Ten people have now died so far this year in California from pertussis (whooping cough), all of them babies, in what may well become the worst whooping cough year in the state’s history. So far, 5,978 of confirmed, probable and suspected cases have been reported to authorities, the highest number since 1950 when there were 6,613 reports. With 2.5 months to go before this year ends, and 320 new reports coming in over the last week, there is a good chance that record will be broken. The latest fatality, a 6-week prematurely born baby, was being treated in San Diego’s Rady Children’s Hospital.

According to CDPH (California Department of Public Health), the state’s whooping cough incidence rate stands at 15.3 cases per 100,000 – the highest since 1959 (16.1 per 100,000). Of the 320 reported cases over the last week, 67% are confirmed, 16% probable and 17% suspect.

57% of all pertussis cases that have been hospitalized were babies up to three months of age, 74% were aged up to six months. Three-quarters of all hospitalized babies with known race and ethnicity were Hispanic.

Of the ten fatalities, 9 were Hispanic babies. All of the babies who died were up to two months of age when whooping cough symptoms emerged – none of them had received any kind of whooping cough vaccine. The other fatality was a 28-week old baby who had been born prematurely and had been given the first DTaP dose just 15 days before the onset of whooping cough symptoms.

CDPH adds that most reported cases of whooping cough this year involved babies up to three months of age.

Highlighted below are some figures published on 19th October by CDPH:

  • Incidence rate for babies aged up to six months – 294.7 per 100,000
  • Rate for babies/children aged 6 months to six years – 36.3 per 100,000
  • Rate for children aged 7 to 9 years – 45.2 per 100,000
  • Rate for children aged 10 to 18 years – 33.2 per 100,000 (mostly 10/11 years old)
  • Rate for Hispanics of all ages – 15.5 per 100,000
  • Rate for Caucasians of all ages – 13.1 per 100,000
  • Rate for Hispanic infants aged up to 3 months – 370 per 100,000
  • County rates range from 0 to 135 per 100,000 for all ages

Below are whooping cough cases and rates by county up to October 19th, 2010 (Source: CDPH):

  • CALIFORNIA, cases 5978, rate (per 100,000) 15.28
  • ALAMEDA, cases 265, rate (per 100,000) 18.49
  • City of Berkeley, cases 9, rate (per 100,000) 8.40
  • ALPINE, cases 0, rate (per 100,000) 0.00
  • AMADOR, cases 3, rate (per 100,000) 7.53
  • BUTTE, cases 27, rate (per 100,000) 11.90
  • CALAVERAS, cases 7, rate (per 100,000) 14.83
  • COLUSA, cases 11, rate (per 100,000) 47.20
  • CONTRA COSTA, cases 133, rate (per 100,000) 12.49
  • DEL NORTE, cases 16, rate (per 100,000) 52.23
  • EL DORADO, cases 42, rate (per 100,000) 22.54
  • FRESNO, cases 489, rate (per 100,000) 50.69
  • GLENN, cases 0 , rate (per 100,000) 0.00
  • HUMBOLDT, cases 40, rate (per 100,000) 29.85
  • IMPERIAL, cases 9, rate (per 100,000) 4.87
  • INYO, cases 3, rate (per 100,000) 15.72
  • KERN, cases 299, rate (per 100,000) 35.04
  • KINGS, cases 18, rate (per 100,000) 11.18
  • LAKE, cases 3, rate (per 100,000) 4.50
  • LASSEN, cases 0, rate (per 100,000) 0.00
  • LOS ANGELES, cases 830, rate (per 100,000) 8.46
  • City of Long Beach, cases 61, rate (per 100,000) 12.38
  • City of Pasadena, cases 15, rate (per 100,000) 9.99
  • MADER, cases 116, rate (per 100,000) 73.30
  • MARI, cases 317, rate (per 100,000) 125.04
  • MARIPOSA, cases 10, rate (per 100,000) 52.81
  • MENDOCINO, cases 24, rate (per 100,000) 25.96
  • MERCED, cases 105, rate (per 100,000) 39.22
  • MODOC, cases 0, rate (per 100,000) 0.00
  • MONO, cases 5, rate (per 100,000) 34.27
  • MONTEREY, cases 42, rate (per 100,000) 9.76
  • NAPA, cases 19, rate (per 100,000) 13.49
  • NEVADA, cases 23, rate (per 100,000) 22.59
  • ORANGE, cases 375, rate (per 100,000) 11.76
  • PLACER, cases 49, rate (per 100,000) 14.38
  • PLUMAS, cases 2, rate (per 100,000) 9.20
  • RIVERSIDE, cases 255, rate (per 100,000) 11.70
  • SACRAMENTO, cases 118, rate (per 100,000) 8.21
  • SAN BENITO, cases 3, rate (per 100,000) 4.80
  • SAN BERNARDINO, cases 77, rate (per 100,000) 3.60
  • SAN DIEGO, cases 543, rate (per 100,000) 17.13
  • SAN FRANCISCO, cases 88, rate (per 100,000) 10.81
  • SAN JOAQUIN, cases 55, rate (per 100,000) 7.60
  • SAN LUIS OBISPO, cases 362, rate (per 100,000) 135.10
  • SAN MATEO, cases 119, rate (per 100,000) 16.21
  • SANTA BARBARA, cases 54, rate (per 100,000) 12.54
  • SANTA CLARA, cases 272, rate (per 100,000) 14.91
  • SANTA CRUZ, cases 62, rate (per 100,000) 23.24
  • SHASTA, cases 20, rate (per 100,000) 10.58
  • SIERRA, cases 0, rate (per 100,000) 0.00
  • SISKIYOU, cases 10, rate (per 100,000) 21.34
  • SOLANO, cases 14, rate (per 100,000) 3.21
  • SONOMA, cases 213, rate (per 100,000) 43.34
  • STANISLAUS, cases 127, rate (per 100,000) 23.12
  • SUTTER, cases 3, rate (per 100,000) 3.00
  • TEHAMA, cases 6, rate (per 100,000) 9.28
  • TRINITY, cases 0, rate (per 100,000) 0.00
  • TULARE, cases 115, rate (per 100,000) 25.19
  • TUOLUMNE, cases 9, rate (per 100,000) 15.40
  • VENTURA, cases 64, rate (per 100,000) 7.56
  • YOLO, cases 18, rate (per 100,000) 8.88
  • YUBA, cases 4, rate (per 100,000) 5.10

Source: California Dept of Public Health (CDPH)

Written by Christian Nordqvist