Regions Of Papua New Guinea Research Articles

Microsatellite polymorphism within pfcrt provides evidence of continuing evolution of chloroquine-resistant alleles in Papua New Guinea

BackgroundPolymorphism in the pfcrt gene underlies Plasmodium falciparum chloroquine resistance (CQR), as sensitive strains consistently carry lysine (K), while CQR strains carry threonine (T) at the codon 76. Previous studies have shown that microsatellite (MS) haplotype variation can be used to study the evolution of CQR polymorphism and to characterize intra- and inter-population dispersal of CQR in Papua New Guinea (PNG).MethodsHere, following identification of new polymorphic MS in introns 2 and 3 within the pfcrt gene (msint2 and msint3, respectively), locus-by-locus and haplotype heterozygosity (H) analyses were performed to determine the distribution of this intronic polymorphism among pfcrt chloroquine-sensitive and CQR alleles.ResultsFor MS flanking the pfcrt CQR allele, H ranged from 0.07 (B5M77, -18 kb) to 0.094 (9B12, +2 kb) suggesting that CQ selection pressure was responsible for strong homogenisation of this gene locus. In a survey of 206 pfcrt-SVMNT allele-containing field samples from malaria-endemic regions of PNG, H for msint2 was 0.201. This observation suggests that pfcrt msint2 exhibits a higher level of diversity than what is expected from the analyses of pfcrt flanking MS. Further analyses showed that one of the three haplotypes present in the early 1980's samples has become the predominant haplotype (frequency = 0.901) in CQR parasite populations collected after 1995 from three PNG sites, when CQR had spread throughout malaria-endemic regions of PNG. Apparent localized diversification of pfcrt haplotypes at each site was also observed among samples collected after 1995, where minor CQR-associated haplotypes were found to be unique to each site.ConclusionIn this study, a higher level of diversity at MS loci within the pfcrt gene was observed when compared with the level of diversity at pfcrt flanking MS. While pfcrt (K76T) and its immediate flanking region indicate homogenisation in PNG CQR parasite populations, pfcrt intronic MS variation provides evidence that the locus is still evolving. Further studies are needed to determine whether these intronic MS introduce the underlying genetic mechanisms that may generate pfcrt allelic diversity.

Triggering of earthquakes during the 2000 Papua New Guinea earthquake sequence

A sequence of large earthquakes occurred in the New Britain/New Ireland region of Papua New Guinea in late 2000. The sequence started with a Mw 6.8 earthquake along the New Britain Trench on 29 October. About 20 days later a Mw 8.2 earthquake occurred in the New Ireland region on 16 November and produced large strike‐slip surface displacements and tsunamis. Following the Mw 8.2 event, two large earthquakes (Mw ∼ 7.5) occurred along the nearby New Britain Trench on 16 and 17 November. Furthermore, small triggered events were observed over a wide area outside of the rupture zones of the large earthquakes, with different focal mechanisms from those of the major events. There is likely some mechanism(s) that triggered this remarkable sequence, and we document the details of the spatial and temporal patterns of the events. We investigated if static stress changes can explain the initiation of the large earthquakes and also some groups of triggered smaller events. There are mixed results. The occurrences of the two M ∼ 7.5 major events may be explained by the static stress changes; however, there are also some earthquakes that are not consistent with triggering by static stress changes. There may be multiple mechanisms, including static and dynamic stress changes, that are needed to explain the complicated sequence of earthquakes.

Fasu Solidarity: A Case Study of Kin Networks, Land Tenure, and Oil Extraction in Kutubu, Papua New Guinea

In the Fasu region of Papua New Guinea's fringe highlands, the oil extraction industry has imposed development values and the identification of corporate groups as beneficiary landowners. In response, Fasu males have tightened the boundaries of their agnatic descent groups to become exclusive patriunits. Cash royalties are incorporated into sociopolitical exchange, so the formation of exclusive kin groups allows males to expand social networks to other regions, whilst ensuring continuing wealth for future generations. Consequently, males are becoming isolated from pre–oil exchange networks, and females are becoming isolated within villages. In this article, I map the transition of Fasu kin networks from an ideology of descent to a dogma of descent and patrilineal solidarity, locating the transition in the symbolic codes that inform kin categories. I aim to highlight some consequences of “development” and to advance knowledge on the link between kinship and descent in a postcolonial, industry‐dominated Papua New Guinea.

