Chapter 1.0 Introduction and Background
This report presents the results of a comparative case study of local-level syphilis prevention efforts, conducted as part of sexually transmitted disease (STD) prevention programs supported by the US Centers for Disease Control and Prevention (CDC). The case studies were completed in eight communities in four southern states: Alabama, Mississippi, South Carolina, and Tennessee. The project investigated past and current responses by the public and private health sectors, and by other community organizations, to a syphilis epidemic observed in the Southern States between 1990 and 1992. Specific objectives of this study are to:
Develop an understanding of affected communities, with a focus on service delivery to persons at high risk of becoming infected with syphilis;
Discover innovative syphilis prevention and control measures currently being planned or implemented in southern states; and
Generate recommendations for community-level prevention strategies.
The project focused on groups at high risk of becoming infected with syphilis, the extent to which public health activities target such groups, and what factors affect the reach of services to this population. In the remainder of Section 1, we describe the syphilis epidemic in the Southern States, summarize previous research on behavioral factors governing the transmission of STDs, and briefly outline CDC's program to support state and local health departments in the prevention and control of STDs.
1.1 The Epidemiology of Syphilis in the Southern US
The 1990-1992 syphilis epidemic in the southern states is an example of the re-emergence of an easily diagnosed and readily treatable STD. Syphilis is a systemic treponemal disease with an initial acute stage followed by a long period of latency. Transmission occurs through lesions - which may be inapparent - normally during sexual contact. Presence of lesions due to syphilis increases the likelihood that HIV transmission will occur as well. Syphilis is diagnosed serologically and treated with penicillin. Syphilis control activities involve identification, testing, and treatment of exposed sex partners. Failure to identify and treat early syphilis infections in reproductive age women results in cases of congenital syphilis in infants, leading to spontaneous abortion, stillbirth, or generalized systemic disease (Benenson 1990: 420-425).
Syphilis morbidity trends reflect the disease prevention and control efforts that aim to reduce what is, in theory, a completely preventable disease (Kilmarx and St. Louis 1995). Figure 1.1 shows the national trend for reported cases of primary and secondary syphilis by race and ethnicity from 1981 through 1994. Syphilis rates increased across the US from 1986 through 1991, beginning to decline in 1991 in all regions except the Midwest. The highest rates of syphilis were found in the southern states throughout this period.
Table 1.1 shows rates of syphilis in 10 southern states from 1980 through 1995 based on CDC surveillance data. While the epidemic showed an early peak in Florida (1988) and rates continued to rise in Mississippi until 1994, most states showed the highest number of incident cases in the period 1990 to 1991. During this two-year period, the highest rates of primary and secondary syphilis were reported by Georgia, Louisiana, Mississippi, and South Carolina.
The 1990-1991 epidemic occurred on top of existing high rates of syphilis in the South. In 1981, all but two of ten southern states had syphilis rates higher than the Year 2000 objective (10 cases per 100,000 population). Moreover, high syphilis morbidity continues in this region. By 1995 only Florida and Texas were at or below the Year 2000 objective.
African Americans in the South have suffered a disproportionate burden of early syphilis and its adverse outcome, congenital syphilis. From 1960 through 1980, syphilis cases were concentrated among homosexuals. Between 1985 and 1990, its greatest impact was among African Americans. During this period, syphilis rose 165 percent in this population, while significantly decreasing for all other races and ethnic groups (Wasserheit 1994). Currently, African Americans represent 90 percent of all reported cases, with a case rate of 143 per 100,000 (SIS 1995).
There is little empirical evidence to explain why primary and secondary syphilis rates are highest specifically in the South and why the disease disproportionately affects African Americans in this region (Buckley 1992; DSTD/HIV 1992 Annual Report). Reported cases of early syphilis are concentrated in low-income African Americans in both urban and rural settings. By early 1996, morbidity rates were generally higher in urban areas, but this marks a departure from immediately prior trends. While higher urban rates had predominated through the mid-1980s, by 1990 rural rates had risen dramatically, equaling or exceeding urban rates throughout the case study sites and other southern states (e.g., Thomas et al. 1995). Rural morbidity has subsequently dropped off, however, so that new cases are now mainly concentrated in urban areas. The one exception is the largely rural Mississippi Delta region, where rates continue to exceed rates for neighboring metropolitan centers.
1.2 Dynamics of STD Transmission - A Brief Overview
The development of a protocol for this study was supported by a targeted review of literature on STD transmission dynamics and public health responses based on sources recommended by CDC and those frequently cited in these articles (Butler et al. 1996). We summarize this literature review here. The complete literature review can be found as part of the research protocol in Appendix A.
Some explanations of the reasons for the persistence of high syphilis morbidity are derived from mathematical models developed to characterize the movement of sexually transmitted diseases through a population (for reviews see Drucker and Vermund 1989 and Morris 1993). Most models of transmission dynamics attend to such factors as the number of infected individuals at a given time, the number of contacts that infected individuals have with persons potentially susceptible to infection, and the probability that a contact will result in infection.
A significant insight from recent analyses of gonorrhea and HIV transmission is that sexual contacts are not randomly distributed (Rothenberg 1983). They are patterned in ways that can be described with the tools of social network analysis (Klovdahl 1985, Rothenberg and Narramore 1996), and the structure of a network of sexual relations within a population has a significant effect on the timing and magnitude of an epidemic (Anderson, Gupta, and Ng 1989). Several observers (e.g., Garnett and Anderson 1993, Potterat 1992, Klovdahl et al. 1994, Rothenberg et al. 1995) have suggested that individuals generally select their sexual partners from a relatively restricted subset of a larger population - most form few partnerships over time, and a few form many.
