The racial cohort phenomenon: seroepidemiology of Helicobacter pylori infection in a multiracial South-East Asian country

Background Malaysia is a multiracial country where three major Asian races live together: Malay, Chinese and Indian. In addition, there are a number o f native or indigenous races, particularly in East Malaysia. Differences in prevalence of gastric diseases between races have been noted, particularly with respect to peptic ulcer disease and gastric cancer. The aim of this s tudy is to determine the prevalence rates and risk factors for Helicobacter pylori infection among various races in Malaysia. Methods A large-scale prospective seroepidemiological study in West and Eas t Malaysia using the HEL-p II commercial enzyme-linked immunosorbent assay kit (AMRAD, Melbourne, Australia) to detect H. pylori antibodies. Populatio ns surveyed in West Malaysia were a rural community from Kuala Pilah, and b lood donors from Kuala Lumpur and Kota Baru. Subjects studied in East Malay sia were volunteer blood donors from Kota Kinabalu, and blood donors and he althy volunteers from Sibu. Statistical analyses using multiple logistic re gression analysis were carried out to identify independent risk factors for H. pylori infection. Results A total of 2381 subjects were evaluated, H. pylori prevalence varie d from different areas of study and ranged from a low of 26.4% in blood don ors from Kota Elaru to a high of 55.0% in Kota Kinabalu. The most striking differences, however, were noted in the prevalence rates among different ra cial groups. Prevalence rates among the Malays ranged from 11.9 to 29.2%, w hile the Chinese ranged from 26.7 to 57.5%, and those of Indians in two stu dies were 49.4 and 52.3%. In every location, Malays had a significantly low er prevalence compared with the other races. The highest prevalence rates w ere recorded among the indigenous races in Kota Kinabalu, East Malaysia. Th ere was no difference between males and females in the studies. An increasi ng trend with age was noted in the majority of studies; however, no increas e in prevalence rates was noted among the Malays. Conclusions The pattern of infection in a multiracial population in Malaysi a points to a 'racial cohort' phenomenon. The infection appears to be confi ned to a racial group, with the Malays having consistently low prevalence r ates. This observation may provide clues to the mode of transmission of inf ection. Eur J Gastroenterol Hepatol 13:177-183 (C) 2001 Lippincott Williams & Wilkins.