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Abstract Background Members of the Anopheles punctulatus group (AP group) are the primary vectors of human malaria in Papua New Guinea. The AP group includes 13 sibling species, most of them morphologically indistinguishable. Understanding why only certain species are able to transmit malaria requires a better comprehension of their evolutionary history. In particular, understanding relationships and divergence times among Anopheles species may enable assessing how malaria-related traits (e.g. blood feeding behaviours, vector competence) have evolved. Methods DNA sequences of 14 mitochondrial (mt) genomes from five AP sibling species and two species of the Anopheles dirus complex of Southeast Asia were sequenced. DNA sequences from all concatenated protein coding genes (10,770 bp) were then analysed using a Bayesian approach to reconstruct phylogenetic relationships and date the divergence of the AP sibling species. Results Phylogenetic reconstruction using the concatenated DNA sequence of all mitochondrial protein coding genes indicates that the ancestors of the AP group arrived in Papua New Guinea 25 to 54 million years ago and rapidly diverged to form the current sibling species. Conclusion Through evaluation of newly described mt genome sequences, this study has revealed a divergence among members of the AP group in Papua New Guinea that would significantly predate the arrival of humans in this region, 50 thousand years ago. The divergence observed among the mtDNA sequences studied here may have resulted from reproductive isolation during historical changes in sea-level through glacial minima and maxima. This leads to a hypothesis that the AP sibling species have evolved independently for potentially thousands of generations. This suggests that the evolution of many phenotypes, such as insecticide resistance will arise independently in each of the AP sibling species studied here.

Abstract Background Papua New Guinea (PNG) is a highly malaria endemic country in the South-West Pacific with a population of approximately 6.6 million (2009). In 2004, the country intensified its malaria control activities with support from the Global Fund. With the aim of achieving 80% ownership and usage, a country-wide campaign distributed two million free long-lasting insecticide-treated nets (LLINs). Methods In order to evaluate outcomes of the campaign against programme targets, a country-wide household survey based on stratified multi-stage random sampling was carried out in 17 of the 20 provinces after the campaign in 2008/09. In addition, a before-after assessment was carried out in six purposively selected sentinel sites. A structured questionnaire was administered to the heads of sampled households to elicit net ownership and usage information. Results After the campaign, 64.6% of households owned a LLIN, 80.1% any type of mosquito net. Overall usage by household members amounted to 32.5% for LLINs and 44.3% for nets in general. Amongst children under five years, 39.5% used a LLIN and 51.8% any type of net, whereas 41.3% of pregnant women used a LLIN and 56.1% any net. Accessibility of villages was the key determinant of net ownership, while usage was mainly determined by ownership. Most (99.5%) of the household members who did not sleep under a net did not have access to a (unused) net in their household. In the sentinel sites, LLIN ownership increased from 9.4% to 88.7%, ownership of any net from 52.7% to 94.1%. Usage of LLINs increased from 5.5% to 55.1%, usage of any net from 37.3% to 66.7%. Among children under five years, usage of LLINs and of nets in general increased from 8.2% to 67.0% and from 44.6% to 76.1%, respectively (all p ≤ 0.001). Conclusions While a single round of free distribution of LLINs significantly increased net ownership, an insufficient number of nets coupled with a heterogeneous distribution led to overall low usage rates. Programme targets were missed mainly as a result of the distribution mechanism itself and operational constraints in this very challenging setting.

