Whooping Cough Outbreaks

According to the Clearfield County Department of Health, there was a recent pertussis outbreak in the local Amish community.

Whooping cough (pertussis) is an endemic (common) disease in the United States. It is a contagious respiratory illness and spreads easily from person to person. Outbreaks may occur in settings such as schools, childcare centers, hospitals, or in large geographic areas.

Infectious agent: Bacteria: Bordetella pertussis (B. pertussis)

Transmission

Commonly occurs by the respiratory route through contact with respiratory droplets, OR

• By direct contact with airborne droplets of respiratory secretions.
• Occurs less frequently by contact with freshly contaminated articles of an infected person.

Clinical manifestations:

Pertussis is an acute infection of the respiratory tract. The clinical course of the illness is divided into three stages:

Catarrhal phase

• Characterized by insidious onset of mild upper respiratory symptoms including low- grade fever, coryza (runny nose), sneezing, and a mild, occasional cough.
• During the 1 – 2 weeks of this stage, the cough gradually becomes more severe.

Paroxysmal phase

• Characterized by spasmodic coughing episodes, or paroxysms, sometimes followed by a long inspiratory whooping sound. Paroxysmal attacks occur more frequently at night.
• Patients may become cyanotic during paroxysms.
• Children and young infants may appear very ill and distressed.
• Post-tussive vomiting and exhaustion commonly follow the episode. • The person does not appear ill between attacks.
• This stage usually lasts 1 – 6 weeks but may persist for up to 10 weeks.

Convalescent phase

• Recovery is gradual.
• Paroxysms subside and the cough may disappear in 2 – 3 weeks.
• Paroxysmal episodes may return with other respiratory infections.
• This stage can persist for weeks to months.

Testing and diagnosis

The diagnosis of pertussis is based on a characteristic clinical history as well as positive culture or PCR results. These tests are more reliable when performed early in the course of the illness. All specimens should be nasopharyngeal specimens, not pharyngeal (throat). Testing of asymptomatic contacts is NOT necessary and should be discouraged.

Antibiotics for pertussis treatment and prophylaxis

Identifying whooping cough outbreaks

Whooping cough outbreaks can be difficult to identify and manage, and cases of whooping cough may go unreported. Other respiratory bacteria and viruses often cause symptoms similar to whooping cough. Also, the bacteria that cause whooping cough can spread at the same time as other bacteria and viruses.

There are peaks in reported cases of whooping cough every few years and frequent outbreaks. During whooping cough outbreaks, public health officials focus on protecting babies and people at high risk from getting sick and dying from whooping cough. A second goal is to protect people of all other ages from getting whooping cough.

Responding to outbreaks

Whooping cough is a nationally notifiable disease and doctors should notify the appropriate health department of all people that may have whooping cough. State and local health departments take the lead on outbreak investigations and may involve CDC as needed.