[Zidovudine plus didanosine in HIV infected asymptomatic patients previously treated with zidovudine]. / Zidovudina más didanosina en pacientes asintomáticos infectados por VIH previamente tratados con zidovudina.

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]. / Seroprevalencias a diversos virus y características sociodemográficas en mujeres que buscan detectarse VIH.

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.

Toxoplasmosis of the central nervous system in patients with AIDS in Mexico.

Toxoplasmosis of the central nervous system (CNS) is the most common cause of intracerebral lesions in patients with AIDS. It is now standard clinical practice to treat empirically, based on clinical and radiographic findings, and to perform a biopsy of the lesion only in those patients who fail to have a clinical and radiographic response after two weeks of therapy. This study describes the presentation and response to therapy of central nervous system toxoplasmosis in patients with AIDS at a private practice in Mexico City. A retrospective chart and radiology review of all patients with AIDS treated empirically for toxoplasmosis between 1988 and 1993 was performed. A total of 177 patients with AIDS were seen, nine (5.1%) had toxoplasmosis. Patients with toxoplasmosis were males with a median age of 39 years (range 26 - 65). In two patients, toxoplamosis of the CNS was the initial manifestation of HIV infection, all others had a prior diagnosis of AIDS with a mean of 10 months between their first AIDS defining event and the diagnosis of toxoplasmosis. The median CD4+ T-cell count at the time of the diagnosis of toxoplamsosis was 78 cells/microL. Most patients had headache associated with other focal neurological symptoms such as hemiplegia (2), hemiparesis (2) or seizures (4). Only 4 out of 9 patients had fever as part of their initial clinical presentation. Serum IgG antibodies against Toxoplasma gondii were positive in 6 out of 7 patients tested, while IgM antibodies were negative in all patients. On imaging studies (Computerized Tomography or Magnetic Resonance Imaging), 4 patients had a single lesion while the rest had two or more lesions. Two patients were initially treated with pyrimethamine/sulfadiazine and were later changed to pyrimethamine/clindamycin, which was the treatment given from the beginning to all other patients. One patient died of an intralesional hemorrhage two weeks after the diagnosis despite adequate therapy. The probability of surviving 6 months after the diagnosis of toxoplasmosis was 60%. The findings of these authors are similar to those reported in other series where toxoplasmosis of the CNS is a late complication of HIV infection associated with a CD4+ cell count of < 100 cells/microL. However, survival was short in spite of a good response to therapy.

[Simplified CD4+ T-lymphocyte count in patients with HIV/AIDS in Mexico]. / Simplificación en el conteo de linfocitos T CD4 positivos en personas con infección por VIH/SIDA en México.

OBJECTIVE: To study the correlation between ALC and CD4 cell counts and to find alternative ways of counting CD4+ T-lymphocytes. MATERIAL AND METHODS: The double positivity for CD3/CD4 antibodies was measured in 175 consecutive HIV-positive patients using flow cytometry; in these cases a difference was made between counting cells that were positive for both antibodies vs those that were positive only to CD4. ALC and CD4 counts were also compared among 500 subjects infected with HIV, using linear regression analysis and comparing the number of dissimilar cases for counts below 200 cells/microliters and ALC counts lower than 1 500 and 2000 cells/microliters. RESULTS: In the 175 cases measured by the CD3/CD4 antibody combination the mean percent was 13.8% and for total CD4 cells 14.2% (p = NS); the mean difference was 0.4% and the median 0.2%. For the 500 patients the mean ALC was 1 700 cells/microliters and the mean CD4 count was 219 cells/microliters; the correlation coefficient was 0.59. CONCLUSIONS: These data suggest a poor correlation of ALC and CD4 cell counts, thus it is impossible to predict CD4 on the basis of ALC. This is the reason why it is necessary to measure CD4 cells separately. The difference between measuring double positive CD3/CD4 cells vs only CD4 positive cells was not significant. Our data suggest that the use of a single CD4 antibody may cut costs and still produce clinically useful information.

Prevalence, incidence, and determinants of syphilis in female commercial sex workers in Mexico City.

