Epidemiological characteristics and laboratory confirmation of a household pertussis cluster in a district of Beijing in 2023
Objective To analyze characteristics and laboratory confirmation of a household pertussis cluster in a district of Beijing.Methods We conducted epidemiological case investigation,collected nasopharyngeal swabs from cases and their close contacts to test for Bordetella pertussis(Bp)nucleic acid and isolate Bp.We conducted whole gene sequencing,multi-site sequence typing,virulence gene identification,and antibiotic sensitivity of the Bp isolates.We collected serum samples to test for pertussis toxin IgG(PT-IgG)antibody.Results The cluster involved 5 pertussis cases.The first was a 7-month-old,very-low-birth-weight premature infant,with frequent medical visits and hospitalization due to respiratory infections who had not been vaccinated against pertussis.The other cases were her grandmother,elder sister,mother,and father,acquired in chronological order.The 1 st to 4th cases were laboratory-confirmed,and were positive for Bp nucleic acids,or Bp was isolated,or had a＞4-fold increase or seroconversion of PT-IgG levels in double serum samples.The last case was clinically confirmed,and was negative to pertussis testing.Two Bp isolates from the first case were ST2 and ptxP3 types,resistant to erythromycin,azithromycin,clindamycin,and sulfamethoxazole.Conclusions The household pertussis cluster may have been due to transmission from the infected infant,who had not been vaccinated.We should strengthen active pertussis surveillance and laboratory diagnosis,early case detection,and rapid prevention and control responses to avoid clusters.
万方数据
维普
