The impact of a filariasis control program on Lihir Island, Papua New Guinea

Background

Annual mass drug administration (MDA) over five years is the WHO''s recommended strategy to eliminate lymphatic filariasis (LF). Some experts, however, consider that longer periods of treatment might be necessary in certain high prevalence and transmission environments based upon past unsuccessful field experience and modelling.

Methodology/Principal Findings

To evaluate predictors of success in a LF control program we conducted an ecological study during a pre-existing MDA program. We studied 27 villages in Lihir Island, Papua New Guinea, from two areas with different infection rates before MDA. We undertook surveys to collect information on variables potentially having an influence on the outcome of the program, including epidemiological (baseline prevalence of infection, immigration rate), entomological (vector density) and operational (treatment coverage, vector control strategies) variables. The success in a village was defined using variables related to the infection (circulating filarial antigenemia prevalence <1%) and transmission (antigenemia prevalence <1 in 1000 children born since start of MDA). 8709 people were involved in the MDA program and average coverage rates were around 70%. The overall prevalence of filariasis fell from an initial 17.91% to 3.76% at round 5 (p<0.001). Viewed on a village by village basis, 12/27 (44%) villages achieved success. In multivariate analysis, low baseline prevalence was the only factor predicting both success in reducing infection rates (OR 19,26; CI 95% 1,12 to 331,82) and success in preventing new infections (OR 27,44; CI 95% 1,05 to 719,6). Low vector density and the use of an optimal vector control strategy were also associated with success in reducing infection rates, but this did not reach statistical significance.

Conclusions/Significance

Our results provide the data that supports the recommendation that high endemic areas may require longer duration MDA programs, or alternative control strategies.     

Men of Kastom and the Customs of Men: Status,Legitimacy and Persistent Values in Lihir,Papua New Guinea

The changing nature of Lihirian masculinity in the context of large‐scale resource development is characterised by ingenuity, disjuncture and struggles for legitimacy. In this paper, I consider the various ways Lihirian masculinity is challenged and shaped by exogenous influences, how Lihirians appropriate particular aspects of modernity for their own purposes, and the ways in which certain Lihirian men have attempted to redefine masculine ideals according to neoliberal democratic values in their quest to modernise Lihir. This paper draws on fieldwork conducted in the Lihir Islands between 2003 and 2007.     

Alpha-thalassemia in Papua New Guinea

Summary A study of the distribution of -thalassemia in Papua New Guinea (PNG) was carried out by DNA analysis. A total of 664 DNA samples were screened for -thalassemia 2 and -thalassemia 1 caused respectively by either deletion of one or both of the duplicated -globin genes. -Thalassemia 2 was detected in high frequencies in coastal and lowland regions where malaria has been holo- to hyperendemic but in low frequencies in non-malarious highland regions. The highest frequency was observed in the north coast of PNG. The distribution of -thalassemia 2 seems to be in accordance with other conditions such as ovalocytosis and G6PD deficiency which are also prevalent in this population, suggesting that they may interact in protection against malaria. However, it appears to be negatively correlated with -thalassemia and -thalassemia 1, the latter being extremely rare in this population. Analysis of the types and subtypes of the single -globin gene deletion revealed a predominance of the –^4.2 type in general, except in some regions in the south where the –^3.7 type is prevalent. The –^3.7 I subtype is the common form of the –^3.7 deletion in the PNG mainland. The –^3.7 III subtype, previously reported to be unique in Melanesians and Polynesians, was detected in an offshore island of PNG. However, this subtype is very rare in Melanesians from the PNG mainland.     

Molecular characterization of TEM-type beta-lactamases identified in cold-seep sediments of Edison Seamount (south of Lihir Island, Papua New Guinea)

To determine the prevalence and genotypes of beta-lactamases among clones of a metagenomic library from the cold-seep sediments of Edison seamount (10,000 years old), we performed pulse-field gel electrophoresis, antibiotic susceptibility testing, pI determination, and DNA sequencing analysis. Among the 8,823 clones of the library, thirty clones produced beta-lactamases and had high levels of genetic diversity. Consistent with minimum inhibitory concentration patterns, we found that five (16.7%) of thirty clones produced an extended-spectrum beta-lactamase. 837- and 259-bp fragments specific to blaTEM genes were amplified, as determined by banding patterns of PCR amplification with designed primers. TEM-1 was the most prevalent beta-lactamase and conferred resistance to ampicillin, piperacillin, and cephalothin. TEM-116 had a spectrum that was extended to ceftazidime, cefotaxime, and aztreonam. The resistance levels conferred by the pre-antibiotic era alleles of TEM-type beta-lactamases were essentially the same as the resistance levels conferred by the TEM-type alleles which had been isolated from clinically resistant strains of bacteria of the antibiotic era. Our first report on TEM-type beta-lactamases of the pre-antibiotic era indicates that TEM-type beta-lactamases paint a picture in which most of the diversity of the enzymes may not be the result of recent evolution, but that of ancient evolution.     

