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Sources of pertussis infection in young babies from São Paulo State, Brazil
Eitan Naaman Berezin1, José Cassio de Moraes, Daniela Leite
1From the *Pediatric Infectious Diseases; †Epidemiology Department-Faculdade de Ciencias Médicas da Santa Casa de São Paulo, School Medicine of Santa Casa de São Paulo; ‡Laboratory for Pertussis-Instituto Adolfo Lutz-State Secretary Office of Health; §Division of Respiratory Diseases, Epidemiological Vigilance Center, State Secretary Office of Health; ¶Instituto Adolfo Lutz MSci-Instituto Adolfo Lutz-State Secretary Office of Health; and ‖Sanofi Pasteur, Sao Paulo, Brazil.
Insights
Household contacts can transmit Bordetella pertussis (whooping cough) to infants, even without showing symptoms. This study found 8% of contacts were positive for pertussis, regardless of their own health status.
Area of Science:
- Infectious Diseases
- Microbiology
- Public Health
Background:
- Household contacts are a primary transmission route for Bordetella pertussis, a significant pathogen in infants.
- Understanding transmission dynamics within households is crucial for preventing infant pertussis.
Purpose of the Study:
- To determine the rate of Bordetella pertussis infection among household contacts of infants with pertussis.
- To investigate whether the presence of symptoms in contacts affects the likelihood of bacteriologic pertussis diagnosis.
Main Methods:
- Evaluated 353 household contacts from 97 index infant pertussis cases.
- Utilized both culture and polymerase chain reaction (PCR) for pertussis detection.
- Correlated bacteriologic findings with the presence or absence of symptoms in contacts.
Main Results:
- Twenty-eight out of 353 contacts (8.0%) tested positive for Bordetella pertussis.
- The presence of symptoms in contacts did not significantly influence the rate of bacteriologic pertussis diagnosis.
- Bacteriologic confirmation of pertussis occurred in asymptomatic household contacts.
Conclusions:
- Household contacts can harbor and potentially transmit Bordetella pertussis irrespective of symptomatic presentation.
- This highlights the importance of considering asymptomatic individuals in pertussis transmission networks.
- Strategies for pertussis control should account for transmission from both symptomatic and asymptomatic contacts.
Abstract:
Household contacts are important sources of Bordetella pertussis in infants. A total of 353 household contacts of 97 index cases were evaluated for pertussis by culture and polymerase chain reaction. Twenty eight contacts were positive (8.0%). The presence of symptoms did not influence the rate of diagnosed bacteriologic pertussis in communicants. We conclude that contacts with an index case can be positive for B. pertussis independently of the presence of symptoms.
