Childhood pneumonia and meningitis in the Eastern Highlands Province, Papua New Guinea in the era of conjugate vaccines: study methods and challenges

Abstract

BackgroundPneumonia and meningitis are common causes of severe childhood illness in Papua New Guinea (PNG). The etiology of both clinical conditions in PNG has not been recently assessed. Changes in lifestyle, provision and access to healthcare, antimicrobial utilization and resistance, and the national childhood vaccination schedule necessitate reassessment.MethodsA prospective case-control study was undertaken, enrolling children <5 years of age to determine the contemporary etiology of clinically defined moderate or severe pneumonia or suspected meningitis. Cases were identified following presentation for inpatient or outpatient care in Goroka town, the major population centre in the Eastern Highlands Province. Following enrolment, routine diagnostic specimens including blood, nasopharyngeal swabs, urine and (if required) cerebrospinal fluid, were obtained. Cases residing within one hour’s drive of Goroka were followed up, and recruitment of healthy contemporaneous controls was undertaken in the cases’ communities.Results998 cases and 978 controls were enrolled over 3 years. This included 784 cases (78.6%) with moderate pneumonia, 187 (18.7%) with severe pneumonia and 75 (7.5%) with suspected meningitis, of whom 48 (4.8%) had concurrent pneumonia. The median age of cases was 7.8 months (Interquartile range [IQR] 3.9–14.3), significantly lower than community controls, which was 20.8 months (IQR 8.2–36.4). Half the cases were admitted to hospital (500/998; 50.1%). Recruitment of cases and controls and successful collection of diagnostic specimens improved throughout the study, with blood volume increasing and rates of blood culture contamination decreasing. The overall case fatality rate was 18/998 (1.8%). Of cases eligible for follow-up, outcome data was available from 76.7%. Low but increasing coverage of Haemophilus influenzae type B conjugate vaccines on the national schedule was observed during the study period: three dose DTPw-HepB-Hib coverage in children >3 months increased from 14.9 to 43.0% and 29.0 to 47.7% in cases and controls (both p < 0.001). Despite inclusion in the national immunization program in 2014, 2015 PCV13 three-dose coverage in cases and controls >3 months was only 4.0 and 6.5%.ConclusionsRecruitment of large numbers of pediatric pneumonia and meningitis cases and community controls in a third-world setting presents unique challenges. Successful enrolment of 998 cases and 978 controls with comprehensive clinical data, biological specimens and follow up was achieved. Increased vaccine coverage remains an ongoing health priority.Electronic supplementary materialThe online version of this article (doi:10.1186/s41479-017-0029-y) contains supplementary material, which is available to authorized users.

Rationale and methods of a randomized controlled trial of immunogenicity, safety and impact on carriage of pneumococcal conjugate and polysaccharide vaccines in infants in Papua New Guinea

“…Despite the launch of the 13vPCV program in PNG in 2014, vaccine was not available in the EHP until 2015 and has been introduced slowly since: coverage with one dose of 13vPCV was only around 25% and with three doses around 5% in late 2015 in the study area [ 55 ]. Herd protection following launch of the PNG 13vPCV program in PNG in late 2014 is therefore unlikely to have impacted on the results of the present study.…”

Determining the pneumococcal conjugate vaccine coverage required for indirect protection against vaccine-type pneumococcal carriage in low and middle-income countries: a protocol for a prospective observational study

“…It is an extension of a pneumonia aetiology study that commenced in 2013. 26 PCV13 was introduced to PNG in October 2014 using a 3+0 schedule at 1, 2 and 3 months of age ( table 1 ); however, it was not widely distributed in the Eastern Highlands Province until late 2015. We are recruiting cases at the Eastern Highlands Provincial Hospital, the major referral hospital for the Eastern Highland Province, as well as nearby clinics in Goroka, the capital of the Eastern Highlands Province.…”

Effectiveness of 13-valent pneumococcal conjugate vaccine against hypoxic pneumonia and hospitalisation in Eastern Highlands Province, Papua New Guinea: An observational cohort study

“…A full description of the study population, health facilities and socioeconomic factors has been previously published. 19 …”

“…The first study commenced in January 2013 prior to the national 13vPCV introduction and recruited clinical pneumonia cases presenting to EHPH or a community healthcare clinic. 17 , 19 The original aim of this study, which finished recruitment in January 2016, was to determine the aetiology of moderate and severe pneumonia 21 (and/or meningitis). The second study, commencing in January 2016, recruited clinical pneumonia cases from EHPH and community clinics and conducted household community surveys to determine community vaccine uptake.…”