Ants,Stem Borers,and Pubescence in Endospermum in Papua New Guinea1

The stems of the ant-plant, Endospermum labios Schodde, serve as colonization sites for the ant, Camponotus quadriceps F. Smith. They are also subject to damage by insect borers. We sampled young E. labios trees in distutbed forest to compare evidence of stem boring insect and stem miner damage in plants with and without colonies of C. quadriceps. Dissections of a subsample of plants showed that dipteran stem borers and stem miner damage were significantly more common in plants lacking C, quadriceps colonies than in plants with established colonies. Evidence from these dissections and from field counts of meristem damage caused by emerging borers suggested that coleopteran stem borers were also more abundant when ants were not present. In addition to the incidence of stem boring insects and ant colonies, we examined relative levels of leaf pubescence by measuring trichome density and leaf size for E. labios trees. We found that trichome density was significantly greater in trees with evidence of prior shoot damage (presumably from stem borer emergence at the meristem) but was not significantly related to the presence or absence of an ant colony. This prompted us to compare trichome density on leaves of nearby small trees and of different branches of the same tree, pairing a stem/branch that appeared damaged with one that appeared healthy. Trichome densities on leaves from damaged stems and branches were significantly greater than were trichome densities on healthy branches and stems. Based on these empirical data, we present several possible explanations for the patterns of association between ants, stem borers, and pubescence. Although feeding preference tests with a common folivore showed no effect of trichome densities on leaves, we suggest further study on how trichomes may affect ovipositing stem borers.     

Anticipating Ulawun Volcano in New Britain,Papua New Guinea

ABSTRACT

This paper outlines some of the ways Mengen speakers have positioned Ulawun volcano, its inhabitants and outputs as beneficial features of daily life. By way of contrast, volcanology and more recent disaster planning discourses in Papua New Guinea, have often positioned Ulawun as a hazard that creates potential dangers and risks. The paper explores how these two distinct orientations to Ulawun’s past and future influence the possibilities of Ulawun’s beneficial and dangerous outcomes. We emphasise how Ulawun’s anticipated future has been articulated into forms of disaster planning involving new modes of action, accountability and world making.     

Hegemony and Voice in Papua New Guinea

Constructing Inequality: The Fabrication of a Hierarchy of Virtue Among the Etoro . Raymond C. Kelly.
Voices of Conflict . Andrew Strathern.     

Culture and Class in Papua New Guinea

Mangrove Man: Dialogics of Culture in the Sepik Estuary. David Lipset. New York: Cambridge University Press, 1997. 335 pp.
Emerging Class in Papua New Guinea: The Telling of Difference. Deborah B. Gewertz and Frederick K. Errington. New York: Cambridge University Press, 1999. 179 pp.     

Health research in Papua New Guinea

The Papua New Guinea Institute of Medical Research (PNGIMR) is one of the most respected health research institutions in the developing world, and its studies of the local health problems of PNG have consistently had international relevance. This article examines the structural and philosophical factors that have enabled the success of the PNGIMR, and presents the PNGIMR approach to research as a potential model for other disease-endemic countries. An overview of PNGIMR research into malaria and filariasis is given with selected examples as an introduction to a Trends in Parasitology series on health research in Papua New Guinea.     