LOW PREVALENCE OF AN ACUTE PHASE RESPONSE IN ASYMPTOMATIC CHILDREN FROM A MALARIA-ENDEMIC AREA OF PAPUA NEW GUINEA

Levels of C-reactive protein (CRP), a classic marker for the acute phase response (APR), were measured in children with asymptomatic malaria infection in the Amele region of Papua New Guinea (PNG). Despite the presence of parasitemia, the prevalence of CRP levels consistent with an APR (CRP > 10 microg/mL) was very low (< 10%). Splenomegaly was significantly associated with increased parasitemia (P < 0.001) and CRP levels (P < 0.001), highlighting the importance of splenomegaly as an indicator of recent high density infection in this population. Multivariate analysis showed that CRP levels were significantly associated with splenomegaly, fever, hemoglobin, and age (P < or = 0.002). CRP levels also increased with increasing parasitemia (P < 0.001) but remained < 3.5 microg/mL. The low levels of CRP indicate that children in the Amele modulate inflammation associated with malaria.

Reflecting on Loss in Papua New Guinea

This article takes up the conundrum of conducting anthropological fieldwork with people who claim that they have ‘lost their culture,’ as is the case with Suau people in the Massim region of Papua New Guinea. But rather than claiming culture loss as a process of dispossession, Suau claim it as a consequence of their own attempts to engage with colonial interests. Suau appear to have responded to missionization and their close proximity to the colonial-era capital by jettisoning many of the practices characteristic of Massim societies, now identified as ‘kastom.’ The rejection of kastom in order to facilitate their relations with Europeans during colonialism, followed by the mourning for kastom after independence, both invite consideration of a kind of reflexivity that requires action based on the presumed perspective of another.

A Multiplex Ligase Detection Reaction-Fluorescent Microsphere Assay for Simultaneous Detection of Single Nucleotide Polymorphisms Associated with Plasmodium falciparum Drug Resistance

Incomplete malaria control efforts have resulted in a worldwide increase in resistance to drugs used to treat the disease. A complex array of mutations underlying antimalarial drug resistance complicates efficient monitoring of parasite populations and limits the success of malaria control efforts in regions of endemicity. To improve the surveillance of Plasmodium falciparum drug resistance, we developed a multiplex ligase detection reaction-fluorescent-microsphere-based assay (LDR-FMA) that identifies single nucleotide polymorphisms (SNPs) in the P. falciparum dhfr (9 alleles), dhps (10 alleles), and pfcrt (3 alleles) genes associated with resistance to Fansidar and chloroquine. We evaluated 1,121 blood samples from study participants in the Wosera region of Papua New Guinea, where malaria is endemic. Results showed that 468 samples were P. falciparum negative and 453 samples were P. falciparum positive by a Plasmodium species assay and all three gene assays (concordance, 82.2%). For P. falciparum infections where the assay for each gene was positive, 2 samples carried resistance alleles for all three genes, 299 carried resistance alleles for dhfr and pfcrt, 131 carried resistance alleles for only one gene (dhfr [n = 40], dhps [n = 1], or pfcrt [n = 90]), and 21 carried only sensitive alleles at all three genes. Mixed-strain infections characterized 100 samples. Overall, 95.4% (432/453) of P. falciparum-infected samples carried at least one allele associated with resistance to Fansidar or chloroquine. In view of the fact that 86.3% (391/453) of P. falciparum-infected samples carried pfcrt mutations, chloroquine is largely ineffective against P. falciparum in Papua New Guinea. Surveillance of additional dhfr and dhps polymorphisms in order to monitor the continued effectiveness of Fansidar is recommended.

