Chemoprophylaxis and the epidemiological characteristics of re-emergent P. vivax malaria in the Republic of Korea.

OBJECTIVE: In the Republic of Korea (ROK), soldiers stationed where there is a risk of contracting malaria have received antimalarial chemoprophylaxis since 1997. However, chemoprophylaxis may facilitate the development of drug resistance, and late primary attacks in individuals who have received chemoprophylaxis are becoming more frequent. We investigated the association between chemoprophylaxis and the epidemiological characteristics and effectiveness of treatment for re-emergent Plasmodium vivax malaria, using a nationwide malaria database. METHODS: Among soldiers at risk of malaria between 1999 and 2001, we reviewed all P. vivax malaria cases (1158) that occurred before 31 December 2003. Early and late primary attacks were defined as cases occurring 2 months after the last day of exposure to risk of malaria, respectively. FINDINGS: Of these cases, 634 (72.0%) had received chemoprophylaxis, and 324 (28.0%) had not. Cases occurred mostly in summer, with a peak in July-August. Stratification by chemoprophylaxis history revealed different times to onset. Early primary attacks were more prevalent in the group not receiving chemoprophylaxis, while in the group receiving chemoprophylaxis most cases were late primary attacks. Of the latter, 312 out of 461 (67.7%) did not take primaquine regularly. After treatment of the first attack, 14 (1.2%) of 1158 were re-treated; all re-treated cases were cured using the same doses and regimen used for the first treatment. CONCLUSION: In ROK, the increase in late primary episodes of re-emergent P. vivax malaria is associated with the use of antimalarial chemoprophylaxis.

Hypertension and stroke in Asia: prevalence, control and strategies in developing countries for prevention.

Reliable statistics related to the prevalence, incidence and mortality of hypertension and stroke are not available from Asia. The data may be in national or institutional reports or journals published in the local language only. The mortality rate for stroke has been on the decline since the mid 1960s in the developed countries of Asia, such as Australia, New Zealand, and Japan, with some improvement in Singapore, Taiwan and Hong Kong, some areas of China and Malaysia about 15 years later. In India, China, Philippines, Thailand, Sri Lanka, Iran, Pakistan, Nepal, there has been a rapid increase in stroke mortality and prevalence of hypertension. The prevalence of hypertension according to new criteria (>140/90 mm Hg) varies between 15-35% in urban adult populations of Asia. In rural populations, the prevalence is two to three times lower than in urban subjects. Hypertension and stroke occur at a relatively younger age in Asians and the risk of hypertension increases at lower levels of body mass index of 23-25 kg/m2. Overweight, sedentary behaviour, alcohol, higher social class, salt intake, diabetes mellitus and smoking are risk factors for hypertension in most of the countries of Asia. In Australia, New Zealand and Japan, lower social class is a risk factor for hypertension and stroke. Population-based long-term follow-up studies are urgently needed to demonstrate the association of risk factors with hypertension in Asia. However prevention programmes should be started based on cross-sectional surveys and case studies without waiting for the cohort studies.

Relationship of change in body mass to blood pressure among children in Korea and black and white children in the United States.

Body mass is a major factor in determining blood pressure levels in children. We compared associations of body mass with blood pressure in 121 white and 91 black children in Bogalusa, Louisiana with that of 370 children in Kangwha, Korea. All children were seven years old at entry into the study and were followed for three years. Korean children were shorter (p < 0.001) thinner (p <0.0001), and had a lower body mass index (p < 0.01) than white or black children. At age seven, systolic blood pressure levels were 2 approximately 5 mm Hg lower, but at age 10, they were 2 approximately 5 mm Hg higher in Korean than white or black children. The increases in blood pressure levels from age seven to ten years were much greater in Korean than black or white children, while changes in height, weight, and body mass index were generally less. Change in blood pressure level was positively associated with change in body mass index for systolic (but not diastolic) levels; however, the association was no stronger for Korean than for U.S. children, except for Korean males vs Bogalusa black males. Cross-cultural studies of other factors, such as diet and physical activity, may explain these differences.