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CD4 T cell counts appear to decline much more rapidly among HIV-infected female prostitutes in Kenya than in other HIV-infected women. The median time to AIDS in these prostitutes is less than five years, compared to 10 years in other groups studied. Researchers used a Markov model to study the transition between different stages of CD4 T cell levels in 485 HIV-infected Nairobi prostitutes and 231 infected mothers. The mothers were more likely to move backward to a stage of higher T cell levels than the prostitutes. It took an estimated 37.4 months for the prostitutes to reach T cell counts of 200 or less, compared to 89.5 months in the mothers. Prostitutes may become infected with several strains of HIV or they may contract other sexually transmitted diseases that cause their HIV infection to progress more rapidly.

Counseling programs that encourage patients with sexually transmitted diseases (STDs) to notify their sexual partners may be effective in controlling the spread of STDs in the developing world. Limited transportation and communication services, fear, and cultural barriers restrict STD patients and clinic staff in notifying STD partners in developing nations. Researchers gave 5-10 minutes of additional counseling to 254 STD patients in a developing country. The researchers counseled them on the importance of informing their sexual partners about their condition and encouraging their partners to seek treatment. The researchers asked these patients to return one week later for follow-up. Only 100 patients returned. Sixty-eight percent of these patients claimed to have informed their partners and 58% claimed that their partners received treatment. Without the additional counseling, only 15% of STD partners received treatment. Married patients and women attending family clinics were most likely to inform their potentially infected partners.

New mothers in developing countries who are HIV-positive should breastfeed their infants no longer than seven months. There is evidence that HIV can be transmitted in breast milk and many new mothers in developing countries do not have access to nutritional substitutes. Researchers used a mathematical model to compare the risk of an infant dying from lack of proper nutrition to its risk of contracting HIV from breast milk. Breast milk is crucial during the first few months, but over a period of time its benefits decline. However, the risk of contracting HIV is constant throughout the breastfeeding period. The model showed that the benefits of breastfeeding outweigh the risk of contracting HIV only during the first three to seven months. Many women continue breastfeeding for a year or more. Additional research may determine approximately when viral transmission occurs during breastfeeding.

Background and Objectives: The basic reproductive rate of an STD is an important parameter from which the success of intervention strategies can be predicted. Goal of the Study: To evaluate different methods to estimate the basic reproductive rate. Results: Two different methods of estimating the basic reproductive rates of Neisseria gonorrhoeae and Chlamydia trachomatis yielded discrepant results. One of the methods, which is based on the assumption of the absence of acquired immunity, yielded unrealistically low estimates of the basic reproductive rates. Conclusion: In conjunction with other epidemiologic evidence, we infer that some form of acquired immunity to these pathogens must exist and discuss its implication for control., One method of estimating the reproductive rate of a sexually transmitted disease provided results more consistent with data than the other. Both mathematical formulas were applied to data from Nairobi, Kenya on the sexual behavior of patients with gonorrhea and chlamydia. The assumptions of the first formula suggested that the rate of spread would be slow enough to possibly extinguish itself without intervention, a result known to be contrary to the case. The alternate formula assumed that groups at high risk for reinfection, such as prostitutes, would develop immunity to individual strains of a sexually transmitted disease. This assumption produced results more consistent with data on the spread of these diseases.

Background and Objectives: Chancroid is endemic in sub-Saharan Africa and enhances the sexual transmission of the human immunodeficiency virus Type 1 (HIV-1). Azithromycin is an orally absorbed macrolide antibiotic that is active against Haemophilus ducreyi, the causative agent of chancroid, and has pharmacokinetic properties that are suitable for single dosing. Study Design: In a randomized single-blinded study of 127 men presenting to a referral STD clinic with culture proven chancroid, we compared the efficacy of azithromycin, administered as a single 1 g dose, with erythromycin 500 mg given 4 times daily for 7 days. Results: Cure rates were 89% (73 of 82) in the azithromycin group and 91% (41 of 45) in the erythromycin group. A failure to respond to treatment was associated with HIV-1 seropositivity and a lack of circumcision. Both regimens were well tolerated. Conclusions: Azithromycin, given as a single 1 g oral dose, is an effective treatment for chancroid in men, and offers major prescribing advantages over erythromycin., A single oral dose of azithromycin may be as effective as a seven-day course of erythromycin in curing chancroid. Chancroid is an ulcerative veneral disease that is endemic in sub-Saharan Africa. In a Nairobi clinic, 127 men with chancroid were randomly assigned to one treatment regimen or the other. Eighty-nine percent of those given azithromycin were cured compared with 91% of those given erythromycin. Lack of cure was associated with HIV-1 infection. The single-dose oral azithromycin treatment offers advantages in ease of administration and ensuring compliance. Reduction in ulcerative veneral disease is a major strategy in attempts to reduce HIV infection in Africa.