α+‐Thalassaemia and pregnancy in a malaria endemic region of Papua New Guinea

The effect of maternal alpha+ -thalassaemia on pregnancy was assessed in the north coastal region of Papua New Guinea (PNG), where malaria is hyperendemic and alpha+ -thalassaemia is extremely common. In a prospective study of 987 singleton hospital deliveries, we correlated maternal alpha-globin genotype with markers of reproductive fitness (age in primigravidae, gravidity, pregnancy interval and the number of miscarriages and stillbirths), Plasmodium falciparum(P. falciparum) infection of the mother and placenta, maternal haemoglobin, preterm delivery and birthweight. The frequency of the -alpha genotype in mothers was 0.61. Markers of reproductive fitness were similar in women with and without alpha+ -thalassaemia. Median haemoglobin concentration during pregnancy and after delivery was about 1.0 g/dl lower in homozygous alpha+ -thalassaemia than in women with a normal alpha- globin genotype (P < or = 0.001). The frequency of placental P. falciparum infection and systemic malaria infection after delivery showed no consistent relationship to alpha-globin genotype. The frequency of preterm delivery and low birthweight did not vary significantly according to maternal alpha-globin genotype. Maternal alpha+ -thalassaemia does not affect reproductive fitness or susceptibility to malaria during pregnancy. Although median haemoglobin concentration was significantly lower in mothers homozygous for alpha+ -thalassaemia than those with a normal alpha-globin genotype, this did not result in an adverse outcome of pregnancy.

Freshwater turtles of the TransFly region of Papua New Guinea - notes on diversity, distribution, reproduction, harvest and trade

The Chelidae is a family of side-necked turtles restricted in distribution to South America and Australasia. While their biology in Australia is reasonably well known, species in New Guinea are very poorly known despite high diversity, especially in the southern lowlands. In this paper, we report on the diversity, distribution, habitat and reproductive biology of the freshwater turtles of the TransFly region of the Western Province of Papua New Guinea, with special emphasis on reproduction of Emydura subglobosa, Elseya branderhorsti and Elseya novaeguineae. Seven species were captured, with reliable records of an eighth. A key to the freshwater turtles of the TransFly region is provided. Harvest methods, consumption, and trade in turtles by the TransFly communities are documented. There is mounting pressure to take advantage of revenue opportunities afforded by the Asian turtle trade, but this is impeded by lack of transport infrastructure. There is also insufficient demographic information on any New Guinean turtle species to make a reasoned judgment on the level of harvest that would be sustainable. Nor is there sufficient information on captive rearing for most species, and where it is available it is not accessible by local villagers. These knowledge gaps need to be addressed and factored into a management plan that is implemented before local communities can capitalise on the commercial opportunities provided by the turtle fauna without risking collapse of the resource and the implications for their concurrent subsistence economy that would follow.

Isolation and pharmacological characterisation of papuantoxin-1, a postsynaptic neurotoxin from the venom of the Papuan black snake ( Pseudechis papuanus)

The Papuan black snake ( Pseudechis papuanus) is found throughout the southern coastal regions of Papua New Guinea and is thought to occur in the adjacent region of Iriyan Jaya. Neurotoxicity is a major symptom of envenomation by this species. This study describes the isolation of the first neurotoxin papuantoxin-1 from the venom of P. papuanus. Papuantoxin-1 (6738 Da), which accounts for approximately 5% of the whole venom, was purified to homogeneity using successive steps of RP-HPLC. The toxin (0.3–1.0 μM) caused concentration dependent inhibition of indirect twitches (0.1 Hz, 0.2 ms and supramaximal V) and inhibited the responses to nicotinic agonists in the chick biventer cervicis nerve-muscle preparation, indicating a postsynaptic mode of action. However, papuantoxin-1 displayed no signs of myotoxicity. Papuantoxin-1 displayed pseudo-irreversible antagonism of cumulative concentration-response curves to carbachol at the skeletal muscle nicotinic receptors with an estimated pA 2 value of 6.9 ± 0.3. CSL black snake antivenom, which is raised against the venom of the Australian black snake Pseudechis australis, appears to be effective in reversing the effects of papuantoxin-1. Thus, black snake antivenom should be considered for the treatment of the neurotoxic effects following envenomation by the Papaun black snake.

