AIDS Alert International

Tijuana’s HIV prevalence rate has had an alarming increase in recent years

Border town’s epidemic could be new trend

A new study has found a rising HIV prevalence rate in the border town of Tijuana, Mexico, and researchers say this could be the start of a disturbing trend.

Overall, the prevalence rate ranged from 0.3% to 0.8% in the general adult population, ages 15-49, in Tijuana, says Kimberly Brouwer, PhD, an assistant professor at the School of Medicine at the University of California, San Diego. UCSD investigators collaborated with researchers from the Centro Nacional para la Prevencion y Control del VIH/SIDA of Mexico City, Mexico, on the study.

Previous information suggested the prevalence rate was 0.09% among pregnant women in Tijuana, who are a sentinel group for HIV surveillance, Brouwer says. Then a recent study of 1,064 women in labor in Tijuana found an HIV prevalence rate of 1.1%, with the HIV prevalence at less than 1% among non-drug using women and 6% for those who use drugs or had partners who used drugs.1,2

"With the magnitude of the rise in HIV prevalence among pregnant women, we thought it was important to look at other risk groups," Brouwer says. "What we did was collect available data from community-based studies, from published reports, from the National Center for the Prevention and Control of HIV/AIDS in Mexico, and they were collaborators on this work," Brouwer explains. "We combined those sources and were able to get an estimate of HIV prevalence and also the size of that population."

When investigators combined this information with Mexican census and other data, they estimated a high risk and low risk scenario of HIV prevalence, she adds.

The prevalence among men who have sex with men (MSM) had increased from 11% in the early 1990s to about 19%, and for injection drug users (IDUs), the prevalence increased from less than 2% in the early 1990s to a current range of 2.3% to 6.5%, Brouwer says.

"It’s not the current magnitude of HIV prevalence, because an infection rate of 0.3% to 0.8% overall means Tijuana now rivals a lot of major U.S. cities, such as San Diego where an estimated one person in every 126 persons is HIV positive," Brouwer says. "What really concerns us is the rapid rate of increase in HIV prevalence in Tijuana, and given that trajectory, it shows a real need for interventions to occur."

Tijuana, located in Baja California, the northernmost state of Mexico, is a rapidly growing city with a growth rate of 6% a year, Brouwer notes. "Tijuana is just south of San Diego, California, just a 20 minute drive between the two cities, and this border crossing is the busiest land border crossing in the world. Over half of the northbound crossings in the United States happen at the junction of the two cities."

The migration goes in both directions, because a lot of Americans will travel to Tijuana for tourism and business, she says. "And you get a huge number of Tijuana residents commuting on a daily basis to work in San Diego or to meet with family. There are a lot of illegal crossings, as well."

Tijuana’s role as a border town hosting people migrating both north and south makes the city at greater risk for the HIV epidemic, she notes. "You’re getting interaction between populations on both sides of the border. And migrants tend to be an at-risk group in and of themselves."

Migrants typically are detached from a support system and they usually don’t have social ties with the communities they are from, so there’s social and cultural alienation, as well as a fear of deportation and violence that affects their decisions, Brouwer says.

"All of these factors have been found in other migrating populations when researchers investigate HIV risks," Brouwer says. "Migrants tend to be at an increased risk for HIV infection."

Sexual tourism possibly another factor

Another factor that might explain Tijuana’s increase in HIV prevalence is sexual tourism, where there is a quasi-legal system of commercial sex work, Brouwer explains.

Tijuana health officials test registered commercial sex workers for sexually-transmitted diseases (STDs), but there are a great number of unregistered sex workers, as well, she says.

"They test for chlamydia and gonorrhea, but not necessarily HIV," Brouwer says. "That’s one concern, and we’re working with authorities in Tijuana to make sure they have increased access to HIV testing."

Commercial sex work is tolerated in Tijuana, and there is a section of town used for MSM sex trade, although the female sex worker population is much larger than the male sex worker population, Brouwer adds.

Tijuana’s increasing HIV prevalence also might be impacted by the city’s role as a major drug trafficking route, Brouwer says.

"Mexico has a much lower rate of the use of drugs and a lower prevalence of injection drug use, but Tijuana has one of the highest rates of drug use in all of Mexico," Brouwer says. "As we saw in our model, injection drug users were the second-largest group of HIV positive persons, and that’s another reason why this border is at increased risk."

Investigators theorize that the HIV prevalence is high among MSM in Tijuana because this is the group in which HIV traditionally has taken hold and because there is a lot of overlap between IDUs and MSM, Brouwer says.

"I believe you’re seeing a lot of high-risk people who may be involved in more than one activity," she says. "We see the same thing between commercial sex workers and drug users because a lot of commercial sex workers are taking methamphetamine and cocaine to be able to stay awake and work in the manner they do."

Researchers have encouraged Tijuana officials to improve prevention and care among HIV positive populations.

Since the study about a high HIV prevalence among pregnant women was publicized, the Tijuana General Hospital decided to offer HIV testing to all pregnant women entering the hospital, and so far 95% have agreed to be tested, Brouwer says. "So that’s a bright spot in the situation in Tijuana," she says. "There also are some non-governmental organizations that are involved in HIV prevention."

For example, the University of California, San Diego School of Medicine donated a recreational vehicle to a non-governmental organization (NGO) called Cirad in Tijuana. The NGO takes the RV to at-risk neighborhoods in the Tijuana community and distributes condoms and literature on HIV/AIDS, Brouwer says.

"The nice thing about this effort of having a mobile prevention vehicle is that if you are going out to people instead of having them come into the clinic, it reduces the stigma people feel when they walk into a specific HIV testing clinic," Brouwer says. "And the RV goes around with this big logo on its side about HIV prevention, and so it’s hopefully increasing HIV awareness in the community as a whole."

The authors of the study about estimated HIV infections in Tijuana also are trying to lobby for increased HIV prevention funding at the U.S./Mexico border, Brouwer says.

"We’re still waiting to hear if that will happen, but hopefully, we’ll see an increase in funding in this area," she says.

San Diego County spends more than $2 million a year on HIV prevention, and part of that money covers concerns about cross-border transmission, she notes.

"Health officials both at local and national levels have been tremendously cooperative," Brouwer says. "Our only concern is having cooperation with those who control the budgets in Mexico."

Since Mexico has had a comparatively low HIV prevalence rate in the past, HIV/AIDS was never treated as an epidemic with great urgency and concern, she says. "Hopefully, studies like ours will start to change this perspective, especially along the U.S.-Mexico border."

Investigators plan to compare the Tijuana epidemic to other parts of Mexico as the next phase of researcher, Brouwer notes. "We picked Tijuana because of its proximity, but also because this city is at a confluence of risk factors that makes it unique compared with other parts of Mexico," she says. "We had a suspicion that this was an area of concern, but it would be good to know if this increase has been seen along the Mexico/U.S. border and penetrated into Mexico."


  1. Brouwer DC, Strathdee SA, Magis-Rodriguez C, et al. Estimated numbers of men and women infected with HIV/AIDS in Tijuana, Mexico. J Urban Health. 2006; DOI: 10.1007/s11524-005-9027-0.
  2. Viani RM, Araneta MR, Ruiz-Calderon J, et al. Perinatal HIV counseling and rapid testing in Tijuana, Baja California, Mexico: seroprevalence and correlates of HIV infection. J Acquir Immune Defic Syndr. 2006; 41(1):87-92.