measles, mumps, pertussis, rubella

• In 1997, there were:

*  2 cases of measles (consistent with the preceding five years)
*  5 cases of pertussis (lower than in 1996, but comparable to 1995)
*  3 cases of rubella (this is the highest number of cases since 1991)
*  1 case of mumps (there has been a steady decrease in mumps cases since 1991) ⁶⁵³

hepatitis C

• 1998 projections predict that there will be 65.7 hepatitis C carriers (seropositives, both acute and non-acute by serology) per 100,000 population in San Mateo County. This rate has climbed substantially over the past four years (up from 1.5 per 100,000 in 1994). Hepatitis C only became reportable in 1994. This increase does not reflect an increase in hepatitis C during the study period, but reflects cases whose infections were in the past or distant past and are just now being diagnosed. Very little is known about the epidemiology, either prevalence or incidence, of hepatitis C in San Mateo County. ⁶⁵⁴

enteric disease

Enteric diseases are gastrointestinal illnesses caused by bacteria, parasites or viruses. Transmission from person to person is via hand-to-mouth. A person must actually ingest the organism in order to become infected. Enteric diseases are among the most frequently reported diseases.

salmonellosis

• In 1997, there were 208 salmonellosis cases reported in San Mateo County. ⁶⁵⁵

• The 1997 salmonellosis case rate in San Mateo County was 29.8 cases per 100,000 population. The 1996 San Mateo County rate was 24.0 per 100,000; this rate is well above both the state and U.S. rates in 1996 (20.2 and 17.2 per 100,000) and fails to satisfy the Year 2000 objective (16 or fewer cases per 100,000). ⁶⁵⁶

• Furthermore, the San Mateo County salmonellosis incidence rates have increased considerably since 1994, as shown in the chart below. ⁶⁵⁷

shigellosis

• In 1997, there were 80 shigellosis cases reported in San Mateo County (shigellosis is also known as dysentery). ⁶⁵⁸
• While shigellosis case rates have decreased in San Mateo County (from 21.3 in 1995 to 12.9 per 100,000 in 1996), the 1996 rate remained above both state (12.2) and U.S. (9.8) rates. The San Mateo County rate, however, decreased to 11.5 per 100,000 in 1997. ⁶⁵⁹

campylobacter

• In 1997, there were 331 campylobacter cases, down from a high of 457 cases reported in 1994. ⁶⁶⁰

Hepatitis A

• There were 73 cases of hepatitis A reported in 1997, down from 106 cases in 1996, but higher than the 66 cases reported in 1995. ⁶⁶¹
• The 1997 case rate for Hepatitis A in San Mateo County was 10.6 per 100,000 population. While this is lower than the 1996 rate, it is higher than any other year since 1990. ⁶⁶²
• The 1996 San Mateo County rate was 15.2 per 100,000 population; the 1996 rate was higher than the national rate (11.7 per 100,000), but lower than the state rate (20.5 per 100,000) and the Year 2000 objective (23 or fewer per 100,000). ⁶⁶³

652  Healthy San Mateo 2000: Health Status Indicators. San Mateo County Department of Public Health. Summer 1998 Edition.