Trichinella infection in a hunting population of Papua New Guinea suggests an ancient relationship between Trichinella and human beings

A new Trichinella species, Trichinella papuae, was discovered in 11.5% of wild pigs in a remote region of Papua New Guinea. A survey was conducted to determine whether the inhabitants of this region are infected with Trichinella, as wild-pig meat represents their main source of protein. The prevalence of anti-Trichinella antibodies and its determinants were assessed among the inhabitants in 51 of the villages in the Morehead District of Papua New Guinea. We tested and interviewed 1536 people (28.8% of the adult population). Anti-Trichinella IgG were detected in 10.0% (95% Cl 8.5-11.6%) of them. The prevalence of seropositivity was higher in males (12.7%) than in females (7.5%) (P<0.01), and the seroprevalence significantly increased with age. In one area, seroprevalence was highest in villages nearest the hunting area in which wild pigs are infected with Trichinella papuae (P<0.01). Seropositivity was also correlated with the consumption of raw or undercooked meat. Persons reporting pain in the muscle joints and limbs were more likely to be seropositive; no severe clinical manifestations were observed. That infection was never severe suggests that the seropositive people are reinfected relatively often, but with very few larvae. If the epidemiological pattern of Trichinella infection observed among the hunting population of this area is any indication of the pattern of infection in prehistoric hunters, we can speculate that Trichinella infection due to the consumption of meat from wild animals was possibly a common disease among prehistoric populations.

Presynaptic neuromuscular activity of venom from the brown-headed snake ( Glyphodon tristis)

The brown-headed snake ( Glyphodon tristis) inhabits the forest regions of Papua New Guinea, Torres Strait Islands, and far northern Queensland, Australia. Although bites by Glyphodon dunmalli have been reported, G. tristis was regarded as innocuous until 1989 when a healthy 20 year old man was bitten (Sutherland, S.K., Tibballs, J., 2001. Australian Animal Toxins, the Creatures, their Toxins and Care of the Poisoned Patient. University Press, Oxford). Treatment of envenomation by this species is empirical with no specific antivenom available. While no published studies on the venom of G. tristis are available, unpublished studies suggest neurotoxicity as being the main symptom of envenomation. In this study, the in vitro effects of G. tristis venom were examined using the chick biventer cervicis nerve muscle (CBCNM) preparation. Venom (10 μg/ml) inhibited indirect (0.2 ms, 0.1 Hz, supramaximal V) twitches of the CBCNM. This inhibition appeared to be presynaptic in origin as evidenced by the lack of effect of venom on responses to exogenous acetylcholine (1 mM), carbachol (20 μM) and KCl (40 mM) in the non-stimulated CBCNM. Prior addition (10 min) of polyvalent snake antivenom (5 U/ml; CSL Ltd) attenuated twitch inhibition. The venom (10–50 μg/ml) also appears to be myotoxic as indicated by a slowly developing contracture and inhibition of direct (2 ms, 0.1 Hz, supramaximal V, in the presence of tubocurarine 10 μM) twitches. Myotoxicity was confirmed by subsequent histological examination of tissues. This myotoxicity was prevented by the prior addition of polyvalent snake antivenom (30 U/ml). The phospholipase A inhibitor 4-BPB (1.8 mM) significantly attenuated the inhibition of indirect and direct twitches of the CBCNM preparation, indicating the involvement of a PLA 2 component in the toxic action of the venom.

