Tags

Type your tag names separated by a space and hit enter

Pneumococcal carriage in households in Karonga District, Malawi, before and after introduction of 13-valent pneumococcal conjugate vaccination.
Vaccine. 2018 11 19; 36(48):7369-7376.V

Abstract

BACKGROUND

Thirteen-valent pneumococcal conjugate vaccine (PCV13) was introduced in Malawi in November 2011 and is offered to infants at 6, 10 and 14 weeks of age as part of routine immunisation. PCV13 is expected to reduce vaccine type (VT) nasopharyngeal carriage, leading to reduced transmission and herd protection.

METHODS

We compared pneumococcal carriage in rural Karonga District, Malawi, pre-vaccine in 2009-2011 and post-vaccine in 2014 using a combination of cross-sectional and longitudinal analyses. Nasopharyngeal swabs were collected from a cohort of mother-infant pairs and household members <16 years. Pneumococci from 2009 to 2011 were serogrouped using latex agglutination and serotyped by Quellung reaction. In 2014, latex agglutination was used for both steps. Carriage prevalence ratios using prevalence data from before and after vaccine introduction were calculated by log-binomial regression, adjusted for age, seasonality and household composition. Participating infants in 2014 received PCV13 as part of routine immunisation.

RESULTS

VT carriage prior to PCV-13 introduction was 11.4%, 45.1%, 28.2%, 21.2% and 6.6% for 6-week old infants, 18-week old infants, children 1-4 years, children 5-15 years and mothers, respectively. After vaccine introduction, VT carriage decreased among vaccinated 18-week old infants (adjusted prevalence ratio 0.24 (95%CI 0.08-0.75)), vaccinated children 1-4 years (0.54 (0.33-0.88)), unvaccinated children 5-15 years (0.37 (0.17-0.78)) and mothers (0.34 (0.15-0.79)). No decrease in VT carriage was observed for 6-week old infants too young to be vaccinated (1.07 (0.38-3.02)) and PCV-13 ineligible children 1-4 years (0.84 (0.53-1.33)). Non-VT carriage increased only among vaccinated children 1-4 years (1.58 (1.21-2.06)).

CONCLUSIONS

There is evidence of reduced VT pneumococcal carriage three years after vaccine introduction in this rural Malawian population with good vaccine coverage using a 3 + 0 schedule. However carriage was sustained among 6-week-old infants and PCV13 ineligible 1-4 year olds, and there was some indication of serotype replacement in vaccinated 1-4 year olds.

Authors+Show Affiliations

Institute of Infection and Global Health, University of Liverpool, Liverpool, UK.Karonga Prevention Study, Chilumba, Malawi.Karonga Prevention Study, Chilumba, Malawi.Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi; Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK.Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi.Karonga Prevention Study, Chilumba, Malawi; London School of Hygiene and Tropical Medicine, London, UK.Karonga Prevention Study, Chilumba, Malawi.Karonga Prevention Study, Chilumba, Malawi.Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Centre for Health Informatics Computing and Statistics, Lancaster Medical School, Lancaster University, Lancaster, UK.Institute of Infection and Global Health, University of Liverpool, Liverpool, UK; Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, University of Malawi, Blantyre, Malawi. Electronic address: N.French@liverpool.ac.uk.

Pub Type(s)