Parasitic zoonoses in Papua New Guinea

Relatively few species of zoonotic parasites have been recorded in humans in Papua New Guinea. A greater number of potentially zoonotic species, mostly nematodes, occur in animals but are yet to be reported from humans. Protozoa is the best represented group of those infecting man, with Giardia duodenalis, Cryptosporidium parvum, Cyclospora cayetanesis, Toxoplasma gondii, Sarcocystis spp., Entamoeba polecki, Balantidium coli and, possibly, Blastocystis hominis. The only zoonotic helminths infecting humans include the trematode Paragonimus westermani, the cestodes Hymenolepis nana, H. diminuta and the sparganum larva of Spirometra erinacea, and the nematodes Trichinella papuae and Angiostrongylus cantonensis and, possibly, Ascaris suum. Other groups represented are Acanthocephala (Macracanthorhynchus hirudinaceus)), insects (Chrysomya bezziana, Cimex sp., Ctenocephalides spp.), and mites (Leptotrombidium spp. and, possibly Sarcoptes scabiei, and Demodex sp.). One leech (Phytobdella lineata) may also be considered as being zoonotic. The paucity of zoonotic parasite species can be attributed to long historical isolation of the island of New Guinea and its people, and the absence until recent times of large placental mammals other than pig and dog. Some zoonotic helminths have entered the country with recent importation of domestic animals, in spite of quarantine regulations, and a few more (two cestodes, one nematode and one tick) are poised to enter from neighbouring countries, given the opportunity. Improvement in water supplies, human hygiene and sanitation would reduce the prevalence of many of these parasites, and thorough cooking of meat would lessen the risk of infection by some others.     

Finding Money: Business and Charity in Auhelawa,Papua New Guinea

There is a growing consensus that money and the market principle have not led to a great transformation into modernity. Rather, market exchange is everywhere socially embedded. But what does this embedding consist of, structural limits, tactics of resistance, or moral boundaries? Auhelawa (Normanby Island, Papua New Guinea) have incorporated money into their local economy in a variety of ways which keep the logic of the market in check. The comparison between two modes of accumulation – business and charity – sheds light on the precise nature of embeddedness. Local entrepreneurs describe themselves as navigating dilemmas which arise from contradictions between accumulation and reciprocity. Church congregations, however, appear to have transcended this conflict by representing their charitable contributions of money as love-gifts which are not subject to reciprocity. While charity, like business, is an embedded form of accumulation, I argue that it creates links to an alternative hierarchy of values, and thus contains the potential to create a great transformation of its own.     

Nutrition, infection and child growth in Papua New Guinea

Growth patterns of populations in Papua New Guinea (PNG) have traditionally shown considerable variation, with the greatest difference lying between coastal and highland populations. While genetic differences in explaining these patterns cannot be excluded, the generally poor growth relative to western growth references is largely due to the complex interactive effects of undernutrition and infection. The effects of diet, nutrition and infection on the nutritional status of a child vary with age, the general disease ecology and the type and extent of exposure to it, patterns of infant and young child feeding, and types of food consumed. There are two possible ways in which the relationship between undernutrition and infection can begin; one in which poor nutritional status leads to impaired immunocompetence and reduced resistance to infection, and the other in which exposure to infectious disease can lead to a range of factors that reduce food intake, absorption of nutrients, or increase nutrient requirements. In PNG prior to, and at early stages of modernisation, primary malnutrition is likely to have been the usual initiating factor in the onset of growth faltering due to undernutrition-infection interactions. However, the possibility that infection may have been the initiating event in some societies cannot be excluded. This would have happened by way of early dietary supplementation of infants with foods of minor nutritional significance, which could have acted as a vehicle for the introduction of infectious disease to the child. With modernisation and adoption of primary health care principles, earlier supplementation of infant diet than was previously the case became common in PNG. This has lead to general improvements in growth and nutritional status. However, in populations where undernutrition is still common, infection has become more important than primary malnutrition as the initiator of growth faltering due to undernutrition-infection interactions.     

Biology and social behaviour of three species ofAnischnogaster (Vespidae,Stenogastrinae) in Papua New Guinea

Summary Level of social organization, adult behaviour, size and development of the brood in three species ofAnischnogaster are described. The normal colony size in all the three species was one female per nest, and colony size never exceeded two females per nest. The social interactions, which were only observed in one species, did not include any marked dominance behaviour, but there was clear caste differentiation, with the older female guarding the nest while the younger female foraged for food. InAnischnogaster sp. A only some eggs and larvae have abdominal secretion, while no secretion at all was found on the eggs and larvae ofA. laticeps. In spite of this, the Dufour's gland was found to be well developed. The significance of this is discussed. Females ofA. laticeps were found to fall into two groups distinguished by the length of the sting. The larvae seem quite similar to those of other Stenogastrinae and have, apparently, only four instars.