Your Health: The lowdown on the whooping cough epidemic

According to a recent public health alert, California is experiencing an epidemic of pertussis. Santa Cruz County has had 20 known cases and probably many more that have not been reported or have yet to be diagnosed.
Pertussis, also called whooping cough, is a highly contagious infection of the lower respiratory tract, involving the lungs. It usually manifests as a mild persistent cough but can advance to a severe cough. Often in children, this cough is followed by a high-pitched intake of breath that sounds like “whoop” — thus the common name whooping cough.
Pertussis is caused by a bacteria germ, not a virus. It is passed from an infected person who sneezes or coughs and therefore spreads by infected tiny droplets into the lungs of anyone who might be nearby. Once in the lungs, the germs can cause an infection, creating inflammation and a narrowing of the lungs’ breathing tubes. This produces the cough and the characteristic whooping sound.
Infants are particularly vulnerable, because they are not fully immune to whooping cough until they’ve received at least three immunization shots. This leaves babies 6 months and younger at greatest risk of catching the infection. Also, the pertussis vaccine one receives as a child wears off in five to 10 years, leaving most teenagers and adults susceptible to the infection during an outbreak.
The diagnosis of pertussis is often delayed or missed in infants, because early symptoms are often mild and the serious cough might not begin until days or even weeks later. A severe infection in infants can be fatal, although thankfully this is rare. Five infant deaths have been reported in California since the beginning of the year.
One must consider pertussis for anyone with a cough that lasts more than two weeks, especially when the cough is worse at night and the patient has prolonged coughing spells but generally feels quite well otherwise.
The vaccine for pertussis comes combined with the tetanus and diphtheria vaccines that are routinely given to children in their first years of life and to adults every 10 years. Talk to your doctor about it.
Besides infants, those who especially need the vaccine’s protection are pregnant women in their third trimester, because they will soon have contact with their unprotected infants. Mothers have been found to be the greatest source of transmitting whooping cough germs to newborns.
Infants can also be protected by vaccinating those people who have close contact with them. This “family” protection has been highly successful with susceptible infants.
Tests are available to diagnose pertussis. The decision whether to test should be left to a doctor, however, as in most cases, the diagnosis can be made on symptoms alone.
Antibiotics can be effective, especially when given soon after symptoms begin. After several weeks of symptoms, they are much less effective. Family members can also be prescribed preventative antibiotics.
Remember that pertussis is caused by bacteria and can usually be treated with an antibiotic, but if you just have a bad cough because of bronchitis, which is caused by a virus, antibiotics will not be effective. Your doctor will be able to determine the proper diagnosis and treatment.
Terry Hollenbeck, M.D., is an urgent-care physician at the Palo Alto Medical Foundation Santa Cruz in Scotts Valley. A doctor with 36 years’ experience, he invites readers to view his previous columns on his website, valleydoctor.wordpress.com. Information in this column is not intended to replace advice from your own health care professional. For any medical concern, consult your doctor.