GALLUP, N.M. - A surge in H.I.V. infections on the Navajo reservation here has doctors and public health workers increasingly alarmed that the virus that causes AIDS has resurfaced with renewed intensity in this impoverished region.
A report released last month by the federal Indian Health Service found that there were 47 new diagnoses of human immunodeficiency virus on the reservation in 2012, up 20 percent from 2011. Since 1999, new H.I.V. cases among Navajo are up nearly fivefold, the report found. The tally of new cases from last year represents the highest annual number recorded among the tribe by the health agency.
“I’m scared to death,” said Dr. Jonathan Iralu, an infectious disease specialist who runs an H.I.V. clinic in this dusty town where old trading posts and ramshackle motels line the main drag on the edge of Navajo land, not far from the Arizona border. “The numbers show there is a dangerous rise, and the time to act is now, before it’s too late.”
Dr. Iralu, who compiled the report, remembers hearing the stories from former colleagues about the late 1980s when AIDS first struck the reservation. Navajo men would walk into the Indian Medical Center in Gallup sick with a fever or a cough, and a few days later they would be dead.
In the period after that, Dr. Iralu, a Harvard-educated doctor who moved here from Boston, treated a small number of Navajo men with H.I.V. each year and lost nearly a third of them.
As with other groups in the United States, infection rates on the reservation leveled off and deaths dropped, with help from new treatments and outreach seeking to cut through the stigma about AIDS among tribal members.
But over the past few years, the H.I.V. numbers on Navajo land have crept up. That increase, Dr. Iralu said, can be partly attributed to the infection being detected earlier, thanks to years of H.I.V. education programs and more routine screening.
But Dr. Iralu and other health workers also said the virus was now being transmitted from one tribal member to another, a disquieting trend. In past years, Navajo were thought to have contracted the disease mostly in cities and returned with it.
And though the numbers are still comparatively low - there are about 200 Navajo patients tracked by area clinics - the challenges of prevention are amplified in a place where sex is still rarely discussed publicly and infection is often hidden from loved ones.
Melvin Harrison, the executive director of the Navajo AIDS Network, which provides services for tribal members with H.I.V., said that of the 65 people his group treats, a majority have not told family or friends.
“That’s how big the stigma is here,” he said. “They are afraid of rejection.”
Mr. Harrison said that when he first started working on H.I.V. education in the 1980s, Navajo elders cautioned him not to talk openly about H.I.V. for fear that he would “wish” it upon the tribe.
Even now, he said, old cultural mores prevail, and gay Navajo men, who make up around 75 percent of the network’s clients, keep relationships private.
According to the recent report, men who have sex with men accounted for nearly half of the new cases.
One Navajo man, who contracted H.I.V. from his partner in 2001, recalled how his mother refused to hug him and served him food on plastic plates when she found out he was infected.
The man, 48, who did not want to be identified because he had not told his entire family, said his mother eventually came to embrace him after he explained the ways H.I.V. could and could not be transmitted.
But the man has not told his three brothers that he has H.I.V. because he fears they will shun him. “I don’t think I’ll ever tell them,” he said. “I don’t want to be pushed out of their lives.”
The intimacy of reservation life, where a hospital receptionist might be a relative or a nurse a close friend, can be a barrier to swift treatment and prevention. Mindful of those challenges, the Indian Health Service allocated $5 million over the past three years for communities to create H.I.V. prevention, treatment and education programs.
“H.I.V. in Indian country is very different than the rest of the world,” said Dr. Susan V. Karol, the agency’s chief medical officer. “Our communities are very small, and that can lead to people avoiding stigma, rather than getting the care they need.”
The tribe’s health department, the Navajo AIDS Network and Dr. Iralu’s clinic have all started outreach efforts, running public service messages in Navajo, promoting awareness through social media and distributing condoms.
Philene S. Herrera, who runs the tribe’s H.I.V. prevention program, said the recent report showed that more people were being screened. But, she said, it also conveyed the need to work to bring the infection rate down.
Data from the Indian Health Service and the Centers for Disease Control and Prevention show why early detection is critical. From 1998 to 2005, new infection rates among American Indians were not much higher than those of whites and were lower than blacks and Hispanics. But the chances of survival after an AIDS diagnosis were lower among Indians than in any other racial group.
It is unclear why this dynamic exists, Dr. Iralu said. But lower rates of routine H.I.V. screening and higher rates of co-morbidity, like diabetes and drug and alcohol abuse, are likely factors.
On a wall in the clinic’s hallway, a banner implores people to get tested. A fresh-faced Navajo man in a cowboy hat stares solemnly ahead, an empty road behind him disappears into the horizon.
“I’m afraid that if we wait too long,” Dr. Iralu said, “it could turn into a true epidemic.”