Background and Objectives: Whether male circumcision reduces the risk of acquiring human immunodeficiency virus (HIV) infection remains controversial. Study Design: As there have now been a number of studies conducted that have examined this issue, we undertook to review their findings. Thirty epidemiological studies identified in the literature that investigated the association between male circumcision status and risk for HIV infection were reviewed. Results: Eighteen cross-sectional studies from six countries reported a statistically significant association, four studies from four countries found a trend toward an association. Four studies from two countries found no association. Two prospective studies reported significant associations, as did two ecological studies. In studies in which significant associations were demonstrated, measures of increased risk ranged from 1.5 to 8.4. The groups in which positive associations were found included sexually transmitted disease (STD) clinic and hospital patients, outpatient clinic and HIV screening clinic attenders, long-distance truck drivers, and general community members. Conclusion: Potential sources of error, assessment of causality, implications of the findings, and future research needs are discussed. Because a substantial body of evidence links noncircumcision in men with risk for HIV infection, consideration should be given to male circumcision as an intervention to reduce HIV transmission., Most epidemiologic studies find an association between a lack of male circumcision and an increased risk of HIV infection. Only 4 of 26 cross-sectional studies reviewed failed to find this association. In addition, two prospective studies and two ecological studies found an association between being uncircumcised and being at a higher risk for HIV infection. . The increase in risk ranged from 1.5 to 8.4. Twenty-five studies took place in Africa, four in the U.S., and one in Mexico. Possible explanations for the association are that with poor hygiene, uncircumcised men often have inflammation under the foreskin, which could act as an entryway for infection; the foreskin may be abraded during intercourse; the warm, moist conditions under the foreskin may be conducive to viral survival; and lack of circumcision predisposes to ulcerative sexually transmitted diseases.

Background and Objectives: The effective rate of partner change is an important variable for determining whether an epidemic of a sexually transmitted disease (STD) occurs. It is essential for understanding the transmission dynamics of STDs. Goal of this Study. The problem of estimating the effective rate of partner change is addressed. Results: Under certain conditions the mean rate of partner change in STD patients estimates the effective rate of partner change in the general population. Conclusion: To estimate the effective rate of partner change in a population, the use of surveys of patients with STD provides a simpler and less costly alternative to population surveys of sexual behavior., Rate of change of partner among sexually transmitted disease (STD) patients can be used in determining mathematically whether an epidemic of an STD is likely to occur. Normally, such predictions are made from rate of change of partner in the general population, but surveys of sexual behavior generate paradoxical results, such as men reporting considerably more sex partners than women in the same population. The mathematical equations and the assumptions on which they are based are analyzed and discussed.

To evaluate the impact of human immunodeficiency virus (HIV) on human papillomavirus (HPV) and cervical intraepithelial neoplasia (CIN), a study was conducted of 147 HIV-seropositive and 51 HIV-seronegative prostitutes in Nairobi, Kenya. Among the women infected with HIV, 10 (7%) had signs or symptoms of significant HIV-related disease, and the remaining 93% were asymptomatic. The prevalence of cervical HPV DNA was 37% among HIV-seropositive women and 24% in HIV-seronegative women (odds ratio [OR] 1.7, 95% confidence intervals [CI] 0.8, 3.6, after adjusting for potential confounding factors). Genital warts, cervical HPV DNA, and cytologic findings consistent with CIN were all significantly associated with younger age and fewer years of prostitution, but were unrelated or weakly related to number of sexual partners per week or frequency of condom use. In a subset of 63 women with evaluable Papanicolau smears, CIN was found in 50% of the women with HPV but only in 8% of those without HPV (adjusted OR 7.2, 95% CI 1.6, 32.1, P = 0.006). However, CIN was unrelated to HIV seropositivity (prevalence of 26% among HIV-seropositive women and 24% in HIV-seronegative women). Among women with cervical HPV DNA, HIV infection was not associated with an increased prevalence of CIN (47% prevalence among women with HIV versus 57% prevalence among women without HIV). Thus, in this population of HIV-seropositive women, most of whom had CDC Stage II or III infection, there was no demonstration of an adverse impact of HIV on CIN.

Human immunodeficiency virus (HIV) causes AIDS. HIV infection attacks the immune system and places infected individuals at risk for developing opportunistic infections, which can be life-threatening. HIV infection first appeared as a disease that was transmitted by anal intercourse among homosexual men and by intravenous drug use. However, it is becoming apparent that HIV infection can be transmitted between heterosexual partners. In the United States, heterosexually-transmitted HIV is not very common, and only accounts for 4 percent of all AIDS cases. Infection of regularly exposed female partners of men with HIV type 1 (HIV-1) is thought to be infrequent. However, a recent study predicted that spouses of male AIDS patients have a 42 percent risk of contracting HIV-1 infection. Although HIV-1 is carried in the semen of infected men, all female sexual partners of men with HIV-1 do not become infected. In Africa, however, HIV-1 is a heterosexually transmitted disease. Those at greatest risk for contracting HIV-1 are prostitutes and their customers, and men and women who have several different sex partners. The reason why heterosexually-transmitted HIV-1 is much more prevalent in Africa than in the US is unknown. To identify the risk factors associated with and the rate of occurrence of heterosexually-transmitted HIV-1 infection in Africa, 595 prostitutes from Nairobi were assessed. When blood samples were tested for HIV-1 at the beginning of the study, it was found that 399 women were infected (seropositive) and 196 were not (seronegative). Within 6 months, 83 of the seronegative women became infected with HIV. Within 1 year, 72 more women became seropositive and only 41 women remained seronegative. Risk factors associated with developing HIV-1 infection included genital sores and infection with Chlamydia trachomatis. The use of condoms reduced the risk of getting HIV-1 infection. The reason for the heterosexual HIV-1 epidemic in Africa is unknown, but frequent heterosexual anal intercourse and the presence of other sexually transmitted diseases may be contributing factors. (Consumer Summary produced by Reliance Medical Information, Inc.)