J.A.G Scott, Kenya

KEMRI-Wellcome Trust Research Programme,Kilifi Epidemiology and Demography

Poster Author Of 1 e-Poster

Online Abstracts Vaccines - Impact of Vaccine programs and Serotype Replacement C2 Impact of Vaccine programs and Serotype Replacement

Author Of 3 Presentations

ANTIMICROBIAL RESISTANCE PATTERNS IN PNEUMOCOCCAL CARRIAGE PRE AND POST PCV10 INTRODUCTION IN NIGERIA (ID 521)

Abstract

Background

Pneumococcal conjugate vaccines (PCVs) reduce antimicrobial resistance (AMR). In Africa, where disease surveillance is limited, nasopharyngeal carriage studies may reveal PCV impact on AMR . We investigated AMR in pneumococcal carriage in Nigeria.

Methods

Nigeria introduced PCV10 between 2014-2016. Random carriage surveys targeting 1000 participants were conducted pre-(2016) and post-PCV10 (2017-2018) in two locations (rural and urban). PCV10 coverage in 2017 and 2018 was 47% and 55%, respectively. Isolates randomly selected from each survey were tested for antimicrobial resistance using broth micro-dilution.

Results

In 571 pneumococcal isolates, prevalence of resistance was -Tetracycline (69%), Cotrimoxazole (68%), Penicillin (43%) and Chloramphenicol (14%). Serotypes 19F, 6A, 11A, 23F, 3, 16F, 19A, 34 and 6B had a high prevalence of resistance. Prevalence of resistance to any antibiotic differed little by pre- vs post-PCV10 era both overall (86% and 85%) and in rural (73% and 71%) and urban (99% and 98%) samples. No difference was seen in prevalence of resistance among vaccine and non-vaccine serotypes by PCV10 era.

Conclusions

Among healthy Nigerians, prevalence of resistance to commonly used antibiotics is high in carried pneumococci. Although the data do not show any impact of PCV10 on resistance prevalence, the lack of effect may be explained by incomplete coverage levels.

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EARLY IMPACT OF INTRODUCING A TEN-VALENT PNEUMOCOCCAL CONJUGATE VACCINE (PCV10) ON PNEUMOCOCCAL CARRIAGE IN NIGERIA (ID 652)

Abstract

Background

As Nigeria transitions from Gavi-support to self-financing of the pneumococcal conjugate vaccine (PCV), decisions on vaccine cost effectiveness should be based on local vaccine impact data. Herd immunity against carriage is a major contributor to PCV impact. So, carriage surveys are a useful option for impact assessments in the absence of disease surveillance systems.

Methods

We conducted nasopharyngeal carriage surveys (2017-2019) according to WHO guidelines among randomly selected residents of two locations (urban and rural) in Nigeria. PCV10 was introduced in 2016 in these locations and reached a modest coverage of 37% and 61% by 2019. Carriage prevalence ratios (PR) before and after PCV10 introduction were estimated using log-binomial regression.

Results

There was a 38% (PR-0.62 [95%CI:0.53-0.72]) and 21% (PR-0.79 [95%CI:0.66-0.94]) reduction in carriage of vaccine serotypes respectively among vaccine-target (<5years) and non-target) (5+ years) groups, mostly due to serotypes 19F, 23F and 6B. Carriage of non-vaccine serotypes increased by 28% (PR-1.28 [95%CI:1.15-1.42]) and 31% (PR-1.31 [95%CI:1.20-1.43]) respectively in these groups; serotypes 6A, 19A, 34, 16F and 11A were prominent.

Conclusions

Within three years of PCV10 introduction, we found early evidence of direct and indirect PCV effects on vaccine serotype carriage as well as serotype replacement in carriage.

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CHILDREN ADMITTED TO HOSPITAL WITH LOWER-CHEST-WALL INDRAWING PNEUMONIA IN SEVEN LOW AND MIDDLE-INCOME COUNTRIES: WHO DIED AND WHO SURVIVED? (ID 758)

Abstract

Background

In 2013, to increase effective distribution of antibiotics, WHO revised treatment guidelines for childhood pneumonia with lower chest wall indrawing (LCWI) to recommend home-based-treatment with oral antibiotics rather than hospital-based management. We analysed the implications of this policy in the PERCH study, where all children were hospitalised.

Methods

In PERCH, 2113 children aged 2-59 months were admitted with LCWI pneumonia between 2011-2014 in Kenya, Zambia, South Africa, Mali, The Gambia, Bangladesh and Thailand. We analysed their mortality risk, and risk factors for mortality using logistic regression.

Results

Among cases with LCWI pneumonia, 76 (3.6%) died in hospital or within 7 days of discharge. Factors associated with fatal outcome included age (aOR 2.03 (95%CI 1.05-3.93) for infants vs older children), absence of cough, oxygen saturation (80-91% oxygen aOR 2.04 (1.07-3.90), <80% aOR 6.51 (2.82-15.0)), low anthropometric scores and HIV exposure.

Conclusions

Despite hospital admission, 3.6% of children with LCWI pneumonia died; mortality may be higher among similar children if treated in the community. Among children with LCWI pneumonia presenting to hospital, selective admission for those who also have hypoxia, features of malnutrition and young age may ensure that those with the greatest risk of death receive optimal supportive therapy.

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