Moses Laman

Background: Over the past decade, the East New Britain Provincial Health Authority in Papua New Guinea has worked with partner research organisations to implement data-driven interventions to improve immunisation coverage. This paper reports on facility assessments conducted as part of a cross-sectional study to understand improvements and identify enablers and barriers to routine childhood immunisation in the province. Methods: Between May and August 2023, nine urban and rural health facilities, providing immunisation services at the time of the study in five areas, were assessed using an adapted World Health Organisation (WHO) Service Availability and Readiness Assessment tool. The tool evaluated facility characteristics, routine childhood immunisation readiness and vaccine supply data. Data were analysed using descriptive statistics and findings were mapped to adapted WHO health system categories to identify service delivery improvement priorities. Findings: Several aspects of immunisation service availability and quality had improved since an assessment in 2016/17. Strengths included fixed-facility and outreach service models tailored to catchment populations, high availability of cold chain and vaccine administration equipment, improved immunisation guidance and job-aids. Priority areas included increasing workforce capacity, improving health record completion to inform outreach, increasing availability of guidelines and reporting tools, reducing stock-outs and enhancing stock tracking. Conclusions: Offering accessible vaccination at every opportunity and using quality data to inform programme implementation and resource allocation are priorities for the Provincial Health Authority. This facility-level assessment identified existing immunisation delivery strengths and highlighted community- and provincial-level priority investment areas to strengthen facility capacity and routine immunisation service delivery.

Objectives: Neisseria gonorrhoeae and Chlamydia trachomatis can be transmitted from an infected woman to her baby during vaginal birth to cause neonatal conjunctivitis (ophthalmia neonatorum). Little is known about how often these pathogens cause infection in babies without conjunctivitis. The objectives of this study were to investigate the frequency of C. trachomatis and N. gonorrhoeae in newborn babies with and without conjunctivitis and to estimate the prevalence of these infections and the proportion that was asymptomatic. Methods: We conducted a cross-sectional study, nested in a randomised controlled trial in Papua New Guinea. At a visit scheduled 1–2-weeks after birth (visit 1), we took conjunctival swabs from babies with clinical signs of conjunctivitis and from a sample of those with no clinical signs. Babies with conjunctivitis received antibiotic treatment. Swabs were tested for N. gonorrhoeae and C. trachomatis by PCR after the end of the study. We estimated the weighted percentage (with 95% confidence intervals, CI) of babies with either organism detected and the asymptomatic proportion. Results: From 21 ^st October, 2017 to 2 ^nd February, 2022, 1699 of 2055 newborn babies attended visit 1. Among 310 babies with clinical data and a result from any swab, 97 had signs of conjunctivitis and 213 did not. Where results were available, C. trachomatis was detected in 12/97 (12.4%) of babies with conjunctivitis and 7/211 (3.3%) without. N. gonorrhoeae was detected in 1/97 (1.0%) of babies with conjunctivitis and 6/210 (2.9%) without. The weighted estimate of C. trachomatis or N. gonorrhoeae prevalence was 6.6% (3.8-9.9%), of which an estimated 87.0% (74.8%-93.8%) was asymptomatic. Conclusions: C. trachomatis and N. gonorrhoeae were detected in the absence of clinical signs of conjunctivitis in about 1 in 15 babies. This finding has implications for estimation of mother-to-child transmission and evaluation of prophylaxis and treatment interventions. Key messages: What is already known on this topic: ▪ Neisseria gonorrhoeae and Chlamydia trachomatis cause neonatal conjunctivitis (ophthalmia neonatorum), which can lead to permanent vision loss if untreated; ▪ Little is known about the occurrence and frequency of N. gonorrhoeae and C. trachomatis in newborn babies without conjunctivitis. What this study adds: ▪ This study included babies with clinical conjunctivitis and a sample of babies without clinical signs of conjunctivitis and tested swabs using PCR at a visit scheduled 1-2 weeks after birth; ▪ The overall prevalence of C. trachomatis or N. gonorrhoeae was estimated to be 6.6% (95% CI 3.8-9.9%), of which an estimated 87.0% (74.8%-93.8%) occurred in babies without clinical signs of conjunctivitis. How this study might affect research, practice or policy: ▪ The clinical relevance of asymptomatic C. trachomatis or N. gonorrhoeae detection remains unclear; all samples from babies with asymptomatic detection tested negative at a visit scheduled 4-6 weeks after birth; ▪ The results are important for research about mother-to-child transmission of C. trachomatis and N. gonorrhoeae and evaluation of prophylaxis and treatment interventions conducted using molecular diagnostics.

Antenatal care (ANC) provides an opportunity to prevent or minimise adverse pregnancy outcomes and enhance women’s health by providing essential inte

: After mass drug administration (MDA) for lymphatic filariasis, which involved a single coadministered dose of ivermectin plus diethylcarbamazine and albendazole (IDA), concerns arose regarding individuals who remained microfilaremic. This situation raised questions about the efficacy of the drugs and whether some individuals had not ingested them. In East New Britain Province, Papua New Guinea (PNG), where 81.7% of the population received IDA, 10 individuals were found to have microfilaremia 12 months after the first round of MDA in an area that had a high baseline of microfilaremia (n = 29 microfilariae [Mf] positive pre-MDA). Of these 10 individuals, 7 reported having taken the IDA medication. When Mf detection was repeated 18 months later, all 10 individuals remained Mf positive. Additionally, three more Mf-positive household members were identified, and they also reported taking the IDA. These Mf-positive individuals were then retreated with IDA under direct observation. At 7 and/or 14 months after retreatment, all initially Mf-positive individuals, except for one, were found to be Mf free. Upon further questioning, it was revealed that all but one individual admitted to not taking the initial MDA. Thus, IDA effectively clears Mf in this region of PNG, and the persistent microfilaremia after MDA is primarily because of individuals failing to take the medications as prescribed.