INFECTION WITH HUMAN IMMUNODEFICIENCY VIRUS, HERPES SIMPLEX VIRUS TYPE 2, AND HUMAN HERPES VIRUS 8 IN REMOTE VILLAGES OF SOUTHWESTERN PAPUA NEW GUINEA

To investigate the spread of human immunodeficiency virus (HIV) and other sexually transmitted viruses, two serosurveys (the first in 1999 among 56 adults and the second in 2001 among 351 adults) were conducted in remote villages of the southwestern part of Papua New Guinea. Only one individual was positive for antibodies to HIV. In 2001, the seroprevalence of human herpes virus 8 (HHV-8) was 32.2%, and the seroprevalence of herpes simplex virus type 2 (HSV-2) was 27.4%. Both prevalence rates increased with age, and were lower in the villages near the Bensbach River. The seropositivity of HSV-2 was independently correlated with HHV-8 infection. Our data show that the inhabitants of the southwestern region of Papua New Guinea currently experience an extremely low circulation of HIV. However, the high prevalence of infectious agents that can be sexually transmitted, such as HSV-2 and to a lesser extent HHV-8, indicates the presence of behavioral patterns that may facilitate the spread of HIV in this area of currently low endemicity.

Places, loss and logging among the Kamula

This paper outlines some of the relationships between Kamula understandings of embodied personhood and place. It seeks to supplement existing accounts of place in the Bosavi region of Papua New Guinea (PNG). Such understandings have largely been based on song, poetry and myth (Feld 1982; Schieffelin 1976). By way of contrast, this paper describes comparatively mundane Kamula experiences of place. The Kamula talk I consider emphasizes socially mediated forms of unification of person and place associated with notions of shared ‘appearance’, ‘equivalence’ and ‘enhancement’. Such terms are further explained by reference to Kamula understandings of the effects of losing a relationship with place. I conclude by showing how such understandings of loss are being deployed in Kamula demands for compensation from the state and logging companies. Through a discussion of these themes the paper contributes to the growing literature on the relationship between personhood, place and development in Papua New Guinea.

MODELS OF TRAPS FOR THE COCONUT PESTS RHYNCOPHORUS BILINEATUS AND SCAPANES AUSTRALIS AND THEIR TRAPPING EFFICIENCY IN PAPUA NEW GUINEA

The beetle pests Scapanes australis, Oryctes rhinocerous and Rhyncophorus bilineatus have been major constraints to coconut production in the Islands region of Papua New Guinea for the last 30 years. Efficient synthetic attractants able to lure and trap all three beetles have been developed. This paper describes several trap designs developed at the Cocoa and Coconut Research Institute and the results obtained for their trapping efficiency in the laboratory and the field. A modification of the “Titus Bucket” trap increased the number of R. bilineatus caught threefold and of female Scapanes twofold. PVC pipe traps caught more Scapanes than the modified “Titus Bucket” trap.

Divided communities and contested landscapes: Mobility, development and shifting identities in migrant destination sites in Papua New Guinea

Abstract: Internal conflicts at the local and national levels in several South Pacific countries have revealed the fragility of national unity and the difficulties nations face in governing and managing their own economic development. In Papua New Guinea, the focus of this paper, an uncertain economic future for many rural and urban communities, and rising inequalities in income opportunities and access to resources, have coincided with greater intolerance of migrants at sites of high in‐migration by customary landowners and provincial and local authorities. This paper draws on fieldwork undertaken in the major oil palm growing regions of Papua New Guinea where migrants from densely populated regions of the country have settled on state land alienated from customary landowners. We examine how struggles over land, resource control and development are polarising migrant and landowner identities resulting in increasing tensions and episodic communal violence. A settler identity is emerging based on a narrative of nation building and national development, while an ethno‐regional identity amongst customary landowners is undermining the citizen rights of migrants and challenging the role and authority of the state in land matters.

The Presence of FYAnull Alele of Duffy Blood Group System in Blood Donors and Individuals from a Malarial Endemic Region of Brazil.