Abstract Background This study aimed to document malaria case management practices in Papua New Guinea prior to the introduction of a revised national malaria treatment protocol. The revised protocol stipulates routine testing of malaria infection by rapid diagnostic test or microscopy, anti-malarial prescription to test positive cases only, and the introduction of a new artemisinin-based first-line anti-malarial. Findings presented in this paper primarily focus on diagnostic, prescription and treatment counselling practices. Methods In a national cross-sectional survey of 79 randomly selected health facilities, data were collected via non-participant observation of the clinical case management of patients presenting with fever or a recent history of fever. Data were recorded on a structured clinical observation instrument. Results Overall, 15% of observed fever patients (n = 468) were tested for malaria infection by rapid diagnostic test and a further 3.6% were tested via microscopy. An anti-malarial prescription was made in 96.4% (451/468) of cases, including 100% (17/17) of test positive cases and 82% (41/50) of test negative cases. In all, 79.8% of anti-malarial prescriptions conformed to the treatment protocol current at the time of data collection. The purpose of the prescribed medication was explained to patients in 63.4% of cases, dosage/regimen instructions were provided in 75.7% of cases and the possibility of adverse effects and what they might look like were discussed in only 1.1% of cases. Conclusion The revised national malaria treatment protocol will require a substantial change in current clinical practice if it is to be correctly implemented and adhered to. Areas that will require the most change include the shift from presumptive to RDT/microscopy confirmed diagnosis, prescribing (or rather non-prescribing) of anti-malarials to patients who test negative for malaria infection, and the provision of thorough treatment counselling. A comprehensive clinician support programme, possibly inclusive of ‘booster’ training opportunities and regular clinical supervision will be needed to support the change.

Abstract Background The Plasmodium falciparum merozoite surface protein Pf38 is targeted by antibodies of malaria immune adults and has been shown to be under balancing (immune) selection in a Gambian parasite population, indicating potential as a malaria vaccine candidate. This study explores the population genetics of Pf38 in Papua New Guinea, to determine the extent and geographic distribution of diversity and to measure selective pressure along the length of the gene. Methods Using samples collected during community-based cross-sectional surveys in the Mugil and Wosera regions, the Pf38 genes of 59 P. falciparum isolates were amplified and sequenced. These sequences, along with previously sequenced Gambian and laboratory isolates, were then subjected to an array of population genetic analyses, examining polymorphisms, haplotype diversity and balancing selection. In addition to whole-gene analysis, the two 6-cys domains were considered separately, to investigate domain specific polymorphism and selection. Results Nineteen polymorphic sites were identified in the Pf 38 gene. Of these, 13 were found in the Gambia, 10 in Mugil and 8 in Wosera. Notably, the majority of common polymorphisms were confined to domain I. Although only moderate levels of nucleotide diversity were observed, the haplotype diversity was high in all populations, suggesting extensive recombination. Analyses of the full-length sequence provided only modest evidence for balancing selection. However, there was a strong contrast between domain I, which showed strong evidence for positive balancing selection, and domain II which was neutral. Analyses of the geographic distribution of Pf38 haplotypes showed that four haplotypes accounted for the majority of sequences found world-wide, but there were many more haplotypes unique to the African than the PNG populations. Conclusion This study confirmed previous findings that Pf38 is a polymorphic gene under balancing selection. However, analysing polymorphism and selection across the length of the gene painted a considerably different picture. Domain I is highly polymorphic and the target of significant balancing selection. In contrast, domain II is relatively conserved and does not show evidence of immune selective pressure. The findings have implications for future population genetic studies on vaccine candidates, showing that the biological context must also be considered as a framework for analysis.

Abstract Background A review of the barriers to mosquito net use in malaria-endemic countries has yet to be presented in the published literature despite considerable research interest in this area. This paper partly addresses this gap by reviewing one component of the evidence base; namely, published research pertaining to self-reported reasons for not using a mosquito net among net 'owning' individuals. It was anticipated that the review findings would potentially inform an intervention or range of interventions best suited to promoting greater net use amongst this group. Method Studies were sought via a search of the Medline database. The key inclusion criteria were: that study participants could be identified as owning a mosquito net or having a mosquito net available for use; that these participants on one or more occasions were identified or self-reported as not using the mosquito net; and that reasons for not using the mosquito net were reported. Studies meeting these criteria were included irrespective of mosquito net type. Results A total of 22 studies met the inclusion criteria. Discomfort, primarily due to heat, and perceived (low) mosquito density were the most widely identified reason for non-use. Social factors, such as sleeping elsewhere, or not sleeping at all, were also reported across studies as were technical factors related to mosquito net use (i.e. not being able to hang a mosquito net or finding it inconvenient to hang) and the temporary unavailability of a normally available mosquito net (primarily due to someone else using it). However, confidence in the reported findings was substantially undermined by a range of methodological limitations and a dearth of dedicated research investigation. Conclusions The findings of this review should be considered highly tentative until such time as greater quantities of dedicated, well-designed and reported studies are available in the published literature. The current evidence-base is not sufficient in scope or quality to reliably inform mosquito net promoting interventions or campaigns targeted at individuals who own, but do not (reliably) use, mosquito nets.