GOAL: To determine the prevalence and the incidence of serologic markers for syphilis, and the characteristics associated with the risk of infection in female commercial sex workers in Mexico City. To identify female commercial sex workers at greater risk of infection with syphilis. STUDY DESIGN: The authors performed a cross-sectional study of 3,100 female commercial sex workers who sought human immunodeficiency virus testing at a National Council on AIDS clinic between January 1992 and April 1993. The authors collected information about socioeconomic and demographic characteristics, history of sexually transmitted diseases, sexual practices, and preventive measures against such diseases. All of the women provided a blood sample for identification of infection markers and in a subgroup of 1,802 women, repeat samples were obtained to estimate the rate of seroconversion to syphilis. RESULTS: Prevalence of syphilis was 8.2%, with an incidence of 2.4 per 100 person years. A positive linear relation between age and time working in commercial sex and prevalence of infection markers was observed. Women with less education, born in states other than Mexico City, and who worked on the street had significantly greater risks of infection with syphilis. CONCLUSIONS: Frequency of infection by both estimators is relatively low in the women studied. Characteristics related with periods of exposure such as age and time working in commercial sex, as well as socioeconomic and demographic characteristics, such as place of birth, education, and type of work site, were significantly related to the frequency of infection.

PIP: The goal of this study was to determine the prevalence and the incidence of serologic markers for syphilis and the characteristics associated with the risk of infection in female commercial sex workers (CSWs) in Mexico City. It also sought to identify female CSWs at greater risk of infection with syphilis. The authors performed a cross-sectional study of 3100 female CSWs who sought human immunodeficiency virus testing at a National Council on AIDS clinic between January 1992 and April 1993. The authors collected information about socioeconomic and demographic characteristics, history of sexually transmitted diseases, sexual practices, and preventive measures against such diseases. All of the women provided a blood sample for identification of infection markers, and in a subgroup of 1802 women repeat samples were obtained to estimate the rate of seroconversion to syphilis. Prevalence of syphilis was 8.2%, with an incidence of 2.4/100 person-years. A positive linear relation between age and time working in commercial sex and prevalence of infection markers was observed. Women with less education, born in states other than Mexico City, and who worked on the street had significantly greater risks of infection with syphilis. Frequency of infection by both estimators is relatively low in the women studied. Characteristics related to periods of exposure such as age and time working in commercial sex, as well as socioeconomic and demographic characteristics, such as place of birth, education, and type of work site, were significantly related to the frequency of infection.

The spectrum of HIV infection in patients seen at a private hospital in Mexico City: 115 patients seen from 1984 to 1990.

The objective of this study was to describe the epidemiology and clinical presentation of HIV infection among upper middle class patients in Mexico City. A retrospective review of outpatient and hospital records of all HIV-infected patients was accomplished by one of the authors between 1984 and 1990. A total of 115 patients were seen during the study period, 109 men and 6 women. One hundred and seven patients acquired HIV infection through sexual contact, six patients had HIV infection associated with blood transfusion and two were homosexual men who also had a history of intravenous drug use. The mean age of the patients was 36.2 years (range 13 - 65 years). CDC classification at presentation was predominantly stage IV (65%) with the most common AIDS associated diseases at presentation being wasting syndrome in 30 (42.2%), P. carinii pneumonia in 22 (30.9%), cytomegalovirus infection in 11 (15.5%), Cryptosporidium parvum diarrhea in 7 (9.8%), and Kaposi's sarcoma in 6 (8.4%). CD4+ T-lymphocyte cell counts at the time of HIV diagnosis were available in 87 patients (median = 150 cells/microliters; mean = 224 cells/microliters, SD +/- 219). Zidovudine was used in 37 patients after 1988 when it first became available in Mexico, in six patients the drug had to be discontinued because of serious hematologic toxicity. The average follow-up on zidovudine was 8.5 months. Similar age, gender, age distribution, risk categories and CDC classification at presentation was seen compared to other series reported from Mexico. However, the spectrum of opportunistic infections found were similar to that seen in the United States.

[Prostitution and AIDS in the city of Mexico]. / Prostitución y SIDA en la Ciudad de México.

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]. / El SIDA y los derechos humanos.

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.

PIP: 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 collection 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. (author's)

[Sexually transmitted diseases and the HIV/AIDS epidemic]. / Las enfermedades de transmisión sexual y la epidemia de VIH/SIDA.