BACKGROUND: Malaria is a virulent disease caused by the Plasmodium parasite. Innate resistance to malaria infections in humans is conferred by various blood group polymorphisms. The Duffy blood group system consists of Fya and Fyb antigens which are encoded by codominant alleles FYA and FYB. Four phenotypes are defined: Fy(a+b+), Fy(a+b−), Fy(a−b+) and Fy(a−b−). Erythrocytes of Duffy-negative individuals are resistant to invasion by P. vivax. In Blacks the Fy(a−b−) phenotype is associated with a single point mutation (-33T-C) in the GATA-1 binding motif for the erythroid promoter of FYB.STUDY DESIGN AND METHODS: We investigated the phenotypes and the genotypes of Duffy blood group system of 250 individuals living in a malarial endemic region (MER) in the state of Amazon (Brazil), and of 199 blood donors (BD) from a non-endemic region. The phenotyping was done by agglutination gel tests (DiaMed-Latino América) using anti-Fya and anti-Fyb reagents. The molecular analysis for FYA, FYB, FYBES (GATA box mutation nt -33T-C), and FYBWeak (mutations 265 C-T, and 298 G-A) alleles, were performed by PCR-RFLP. The PCR products were digested by Ban I for FYA and FYB identifications; by Sty I for GATA box mutation; Acy I and Mwo I for 265 C-T and 298 G-A mutations, respectively. Some samples that showed discrepancy between the phenotype and genotype results were examined by sequence analysis using the ABI PrismâBig Dyeä Terminator Cycle Sequencing Ready Reaction Kit” (Perkin Elmer), and the interpretation by the software ABI PRISMä 377 DNA Sequencer”, 3.3 version (Perkin Elmer).RESULTS: We found that 34/250 (13.6%) of 250 persons living in the MER and 37/199 (18.6%) of BD had phenotype and genotype discrepant results [Fy(a+b−) FYA/FYB]. In addition, we found that 16/34 (47%) of people living in the MER, and 4/37 (10.8%) of BD did not present the -33T-C mutation, the 265 C-T, or the 298 G-A mutations. The sequence analysis of 2 samples from persons from MER indicated the presence of -33T-C mutation in the FYA allele in one individual (1 FYA/FYB and W/M; FYA/FYB and M/M). Additionally, we detected that 18/34 (53%) of people living in the MER, and 33/37 (89.2%) of BD presented the -33T-C mutation. The sequence analysis of 5 samples indicated the presence of -33T-C mutation in the FYA allele in 4 cases [2 persons from MER and 2 from BD (FYA/FYB e M/M)].CONCLUSION: Recently the mutation responsible for erythrocyte Duffy antigen-negativity [Fy(a−b−)] was demonstrated in FYA allele in a malarial endemic region of Papua New Guinea. The present data demonstrated the presence of the FYAnull allele not only in persons living in a malarial endemic region but also in Brazilian blood donors from non-endemic areas. In contrast with that which happens with the FYB allele, our results indicated that the presence of the -33T-C mutation in the FYA allele does not abolish the expression of the Fya antigen in the erythrocyte.

Trichinella papuaein Saltwater Crocodiles (Crocodylus porosus) of Papua New Guinea

<i>Trichinella papuae</i>in Saltwater Crocodiles (<i>Crocodylus porosus</i>) of Papua New Guinea

Plasmodium falciparum: distribution of msp2 genotypes among symptomatic and asymptomatic individuals from the Wosera region of Papua New Guinea

