COMMUNICABLE DISEASES

What Was Measured?
The incidence of communicable diseases in San Mateo County is measured.  The data shows AIDS and tuberculosis cases from 1985-1992 and sexually transmitted diseases (STD) and enteric (intestinal) diseases (i.e. salmonella, hepatitis A, shigella, and campylobacter) cases from 1990-1992.

Why Is This Important?
Measuring a community's incidence of communicable diseases is a way to monitor its progress in reducing preventable disease and death.  It can also help a community evaluate the effectiveness of educational and preventative programs and reduce disparities in health care for different segments of the population.  Rising numbers indicate higher health care costs as well as increased suffering and a lower quality of life for both those who are ill and their family members.  Higher numbers of communicable diseases frequently result in high rates of absenteeism in schools and places of employment.

What Was Found?
The number of new AIDS cases reported each year in San Mateo County went from 0 in 1982 to 140 cases in 1992 with a total of 836 new cases reported during that ten-year period.  Whites accounted for 73 percent of the cases, followed by 13 percent for African-Americans, and 10 percent for Hispanics.

The number of new tuberculosis cases rose from 32 in 1985 to 82 cases in 1992, an increase of 156 percent.  The majority of cases occurred in those born outside the United States, although the number among US born has been increasing since 1989.

Between 1990 and 1992, the cases of salmonella and hepatitis A remained stable, shigella cases declined, and campylobacter cases increased.  In 1992, 33 percent of shigella cases and 21 percent of salmonella cases occurred in children under 5 years of age, while campylobacter occurred most frequently in 19-34 year olds.

Between 1990 and 1992, chlamydia cases remained relatively stable while both gonorrhea and syphilis cases declined, 44 percent and 65 percent, respectively.  Women accounted for nearly three-fourths of all STD cases, and people under 25 years of age made up over 50 percent of cases reported during 1992.  Of cases reported with race/ethnicity information, 35 percent were Hispanic, 33 percent were African-American, and 20 percent were White.

What Is The Trend?
There was a significant rise in communicable diseases in San Mateo County between 1985 and 1991, but the reported cases declined between 1991 and 1992.  While sexual contact continues to be the primary mode of transmission, AIDS cases among intravenous drug users and women have been increasing steadily.  Reasons for the rise in tuberculosis cases include increased immigration, less rigorous control programs, and a rise in HIV infections.  Though the rate of STDs is declining, young women continue to have a high rate of infection.

Source: Healthy San Mateo 2000, Health Status Indicators, Fall 1994

Researcher: Carla Bagneschi