Syphilis elimination seen as good HIV prevention

Lowest-ever rate gives chance to stamp out disease

The syphilis epidemic of the late 1980s that fueled the HIV epidemic has subsided to the lowest levels of syphilis ever recorded, prompting health officials to set in motion a plan for eliminating the chronic disease within the next ten years. The effort not only has congressional backing and financial support, but is planned to enhance prevention for other infectious disease control efforts, particularly HIV.

Although the United States has the highest rates of syphilis in the industrialized world, the epidemic is concentrated in fewer than 40 counties, primarily in the South. Last year, the nationwide rate was the lowest ever, with 72% (2,300) of counties reporting no cases. And yet, syphilis has become intractable in several large cities, such as Baltimore and Atlanta, as well as in concentrated rural areas, where syphilis is passed on at birth to 2% to 3% of African-American babies, the Centers for Disease Control and Prevention reports. (See CDC syphilis statistics, inserted in this issue.)

"The trends are going down, so we are improving," says Judith Wasserheit, MD, MPH, director of the division of STDs for the CDC. "But we estimate it would take about $25 million in new money per year for the next five years as a starting point and will take at least a decade to eliminate."

Last year, the House Appropriations Committee requested that the CDC report by February 1998 on its progress toward eliminating the disease. An additional $2.5 million was allocated for syphilis programs this year, and the Clinton administration's 1999 budget has earmarked an additional $10 million.

The low prevalence of syphilis and the relatively confined area in which it is contained provide a unique opportunity to eliminate syphilis from the United States. Elimination programs make good press, being the poster child of public health, but there is confusion over what constitutes elimination. One definition of elimination is less than one case per million population. Two years ago, health officials declared syphilis eliminated in Seattle when only two cases of early syphilis were reported in 1995 and no cases in 1996. Last year, 20 cases were reported, but all of them appeared to be "imported" from sources outside the United States, says King Holmes, MD, PhD, director of the Center for AIDS and STD at the University of Washington in Seattle.

However syphilis elimination will be defined, one of its primary goals is reducing the risk of HIV transmission while at the same time targeting minority health, CDC officials note.

"One major rationale for doing this is the benefits it provides for HIV prevention," Wasserheit notes. "Another would be infant health because of what happens to congenital syphilis in the same vulnerable communities."

Like HIV, syphilis resides disproportionately in African-American communities, which have rates 50 times higher than white communities. The behaviors that put one at high risk for syphilis parallel those for HIV infection. Studies have shown conclusively that open genital sores caused by syphilis allow HIV to be transmitted more efficiently. Studies in the United States and Europe have consistently shown that genital ulcers are prevalent in 3% to 4% of people recently infected with HIV. The presence of syphilis infection and its treatment also may be responsible for increasing viral load in HIV-positive patients, researchers note.

A recent CDC epidemiological study found a 13% HIV prevalence rate among people infected with syphilis in a North Carolina county. More recently, an analysis of syphilis cases in Baltimore, which reported the highest rates in the country, found an 18% HIV prevalence, a 40% decline in STD clinic capacity, a 50% decline in partner notification, and a 340% increase in crack cocaine use.

Baltimore is an example of the unforeseen consequences of an influx of federal money into a disease control project: When the federal dollars roll in, the state and local dollars often disappear, says Holmes.

Program has six components

In the past year, several states, such as California, Massachusetts, and Connecticut, have devised plans for a syphilis elimination strategy, says Michael St. Louis, MD, chief of the epidemiology and surveillance branch of the CDC's division of STD prevention. There also has been support from federal agencies. The Health Resources and Services Administra tion has funded a syphilis control program in Baltimore, and the National Institute of Allergy and Infectious Diseases recently has instituted funding for syphilis research. The potential for vaccines against syphilis, the ability to identify genetic subtypes of the disease, and the use of oral diagnostic testing are tools in the syphilis elimination arsenal, he adds.

At the March meeting of the CDC's Advisory Committee for HIV and STD Prevention, the CDC outlined the six components of its proposed syphilis elimination initiative. They are:

1. Development of a national task force and national plan.

The task force, made up of a diverse group of experts and organization representatives, would refine the concept of syphilis elimination, develop a national plan, provide specific morbidity goals, and define methods for evaluating progress and cost-effectiveness.

2. Community participation and partnership development.

Citing recent studies showing that many Americans have inadequate awareness and knowledge of STDs, the CDC has defined community involvement in the design and evaluation of the initiative as an essential key to its success. In addition to organizations that share the perspectives of marginalized African-American communities, crucial community partners would include local public and private providers of medical care, including managed care organizations, prenatal care providers, drug treatment agencies, correctional health entities, and public and medical research communities.

Community activities would be closely coordinated with the HIV prevention community planning process, St. Louis says.

"The other key community-based partner is the HIV prevention community," he says. "When we explain to them the potential role of other STDs in facilitating HIV transmission and the opportunity for using outreach workers for multiple diseases, there has been a lot of enthusiasm in putting together a joint effort."

3. Demonstration projects of enhanced prevention services and systems.

The CDC will fund competitive demonstration projects for states with primary and secondary syphilis rates higher than the Year 2000 objective of 4 cases per 100,000. The projects will target high-morbidity communities and will be based on new and existing approaches, combining community involvement, enhanced community outreach, high-quality surveillance, and monitoring of high-risk behaviors. This kind of systems approach to syphilis elimination also will build a prevention infrastructure for other infectious diseases as well.

"When these programs are put into place and done correctly, they will build sustainable capacity that has ancillary benefits, such as surveillance and outbreak response," Wasserheit explains.

4. Enhanced surveillance systems.

Because reliable surveillance is essential to elimination, the initiative would improve syphilis case surveillance systems by extending screening and reporting to high-risk institutional settings, such as correctional health facilities, drug treatment centers, and hospital emergency departments. Reporting, analysis, and utilization of surveillance data at local, state, and national levels also would be improved.

5. Outbreak response teams.

The initiative would deploy mobile technical assistance and response teams to key communities at risk as outbreaks are identified by surveillance systems. The multidisciplinary teams would be available for other emerging infectious disease outbreaks, as well.

Indeed, as fewer counties confront syphilis cases, local resources will have to be reallocated primarily to outbreak response, says Holmes.

"In some ways, the focus on outbreak containment is increasingly going to be the raison d'être of maintaining a public health infrastructure as these diseases drop to the point where the private sector no longer sees them or has the capacity to even be looking for them," he notes.

6. Targeting prevention and operations research.

Applied prevention and operations research will be vital to developing an effective syphilis elimination in the demonstration projects, CDC officials say. "The assessment of strategies, such as new diagnostic tests that do not require blood-drawing, oral therapies that do not require injections, behavioral outreach to ensure timely and appropriate health care, and better definition of epidemiology of persisting infections within communities will allow prevention to move from STD clinics into communities where syphilis persists," they write.

CDC officials note that one of the barriers to syphilis treatment is the need to administer penicillin through injection. New studies have shown that azithromycin taken as a single oral dose is an effective treatment for incubating syphilis and may prove to be effective for early syphilis treatment as well. Providing an oral treatment would eliminate the need for trained clinical nurses in some settings, and would make treatment more attractive to patients who fear needles, CDC officials note.

"The early data on azithromycin is encouraging," St. Louis says. "The drug may not be as effective as penicillin, but it may be important in settings where trying to eliminate reservoirs of infection is part of an outreach campaign."