Neonatal Pertussis, an Under-Recognized Health Burden and Rationale for Maternal Immunization: A Systematic Review of South and South-East Asian Countries

Pertussis is an under-recognized cause of neonatal morbidity and mortality. To review information on the epidemiology and disease burden of neonatal pertussis in South and Southeast Asian countries, a systematic literature review of three bibliographic databases was undertaken. Peer-reviewed original studies on neonatal pertussis epidemiology and burden published since 2000, with a geographical scope limited to South and Southeast Asian countries, were included. Data were systematically extracted based on parameters defined a priori. Our findings show that the burden of neonatal pertussis and its complications is substantial. An increase in the number of pertussis cases has been noted since early 2000, ranging from 61 to 92.9% in infants 0-3 months old. The most common symptoms an infant is likely to present with are cough with or without paroxysms, cyanosis, apnea, tachypnea, difficulty in breathing and leukocytosis. In addition, it can lead to hospitalization (length of stay: 5-7 days), complications (e.g., pneumonia, seizures) and mortality ranging from 5.6 to 14.7%. Other observations indicate that diagnosis is challenging because of non-specific clinical symptoms. Specifically, for obstetricians and gynecologists, the information available for making informed decisions on the prevention of neonatal pertussis is unreliable. Maternal immunization against pertussis during late stages of pregnancy has proven to be efficacious and well tolerated. A high burden of neonatal pertussis, as well as its complications, is observed in South and Southeast Asian countries. There is a need to intensify efforts to protect this vulnerable population with maternal vaccination.