The Hundred Day Cough
Author's note: the accompanying photo is not the patient described in this story. The story is fiction.
The latest epidemic of whooping cough to hit southwest Alaska started about two months ago in one of the coastal villages. An eight-week old girl, scheduled to have her first round of immunizations in a week, was brought to the village clinic by her mother because "sometimes she just stops breathing." Mom had noticed two episodes of apnea with peri-oral cyanosis; both times she responded to direct stimulation and started breathing again, but Mom was worried. Mom reported that the infant had a slight cough which seemed worse at night.
On physical exam by the health aide, the baby looked fine. She had normal vitals, was breathing well, and had no runny nose or watery eyes. Her cough was minimal. But as the health aide watched her lying on the exam table, she simply stopped breathing. Again, she responded to stimulation.
The baby was medevac'd to the Alaska Native Medical Center in Anchorage, where she was diagnosed with pertussis. She was treated with antibiotics and admitted for supportive care for a few days, and then discharged home with her parents.
Within two weeks there were four more cases of pertussis in her village, two in kids less than one year of age, and two in teenagers. Soon cases showed up in a neighboring village. By the time the epidemic ended there were 24 cases in four villages. Health aides became very adept at performing nasopharyngeal swabs.
Whooping cough is an infection of the respiratory system caused by a bacterium, Bordetella pertussis. Its close cousin, Bordetella bronchiseptica, causes kennel cough in dogs. When untreated, whooping cough is an illness with three stages. The early stage, or catarrhal phase, is much like any viral upper respiratory illness; it produces runny nose, watery eyes, dry cough and sometimes low-grade fever. It lasts for one to two weeks. The middle, or paroxismal phase, causes the characteristic coughing paroxisms that end in a sudden whooping inspiration, and can end in vomiting. This phase may last several weeks. The final or convalescent phase is a gradual decline of all symptoms; though a persistent cough may last for many more weeks, it will not be as intense or paroxysmal as earlier in the illness.
Pertussis is highly contagious and is spread by droplet transmission of respiratory secretions. The biggest risk factor for getting it is being coughed on by someone with active disease. In most village homes in southwest Alaska, crowding is the norm; from five to twelve people often live in a rather small home, which increases the likelihood of disease transmission.
The population at biggest risk from the infection is very young babies, who do not usually have the characteristic whoop. Neither immunization nor disease confers immunity for more than a few years, and children are not routinely immunized for it after age 5 years. In adults, it typically causes minimal illness, and boosters have not been routinely recommended. Adults are recognized as a potential reservoir of bacteria which can be transmitted to children.
When the epidemic was recognized in the coastal villages, a public health effort was quickly put into place. The physician assistant/nurse practitioner team from the closest subregional center traveled to each village with identified cases. They addressed a "town hall" type meeting of the entire village and educated the villagers about pertussis with handouts, videos, and an audio tape of the sound of the cough. Villagers were asked to identify themselves to their health aides, or to the PA and NP if they felt they had symptoms consistent with pertussis. Many came forward. All were tested. Those the mid-levels felt had symptoms truly consistent with the disease were treated prophalactically with macrolide antibiotics (erythromycin, azithromycin); and all positives were treated.
The educational sessions were also an opportunity to get immunizations updated on those who were behind. Over a hundred DTaPs were given during the four educational sessions. Adults are also now being immunized with TDaP to see if boosting them with pertussis vaccine will decrease the burden of disease in young children.
Labels: Bush Medicine