The merozoite surface protein 2 (MSP2) is a leading asexual-stage malaria vaccine candidate that has already proven to have an effect in phase I/IIb vaccine trials, where it was tested in combination with other antigens. Alleles of msp2 fall within two major allelic families, 3D7 and FC27. We analyzed the msp2 genotype in 306 asymptomatic and 63 symptomatic infections from the Wosera region of Papua New Guinea. The multiplicity of infection and the distribution of msp2 alleles was similar to that found in previous studies in the region, but there was no association found between FC27-type or 3D7-type forms of MSP2 and clinical malaria. Index Descriptors and Abbreviations: Plasmodium falciparum; Apicomplexan parasites; Malaria; Antigenic diversity; Vaccine candidates; Morbidity; MSP1, merozoite surface protein 1; MSP2, merozoite surface protein 2; AMA1, apical membrane antigen 1; DNA, deoxyribonucleic acid; PCR, polymerase chain reaction; RFLP, restriction fragment length polymorphism; bp, base pairs; PNG, Papua New Guinea

A human complement receptor 1 polymorphism that reduces Plasmodium falciparum rosetting confers protection against severe malaria.

Parasitized red blood cells (RBCs) from children suffering from severe malaria often adhere to complement receptor 1 (CR1) on uninfected RBCs to form clumps of cells known as "rosettes." Despite a well documented association between rosetting and severe malaria, it is controversial whether rosetting is a cause or a correlate of parasite virulence. CR1-deficient RBC show greatly reduced rosetting; therefore, we hypothesized that, if rosetting is a direct cause of malaria pathology, CR1-deficient individuals should be protected against severe disease. In this study, we show that RBC CR1 deficiency occurs in up to 80% of healthy individuals from the malaria-endemic regions of Papua New Guinea. This RBC CR1 deficiency is associated with polymorphisms in the CR1 gene and, unexpectedly, with alpha-thalassemia, a common genetic disorder in Melanesian populations. Analysis of a case-control study demonstrated that the CR1 polymorphisms and alpha-thalassemia independently confer protection against severe malaria. We have therefore identified CR1 as a new malaria resistance gene and provided compelling evidence that rosetting is an important parasite virulence phenotype that should be a target for drug and vaccine development.

Glycophorin C (Gerbich antigen blood group) and band 3 polymorphisms in two malaria holoendemic regions of Papua New Guinea.

The geographic overlap between the prevalence of erythrocyte polymorphisms and malaria endemicity is thought to be an example of natural selection on human populations. In Papua New Guinea (PNG), the Gerbich-negative phenotype is caused by an exon 3 deletion in the glycophorin C gene (GYPCDeltaex3) while heterozygosity for a 27-base pair deletion in the SLC4A1 gene (anion exchanger 1 or erythrocyte membrane protein, band 3), SLC4A1Delta27, results in Southeast Asian ovalocytosis. Two geographically and ethnically distinct malaria endemic regions of PNG (the Wosera [East Sepik Province] and Liksul [Madang Province]) were studied to illustrate the distribution of two prominent deletion polymorphisms (GYPCDeltaex3 and SLC4A1Delta27) and to determine if the genetic load associated with SLC4A1Delta27 would constrain independent assortment of GYPCDeltaex3 heterozygous and homozygous genotypes. The frequency of the GYPCDeltaex3 allele was higher in the Wosera (0.463) than Liksul (0.176) (chi(2); P < 0.0001). Conversely, the frequency of the SLC4A1Delta27 allele was higher in Liksul (0.0740) than the Wosera (0.0005) (chi(2); P < 0.0001). No individuals were homozygous for SLC4A1Delta27. In 355 Liksul residents, independent assortment of these two deletion polymorphisms resulted in 14 SLC4A1Delta27 carriers heterozygous for GYPCDeltaex3 and one SLC4A1Delta27 carrier homozygous for GYPCDeltaex3 (Fisher's exact test; P = 0.8040). While homozygosity for SLC4A1Delta27 appears to be nonviable, the GYPCDeltaex3 allele is not lethal when combined with SLC4A1Delta27. Neither mutation was associated with altered susceptibility to asymptomatic Plasmodium falciparum or P. vivax infection. While these erythrocyte polymorphisms apparently have no effect on blood-stage malaria infection, their contribution to susceptibility to clinical malaria morbidity requires further study.