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

Language

eng

PubMed ID

30352744

Citation

Heinsbroek, Ellen, et al. "Pneumococcal Carriage in Households in Karonga District, Malawi, Before and After Introduction of 13-valent Pneumococcal Conjugate Vaccination." Vaccine, vol. 36, no. 48, 2018, pp. 7369-7376.
Heinsbroek E, Tafatatha T, Phiri A, et al. Pneumococcal carriage in households in Karonga District, Malawi, before and after introduction of 13-valent pneumococcal conjugate vaccination. Vaccine. 2018;36(48):7369-7376.
Heinsbroek, E., Tafatatha, T., Phiri, A., Swarthout, T. D., Alaerts, M., Crampin, A. C., Chisambo, C., Mwiba, O., Read, J. M., & French, N. (2018). Pneumococcal carriage in households in Karonga District, Malawi, before and after introduction of 13-valent pneumococcal conjugate vaccination. Vaccine, 36(48), 7369-7376. https://doi.org/10.1016/j.vaccine.2018.10.021
Heinsbroek E, et al. Pneumococcal Carriage in Households in Karonga District, Malawi, Before and After Introduction of 13-valent Pneumococcal Conjugate Vaccination. Vaccine. 2018 11 19;36(48):7369-7376. PubMed PMID: 30352744.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Pneumococcal carriage in households in Karonga District, Malawi, before and after introduction of 13-valent pneumococcal conjugate vaccination. AU - Heinsbroek,Ellen, AU - Tafatatha,Terence, AU - Phiri,Amos, AU - Swarthout,Todd D, AU - Alaerts,Maaike, AU - Crampin,Amelia C, AU - Chisambo,Christina, AU - Mwiba,Oddie, AU - Read,Jonathan M, AU - French,Neil, Y1 - 2018/10/21/ PY - 2018/01/21/received PY - 2018/08/24/revised PY - 2018/10/05/accepted PY - 2018/10/26/pubmed PY - 2019/4/16/medline PY - 2018/10/25/entrez KW - Africa KW - Carriage KW - Cohort studies KW - Infant KW - Pneumococcal conjugate vaccine KW - Streptococcus pneumoniae SP - 7369 EP - 7376 JF - Vaccine JO - Vaccine VL - 36 IS - 48 N2 - BACKGROUND: Thirteen-valent pneumococcal conjugate vaccine (PCV13) was introduced in Malawi in November 2011 and is offered to infants at 6, 10 and 14 weeks of age as part of routine immunisation. PCV13 is expected to reduce vaccine type (VT) nasopharyngeal carriage, leading to reduced transmission and herd protection. METHODS: We compared pneumococcal carriage in rural Karonga District, Malawi, pre-vaccine in 2009-2011 and post-vaccine in 2014 using a combination of cross-sectional and longitudinal analyses. Nasopharyngeal swabs were collected from a cohort of mother-infant pairs and household members <16 years. Pneumococci from 2009 to 2011 were serogrouped using latex agglutination and serotyped by Quellung reaction. In 2014, latex agglutination was used for both steps. Carriage prevalence ratios using prevalence data from before and after vaccine introduction were calculated by log-binomial regression, adjusted for age, seasonality and household composition. Participating infants in 2014 received PCV13 as part of routine immunisation. RESULTS: VT carriage prior to PCV-13 introduction was 11.4%, 45.1%, 28.2%, 21.2% and 6.6% for 6-week old infants, 18-week old infants, children 1-4 years, children 5-15 years and mothers, respectively. After vaccine introduction, VT carriage decreased among vaccinated 18-week old infants (adjusted prevalence ratio 0.24 (95%CI 0.08-0.75)), vaccinated children 1-4 years (0.54 (0.33-0.88)), unvaccinated children 5-15 years (0.37 (0.17-0.78)) and mothers (0.34 (0.15-0.79)). No decrease in VT carriage was observed for 6-week old infants too young to be vaccinated (1.07 (0.38-3.02)) and PCV-13 ineligible children 1-4 years (0.84 (0.53-1.33)). Non-VT carriage increased only among vaccinated children 1-4 years (1.58 (1.21-2.06)). CONCLUSIONS: There is evidence of reduced VT pneumococcal carriage three years after vaccine introduction in this rural Malawian population with good vaccine coverage using a 3 + 0 schedule. However carriage was sustained among 6-week-old infants and PCV13 ineligible 1-4 year olds, and there was some indication of serotype replacement in vaccinated 1-4 year olds. SN - 1873-2518 UR - https://www.unboundmedicine.com/medline/citation/30352744/Pneumococcal_carriage_in_households_in_Karonga_District_Malawi_before_and_after_introduction_of_13_valent_pneumococcal_conjugate_vaccination_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0264-410X(18)31387-2 DB - PRIME DP - Unbound Medicine ER -