Prevalence of Human Melioidosis on Hainan Island in China

Abstract

Melioidosis caused by Burkholderia pseudomallei is regarded as both a tropical and subtropical disease, and has received considerable attention in Southeast Asia and Northern Australia. During the last decade, reviewers' attention seems to have focused on Thailand, where melioidosis was once reported to be a major cause of community-acquired septicemia (2), and yearly case reports reached to more than 800 (8). Hainan Island, now an isolated province having the same latitude as Thailand, was bacteriologically and serologically confirmed to be an endemic area for the pathogen in 1981 (6). Animal melioidosis was first discovered in 1986 (12), however human cases failed to be identified till the first case was discovered in 1991 (7). Seeing the island so close and so similar in natural conditions to the epidemic countries around it, we conducted this study in an attempt to reveal the actual conditions of human melioidosis prevalence on this island.Ashdown medium (ASH) was prepared as previously described (10). Briefly, one liter of ASH contained 30 g nutrient agar, 40 ml glycerol, 5 ml selective solution (0.1% crystal violet and 1% neutral red, w/v), and distilled water to a final volume of 1,000 ml. The mixture was autoclaved at 121 C for 15 min. Before plates were made, gentamicin was added aseptically to a final concentration of 5 mg/liter.Clinical isolation of B. pseudomallei was conducted in Hainan People's Hospital, a provincial hospital with 1,200 beds, an annual 26,100 inpatients and 600,000 outpatients. The study lasted one year from October 1995 to October 1996. Specimens like swabs from wounds, skin lesions and abscesses were directly inoculated into ASH plate. Blood cultures were made in nutrient broth. B. pseudomallei was first suspected by its special morphology on ASH, and then identified by conventional methods. The isolates were confirmed by the Sceptor system (Becton Dickinson, U.S.A.), and antibiotic susceptibility tests were done simultaneously.Indirect hemagglutination (IHA) tests were done as previously described (11). The IHA tests were performed using V-bottomed microtiter plates. First, 0.05 ml of the sera to be tested was inactivated at 56 C for 30 min, and then absorbed with 0.45 ml of 10% unsensitized erythrocytes at room temperature for 3 hr. Doubled dilutions of the absorbed sera were made at 0.025 ml/well in 0.01 M PBS, pH 7.2, with a commencing dilution of 1:20. Then, 0.025 ml of 1% sensitized erythrocytes with 0.5% rabbit serum supplemented was added to each well, giving the starting well a dilution of 1:40; positive and negative controls were included in each plate.

Pediatric suppurative parotitis caused by Burkholderia pseudomallei

“…Although data are lacking with regard to the exact locations, eight human cases of melioidosis were registered around Hainan province [8]. In this study, we have described a case of B. pseudomallei suppurative parotitis in China.…”

Melioidosis: Epidemiology, Pathophysiology, and Management

“…On mainland China, B. pseudomallei has been isolated from 4.2% of soil and water specimens in Hainan Island and adjoining coastal provinces as far north as 25°N (500), as confirmed by human cases and seroprevalences (IHA titers of Ͼ1:40) of up to 34% in farmers in the region (499,501). In the seven isolates from culture-positive cases tested, a high rate of ceftazidime resistance (57%) was observed (501).…”

“…In the seven isolates from culture-positive cases tested, a high rate of ceftazidime resistance (57%) was observed (501).…”

Endemic Melioidosis in Southern China: Past and Present

“…Two patients with fatal septicaemic melioidosis, both local farmers, were reported in 1990 from Zhanjiang City in Guangdong, which is located at the southernmost peninsula of mainland China opposite Hainan island [11]. Subsequently, Song et al conducted a prospective survey looking for human cases at the largest provincial hospital on Hainan, Hainan People’s Hospital, in 1995 [12]. Within a one-year period, a total of eight culture-confirmed cases were identified, four of whom had acute septicaemia and the others chronic forms with abscesses in different organs.…”