The conventional epidemiological wisdom holds that the persistence of many sexually transmitted diseases within a population is dependent on whether there exists a group of individuals who frequently change partners, as this group can serve as a reservoir of infection among sexually active persons in the population. This group is referred to as a "core" group of transmitters (Lajmanovich and Yorke 1976, Hethcote and Yorke 1984, Anderson et al. 1990, Morris 1993). The members of this "core" group are thought to have a stable set of personal attributes or patterned behaviors (e.g., age, gender, ethnicity, sexual orientation, location, patterns of drug use [Garnett and Anderson 1993]), rather than transient attributes (e.g., contact with a case of sexually transmitted disease [Rothenberg 1983:688]). If such a group or groups can be identified, it is widely believed to provide a sensible target for control interventions.
Depending on the particular disease and the pattern of partnership formation, STDs may remain within the members of the group who tend to change partners frequently, or they may be transmitted more widely, among persons who tend to change partners less frequently. Evidence suggests that different diseases (e.g., gonorrhea and chlamydia) have different transmission patterns (Potterat 1992) and are therefore potentially associated with different "core" transmitter groups. The social and geographic settings associated with gonorrhea and syphilis are likely to be distinct (Gershman and Rolfs 1991), although these differences are difficult to discern when viewed against the backdrop of more encompassing ecological features of poverty and its accompanying social disruption (Wallace and Fullilove 1991, Wallace and Wallace 1990, Wasserheit 1994).
At the beginning of this study, some experts hypothesized that one contributing factor to the epidemic may have been the epidemic of substance abuse, primarily "crack cocaine." The epidemic and its related behavior have both changed disease transmission dynamics and hampered outreach and prevention staff in their efforts to reduce morbidity (Felman 1993). While it is likely that decreasing use of "crack" cocaine was partly responsible for changes in behavior that brought the epidemic under control in the early 1990s, increased use of partner notification and similar interventions in affected areas were also helpful (DSTD/HIV 1991 Annual Report), along with better staffing and possibly other clinic-based changes (Hare et al. 1993).
Another factor in the spread of syphilis among African Americans is a perception that African-American clients are treated with a lack of respect by staff in public health clinics (Jones 1981, Thomas and Quinn 1991). This atmosphere of distrust was heightened in 1972 with disclosure of the failure to protect the health interests of African-American subjects in the Tuskegee Syphilis Study. This study recruited 399 men with syphilis and an additional 201 controls from rural Macon County, Alabama, beginning in 1932. Its initial intent was to inform the design of effective programs for testing and treating African Americans in the rural South and also to resolve an epidemiological debate about the health consequences of untreated syphilis. Study participants were not informed of the consequences of their participation, and treatment was withheld from the experimental group even after penicillin became the treatment of choice for syphilis.
Wallace and Wallace's (1990) findings suggest that the origins of public health and public order are much the same and are deeply embedded in the security of personal, domestic, and community networks. Disruption of such networks from any cause will lead to the behaviors that increase the risk of infectious diseases because of the erosion of urban infrastructure. Wallace and Fullilove (1991) believe that in order to prevent high rates of infection and widespread patterns of transmission in the urban ghettos of the United States, we need "intensive programs of community organization and empowerment to reknit the shredded social networks of the poor in affected communities."
1.3 CDC's Efforts in Syphilis Prevention
The Centers for Disease Control and Prevention operates a program of support to state and local health departments in implementing and managing effective STD control programs based on state-of-the-art prevention science applied to specific community demographic, social, and cultural conditions. Syphilis prevention and control itself is conducted in state and local health departments. CDC is in a position to influence state and local practice through funding priorities, assignment of federal field staff, training programs, technical assistance, and the dissemination of technical information to public health practitioners.
As part of the STD prevention and control program, CDC provides grant awards and personnel resources to state and local health departments. CDC's support has aimed to bolster clinic-based case detection, treatment, partner notification, and various prevention activities. The impact of funding is augmented by the work of federal technical staff, employed and trained by CDC, and assigned to work in state and local health departments.
CDC is connected to a training network with the capacity to access health professionals working at the federal, state, and local levels. Direct training of field staff by CDC staff is less important than it once was as management of STD programs has become more decentralized. However, CDC remains in a position to have an impact on public health practice through funding and guidance of training in schools of public health, professional schools, and other professional settings.
Prevention Training Centers are funded by CDC in 10 schools of public health to provide specialized training in STD prevention and control. Courses are delivered largely by faculty in grantee institutions - usually schools of public health or medical schools - with CDC providing guidance in curriculum development and methodology. Specific content of these programs depends on individual schools, but a core of STD prevention and control topics are specified in the funding document, including courses in community mobilization and community capacity building. Another program, recently implemented, will fund certification programs for federal STD field staff in five universities across the country.
CDC also exerts leadership in the development of STD prevention and control methodologies by publishing technical guidance documents and guidelines for the public and private health sectors. The development of program and practice guidelines for STD prevention and control is an important CDC function in support of state and local health departments. Examples of these are the 1993 Sexually Transmitted Diseases Treatment Guidelines and CDC Guidelines: Improving the Quality, published in September 1996. In addition to guidelines, CDC provides surveillance reports and other technical guidance reports to the public.
1.4 Report Organization
The following sections describe our case studies of factors affecting the epidemiology and management of syphilis in the South. Section 2 presents the project's methodology including the site selection criteria and data collection and analysis methods. Section 3 summarizes the case studies and Section 4 develops findings from the case study evidence. Section 5 discusses the implications of these findings for the prevention and control of syphilis and, more broadly, for STDs generally. We conclude this section with recommendations for improvements to STD programs based on what we have learned.
This report is accompanied by four appendices. Appendix A contains the case study protocol, Appendix B contains the study instruments, Appendix C contains the study code book, and Appendix D contains the full case study reports.