Elijah Scriver, 62, rests with one of the Joseph's House cats during his stay there. Scriver died of complications from HIV/AIDs in January. Joseph's House is a Hospice in Washington, D.C., for homeless men and women. (Lucian Perkins)

Although the number of District residents living with HIV or AIDS remains high enough to rate as an epidemic, the tally of new cases has dropped by nearly 50 percent over two years, according to a report released Wednesday.

The annual report by the D.C. Department of Health also noted a 60 percent drop in the number of newly diagnosed HIV/AIDS cases from injection drug use, from 153 cases in 2007 to 62 in 2009, the most recent data available. Health officials cited expanded needle-exchange programs as the probable reason.

More than 3 percent of District residents older than 12 were living with HIV or AIDS in 2009, the year covered by the 108-page report. The epidemic continues to disproportionately affect blacks, adults ages 30 to 59 and those living in Wards 5, 6, 7 and 8.

Although the prevalence rate — the total percentage of people in a population with the condition or disease at a given time — is the highest for any city in the United States and has remained steady for three years, it also reflects the fact people are living longer with the virus or the disease, officials said. Someone who is diagnosed and in treatment still gets counted by the city.

The number of new cases is a better measure of progress in fighting the disease. On that front, the report had some nuggets of encouraging news. Newly diagnosed cases of HIV and AIDS fell from 1,311 in 2007 to 755 in 2009. Although the Health Department reported last year the first-ever decline in new AIDS cases, Wednesday’s report found a decrease not only in the number of new full-blown AIDS cases but also the number of new HIV cases. Health officials suggested that could be the result of preventive measures gaining traction, they said.

New HIV and AIDS cases from intravenous drug use began declining in 2008, but they fell more sharply in 2009. Officials said they have reallocated funds to three providers of clean needles to drug addicts after the main provider shut its doors this year.

Health officials cautioned, however, that the data were preliminary because the District is moving to a more accurate reporting system that avoids double-counting. The drop by nearly half in the number of new HIV and AIDS cases cannot yet be characterized as “a substantial change in the District’s epidemic,” according to the report.

Earlier this year, an advocacy group that has been tracking the District’s HIV/AIDS rate since 2005 said the city was falling behind on its efforts to combat the disease.

But Gregory Pappas, senior deputy health director, pointed to progress. “The picture in D.C. — we have a serious epidemic, but we’re making strides in combating the disease,” he said.

Pappas said the “waiting time between diagnosis and care” has been reduced on average from a year to three months. And he pointed to what he called a successful pilot program, begun in October, that allows residents to be tested free at the Department of Motor Vehicles office in Penn Branch Shopping Center in Southeast Washington.

Pappas said the agency is learning that many residents are not being tested by their own doctors, a trend that continues.

People going to doctors aren’t necessarily offered screening because some doctors think older people cannot get infected, health officials said.

In fact, the proportion of new AIDS cases among older adults ages 50 and older has increased from 19 percent in 2005 to 26 percent in 2009, the report said. Nearly three-quarters of people living with HIV/AIDS are 40 or older.

Health officials said they are focusing on three groups of people: those 50 and older; younger substance abusers, particularly women; and Hispanics in their 20s and 30s. A greater proportion of Hispanics were diagnosed with AIDS in that age group than whites and blacks, the report found. Seniors and Hispanics also seek treatment later.

Of those living with HIV/AIDS, the most commonly reported transmission mode was sex between men. The modes differed greatly by race and ethnicity.

Among whites and Hispanics, sex among men continued to be the most commonly reported mode. Among blacks, the leading transmission mode was heterosexual contact.

At the end of 2009, at least 16,721 residents were aware from testing that they had a form of the disease, an increase from 16,513 reported in 2008.

Health officials based the prevalence rate on a population of about 510,000 residents age 12 and older. The District’s population is slightly over 600,000, according to the latest census figures.

The report, an annual analysis performed by the Department of Health HIV/AIDS, Hepatitis, STD, and TB Administration, also paints a dismal public health picture about sexually transmitted diseases and tuberculosis:

Nearly half of the chlamydia and gonorrhea diagnoses were among District residents 15 to 19 years old, with two-thirds of all diagnoses among those under 24.

Syphilis is disproportionately affecting blacks, who had 57 percent of all cases; 40 percent of all cases were in wards 1 and 2.

Women now represent a higher proportion of TB cases, increasing from 36 percent in 2005 to 59 percent in 2009.

Staff writer Nikita Stewart contributed to this report.