Studies on sexually transmitted diseases (STD) during the previous years in Mexico are discussed. The information sources were: a) Surveys among commercial sex workers. Since 1990, 1,386 women have been studied in four federal states through structured questionnaires and laboratory tests. Prevalence of different STD's has been significant (syphilis (VDRL, FTA-abs) 23.7%; chlamydiosis (Ag IF) 12.9%; gonorrhea (Ag, ELISA) 11.5%; anti-HBs 11.0%; herpes 1,2 (IgM) 9.3%, HBsAg 5.7%. Frequency of HIV (ELISA, Western blot) has been low; 0.5%. In 1994, 662 women were studied in Mexico City, with different laboratory techniques for chlamydiosis and gonorrhea (culture), hepatitis B (anticore antibodies) and herpes (total antibodies) with the following results: syphilis 1.5-12%; chlamydiosis 10.8-11.7%; gonorrhea 0-5.9%; hepatitis B 0-7.1%; herpes 44.7-78%; and HIV 0-1.4%. b) Surveys among men with homosexual and bisexual practices. 325 subjects have been studied in three federal states using methods similar to those of the 1990 survey. Contrasting with results among women, HIV prevalence was found to be high; (18.8%), and considerable for other STD's: anti-HBsAg 28.6%, syphilis 34.9%, recent herpes 10.9%, HBsAg 5.0%, chlamydiosis (Ag, IF) 4.3%, herpes simplex 1,2 (Ag, IF) 4.7%, gonorrhea (Ag, ELISA) 2.8%. c) Patient clinical studies. The clinical interrelationship between different STD and HIV infection has been studied; clinical differences are described between patients with condylomata or syphilis depending on HIV serostatus. Implications of the interrelationship between different STD's and HIV infection for the prevention and control of these diseases are discussed.

[Campaigns against AIDS in Mexico: the sounds of silence or a bridge over troubled waters?]. / Las campañas contra el SIDA en México: los sonidos del silencio o puente sobre aguas turbulentas?

This paper analyzes the mass media campaigns developed by the Mexican Council for AIDS Control and Prevention (CONASIDA) from 1987 to 1994. This paper presents the lessons learned, a discussion of obstacles and mistakes, and the different evaluation methods which have been used in CONASIDA'S mass media communication strategies and their results. Knowing the opinion of some clue informants was considered relevant--taking into account that evaluations were made by and at CONASIDA--and seven in-depth interviews were conducted among intellectuals, non-governmental organizations (NGO) leaders and public opinion leaders. The importance of society's involvement in AIDS prevention is stated, and two examples of mass media campaigns developed by civil groups are commented. A section about the importance of research as a requisite to produce preventive messages is included, along with some examples. Finally, some conclusions are presented, useful to us, as well as others, in developing new educational campaigns.

[The health worker and counseling about HIV and AIDS]. / El trabajador de salud y la consejería sobre el VIH y SIDA.

By December 1993, more than 17,000 AIDS cases had been reported in Mexico and some estimates indicate approximately 100,000 individuals currently infected with HIV. From the patient's perspective, being HIV positive or having AIDS, places an enormous burden on psychosocial coping mechanisms. Thus, psychosocial support is required for all of these patients. This paper summarizes our educational intervention on counseling techniques and provides information of our demonstration project on the effectiveness of the educational intervention among 89 Mexican health care workers. Overall, these professionals showed improvement in their knowledge and goals of providing counseling. One of the more striking was the discovery of homophobic attitudes among them, particularly those with no previous experience in the care of HIV infected people. This exploratory study allowed us to identify research and educational needs of health care workers. The overwhelming number of estimated cases of HIV infections and the current trends of the epidemic reveal the necessity for training in medical counseling that over 73,000 physicians in Mexico will face in the immediate future.

[The homosexual transmission of HIV/AIDS in Mexico]. / Transmisión homosexual del VIH/SIDA en México.

OBJECTIVE: To analyze HIV homosexual transmission in Mexico, epidemic trends and biological and social risk factors. METHODS: This analysis is based on 19,090 notifications of AIDS cases and on a review of two previous studies that include 3,029 behavioral interviews (together with HIV serological screening tests) carried out at the Information Center of the Mexican Council for Control and Prevention of AIDS (CONASIDA) (1988-89) and during a 1988 study in six Mexican cities. Cities were included because they were the larger in the country and/or because they were the larger in the country and/or because they were touristic places (Mexico City, Guadalajara, Monterrey, Acapulco, Tijuana and Merida). Logistic regressions were used to estimate the odds ratios for HIV seropositivity and for condom use. RESULTS: Seventy-two percent of the total reported AIDS cases (19,090) up to June 30, 1994, were associated with male homosexual behaviors. In absolute numbers, cases under this category exhibited a rising trend until the end of 1993. HIV seroprevalence was 31% in 2,314 men with homosexual practices who attended "FLORA", the AIDS Information Center in Mexico, from January 1988 to June 30, 1989. The main predictive variables for seropositivity were exclusive homosexual behavior, more than 40 lifetime sexual partners, mixed sexual behavior (both insertive and receptive and intercourse), sex with a person with AIDS, history of syphilis, and anal or genital warts. In general, these risk factors (data from the Information Center) are similar to those found in the six Mexican cities study. There were significant differences in HIV prevalence among the high-risk city samples (the highest in Mexico City with 25% and the lowest in Monterrey with 2.4%). Reported condom use was very low in both studies: only 5% used a condom in all of their sexual relationships. A statistically significant protective effect for HIV infection was found only for those who reported using a condom in all sexual encounters. In the six cities study, city of residence was a strong predictor of condom use. CONCLUSIONS: HIV homosexual transmission is steadily increasing; the recent decline in the percentage of homosexual cases is artificial because of the increment of cases under other categories. Men who report exclusive homosexual behavior have higher prevalence rates of infection than bisexual men. Individuals with insertive/receptive behavior (mixed) have the highest risk for HIV seropositivity, mainly because of sociological, rather than biological reasons. This difference in risks for HIV and condom use may be related to the selection of sexual partners from specific social networks. Condom use was demonstrated to be an effective method for preventing HIV seropositivity among those who always use condoms. However, it is alarming that only 5% of respondents reported condom use in all sexual encounters. Social and geographic differences in the cumulative numbers of cases, HIV prevalence, sexual practices and condom use must be taken into account in the planning of preventive programs.

