HIV transmission patterns in Latin American countries are similar to transmission patterns in industrialized countries. While it appears that the current rate of infection is decreasing or at least stabilized, the outlook is not uniform across the Latin American region. In most Latin American countries the epidemic is classified as "concentrated" in specific populations. Seroprevalence rates in these at-risk populations range from one to 25 percent. A seroprevalence rate of under five percent is seen in the total population. However, in recent years some countries in the region -- Nicaragua, Venezuela, and Peru -- appear to have rapidly increasing seroprevalence rates.
Mexico ranks 13th globally and third in the Americas in the total number of HIV cases reported. However, when rated on the accumulated number of cases, Mexico ranks 69th globally, 29th in Latin America and the Caribbean, and in 11th place in the Americas, which reflects a comparatively low incidence rate.1
The first AIDS case in Mexico was diagnosed in 1983. Based on retrospective analyses and other public health investigation techniques, HIV in Mexico can be traced back to 1981. Since 1981, the increase in new cases has been continuous, with four types of trends noted: (1) up to the end of 1987, the increase was slow; (2) from 1988 to 1991, the increase was exponential; (3) from 1992 to 1995, the increase was exponential but subdued; and (4) as of 1996 there appeared to be a leveling off of the epidemic, stabilizing with an average of 4,000 new cases of AIDS annually. (see Figure 1).
Epidemiological analyses of HIV/AIDS in Mexico are made by classifying patients by age, sex, and method of transmission. In males, the primary source of transmission has been sexual (homosexual and heterosexual) and only secondarily through blood transfusions. In women, the initial source of transmission had been by blood transfusion, but now it is primarily through heterosexual contact. The initial cases of pediatric (children under 15) transmission were also by blood transfusion. However, that has now shifted primarily to perinatal transmission with a few incidences of sexual transmission.
Since the beginning of the epidemic in Mexico, 37,381 cumulative AIDS cases have been reported through October 1, 1998. When adjusted for undernotification and delays in notification, this total increases to 58,900 accumulated cases3 (see Figure 2).
AIDS has been reported in all states of the Mexican Republic. Fifty-five percent of AIDS cases are concentrated in the Federal District, State of Mexico, and in Jalisco. The majority of cases are in the 25 to 44 age group. Thus, AIDS has become the No. 3 cause of death in men and the 6th cause of death in women within this age group.
Pediatric AIDS represents 2.6 percent of the cumulative number of cases in Mexico; of these 50 percent were infected perinatally.
Global patterns of HIV transmission vary by region and country, and are influenced by culture, values, social conditions, sexual dynamics, and socioeconomic situations. In Mexico, two primary patterns have been reported: (1) an urban pattern, observed primarily in the large cities of the Mexican Republic and in the northern border with the United States, where there is a larger percentage of males infected and longer incubation periods (18 months); (2) and a rural pattern, with a higher proportion of females infected and shorter incubation (eight months), which is being observed in the central and southern regions of the country.
Because the dynamics and rate of HIV infection in Mexico is changing, it is more difficult to accurately predict the total number of people infected. The estimated number of persons infected by HIV in Mexico ranges between 116,000 to 174,0004. This estimate is based on HIV incidence in blood donors, sentinel studies in pregnant women, and seroepidemiological studies in specific subpopulations. (see Figure 3, Figure 4).
Based on current HIV surveillance data, the HIV epidemic is primarily concentrated among men who have sex with men (homosexual and bisexual). Most of those infected live in large cities where the seroprevalence rate has remained stable for several years. However, the seroprevalence rates in smaller and medium cities has begun to increase.
There has also been an increase in seroprevalence rates in heterosexuals, particularly in females who are sex workers and/or sexual partners of HIV-infected males. While the current infection rate in heterosexuals is low, risk factors are present which could increase the rate of infection in this group. For example, there is an increasing trend in HIV seroprevalence in tuberculosis patients.
Injection drug use is unusual in Mexico, with the practice more common in northern border states. Thus, the incidence of HIV infection in injection drug users is primarily concentrated there. Seroprevalence rates in this group are increasing.
In 1986, Mexico established the National Committee against AIDS. Initially the committee was comprised of professionals who provided their services on a part-time basis to coordinate the fight against AIDS. In August 1988, the National Council for Prevention and Control of AIDS (CONASIDA) was established by presidential decree. CONASIDA became the official government agency charged with the responsibility for meeting the diverse challenges of the HIV/AIDS epidemic in Mexico.5
The number of CONASIDA staff gradually increased. Initially financial support came from international funds. As of 1991, most of the activities were financed by the Secretariat of Health. At present, more than 90 percent of funds used by the program are provided by the Mexican government.
CONASIDA initially carried out various activities according to a strategic plan. Unfortunately, many of these activities were not properly carried out at a state level. For many years, the Secretariat of Health was centralized, with human and financial resources concentrated at a federal level, and services varied significantly in each of the 32 states.
In 1995 the need for healthcare reform was proposed to respond to existing challenges. A fundamental part of this reform is the decentralization process which transfers the operation of services to the federal entities, as well as restructures the functions of the Secretariat of Health at a federal level. This was expressed in the 1995-2000 National Development Program and the 1995-2000 Reform Program of the health sector.
In 1997 an analysis of healthcare services and needs was made to help prioritize the primary responsibilities of the Secretariat of Health. As a result of this analysis, substantive programs were identified and recommendations were made for new programs at both the federal and state levels. Thus, eleven substantive programs were defined, one of which was the Program for HIV/AIDS and other Sexually Transmitted Diseases6, which is the direct responsibility of the CONASIDA.
