AIDS/HIV Surveillance and Epidemiologic Investigation

Surveillance activities measure and monitor the prevalence and patterns of progression of HIV and AIDS. An HIV surveillance system continuously and systematically collects, analyzes, evaluates, and disseminates data describing characteristics of the HIV epidemic. Much of surveillance focuses on case finding because it provides the data upon which other activities and services (trend analysis, partner notification, early intervention and prevention) are based.

Data gathered through surveillance

  • Provides current information on the status of the epidemic and the development of trends.
  • Indicates the magnitude and extent of medical, economic and social impact and need.
  • Identifies levels and trends of HIV infection that are necessary for developing, targeting, and evaluating both prevention and care and treatment programs.
  • Provides information on which to base decisions about policy development and resource allocation.

History of AIDS/HIV surveillance in Wisconsin

In the early to mid-1980s, AIDS surveillance in Wisconsin was strictly passive. It was conducted by one person on a case-by-case basis from reports submitted by physicians, many who were seeing their first patient with AIDS. Because there was no approved test for HIV in the early 1980s, cases were confirmed using clinical criteria based on a crude CDC case definition.

In March 1985, the FDA approved the HIV enzyme immunoassay (EIA) and Western blot test for screening blood products to ensure safety of the blood supply. The test was quickly adapted in clinical settings and the Wisconsin legislature enacted legislation in the fall of 1985 requiring all positive confidential HIV tests be reported to the state epidemiologist. Wisconsin was one of the first three states in the nation to enact such legislation. Simultaneously, the Wisconsin Alternate Counseling and Testing Site (CTS) Program was established to defer persons at risk of HIV infection from seeking testing at blood/plasma centers.

By the spring of 1986, the AIDS/HIV Program initiated active surveillance with hospitals statewide and passive laboratory-based reporting. Over time, surveillance data collection methods have been streamlined and automated. Sentinel physicians and hospitals/clinics are continuously visited by surveillance staff to strengthen the surveillance network and enhance reporting.

Surveillance activities

Confidential, name-associated reporting of confirmed HIV infection and AIDS to the state epidemiologist is required by Wisconsin statute (s. 252.15). Case reports are submitted to the Wisconsin AIDS/HIV Program from private physicians, hospitals, clinics, ambulatory care facilities, sexually transmitted disease clinics, the Wisconsin correctional system, family planning clinics, perinatal clinics, Indian health clinics, blood and plasma centers, military entrance processing stations, and laboratories performing HIV testing.

Other sources of AIDS/HIV surveillance data include state entitlement programs (AIDS/HIV Drug Assistance Program and AIDS/HIV Health Insurance Premium Subsidy Program), the vital records death certificate registry, and the tuberculosis (TB) registry.

AIDS and HIV reports are reported directly to the state epidemiologist rather than to local health departments.

Laboratory-based reporting is required by law. Laboratories performing confidential name-associated HIV confirmatory testing (Western blot, viral load, CD4) report to the AIDS/HIV Program the name of the subject of all positive samples and the name of the physician who ordered the test. This is useful in identifying newly infected persons. The surveillance team uses these lists to ensure that all case reports are received from clinicians.

Once collected, surveillance data is analyzed to define the demographics of the epidemic in Wisconsin. This information can be used by prevention staff to focus interventions, identify objectives for the Statewide Action Planning Group, identify trends, and provide essential data for program planning and resource allocation. The numbers of cases of AIDS and HIV are also used to determine program funding from the federal and state government.

Security of surveillance records has always been a priority for the Wisconsin AIDS/HIV Program. Physical security measures have become increasingly sophisticated through the use of automated technology that is integrated with the security services of state law enforcement personnel. Written policies and procedures ensuring security include annual in-servicing of staff, locating staff who handle patient/client data in a restricted area, and signed confidentiality assurances by individual Program staff.

Surveillance staff continue to look for ways to improve case-finding methods, increase onsite visits at clinical settings (especially outpatient clinics), and investigate new technologies for efficiently managing highly confidential information.

For additional information about the surveillance activities of the Wisconsin AIDS/HIV Program, contact Emily Lankau at 608-264-9823.

Last Revised: May 1, 2018