Risk Factors for Herpes Simplex Virus Type 2 Infection among Female Commercial Sex Workers in Mexico City

A scarce number of studies have been carried out to determine the epidemiology of herpes simplex virus type 2 (HSV-2) infection in female sex workers (FSWs). The objective of this study was to examine the correlates of infection for HSV-2 with socioeconomic and demographic characteristics, sexual behaviour and history of sexually transmitted diseases (STDs) among FSWs in Mexico City. A sample frame of commercial sex work sites was constructed during the fall of 1992. Sites identified were streets, bars and massage parlours. During 1993 we surveyed 757 FSWs aged 18–76 years, from a random sample of sites. Participating women provided a blood sample and answered a standardized questionnaire. HSV-2 antibodies were identified based on a Western blot assay, using type-specific recombinant glycoprotein gG2. In a multivariate analysis, the presence of HSV-2 antibodies was correlated (P < 0.005) with increasing age and time working as prostitutes, low education, street working site and positive serology for syphilis. The results showed that the working site and the education level are contextual variables related to the risk of HSV-2 infection, where poorly educated and street FSWs had the highest probability of infection. Characteristics that represent periods of exposure to the virus as age and time working in prostitution were predictors of the HSV-2 infection.

Risk factors for herpes simplex virus type 2 infection among female commercial sex workers in Mexico City

A scarce number of studies have been carried out to determine the epidemiology of herpes simplex virus type 2 (HSV-2) infection in female sex workers (FSWs). The objective of this study was to examine the correlates of infection for HSV-2 with socioeconomic and demographic characteristics, sexual behaviour and history of sexually transmitted diseases (STDs) among FSWs in Mexico City. A sample frame of commercial sex work sites was constructed during the fall of 1992. Sites identified were streets, bars and massage parlours. During 1993 we surveyed 757 FSWs aged 18-76 years, from a random sample of sites. Participating women provided a blood sample and answered a standardized questionnaire. HSV-2 antibodies were identified based on a Western blot assay, using type-specific recombinant glycoprotein gG2. In a multivariate analysis, the presence of HSV-2 antibodies was correlated (P < 0.005) with increasing age and time working as prostitutes, low education, street working site and positive serology for syphilis. The results showed that the working site and the education level are contextual variables related to the risk of HSV-2 infection, where poorly educated and street FSWs had the highest probability of infection. Characteristics that represent periods of exposure to the virus as age and time working in prostitution were predictors of the HSV-2 infection.

Low prevalence of hepatitis B markers among Mexican female sex workers

OBJECTIVES

To estimate the prevalence and associated risk factors of hepatitis B virus (HBV) serological markers in female sex workers (FSW) in Mexico City.

METHODS

The study population consisted of 1498 FSW who attended a detection centre for human immunodeficiency virus (HIV) in Mexico City, between January and October 1992. Study participants responded to a standardised questionnaire and provided a blood sample for serology of syphilis, HIV, and HBV.

RESULTS

A total of 0.2% (95% CI 0.1-0.3) of the population were hepatitis B surface antigen (HBsAg) carriers. The general prevalence of antibodies to hepatitis B core antigen (anti-HBc) was 6.3% (95% CI 5.5-7.1). This marker of previous exposition to HBV, was independently associated by logistic regression multivariate analysis with age, working in the street, and history of blood transfusion (BT) before 1987 (OR 4.8, 95% CI 2.1-11.3). Syphilis prevalence was 7.6% (95% CI 6.2-8.9) and HIV prevalence was 0.1% (95% CI 0-0.3).

CONCLUSIONS

The prevalence of HBV infection in this group of Mexican FSW is lower than previously reported in other countries. In addition, the frequency of HBsAg carriers is similar to that in the general Mexican population. The absence of two major risk factors for HBV transmission in this group of FSW--that is, injecting drug use and anal intercourse, could help to explain this finding. However, the positive association between anti-HBc and history of blood transfusion demonstrated here, highlights the need to reinforce strict control of blood supplies in Mexico.

[Zidovudine plus didanosine in HIV infected asymptomatic patients previously treated with zidovudine]

OBJECTIVE

To evaluate if the combination of AZT/ddl offered any advantages in surrogate markers among HIV infected asymptomatic patients previously treated with AZT for at least six months.

METHODS

We used a prospective cohort of 269 asymptomatic HIV patients with CD4+ cell counts between 200 and 500 cells/microL. They were given didanosine (ddl 400 mg/d) in addition to AZT (500 mg/d) and had received AZT monotherapy for an average of 20 months. End points were progression to AIDS, death, or toxicity.

