As global cases of whooping cough rise, PAHO calls on countries to strengthen surveillance and increase vaccination – PAHO/WHO

Washington DC, July 24, 2024 (PAHO).- In light of the increase in cases of whooping cough worldwide and in some countries in the Americas, the Pan American Health Organization (PAHO) has issued an epidemiological alert, calling on countries to strengthen surveillance and ensure constant monitoring of vaccination coverage in children.

Whooping cough is a highly contagious respiratory infection caused by the bacteria Bordetella pertussis. It is easily spread from person to person through coughing and sneezing and is a leading cause of illness and death among children. If treated early, antibiotics can help prevent severe symptoms.

Globally, an average of 170,000 cases of pertussis were reported annually between 2010 and 2019, and a significant decrease in this number was observed during the COVID-19 pandemic. However, in the World Health Organization’s European region, a significant increase in cases was recorded during the second half of 2023 and during the first months of 2024.

In the Region of the Americas, since 2012, when pertussis cases reached 72,328, there has been a progressive annual decrease in the number of reported cases, reaching 3,283 in 2022. However, in 2024, cases have increased in several countries, including Brazil, Mexico, Peru and the United States.

The reported increase in cases is likely due to a significant decline in coverage of diphtheria, tetanus, and pertussis (DTP) vaccines, mainly during the COVID-19 pandemic period. In 2021, coverage of the first and third doses of this vaccine in the Americas region reached a 20-year low, at 87% and 81% respectively. Coverage data for 2023 show a recovery of 90% and 88% respectively, with variations both between and within countries.

Symptoms of whooping cough usually appear 7 to 10 days after infection. They include a mild fever, runny nose, and a dry cough followed by a wheezing sound when coughing (hence the name of the disease).

To address the surge in cases, in its alert, PAHO recommends that countries ensure that vaccination coverage of the three doses of DTP is greater than 95% in children and “they should analyze vaccination coverage in children aged 1 year and under 5 years, with special emphasis on identifying population groups with low coverage.”

Vaccination is also recommended for healthcare workers, particularly those working in maternity wards, as well as pregnant women.

The PAHO alert also calls on countries to strengthen surveillance to ensure that each outbreak of whooping cough is “carefully investigated to improve understanding of the epidemiology of the disease in the Americas.”

Countries should also strengthen their laboratory diagnostic capabilities “to improve the reporting and characterization of pertussis outbreaks in the region.”

Suspected cases should be kept separate from infants and young children until patients have received antibiotics for at least five days. Treatment with erythromycin, clarithromycin, and azithromycin is recommended to shorten the period of communicability.

PAHO continues to work with countries in the Americas and its partners to strengthen immunization programs and support the implementation of campaigns to regain coverage, as well as to strengthen the infrastructure of national immunization programs and improve epidemiological and laboratory surveillance to detect outbreaks and respond immediately.