Abstract Background The South West Pacific nation of Papua New Guinea has intense year round transmission of Plasmodium falciparum on the coast and in the low-lying inland areas. Local heterogeneity in the epidemiology of malaria suggests that parasites from multiple locations will need to be surveyed to define the population biology of P. falciparum in the region. This study describes the population genetics of P. falciparum in thirteen villages spread over four distinct catchment areas of Papua New Guinea. Methods Ten microsatellite loci were genotyped in 318 P. falciparum isolates from the parasite populations of two inland catchment areas, namely Wosera (number of villages (n) = 7) and Utu (n = 1) and; and two coastal catchments, Malala (n = 3) and Mugil (n = 3). Analysis of the resultant multilocus haplotypes was done at different spatial scales (2-336 km) to define the genetic diversity (allelic richness and expected heterozygosity), linkage disequilibrium and population structure throughout the study area. Results Although genetic diversity was high in all parasite populations, it was also variable with a lower allelic richness and expected heterozygosity for inland populations compared to those from the more accessible coast. This variability was not correlated with two proxy measures of transmission intensity, the infection prevalence and the proportion multiple infections. Random associations among the microsatellite loci were observed in all four catchments showing that a substantial degree of out-crossing occurs in the region. Moderate to very high levels of population structure were found but the amount of genetic differentiation (FST) did not correlate with geographic distance suggesting that parasite populations are fragmented. Population structure was also identified between villages within the Malala area, with the haplotypes of one parasite population clustering with the neighbouring catchment of Mugil. Conclusion The observed population genetics of P. falciparum in this region is likely to be a consequence of the high transmission intensity combined with the isolation of human and vector populations, especially those located inland and migration of parasites via human movement into coastal populations. The variable genetic diversity and population structure of P. falciparum has important implications for malaria control strategies and warrants further fine scale sampling throughout Papua New Guinea.

Reproductive tract infections (RTIs), including sexually transmitted infections (STIs), are preventable and often curable health conditions. Public health officials consider Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis, and Treponema pallidum subspecies [...]