RESULTS

Median CD4+ cell count at the start of the combination therapy was 339 cells/microL which increased at three months to 451 and subsequently declined at 6, 12 and 18 months of followup (medians of 392, 360, 307 cells/microL respectively). Five patients progressed to AIDS, six developed toxicity (myelosuppression, hepatitis or pancreatitis) and 26 had minor side effects that required only dose reduction.

CONCLUSIONS

The addition of ddl to patients with prolonged ZDV monotherapy can be useful. CD4+ T cell counts showed a significant increase at 3 months with a gradual subsequent decline to below baseline at 18 months. Adverse effect of the drugs, although frequent, did not stop therapy in most patients.

Low prevalences of HIV infection and sexually transmitted disease among female commercial sex workers in Mexico City

OBJECTIVES

This study tried to determine human immunodeficiency virus (HIV)/sexually transmitted disease (STD) prevalences among female commercial sex workers in Mexico City.

METHODS

A sampling frame was constructed that included bars, massage parlors, and street corners.

RESULTS

Prevalences for Treponema pallidum, herpes simplex virus type 2, HIV, Neisseria gonorrhoeae, and Chlamydia trachomatis were 6.4%, 65%, 0.6%, 3.7%, and 11.1%, respectively. A significant association was found between higher STD frequencies and working at street sites.

CONCLUSIONS

Most STD frequencies were lower in comparison with rates found for female sex workers in other countries. However, preventive programs against STD/ HIV are needed in this population.

Hepatitis B markers in men seeking human immunodeficiency virus antibody testing in Mexico City

OBJECTIVES

To estimate the prevalence and associated risk factors of hepatitis B virus (HBV) serologic markers in 1,377 men with high-risk sexual behavior attending a center for human immunodeficiency virus (HIV) detection in Mexico City.

METHODS

The study population consisted of all men who were tested for HIV from March to September, 1992. Study participants responded to a standardized questionnaire and provided a blood sample for serology.

RESULTS

A total of 1.9% of the population were hepatitis B surface antigen (HBsAg) carriers, and there was a significant difference in HBsAg prevalence between HIV-negative (0.8%) and HIV-positive individuals (7.9%). Sexual preference was associated with HBsAg prevalence; only 0.3% of men who had female sexual partners exclusively were HBsAg carriers, compared with 4.8% of men who had male sexual partners exclusively. Prevalence of antibodies to hepatitis B core antigen (anti-HBc) was 15.4%. However, men who reported only female partners had a 4.6% prevalence, whereas men who had only male partners had a 30.4% prevalence. Logistic regression analysis demonstrated an association of anti-HBc prevalence with age, marital status, sexual preference, seropositivity for HIV, and antibodies to herpes simplex virus type 2.

CONCLUSIONS

These data demonstrate that coinfection with HBV is common in the HIV-positive men studied. The highest prevalences of HBsAg and anti-HBc were observed among homosexual men. These results highlight the need to intensify safe-sex education campaigns and to promote hepatitis B vaccination especially among this population group.

[Seroprevalence of various viruses and sociodemographic characteristics of women seeking HIV screening]

OBJECTIVES

To study the seroprevalence of syphilis, herpes simplex-2, hepatitis B and HIV, and main sociodemographic characteristics and sexual behavior in women seeking testing for human immunodeficiency virus (HIV) in Mexico City.

METHODOLOGY

A self-applied questionnaire was used in 454 women; and a blood sample was taken for the detection of markers for syphilis, herpes simplex virus-2 (HSV-2)), antibodies against core and surface antigens for hepatitis B virus (HBV), and ELISA and Western blot for HIV.

RESULTS

Seroprevalences for antibodies against T. pallidum, HSV-2, HBV and HIV were 4.6%, 29.3%, 3.5% and 4.0%, respectively. Forty-six percent of the women were 20 to 29 years old; 70% reported complete junior high school or higher education level; 75% were sexually active; 56% reported at least one stable male sexual partner, 17% reported at least one occasional male sexual partner in the last three months, and 60% had had at least one sexual relation in the last three months; of these, only 18% (n = 82) reported the use of a condom as a preventive measure. Almost 30% of the HIV positive women had a history of blood transfusion, while less than 10% of the HIV negative women had received a transfusion. In addition, 10.6% said that one of their sexual partners was infected with HIV or had AIDS.

CONCLUSIONS

Risks of HIV/STD transmission for this group of self-selected women were linked to blood transfusion, low education and, most important, the risk from male sexual partners who were HIV seropositive. It is expected that these results will contribute to the improvement and development of strategies for the control and prevention of STD among this population group, as well as the general population in Mexico.

