Key Points

Whooping cough is a highly contagious bacterial respiratory infection that causes severe coughing fits and is often followed by a high-pitched "whoop" sound as the person inhales. It can last for months in both adults and children.

"Pertussis symptoms are different in infants," said leading author Caitlin Li, infectious diseases specialist at Ann & Robert H. Lurie Children's Hospital of Chicago.

"The characteristic whooping cough may be absent, but apnoea, or breathing interruption, is common," added Li, also Assistant Professor of paediatrics at Northwestern University Feinberg School of Medicine.

Pertussis in infants can also present with very high white blood cell count ("leukocytosis"), which pediatricians might mistake for cancer or other non-infectious conditions.

Extremely high white blood cell counts in infants should prompt strong consideration of pertussis, said the researchers in a special article published in the journal Pediatrics. They also strongly encourage vaccination during pregnancy.

"Given that infants are at high risk for complications, pertussis vaccination of mothers during pregnancy is critical, as it protects newborns against this potentially fatal illness," Li said.

"Widespread vaccination is also an important tool to protect everyone."

The US Centers for Disease Control and Prevention (CDC) currently recommend vaccine doses at 2, 4, 6, 15-18 months, and 4-6 years of age.

A booster dose is recommended at 11-12 years, with catch-up at 18 years. The CDC also recommends universal vaccination during pregnancy, optimally between 27 and 36 weeks of gestation, as the primary tool to prevent pertussis-related deaths.

Rapid initiation of antibiotics is recommended for all patients with confirmed or suspected pertussis. If given early in the disease course, this therapy may improve symptoms. While later treatment is unlikely to impact symptoms, it does reduce transmission, the team said.

- IANS