Incidence of sexually transmitted diseases among massage parlour employees in Bangkok, Thailand.

The results of a study of sexually transmitted disease (STD) incidence and related risk factors for STDs among uninfected women at high risk of contracting STD infection in Bangkok are reported. Comprising the control arm of a randomized controlled trial of a vaginal contraceptive sponge and STD incidence, 163 women aged 18 or older were recruited from 4 massage parlours and followed for evidence of new infections over a 6-week period or until cervical infection occurred. Gynaecological examinations were performed and endocervical specimens were obtained at weekly intervals, at which time women returned coital logs recording their number of sexual partners. There were 76.5 new STD infections per 100 woman-months, including 31.7 with gonorrhoea, 43.1 with chlamydia, 1.8 of trichomoniasis and 3.5 of candidiasis. None of the risk factors examined were good predictors of STD infection in this population, which may be related to the restricted admission criteria in the study.

Effects of paternal occupational exposure on spontaneous abortions.

BACKGROUND: Paternal exposure to mutagenic agents has been suggested to affect pregnancy outcome adversely. METHODS: A nationwide data base of medically diagnosed spontaneous abortions and other pregnancies and national census data was used to evaluate the effects of men's occupational exposures on risk of spontaneous abortion in 99,186 pregnancies in Finland. Census data from the years 1975 and 1980 provided information about the occupation, industry, and socioeconomic status. A job-exposure classification was developed to classify women and their husbands according to possible occupational exposures on the basis of their occupational title and industry. RESULTS: In 10% of the pregnancies, the husband was exposed to one or more of the mutagens, and the rate of spontaneous abortion was unaffected (OR = 1.0). Of the 25 specific mutagenic exposures evaluated, paternal exposure to four (ethylene oxide, rubber chemicals, solvents used in refineries, and solvents used in the manufacturing of rubber products) was associated with an increased relative risk of spontaneous abortion. In addition, the risk of spontaneous abortion was higher among wives of rubber products workers than among unexposed men. CONCLUSIONS: Although there is some biological rationale for the findings of this study, these findings need to be confirmed by studies in which individual exposures can be measured directly.

Do the benefits of breastfeeding outweigh the risk of postnatal transmission of HIV via breastmilk?

Conflicting recommendations have been offered about whether HIV+ mothers should breastfeed. Since there is a strong precedent for US infant feeding practices to be imitated in developing countries, a model was constructed to estimate infant mortality if the CDC admonition for HIV+ mothers not to breastfeed were upheld in less developed settings. Estimates are given for infant mortality in the presence and absence of breastfeeding across several baseline levels of infant mortality and across several theoretical rates of transmission through breastfeeding. The infant mortality associated with HIV infection acquired through breastfeeding is estimated to be lower than the mortality associated with the diseases of infancy that would result if breastmilk were withheld. The difference in these estimates is greater in areas with high baseline levels of infant mortality.

PIP: Conflicting advice is available on breast feeding for HIV-positive mothers to developing countries. WHO recommends that mothers regardless of HIV status should continue breast feeding where alternatives are not safe. In the US, CDC advises against breast feeding for HTLV-III/LAV-infected women to avoid transmission to an as yet unaffected newborn. The British have a similar recommendation. Industrialized countries tend to set the standard for developing countries, even though CDC has not directed its policy to developing countries. This study examined the effects of breast feeding by HIV-infected mothers on infant/child mortality compared with bottle feeding. Countries are selected with varying levels of infant mortality (5%, 10%, and 15%). The risk of infection/100,000 uninfected infants is hypothetically modeled. Calculations are made 1) for the number of expected deaths among breast-fed infants due to HIV-related infections from breast milk and to other diseases, and the number of deaths for other diseases is uninfected babies; 2) expected deaths among bottle-fed infants; and 3) total deaths for all babies. It is assume that HIV transmission through breast milk is 20%, that 95% of HIV-infected babies will die before 1 year, and that there are 4 relative risks of death (3 the lowest; 4; 5; and 6 the highest risk) due to diseases of childhood for bottle-fed babies. The confirmed expectation was that reduction in breast feeding will contribute to greater infant mortality. Breast feeding as a method of HIV transmission is still open to question, particularly when mothers are asymptomatic seropositive. The results show that in countries with a 10% infant mortality rate, and the lowest relative risk of 3, 30,000/100,000 uninfected bottle-fed babies are expected to die, however, if breast fed by HIV-infected mothers with a 5% transmission rate, mortality would be 14,000/100,000. Only at a 20% infant mortality rate do expected HIV deaths among breast-fed babies approach the breast-fed babies approach the rate for bottle-fed babies. The likely transmission rate is 1% or 11,000 deaths. Breast milk transmission rates of 1% would yield rate is 1% or 11,000 deaths. Breast milk transmission rates of 1% would yield an estimated 950 additional infant deaths, at 5% 4750, at 10% 9500, and 20% 19,000. These numbers contrast with a 10% infant mortality among bottle-fed babies and 20,000 deaths.