Objective To investigate changes in malaria prevalence in Papua New Guinea after the distribution of long-lasting Insecticide-treated nets, starting in 2004, and the introduction of artemisinin-based combination therapy in 2011. Methods Two malaria surveys were conducted in 2010-2011 and 2013-2014. They included 77 and 92 randomly selected villages, respectively. In each village, all members of 30 randomly selected households gave blood samples and were assessed for malaria infection by light microscopy. In addition, data were obtained from a malaria survey performed in 2008-2009. Results The prevalence of malaria below 1600 m in altitude decreased from 11.1% (95% confidence interval, CI: 8.5-14.3) in 2008-2009 to 5.1% (95% CI 3.6-7.4) in 2010-2011 and 0.9% (95% CI 0.6-1.5) in 2013-2014. Prevalence decreased with altitude. Plasmodium falciparum was more common than P. vivax overall, but not everywhere, and initially the prevalence of P. vivax infection decreased more slowly than P. falciparum infection. Malaria infections were clustered in households. In contrast to findings in 2008-2009, no significant association between net use and prevalence was found in the later two surveys. The prevalence of both fever and splenomegaly also decreased but their association with malaria infection became stronger. Conclusion Large-scale insecticide-treated net distribution was associated with an unprecedented decline in malaria prevalence throughout Papua New Guinea, including epidemic-prone highland areas.The decline was accompanied by broader health benefits, such as decreased morbidity. Better clinical management of nonmalarial fever and research into residual malaria transmission are required. Objectif Etudier les changements observes a legard de la prevalence du paludisme en Papouasie-Nouvelle-Gulnee suite a la distribution, depuis 2004, de moustiquaires impregnees d'Insecticides de longue duree et a l'introduction, depuis 2011, d'une combinaison therapeutique a base d'artemisinine. Methodes Deux enquetes portant sur le paludisme ont ete menees en 2010-2011 et 2013-2014. Elles incluaient respectivement 77 et 92 villages, selectionnes d'une maniere aleatoire. Dans chacun de ces villages, tous les membres de 30 foyers selectionnes aleatoirement ont donne des echantillons sanguins et ete soumis a un test de depistage de l'infection palustre par microscopie optique. Des donnees ont par ailleurs ete tirees d'une enquete sur le paludisme realisee en 2008-2009. Resultats La prevalencedu paludisme a moins de 1600 m d'altitude est passee de 11,1 % (intervalle de confiance, IC, a 95%: 8,5-14,3) en 2008-2009 a 5,1 % (IC a 95%: 3,6-7,4) en 2010-2011 et 0,9% (IC a 95%: 0,6-1,5) en 2013-2014. La prevalence diminuait avec l'altitude. Plasmodium falciparum n'etait pas systematiquement plus courant que R vivax, mais l'etait dans l'ensemble et, dans un premier temps, la prevalence de l'infection a R vivax a diminue plus lentement que la prevalence de l'Infection a P. falciparum. Les infections palustres ont ete regroupees par foyers. Contrairement a ce qu'indiquaient les resultats obtenus en 2008-2009, aucune correlation significative entre l'utilisation d'une moustiquaire et la prevalence n'a ete constatee dans le cadre des deux dernieres enquetes. Les prevalences de la fievre et de la splenomegalle ont egalement diminue, mais leur correlation avec l'infection palustre est devenue plus forte. Conclusion La distribution a grande echelle de moustiquaires impregnees d'insecticides a ete associee a un declin sans precedent de la prevalence du paludisme dans l'ensemble de la Papouasie-Nouvelle-Guinee, et notamment dans les reglons montagneuses sujettes aux epidemies. Ce declin s'est accompagne d'autres bienfaits sur la sante, et notamment d'une diminution de la morbidite. Il est necessaire d'ameliorer la prise en charge clinique de la fievre non palustre ainsi que les recherches sur la transmission residuelle du paludisme. Objetivo Investigar los cambios en la prevalencia de la malaria en Papua Nueva Guinea tras la distribucion de mosquiteros tratados con insecticida de larga duracion, a partir de 2004, y la introduccion de terapias combinadas basadas en la artemisinina en 2011. Metodos Se llevaron a cabo dos encuestas sobre la malaria en 2010-2011 y 2013-2014. Incluian 77y 92 aldeas seleccionadas al azar, respectivamente. En cada aldea, todos los miembros de 30 hogares seleccionados al azar dieron muestras de sangre y se evaluaron de infeccion de malaria con microscopio optico. Ademas, se obtuvieron datos de la encuesta sobre la malaria realizada en 2008-2009. Resultados La prevalencia de la malaria por debajo de 1600 m de altitud descendio del 11.1% (intervalo de confidencia (IC) del 95%: 8.5-14.3) en 2008-2009 al 5.1% (95% IC 3.6-7.4) en 2010-2011 y 0.9% (95% IC 0.6-1.5) en 2013-2014. La prevalencia descendia con la altitud. Plasmodium falciparum fue mas comun que P. vivax en general, pero no en todas partes e inicialmente la prevalencia de la infeccion P. vivax descendio mas lentamente que la infeccion P. falciparum. Las infecciones de malaria se agruparon en los hogares. Al contrario que los hallazgos en 2008-2009, no se encontro ninguna asociacion significativa entre el uso del mosquitero y la prevalencia en las dos ultimas encuestas. La prevalencia tanto de la fiebre como de la esplenomegalia tambien descendio, pero su asociacion con la infeccion de malaria se hizo mas fuerte. Conclusion La distribucion de mosquiteros tratados con insecticida a gran escala se asocio con un descenso sin precedentes en la prevalencia de la malaria en toda Papua Nueva Guinea, incluidas las areas altas con propension a causar epidemias. El descenso estuvo acompanado de beneficios saludables mas amplios, como el descenso de la morbilidad. Se requieren una mejor gestion clinica de la fiebre no relacionada con la malaria y la Investigacion de la transmision residual de la malaria., Introduction Historically, malaria has been endemic throughout Papua New Guinea, except in highland areas over 1600 m, where temperatures are low and there is no stable local transmission, though imported [...]