The epidemiological characteristics of HIV-1 infection in Africa have gradually been elucidated through various studies. The HIV-1 infection is believed to have existed in the 1960s in Africa and is presently epidemic in Africa. The HIV-I seropositive rate for the general population is higher in urban regions than in rural areas. The peak age of males infected with the HIV-1 tends to be higher than that of females infected with the HIV-1 Sex difference is recognized in the HIV-1 serpopositive rates. Heterosexual contact, mother-to-child transmission and contaminated blood transfusion are confirmed as the modes of HIV-1transmission. Prostitutes and STD patients are recognized as being high-risk groups for the HIV-1 infection. Where HIV-1 infection is widely distributed in the general population, risk reduction strategies should place strong emphasis on safe-sex techniques in addition to the promotion of partner reduction. J Epidemiol, 1995; 5 : 1-9.
The present study aims at showing the association of self-rated health with a long active life based on a 7-year longitudinal study of the community elderly. Baseline survey was carried out at home by interviewers in 1983. Ten hundred and twenty-four subjects who were independent in activity of daily living (ADL) at baseline, were followed-up in 1990. Those who were completely independent for every item of ADL at the follow-up were regarded as being in active life. Inactive life was defined as status changed into dependence in any item of ADL, admission to institution or deceased, at the follow-up. In 1990, 62.4% of men and 60.4% of women were defined to be in active life. Percentage with active life was the highest in the good self-rated health, followed by fair and poor in both sexes. A significantly direct relationship of the self-rated health to the active life was observed after controling for age, education, spouse, drinking, smoking, physician visits, history of stroke using a logistic model. The present study shows that self-rated health is a useful predictor of active life. J Epidemiol, 1995; 5 : 11-15.
The association of the severity of coronary atherosclerosis with hypertension and dyslipidemia, independent of other known coronary risk factors, was examined in 313 men and 155 women who underwent coronary angiography. The severity of coronary atherosclerosis was quantified using Gensini's scoring system. The following criteria were used to define dyslipidemia : hypercholesterolemia (total serum cholesterol concentration ≥220 mg/dl), hypertriglyceridemia (serum triglyceride concentration ≥150 mg/dl), and low HDL-cholesterolemia (serum HDL-cholesterol concentration<40 mg/dl). In men, age, total cholesterol, fasting blood sugar, uric acid, and plasma fibrinogen levels were significantly higher inpatients with coronary atherosclerosis than in those without. Significantly higher frequency of hypertension and lower levels of HDL-cholesterol were also found in male patients with coronary atherosclerosis. In women, age, total cholesterol, fasting blood sugar, and plasma fibrinogen levels were significantly higher in patients with coronary atherosclerosis than in those without. No significant interaction between hypertension and each dyslipidemia was found after adjustment for the other coronary risk factors ; only hypercholesterlemia in men was significantly associated with coronary atherosclerosis. However, the degree of coronary atherosclerosis was most severe among patients with both hypertension and hypercholesterolemia in both sexes. The combination of hypertension and hypercholesterolemia seems to be important in the progression of coronary atherosclerosis. J Epidemiol, 1995; 5 : 17-22.
To examine menopause-related changes in cardiovascular risk factors in women, we analyzed the data of a 1981-84 cross-sectional study of rural Japanese women aged 40-69 years and a 4. 3-year subsequent follow-up of premenopausal women. In the cross-sectional study, mean serum total cholesterol was higher in women aged 50 and over than in women aged 40-44 years. Women showed a significantly higher serum cholesterol level than men for aged 50 and over. For women aged 45-49, in which 50% of women turned into postmenopausal status, postmenopausal women showed a significantly higher cholesterol level than premenopausal women : 194 mg/dl vs. 183 mg/ dl, respectively (p<0.05). Blood pressure levels were lower in women than in men, but the sex difference was smaller for aged 50 and over. Mean body mass index and skinfold thickness were higher in women than in men. During the follow-up period, women showed a significant increase in mean serum total cholesterol (16 mg/dl) and subscapular skinfold thickness (2 mm) while men did not. Triceps skinfold thickness did not change in either sex. Blood pressure levels increased for both women and men in a similar magnitude. In conclusion, we found the increase in serum total cholesterol and the change in body fat distribution related with menopause in Japanese women. Whether these menopause-related risk factor changes would raise the risk of subsequent cardiovascular disease require further studies. J Epidemiol, 1995; 5 : 23-28.
