Plaque reduction neutralization tests, using five group A arboviruses (chikungunya, Ross River, Getah, Bebaru and Sindbis), were done on sera from human populations in 44 Southeast Asia and Pacific island localities. Specificity of the plaque neutralization test was determined by examining convalescent sera from patients with known alphavirus infections. Chikungunya-specific neutralizing antibodies were demonstrated in sera of persons living in South Vietnam, Northern Malaysia, Indonesia (Kalimantan and Sulawesi), as well as Luzon, Marinduque, Cebu and Mindanao islands in the Philippines. Evidence of Ross River virus infection was found among populations living in West New Guinea and Papua New Guinea mainland, the Bismark Archipelago, Rossel Island and the Solomon Islands. There appeared to be no geographic overlap in the distribution of chikungunya and Ross River viruses, with the separation in their distribution corresponding with Weber's line in the Pacific. Sindbis neutralizing antibodies were found in 7 of 21 populations sampled, but in general the prevalence of infection was low. Four sera, from Vietnam, Malaysia and Mindanao gave monospecific reactions with Getah virus. No evidence of specific Bebaru virus infection was detected. The epidemiology of these five alphaviruses in Southeast Asia and the Pacific islands is discussed.
To determine if the unusually high incidence of salmonellosis reported on Guam for several years might be the result of more frequent bacteriologic examination of gastroenteritis/diarrhoea patient stool specimens, a survey of medical clinic and laboratory activities was undertaken among countries in the Pacific Basin Area. Survey results suggest that while Guam laboratories may be particularly proficient in isolating Salmonella organisms, the quantity of stool specimens examined could not account for the higher incidence of salmonellosis observed on the island.
Fertility differentials between rural and urban populations are investigated using World Fertility Survey data for Bangladesh, Fiji, Indonesia, Malaysia, Nepal, Pakistan, the Philippines, the Republic of Korea, Sri Lanka, and Thailand. "The fertility measure used in this analysis is the number of children ever born to a woman. An attempt is made first to establish the differential in fertility levels between urban and rural areas after necessary control of the demographic factors..., and then the possible explanation of the differential is sought in terms of socio-economic variables such as education of the respondent, and occupation, work pattern, work status and place of work of the respondent as well as that of the husband." Data concerning the fertility differentials and the associated explanatory variables are presented in tables and charts. "The results tend to show that the countries of Asia are undergoing similar patterns of fertility transition as was experienced in the advanced countries. Perhaps one can graduate the countries in the transition scale as follows: Bangladesh, Indonesia, Nepal, Pakistan and Malaysia are in the initial stage; Fiji, the Philippines, the Republic of Korea, Sri Lanka and Thailand are in the middle stage of transition."