[Prostitution and AIDS in the city of Mexico]

Since 1987 The National AIDS Council in Mexico (CONASIDA), has conducted research projects among female commercial sex workers (CSW), who are seen at the AIDS Information Centers. Through these studies, we have been able to find out how different issues influence commercial sex work in Mexico City. Since the beginning of our own studies in 1989, HIV prevalence in this particular group has remained low (0.04%-0.2%). Factors found to be associated with condom use were: educational level, not having children, more experience in sex work and younger age. Condom use was reported by 88% of the women; however, qualitative information and high STD prevalence rates suggest a much lower condom use. Mandatory HIV testing is not useful as a preventive measure among sex workers. Persuasive and structural interventions must be implemented in accordance with local and legal situations.

[AIDS and human rights]

AIDS and human rights are closely related issues. This paper describes the relationship between AIDS and human rights, the impact and consequences of discrimination and the importance of the defense of human rights as a cornerstone strategy in AIDS prevention. Some general ethical aspects are addressed and two dilemmas which have been raised by the epidemic are discussed: the apparent conflict between individual and community rights and the reactions of intolerance and repression from those who claim that only through coercive strategies will the epidemic be brought under control. Specific problems in Mexico are described based on data collected at CONASIDA's Human Rights Department between 1992 and 1994. Finally some conclusions are stated emphasizing that, in the AIDS epidemic, the defense of human rights is the cornerstone of any public health strategy.

[Prevalence of antitreponemal antibodies in 3,098 female prostitutes in Mexico City]

This paper describes a serological survey applied to 3098 female commercial sex workers, in order to determine the prevalence of syphilis. The women attend regularly an AIDS orientation center sponsored by CONASIDA in Mexico City. The laboratory tests included the rapid plasma reagin assay (presumptive analysis) and the fluorescent treponemal antibody-absorption technique (confirmatory test). No primary syphilis cases were detected and the prevalence of latent asymptomatic syphilis was 8.2% (255/3098). The sensitivity and specificity of the presumptive test compared to the confirmatory test were 74% and 98% respectively, and the positive predictive value was 77% and the negative predictive value 98%. All seropositive women received the standard penicillin treatment for syphilis. Considerations of importance are offered regarding interpretation and usefulness of this kind of research.

[The prevention of sexually transmitted diseases and AIDS by the use of the condom]

This paper deals with the last literature and examines the most relevant studies of recent years related to condom effectiveness in preventing sexually transmitted diseases (STD), with experimental, epidemiological and seroconversion models. On the basis of these studies, it can be stated that the efficacy of condoms is close to 100 per cent when used correctly and consistently. Condom breakage has been reported in 0.5 per cent of vaginal intercourse and 3.6 to 10 per cent of anal intercourse. Most studies refer low failure rates due to manufacturing defects. Considering all constraints involved in masculine condom use and their implications for women, a female condom has been developed recently. It is not enough to give information or to make condoms available, if all the elements involved in the enhancement or failure of its use are not considered. Sexual education programs are the fundamental strategy in preventing STD and pregnancy.

[Prevalence of antibodies to Pneumocystis carinii in subjects with high risk behavior for AIDS]

P. carinii pneumonia affects more than 80% of patients with AIDS in developed countries. In Mexico this complication has been described in 12 to 23% of patients with AIDS, and it has been proposed that competitive disease such as TB and the low life expectancy of AIDS patients in Mexico are the possible explanations of this low percentage. However, in Mexico the frequency with which the population at risk of contracting AIDS is exposed to P. carinii is unknown. Therefore, we looked for P. carinii antibodies in a group of blood samples obtained in an AIDS detection center in Mexico City. A Western blot analysis was performed on 157 blood samples from homosexual and bisexual men and on 21 from female partners of HIV positive men. Positive results were obtained for 76.9% of the samples. No difference was observed in the frequency of P. carinii antibodies between HIV positive and negative individuals. Also, no differences by sex or age were found. Prevalence of P. carinii antibodies in this group is 76.9%, similar to that found in a comparable group in the U.S.

[Do AIDS cases in adolescence really exist?]

Adolescents are a specific population group, with risk practices for the acquisition of sexually transmitted diseases. The Centers for Diseases Control consider the adolescents specific group ranging between 13-19 years and they reported, until September 1991 that 0.4% of global AIDS cases corresponded to this group. In Mexico, we did an analysis of the AIDS cases reported at AIDS Surveillance Committee until September 1991, and found that 1.4% of the global AIDS cases corresponded to adolescents. The AIDS transmission pattern in adolescents is different from adults and children. It is very important to classify adolescents as a specific group in health surveillance and to considered all the factors related to them for AIDS prevention strategies.