Cervical cancer risk and use of depot-medroxyprogesterone acetate in Costa Rica.

The relationship between cervical cancer and the use of depot-medroxyprogesterone acetate (DMPA) was examined in a nationwide case-control study in Costa Rica. Cases were women ages 25-58 years of age with invasive squamous cell cancer (N = 149) or carcinoma in situ (CIS, N = 415) reported by the National Tumor Registry during 1982-84. Controls (N = 764) were randomly selected during a nationwide household survey. Using logistic regression, we adjusted for known risk factors for cervical cancer. DMPA use was associated with a risk of CIS of 1.1 (95% confidence interval 0.6-1.8) and a risk of invasive cancer of 1.4 (95% confidence interval 0.6-3.1). The slightly elevated risks observed may be the result of chance or a detection bias. One limitation of this study is that few women had used DMPA for longer than two years.

PIP: A nationwide case-control study was conducted in Costa Rica in 1984-85 to examine the association between depot-medroxyprogesterone acetate (DMPA) and cervical cancer. Cases, restricted to women 25-58 years of age at the time of diagnosis, were women with invasive squamous cell cancer (n = 149) or carcinoma in situ (CIS, n=415) reported by the National Tumor Registry during 1982-84. The 764 controls were randomly selected during a nationwide household survey. On average, the CIS cases were younger than controls; the invasive cases were older than controls. Both case groups were more likely than controls to be of low socioeconomic status, to have become sexually active at a young age, to report a history of a sexually transmitted disease or pelvic inflammatory disease, and to report having 3 or more partners in their lifetime. Ever users of DMPA had a risk of CIS of 1.1 when compared with never users. Women who 1st used DMPA before age 30 had a CIS risk of 0.6 whereas users who began use after age 39 had a risk of 2.0. Both of these risk estimates were based on small numbers of users. Ever users of DMPA had a risk of invasive cancer of 1.4 when compared with never users, but all estimates for invasive cancer were based on only 10 cases who reported use of DMPA. Few of the women had used DMPA for longer than 2 years.

Oral contraceptives and cervical cancer risk in Costa Rica. Detection bias or causal association?

To examine the relationship between cervical cancer and oral contraceptive (OC) use, we analyzed data from a population-based, case-control study in Costa Rica. Women aged 25 to 58 years in whom cervical cancer was diagnosed and reported to the National Tumor Registry were examined as two separate case groups: invasive cervical cancer and carcinoma in situ (CIS). Controls were women aged 25 to 58 years identified through a national survey. Women who had used OCs had no increased risk of invasive cervical cancer compared with women who had never used OCs (relative risk, 0.8; 95% confidence interval, 0.5 to 1.3). Women who had used OCs had an increased risk of CIS compared with those who had never used OCs (relative risk, 1.6; 95% confidence interval, 1.2 to 2.2). However, further analyses indicated that this increased risk was confined to those who had recently used OCs. Also, the risk of CIS was not elevated in subgroups in which a history of cervical smears was not strongly linked to OC use. The elevated risk of CIS among OC users may therefore reflect a bias caused by enhanced detection of disease rather than a causal association.