[AIDS mortality in Mexico from 1983 to 1992. The trends and years of potential life lost]. / La mortalidad por el SIDA en México de 1983 a 1992. Tendencias y años perdidos de vida potencial.

OBJECTIVE: To describe trends in AIDS mortality in Mexico from 1983 to 1992, as well as years of potential life lost (YPLL) and years of potential productive life lost (YPPLL) due to AIDS. MATERIAL AND METHODS: A retrospective review of databases available in Mexico that code mortality from AIDS was performed. Since AIDS was not coded specifically as a cause of death until 1988, for the period 1983-1987 the database of AIDS cases from the national AIDS registry provided by the Instituto Nacional de Diagnóstico y Referencia Epidemiológicos of the Ministry of Health was used. For the 1988-1992 period, a review of the mortality registry was provided by the Dirección General de Estadística, Informática y Evaluación of the Ministry of Health. To calculate YPLL and YPPLL we used the upper limit of expected life in Mexico for 1990 (70.79 years for men and 75.71 for women). RESULTS: Through 1992, there have been 8,204 deaths attributable to AIDS in Mexico (86% were men) with a rate of 2.9 deaths/100,000. In 1992 AIDS was the 19th leading cause of death in the country. The most affected age groups are the 25-34 and 35-44 years-old (especially amongst men) in which AIDS has now displaced pulmonary tuberculosis, suicide and self-inflicted injuries, diabetes mellitus, cerebro-vascular disease and alcohol dependency syndrome as leading causes of death in men. Our data suggests that AIDS has caused, from 1983 through 1992, 247,045 YPLL in men and 48,703 in women as well as 206,211 YPPLL in men and 29,793 in women. CONCLUSIONS: AIDS is at present one of the leading causes of death in Mexico. However, due to under-reporting, these estimates should be considered conservative and as lower-bound estimates. This data suggests that professionals are over-represented among AIDS cases, in comparison with the 1990 Population Census. This does not happen to be the case among women who are housewives.

[The prevalence of markers for hepatitis A, B and C in a hospital in Mexico]. / Prevalencia de marcadores para hepatitis A, B y C en un hospital de México.

A prospective study was carried to determine the relative frequency of hepatitis A, B and C in patients with elevated liver enzymes (transaminases greater than two times normal) who had a viral hepatitis profile requested by their physicians between August of 1990 and July of 1992 in the Angeles Hospital in Mexico City. Prevalence of serological evidence of HBsAg and anti-hepatitis C antibodies was also studied in healthy blood donors seen at the hospital's blood bank during the same period. Among the 405 patients with elevated liver enzymes, 24.7 per cent had acute hepatitis A (positive anti-hepatitis A IgM), 7.9 per cent had active hepatitis B (positive HBsAg and/or HBcAb IgM) and 14.8 per cent had active or previous hepatitis C as evidenced by the presence of anti-hepatitis C antibodies. In blood donors the incidence of anti-hepatitis C and HBsAg was 0.61 and 0.32 per cent, respectively. A percentage of 46.2 of patients with anti-hepatitis C antibodies and transaminases greater than two-times normal had a past history of one or more blood transfusions. These data suggest that infection with the hepatitis C virus is more common than that caused by the B virus in both healthy blood donors, as well as in patients with hepatitis in this hospital.