Associations between ethnicity, social contact, and pneumococcal carriage three years post-PCV10 in Fiji

Eleanor F G Neal; Stefan Flasche; Cattram D Nguyen; F Tupou Ratu; Eileen M Dunne; Lanieta Koyamaibole; Rita Reyburn; Eric Rafai; Mike Kama; Belinda D Ortika; Laura K Boelsen; Joseph Kado; Lisi Tikoduadua; Rachel Devi; Evelyn Tuivaga; Catherine Satzke; E Kim Mulholland; W John Edmunds; Fiona M Russell

doi:10.1016/j.vaccine.2019.10.030

Associations between ethnicity, social contact, and pneumococcal carriage three years post-PCV10 in Fiji

Vaccine. 2020 Jan 10;38(2):202-211. doi: 10.1016/j.vaccine.2019.10.030. Epub 2019 Oct 23.

Authors

Eleanor F G Neal¹, Stefan Flasche², Cattram D Nguyen³, F Tupou Ratu⁴, Eileen M Dunne³, Lanieta Koyamaibole⁴, Rita Reyburn⁵, Eric Rafai⁴, Mike Kama⁴, Belinda D Ortika⁵, Laura K Boelsen⁵, Joseph Kado⁶, Lisi Tikoduadua⁴, Rachel Devi⁴, Evelyn Tuivaga⁴, Catherine Satzke⁷, E Kim Mulholland⁸, W John Edmunds², Fiona M Russell⁹

Affiliations

¹ Infection and Immunity, Murdoch Children's Research Institute, Parkville, Victoria, Australia; Centre for International Child Health, Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia. Electronic address: eleanor.neal@rch.org.au.
² Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom.
³ Infection and Immunity, Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia.
⁴ Ministry of Health and Medical Services, Suva, Fiji.
⁵ Infection and Immunity, Murdoch Children's Research Institute, Parkville, Victoria, Australia.
⁶ College of Medicine Nursing and Health Sciences, Fiji National University, Suva, Fiji; Telethon Kids Institute, University of Western Australia, Nedlands, Western Australia, Australia.
⁷ Infection and Immunity, Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia; Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Parkville, Victoria, Australia.
⁸ Infection and Immunity, Murdoch Children's Research Institute, Parkville, Victoria, Australia; Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom.
⁹ Infection and Immunity, Murdoch Children's Research Institute, Parkville, Victoria, Australia; Centre for International Child Health, Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia.

Abstract

Background: Pneumococcal carriage is a prerequisite for pneumococcal disease. Little is known about whether social contact frequency and intensity are associated with pneumococcal carriage. In Fiji, indigenous iTaukei have higher prevalence of pneumococcal carriage compared with Fijians of Indian Descent (FID). We hypothesised that contact differences may contribute to ethnic differences in pneumococcal carriage prevalence and density.

Methods: In 2015, young infants (5-8 weeks), toddlers (12-23 months), children (2-6 years), and caregivers from Suva and surrounding areas, participated in a cross-sectional survey (n = 2014), three years post pneumococcal conjugate vaccine introduction. Demographic and contact data, and nasopharyngeal swabs were collected. Pneumococci were detected, and quantified using quantitative real-time PCR, with molecular serotyping by microarray. Associations between ethnicity, contact, and pneumococcal carriage and density were estimated using multivariable generalised estimating equation regression models.

Results: iTaukei participants had larger household sizes, higher pneumococcal carriage rates, more contacts, and more frequent contacts of longer duration, compared with FID. The odds of vaccine-type carriage increased by 28% (95% CI 8-53%) P < 0.01 in association with physical contact with 7-14 year old children. iTaukei ethnicity was associated with vaccine-type carriage (aOR) 1.73; 95% CI 1.06-2.82, P = 0.03) and non-vaccine type carriage (aOR 5.98; 95% CI 4.47-8.00, P < 0.01). Ethnicity and contact were not associated with pneumococcal density.

Conclusions: iTaukei had greater frequency and intensity of contact compared with FID. Physical contact was associated with pneumococcal carriage. Observed differences in pneumococcal nasopharyngeal carriage prevalence between iTaukei and FID were not explained by differences in social contact patterns by ethnicity.

Keywords: Carriage; Density; Indigenous; PCV10; Pneumococcal; Social contact.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Adult
Carrier State / epidemiology*
Carrier State / immunology
Carrier State / microbiology
Child
Child, Preschool
Cross-Sectional Studies
Ethnicity
Female
Fiji / epidemiology
Humans
Infant
Male
Middle Aged
Nasopharynx / microbiology
Pneumococcal Infections / epidemiology*
Pneumococcal Infections / immunology
Pneumococcal Infections / prevention & control
Pneumococcal Vaccines / administration & dosage*
Prevalence
Serotyping
Streptococcus pneumoniae / immunology
Streptococcus pneumoniae / isolation & purification*

Substances

10-valent pneumococcal conjugate vaccine
Pneumococcal Vaccines

Grants and funding

WT_/Wellcome Trust/United Kingdom