Hospital-based prospective study of pertussis in infants and close contacts in Tehran, Iran

Background Whooping cough due to Bordetella pertussis (BP) and/or B. parapertussis (BPP) is a highly contagious infection sometimes fatal for infants. Africa accounts for the largest share of cases and deaths worldwide. To evaluate pertussis circulation, we conducted a hospital-based prospective study (PS) including household contact-cases investigation (CCS) and a sero-epidemiological cross-sectional study (SECS). Methods The PS, in which Bordetella diagnostics (qPCR) were performed, included infants aged ≤6 months presenting with ≥5 days of cough associated with one pertussis-like symptom. CCS was performed using qPCR and serology regardless of clinical signs. In the SECS, serology was performed in children aged 3–15 years with primary pertussis immunization. Results Study took place in Abidjan between April 2019 and July 2021. In the PS, 187 infants with median age of 2.8 months were enrolled. A total of 42 (22.5%) were confirmed as positive, including 29 (15.5%), 4 (2.1%) and 9 (4.8%) of BP, BPP and BP/BPP coinfections respectively. Age <3 months, low BMI, apnea and inclusion period were identified as risk factors of infection. In the CCIS, 36 households were investigated, representing 158 people with median age of 21.4 years. BP and/or BPP infection was confirmed for 77/157 (49.0%). Twenty-nine households (81%) had at least one positive case. Sixty-seven (42.7%) contact cases were categorized as possibly contaminated, mainly siblings older than five years (25.4%). Twenty-seven contact cases were considered as possible contaminators, primarily mothers (26%). In the SECS, 444 people were enrolled. Two hundred and thirty-eight (53.6%) and nine (2.0%) children had received one and two boosters, respectively. A positive serology was observed in 96 (21.7%) of children and adolescents. Conclusion Our study highlighted high circulation of pertussis. Barriers to accessing boosters recommended by WHO need to be overcome. Laboratory capacities are key at individual level and to build an effective surveillance system.

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High circulation of pertussis in infants and close contacts in Antananarivo, the capital of Madagascar, and Cambodia

Noel,

Harimanana,

Borand

et al. 2024

Preprint

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Background: Reliable data on whooping cough, a highly contagious disease sometimes fatal for infants, are largely lacking in low- and middle-income countries. Methods: We conducted a hospital-based prospective study (PS) on infants, and a household contact-case investigation (CCI) for positive cases throughout Cambodia and in the city of Antananarivo, Madagascar, between 2017 and 2019. The PS, in which Bordetella diagnostics (qPCR) were performed, included infants aged ≤6 months presenting with ≥5 days of cough associated with one pertussis-like symptom. CCI was performed using qPCR and serology regardless of clinical signs. Results: In this study, 207 and 173 participants from Cambodia and Antananarivo were respectively enrolled. Respectively 26.1% (54/207) and 22.0% (38/173) of the infants were infected in the cohorts from Cambodia and Antananarivo. Cough longer than 10 days appeared as a risk factor in both countries, as well as coughing spells, apnea and normal pulmonary auscultation, having a coughing contact in Cambodia. In Antananarivo, good condition between cough appeared as a risk factor. Five infants, all positive, died during the study. In Cambodia and Antananarivo respectively, 50.9% (118/232) and 67.8% (82/121) of the contact cases were positive. Respectively 94.4% (51/54) and 90.3% (28/31) of the households had at least one positive contact case. Conclusion: The data show that pertussis circulates at high levels among infants and in their households both in Cambodia and in Antananarivo. Given the vulnerability of youngest infants, who are too young to receive fully primary vaccination, they need to be protected through boosters breaking transmission chains. Molecular diagnosis, as well as trained medical human resources to detect the disease early, are absolutely key to protect populations.

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Hospital-based prospective study of pertussis in infants and close contacts in Tehran, Iran

Cited by 4 publications

References 27 publications

Evaluation of Pertussis Disease in Young Infants in India: A Hospital-Based Multicentric Observational Study

Evaluation of Pertussis Disease in Young Infants in India: A Hospital-Based Multicentric Observational Study

High pertussis circulation among infants, children and adolescents in Abidjan, Côte d’Ivoire

High circulation of pertussis in infants and close contacts in Antananarivo, the capital of Madagascar, and Cambodia

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