Pertussis (Whooping caugh)

-Automatic translation

Whooping cough is a severe respiratory infection in children, especially in the first months of life, but in adolescents and adults the disease is known by chronic and persistent coughing, but it is more common that the infection simply causes cold symptoms in these age groups. The infection is caused by a toxin-producing bacterium that causes severe coughing fits that can be life-threatening in children within the first six months of life.

Epidemiology

In the years around 1930-1940, thousands of people died from whooping cough, but the introduction of a vaccine against the disease has dramatically reduced the mortality rate from it. The spread of the disease has been increasing in the last 20 years, however, and the World Health Organization believes that between 20–40 million cases occur every year in the world, mostly in developing countries.

Despite good participation in pertussis vaccination, epidemics have occurred every 3–5 years in many countries among adults and older children. The reason is that the protective effect of the vaccination is greatest in the first years following vaccination and repeated booster doses are needed to maintain the protection. Moreover, vaccination does not completely protect against infection, but primarily against serious illness.

Transmission routes and incubation periods

Human-to-human transmission occurs via respiratory (e.g. coughing, sneezing) techniques. Individuals are infectious from the onset of symptoms and generally for two weeks after the onset of cough. The incubation period of the disease, the period between the time an individual becomes infected and the onset of symptoms, is usually around 2–3 weeks.

Symptoms of the disease

Symptoms are, at first, mild colds, followed by a growing cough, mucus build-up, and severe coughing fits, especially at night. After about two weeks, symptoms progress to growth with an intense coughing fit accompanied by characteristic sucking sounds upon inhalation. Other symptoms include sneezing, runny nose and fever. Symptoms of the disease may persist for up to 10 weeks. Young children in the first six months of life are particularly prone to severe consequences of the infection, which may include respiratory arrest, seizures, pneumonia, brain dysfunction and death.

Diagnosis

Confirmation of the disease can be achieved by nasopharyngeal biopsy and bacterial DNA search (PCR test). Samples should be taken as soon as possible after the onset of illness. The throat smear is a much smaller sample for pertussis detection than the nasopharyngeal smear.

Culture of the bacteria from the nose/nasopharynx and serological testing are possible tests that are currently under-represented.

Treatment

Treatment depends on the severity of the disease. Antibiotics do little good, except very early on in the disease process, primarily to reduce the transmission of the bacteria to others. Other treatments include rest, fluid intake, and nutrition. Small children with pertussis often need to remain in the hospital for long periods.

Prevention

Vaccination is effective in preventing the disease in young children. It is essential to start vaccinating young children because the disease is most dangerous in children under six months of age. In Iceland, children are vaccinated at 3, 5 and 12 months of age and revaccinated at ages 4 and 14. The vaccine does not protect for longer than ten years, so there is a chance of infection later in life. Regular immunisation of adults has been recommended in many countries, but routine revaccination of health care workers is recommended only for health care professionals in Iceland.

Vaccination of pregnant women significantly reduces the disease in children in the first year, especially children under three months of age who have not been vaccinated themselves. Since 2019, all pregnant women have been offered pertussis vaccination in antenatal care.

Stopping pertussis spread

Once symptoms start, individuals with pertussis should reduce contact with infants to a minimum of two weeks after the start of coughing (if vaccinated within ten years) or longer (unvaccinated or more than ten years after the last dose). People with whooping cough are generally contagious when symptoms appear and for 2 weeks after the cough starts, often total about 4 weeks. Unvaccinated people can be contagious for longer.

• Avoid being around young children (<1 year old) and pregnant women while you are contagious.

• Avoid large gatherings for approx. two weeks and use a face mask if you have to go places where there are others while symptoms are severe.
  

If a child in kindergarten or school gets pertussis, it is right for the child's family to alert the school so that other children's relatives can be informed about pertussis infection at school. Families in a vulnerable position due to whooping cough can then receive advice from their doctor on measures to reduce the risk of infection within the family.

How to Avoid Children from Whooping Cough?

• Vaccination against pertussis with the two-dose vaccine is a safe protection.

• In Iceland, pertussis vaccinations are given at 3, 5, and 12 months of age and revaccinated at 4 and 14 years of age.

Complications of pertussis

Most of the time, whooping cough improves without causing significant problems. Those at highest risk of complications are children under one year of age, especially under six months of age and unvaccinated.

The risk of complications is reduced in older children and adults and in the vaccinated population in general.

Vaccination of pregnant women significantly reduces the disease in children in the first year, especially children under three months of age who have not been vaccinated themselves. Vaccination against pertussis is recommended during each pregnancy.

In children under six months of age and particularly under three months of age who are not vaccinated, there is a high risk of serious illness with complications such as respiratory arrest, seizures, pneumonia, encephalitis and even death.

Common complications

Under one year of age:

• Respiratory arrest

• Pneumonia

• Seizures

Older children and adolescents (in relation to coughing fits):

• Fainting

• Broken rib

Uncommon complications

Under one year of age:

• Encephalitis

• Death

See more:

• European Centre for Disease Prevention and Control (ECDC)

• World Health Organization (WHO)

• Pertussis (whooping cough) diagnosed in Iceland - First cases since 2019. News published on April 10, 2024

Diseases subject to registration

Diseases subject to registration can spread widely in society and, at the same time, threaten public health. Doctors must notify The Chief Epidemiologist of persons sickened by whooping cough with the personal identification number of the infected person. Still, reports to the Chief Epidemiologist are also received from laboratories that confirm the diagnosis. The purpose of reporting an infectious disease is to prevent the spread of infection through targeted measures, e.g., isolation, treatment of the infected, and tracking of transmission between individuals. Information about the probable transmission place, transmission time, and symptoms must accompany notifications to satisfy these conditions. In this way, infected persons can be linked epidemiologically, the effects of the infection can be assessed, and a response can be taken.