To determine whether several factors affect the occurrence of ossification of the posterior longitudinal ligament of the spine (OPLL), we conducted a case-control study in Japan in 1988-90. Patients selected for the study were receiving financial aid for treatment of the disease ; the equal number of population-based controls matched by age and sex were selected. Age-adjusted odds ratios (ORs) and their 95% confidence intervals (Cls) were calculated using conditional logistic regression models. A medical history of hypertension increased the risk of OPLL (OR=1.58 ; 95% Cl, 1.01-2.46), and so did injury with hospitalization (OR=1.83 ; 95% CI, 1.14-2.93) and blood transfusion (OR=1.77 ; 95% Cl, 1.01-3.10). On the other hand, indoor working (OR=0.65 ; 95% Cl, 0.44-0.96) and a medical history of allergic rhinitis (OR=0.35 ; 95% Cl, 0.15-0.84) decreased the risk. After adjustment for these factors each other, similar trends still existed. J Epidemiol, 1995; 5 : 29-33.
We predicted the cost-effectiveness of undertaking human immunodeficiency virus screening programs in Japan. Effectiveness of antiviral drug, zidovudine as prophylactic treatment for asymptomatic HIV infected persons brought the concept of widespread screening programs. The cost-effectiveness of two strategies : 1) screening and prophylactic treatment for asymptomatic HIV positive person whose T4 cells fall below 500/cubic millimeter and 2) no screening, were compared in different groups of populations (blood donors, homosexuals, and Thai females). The key data such as the life years gained by prophylactic treatment, the prevalence of HIV among different groups, the initial T4 cell count, the time to develop AIDS, and the efficacy of aerosolized pentamidine were obtained from published literatures. The costs were estimated according to the cost book of health care published by Ministry of Health and Welfare of Japan. In the population with prevalence of 1-4%, which includes homosexuals of Tokyo and Thai females, the incremental cost-effectiveness ratio is US 12, 836-13, 333 per life year gained. In the population with very low prevalence such as average blood donors, the incremental cost-effectiveness ratio rises to $1, 444, 092 per life year gained. Comparing with other medical intervention it is found that the HIV screening program for the population with prevalence over 0.1% is cost-effective. Sensitivity analyses which alter each of the variables in the analysis indicate that if the effectiveness of zidovudine is 50% and 25% of the published rate, then the program remains cost-effective at the prevalence rate of 0.5% and 3% respectively. J Epidemiol, 1995; 5 : 35-41.
Tuberculosis (TB) is a major public health problem in developing countries. BCG vaccination is a preventive intervention and part of a Universal Childhood Immunization Programme in India. Doubts have been raised regarding the efficacy of the BCG vaccines, and studies around the world have reported an efficacy ranging from 0% to 90%. We have carried out a case-control study to estimate the ageand site-specific protective effect of BCG against childhood TB in Pondicherry, South India. One-hundred cases of TB in children were identified from paediatric inpatient and outpatient departments. Four ageand sex-matched hospital controls were selected randomly from the Department of Paediatrics, the Paediatric Surgery and the Trauma Department. The BCG vaccination status was ascertained by BCG scar and from the children's clinic cards. For children up to five years of age, the protective effect of BCG was higher against TB meningitis (97%, 95% Cl 78%, 99%) than against pulmonary TB (64% CI 20%, 80%). The protective effect was lower against both types of TB in children aged five years and older. We conclude that BCG provides a high degree of protection against both TB meningitis and pulmonary TB in children up to the age of five years. J Epidemiol, 1995; 5 : 43-48.