Integration of HIV and STD services was based on recommendations by various federal and state agencies who had been working together to better coordinate activities and services between both programs. CONASIDA is a part of the federal level of the Secretariat of Health. Its main function is a normative one of coordination and counseling at a national level.
Similar to most Latin American countries, Mexico has a segmented healthcare system. Mexico's three-tiered healthcare system is based on the economic status of the populations served. Individuals who fall under the first tier -- private sector -- are those who have sufficient income to pay for the cost of their own healthcare. The second tier is public sector healthcare, otherwise known as Seguro Social, or "Social Security," which provides to employed individuals within certain income brackets comprehensive healthcare services, albeit somewhat more limited than those which can be accessed by individuals in the private sector tier. The third tier includes low-income individuals who receive limited, federally subsidized healthcare. The medical care available to an HIV patient is determined by her or his ranking among the three tiers.
At the end of 1997, it was estimated that 55 percent of people living with AIDS in Mexico did not have social security.
In 1992 a guide was developed for the medical care of patients with HIV/AIDS; this guide has been updated at various times according to internationally-excepted treatment guidelines. This medical guide is evaluated by HIV/AIDS experts in Mexico and it has the approval of all institutions that make up the health sector.
As of 1996 the system was streamlined to allow internationally approved drugs to be rapidly approved and available in Mexico. The average approval time for new drugs was reduced from four years to two-to-four weeks. Currently most of the antiretroviral drugs are listed in the Medicines Catalog, which makes it compulsory for Social Security institutions to provide them free of charge.
Parallel to this, four regional laboratories were installed which provide the special tests required for the attention and follow up of HIV/AIDS patients. These four regional laboratories are located in Mexico City, Guadalajara, Monterrey, and Villahermosa.
To ensure the appropriate care of persons who live with HIV/AIDS, various training courses were given to establish in each federal entity a specialized service for the attention of persons affected. Out of the 32 states, 19 already have a specialized service integrated to state health services.
In healthcare institutions for uninsured populations, persons with AIDS are provided with medical attention, consultations, laboratory, and medications for the prevention and treatment of opportunistic infections. However, no antiretroviral drugs are provided. The estimated cost of ideal ambulatory care, including triple combination therapy with protease inhibitors for 1997 is $10,197.50 (USD), with 86 percent of total cost represented by the expense on antiretrovirals7.
In Mexico, an alternative was proposed to increase availability of antiretroviral drugs for the population with neither Social Security nor independent financial resources. FONSIDA A.C.'s main purpose is fundraising for the purchase of antiretroviral drugs, with donations sought from all sectors of society.
The FONSIDA, A.C. project was presented on December 12, 1997, at the Health National Council, and was made official three days later when an incorporation deed was signed. The initial fund of $30 million was allocated by the Secretariat of Health; National Autonomous University of Mexico freely provides facilities, equipment, and personnel for project operation; Banamex grants an exemption of fees for the trust; Merck Foundation provided financing for the training of health personnel in charge of specialized services of integral care at the state level; and several specialized laboratories have donated medications. FONSIDA A.C. today provides free treatment to 100 percent of minors under age 18 who have neither Social Security nor other financial resources, as well as to HIV-infected pregnant women for the prevention of perinatal transmission and postpartum for their own treatment. The fundraising campaign has not yet started, but as more funds are obtained coverage is expected to increase8.
Mexico has 138 non-governmental organizations (NGOs), and organizations of persons who live with HIV/AIDS. Both have played a decisive role in meeting the challenges of HIV/AIDS since the epidemic began in Mexico; this is why CONASIDA maintains a strong connection and coordination with these organizations9.
In many countries there is little experience in horizontal cooperation orimplementation mechanisms to incorporate the participation of community in the planning and evaluation of health programs. In Mexico, as in other countries, AIDS is a public health challenge which has accelerated the process of learning to listen, incorporate, coordinate, and work jointly with various sectors of society, including civil organizations and representatives of persons affected by this epidemic.
It is undeniable that achieving an ample and efficient answer that reaches communities to which the various interventions are addressed, including native groups, migrants, prisoners, teenagers, women and men of the most remote communities, requires the support and active participation of community-based organizations. Likewise, it is indispensable to create regional and international networks of communication and interchange of experiences among all parties to potentiate the efforts each country carries out at a national level.
Patricia Uribe Zúñiga, MD is coordinator general of the National Council for Prevention and Control of AIDS (CONSAIDA). She is also conference chair of the Second International Conference on Healthcare Resource Allocation for HIV/AIDS and Other Life-Threatening Illnesses. Carlos Magis Rodríguez, MD, is deputy director for investigations at CONASIDA. Enrique Bravo García is chief of CONASIDA's information systems department.
1. OPS. Vigilancia del SIDA en las Américas. Actualización al 10 de septiembre de 1997.
2. Magis-Rodríguez C, Bravo-García E., et al. "El SIDA en México: panorama en 1997". SIDA ETS (México). Vol. 4, no. 3, nov/dic 1997.
4. Magis-Rodríguez C, Bravo-García E., Anaya-López L, Uribe-Zúñiga P. "La situación del SIDA en México a finales de 1998". SIDA ETS (México). Vol. 5, no. 4, oct/dic 1998 (en prensa).
5. MEXICO. Secretaría de Salud. Decreto de creación del Consejo Nacional para la Prevención y Control del SIDA. Diario Oficial de la Federación. 24 de agosto de 1988.
6. CONASIDA. Programa de fortalecimiento para la Prevención y Control del VIH/SIDA y otras enfermedades de transmisión sexual. México, 1997.
7. Saavedra J. Magis C. et al. Costo y gastos en atención médica del SIDA en México. México: Secretaría de Salud, 1997 (Serie Angulos del SIDA).