While many Navajo officials shy away from those subjects, the 24-year-old Billy has used her unique and prominent status -- as Miss Navajo Nation -- to get the word out.
"For her to talk about HIV and STDs is phenomenal," said Marco Arviso of the Navajo AIDS Network.
On the 27,000 square-mile Navajo Nation, the challenges in addressing sexually transmitted diseases are many. Among them: How to relay to traditional healers that HIV and AIDS are not non-Native diseases, how to obtain services when the nearest clinic is sometimes hours away, and how to ensure patient confidentiality in often close-knit communities.
Another problem is overcoming a Navajo belief that to speak of death and disease is to bring it upon oneself or a loved one.
But as long as Navajos ignore the problems and fail to educate the community about how the diseases are contracted and how to deal with people living with AIDS, the more divided communities will become, Billy said.
"That's not our way of life as Dine people," she said.
Beyond the Navajo Nation, the overall rate of HIV and AIDS diagnosis for American Indians and Alaska Natives has been higher than that for whites since 1995, but generally lower than for blacks or Hispanics, according to the Centers for Disease Control and Prevention.
In 2005, data from the CDC showed that the rate of HIV and AIDS diagnosis for American Indians and Alaska Natives was 10.6 per 100,000, compared with 72.8 for blacks, 28.5 for Hispanics, 9.0 for whites and 7.6 for Asians and Pacific Islanders.
Among Navajo-area American Indians, the incidence rate was 7.6 per 100,000 for the same year and slightly higher in 2006 at 7.8 per 100,000.
The Navajo Area Indian Health Service identified a total of 240 HIV and AIDS cases among the group between 1985 and 2006.
"Things for the moment seem to have stabilized," said Jonathan Iralu, the infectious disease consultant for the health service. "...We're thankful things look good right now."
Four years ago, one statistic caught the attention of the health care community -- the first local transmission of HIV and AIDS. Before then, it was believed that all cases were coming in from off the reservation.
Tribal officials responded with public service announcements on radio, TV and in newspapers, urging Navajos to practice safe sex, get tested and learn how to prevent the spread of HIV and AIDS.
In 2003, the number of new cases climbed to 24, up from 15 the previous year. Since then, the number of new cases each year has ranged from 19 to 23.
And still, many Navajos aren't seeking treatment if they test positive -- mainly for fear they would be rejected by their family or communities, said Melvin Harrison, executive director of the nonprofit Navajo AIDS Network.
"They just wait until they get really, really sick," he said.
Traditional healers, to whom some HIV and AIDS patients turn, also have minimal experience dealing with the patients, and often turn them away, said Rita Gilmore, a traditional healer. Their reluctance comes from misconceptions about HIV and AIDS, mainly that it's a gay disease spread by other minorities.
Navajos think of it as a non-Native illness, she said.
"And it's like, 'Why would you want to go in there and deal with this when it's not our disease,'" she said.
Gilmore, who saw her first HIV patient on the reservation about 10 years ago, said she aims to keep an open mind when treating such patients, which can be tricky. She cannot ask them direct questions because in Navajo culture, that is perceived as being rude. She also cannot conduct ceremonies such as the sweat lodge for patients who have open sores or wounds.
A purification ceremony usually is administered to the patients "to bring hope to the patients and to purify them of the negative thoughts that they have, including the impending death that they've been told," she says.
She says it's important that there be parallel treatment from both Western health care providers and traditional healers.
"It's not about who has the best remedies to cure this, because right now, both sides don't have a cure," Gilmore said. "We must come together and finds ways to prolong the lives of these patients."