News Release

HDHHS Office of Public Affairs

Contact: Kathy Barton at 713-794-9998 or Porfirio Villarreal at 713-794-9021,

March 6, 2002


Local AIDS Cases Decline; Federal Report Confuses True Scope of Disease Pattern

Officials at the Houston Department of Health and Human Services (HDHHS) report a continuing decline in AIDS case rates for Houston and Harris County since 1997. A recently released federal report which utilized mid-year figures (July through June 1999-2001) and date-of-report data led many media outlets throughout the nation to jump to erroneous conclusions about rising and falling AIDS case rates.

"Various methods of analysis may appear to be in conflict when in fact they are not. Some data analysis methods may also be a measure of work activity, such as the implementation of reporting of HIV infection by name, rather than a reflection of changes in the epidemic," says Kaye Reynolds, HDHHS' HIV/AIDS Surveillance Coordinator.

HDHHS and most state and federal public health agencies utilize the date of diagnosis for public reporting of disease trends. Physicians, laboratories and hospitals are required by law to report communicable diseases, including HIV infection and AIDS, to local public health authorities so that analysis, investigation and prevention efforts can occur. Physicians, laboratories and hospitals may batch reports and delay reporting by weeks or months and local public health authorities may be further delayed in entering cases into data bases for analysis.

"Statistical analysis for any disease by date of report will often provide seeming peaks and valleys of disease which do not really exist," says Reynolds.

Also case numbers may be affected by changes in the case definition, the medical criteria which defines a disease. A major spike occurred nationally in 1993 when the case definition for AIDS was expanded to include additional opportunistic infections. Because of the new definition, hundreds of new cases locally were reported for disease that began, sometimes, years before (see chart).

The following chart shows superimposed on each other the number of AIDS cases diagnosed in Houston and Harris County in each year and the number of AIDS cases reported the last 20 years. The dashed line represents the number of reported cases, showing various peaks and valleys caused by surveillance changes; the solid line shows the number of AIDS cases diagnosed, a much smoother line with a significant downward trend in the last five years.

Note: to see the color-coded charts better, click here for the pdf version of this news release.

Most of the decrease in the number of AIDS cases diagnosed each year can be attributed to the advances in medical therapy protocols for treatment of HIV infection. Since the advent of highly active antiretoviral therapy (HAART) including protease inhibitors in 1996, many more people are able to live longer and healthier lives with HIV infection, without progressing to the severe illness of immunosuppression that is termed AIDS.

Note: to see the color-coded charts better, click here for the pdf version of this news release.

As can be seen by the above chart, the numbers of people living with reportable HIV disease each year is increasing. The estimate of the total number of people living with HIV disease, whether reportable or not, whether diagnosed or not, exceeds 20,000.

Another important feature of the epidemic is the increasing number of minorities and women living with HIV. Prevention and care efforts are targeted towards addressing both the increasing number of people needing services and prevention messages, as well as the differing populations who need those services and messages.