Whooping Cough Cases Up Sharply in the Southland

Whooping cough, a once-dreaded childhood disease that became a rarity a generation ago, is up sharply across Southern California, particularly in Orange County.

Health officials counted 96 cases of the disease -- including two deaths -- through Nov. 29 in Orange County, compared to 15 cases in the same period last year. The figure is higher than any annual total recorded since 1958, when there were 133 cases.

Similar patterns, though less dramatic, are seen elsewhere in the region. Los Angeles County, with about 120 cases and two deaths, is running about 20% above last year’s figure.

The trend is part of a general rise that has been underway for years and far exceeds population growth. Nationally, the number of cases reported to the Centers for Disease Control has grown more than seven-fold over the last 25 years.

Much of the increase is seen in babies who have not completed their vaccinations, said A. Nelson El Amin, medical director of the Los Angeles County Immunization Program.

But the reason for the increase remains a puzzle.

“No one really knows the answer why there’s this long-term trend of gradual increase, even though immunization coverage has gotten higher,” said Dr. Loring Dales, medical officer in the Immunization Branch of the California Department of Health Services.

Whooping cough was a major cause of death among infants before the vaccine was introduced in the mid-1940s.

The disease, also called pertussis, is caused by a bacteria that is spread when a sick person coughs. The disease is characterized by fits of coughing so severe that the victim may turn blue around the mouth as a result of lack of oxygen.

The disease gets its name from the high-pitched “whoop” the sick person makes when trying to suck in air while coughing.

Whooping cough can kill by cutting off the oxygen supply or by leading to secondary infections such as pneumonia. The bacteria also produce toxins that can kill. The disease is treated with antibiotics.

Children receive whooping cough immunizations as part of the DPT or DTaP series, along with diphtheria and tetanus vaccines. The series of five vaccinations are recommended at 2, 4 and 6 months, between 12 and 18 months, and between 4 and 6 years. The complete series is required in California before a child enters kindergarten.

When the series is completed, the vaccine is about 85% effective. Unlike the measles vaccine, the pertussis series wears off after several years. When introduced, the vaccine dramatically reduced the number of cases of whooping cough, which peaked at 21,344 in California in 1941, killing 112. The number of cases dropped to 75 in 1976.

The disease runs in cycles, spiking higher for three to four years and then falling. But beneath that has been the general trend of an increasing number of cases. The peak in recent years was 1,140 in 1999.

According to the CDC, the number of whooping cough cases among children 6 months to 4 years old has remained stable, meaning the vaccine still works. Babies who catch the disease before their vaccinations are complete are infected by adults who may not realize they have whooping cough.