pseudomallei and the positivity rate of antibodies against the bacterium. The bacteria were found in water and tissue samples in 13 different counties and cities in China over a 14-year period, indicating its prevalence and survival in these diverse geographic locations.
• The strains of P. pseudomallei were predominantly found in the southern subtropical zone and the edge of the tropical zone, in the provinces of Qiong, Yue and Gui. This suggests that these climatic conditions may enhance the survival and spread of the bacterium.

Antibody Positivity Rates in Humans and Animals

• Antibodies against P. pseudomallei were detected at varying rates in different population groups. In humans, the positivity rate ranged between 3.8% and 15.2%, indicating a wide range of immune responses to P. pseudomallei exposure.
• In domestic animals such as horses, oxen and pigs, the positivity rates were 9.1%-18.4%, 6.6%-33.0% and 35% respectively. This suggests these animals may be reservoirs for the bacteria, potentially impacting the control and prevention of the disease.

Implications for Public Health and Animal Quarantine

• The study showed that horses and mules infected with P. pseudomallei could interfere with quarantine efforts, suggesting that these animals could inadvertently spread the bacterium.
• The public health could be put at risk if meat contaminated by the bacterium is consumed, highlighting the importance of strict food safety measures.

Case Studies and Misdiagnosis

• Three cases of melioidosis were reported in September and October of 1989 in Zhanjiang and Sanya of Hainan. Two patients ultimately died of acute melioidosis with septicemia, while the third had chronic leg ulcers.This implies that the severity of symptoms can vary amongst infected individuals.
• The research suggests that several cases of melioidosis might have been misdiagnosed or overlooked due to lack of awareness or diagnostic facilities, emphasizing the need for enhanced disease detection and reporting.