Background: Immunization coverage varies across Papua New Guinea. In East New Britain (ENB) Province in 2022, only 65.5% and 50.2% of children under one year received their first dose of pentavalent (DTP1) and measles–rubella (MR1) vaccine, respectively. This study aimed to examine barriers and enablers to routine immunization in areas of un(der)-vaccination in ENB. Methods: A face-to-face survey was conducted with caregivers of children aged 12–23 months in ENB. We used Poisson regression to calculate incidence rate ratios (IRR) and 95% confidence intervals (95% CI) for factors associated with timely receipt of DTP1 or MR1 vaccines, defined as a child who was vaccinated between –2 and +30 days of the vaccine schedule. Delayed receipt is defined as a child who was vaccinated >30 days from the recommended due date. Results: Among 237 caregivers surveyed, 59.9% of children were vaccinated within the “timely” window for DTP1 and 34.1% for MR1. Timely DTP1 receipt was associated with a facility-based birth (IRR:1.93; 95% CI: 1.10–3.38) and trusting healthcare workers “very much”, compared to “a little or moderately” (IRR:1.53; 95% CI: 1.17–1.99). For MR1, the caregiver having completed tertiary/vocational education (IRR:1.79; 95% CI: 1.15–2.78), reporting taking a child to be vaccinated is affordable (IRR:1.52; 95% CI: 1.04–2.22), and healthcare workers explaining immunization services and answering associated questions (IRR:1.68; 95% CI: 1.18–2.41) were associated with timely vaccination. Conclusions: Activities to improve timely vaccination in ENB could include strengthening healthcare worker interpersonal communication skills to optimize trust and incentivizing women to give birth in a health facility.

Background: Measles is consistently one of the leading causes of death from vaccine-preventable diseases in children, and cases and deaths have increased globally since 2019. While measles often serves as a ‘canary in the coalmine’ for health system weaknesses, global definitions of zero-dose and under-immunised children continue to centre on those who have missed diphtheria-tetanus-pertussis (DTP) containing vaccine. We propose that lack of receipt of measles vaccine is included in global definitions of ‘under-immunised’ children. Methods: We used publicly available WHO/UNICEF estimates of national immunization coverage (WUENIC) data to determine the number and proportion of children missing out on routine immunisations in each country globally in 2019 and 2022. We stratified countries by income status to further investigate inequalities in vaccine coverage between different countries. Results: In 2022, 50% more children missed out on their first dose measles-containing vaccine compared to DTP1, and 96% of these children resided in low-middle income countries (LMICs), highlighting the compounding inequities in measles immunisations globally. Furthermore, countries with the largest number of children missing out on DTP1 were not reflective of countries with the lowest measles immunisation coverage rates, suggesting targeted programs are needed to reach children who are missing out on measles vaccination. Recommendations: Given the high transmissibility and inequitable burden measles outbreaks pose to both at-risk individuals and communities, especially in LMICs, measles immunisation coverage should be included as a key metric when reporting and estimating the number of under-immunised children globally.

Infectious disease research requires expertise from multiple diverse backgrounds. In Papua New Guinea (PNG), relationships are an integral part of the culture, both historically and today, and play a critical role in conducting infectious disease research activities across the country. Research efforts on vector-borne diseases (VBDs), such as malaria and dengue, run parallel to rigorous implementation research to reduce the burden of other neglected tropical diseases and combat growing anti-microbial resistance in the country. This chapter will highlight the history of collaborative research in Papua New Guinea and specifically, how the partnership-based approach to implementation research has been adopted to conduct infectious disease research at different levels of the health system. In PNG, genuine trust-based relationships have been established over time by incorporating a set of guiding principles into daily practice and focusing on principles such as authenticity, courage, equality, equity, mutual benefit, and transparency throughout the research cycle. This chapter showcases key learnings across multiple and interconnected levels of the health system. It also sheds light on nuanced approaches to partnerships which harness local knowledge and empower champions to enable meaningful research and systemic change.

Plasmodium falciparum Reticulocyte Binding Protein Homologue (RH5), a leading malaria vaccine candidate, is essential for erythrocyte invasion by the parasite, interacting with the human host receptor, basigin. RH5 has a small number of polymorphisms relative to other blood-stage antigens, and in vitro studies have shown that vaccine-induced antibodies raised against RH5 are strain-transcending, however most studies investigating RH5 diversity have been done in Africa. Understanding the genetic diversity and evolution of malaria antigens in other regions is important for their validation as vaccine candidates. In this study the rh5 gene was sequenced in 677 samples from a longitudinal cohort of Papua New Guinean (PNG) children aged 1-3 years. Of 677 samples successfully sequenced, 566 were identified as independent infections (i.e. one of each pair of identical sequences within hosts were removed). A total of 14 non-synonymous polymorphisms were identified, eight that are ‘common’ in the population (minor allele frequency > 1%), with 44 haplotypes ranging in frequency from 1% to 21%. Modeling of common SNPs to the cryo-EM structure of the RH5/CyRPA/RIPR complex mapped them to the Basigin binding site and near the contact point of CyRPA. Tajima’s D analyses of the corresponding nucleotide sequences produced positive values indicating potential hotspots of balancing selection. We attempted to confirm whether these signals were due to immune selection by measuring the rate of polymorphism between independent infections within the same host, and the association with clinical symptoms, however, no such associations were identified. Together these results suggest that while there is evidence of balancing selection driving RH5 diversity in the PNG P. falciparum population, immune escape was not observed within the cohort of young children. Limited immunity and therefore low selective pressure may explain this result, alternatively other evolutionary forces may contribute to balancing selection at the RH5-BSG binding interface in PNG.