Fertility and infertility in Papua New Guinea

Fertility levels in selected populations of coastal and highland Madang Province of Papua New Guinea are analyzed from reproductive history data. Changing levels of fertility between 1964 and 1984 are examined using reconstructed censuses. Age-specific infertility rates are calculated and evaluated with available data on rates of sexually transmitted diseases (STD) and contraceptive usage. These suggest that STD-associated infertility may be a major factor underlying levels of fertility lower than expected. © 1993 Wiley-Liss, Inc.     

Acetylator phenotypes in Papua New Guinea

Acetylator phenotypes have been determined in 139 unrelated subjects from the hitherto untested populations of Papua New Guinea, and their relevance to current antituberculous isoniazid chemotherapy is discussed.     

Non-deletion haemoglobin H disease in Papua New Guinea.

Analysis of DNA from members of a Melanesian family from Papua New Guinea with haemoglobin (Hb) H disease revealed that all four alpha globin genes are intact in affected subjects. Study of restriction enzyme site and length polymorphisms and the use of oligonucleotide probes indicated that the molecular basis of this Papuan form of non-deletion Hb H disease differs from the previously described Middle Eastern and Mediterranean types.     

Red cell enzyme and serum protein types in the Watut Anga of Papua New Guinea.

Historically, the Angan populations of Papua New Guinea have maintained a strong isolation and absorbed limited genes from their neighbours. This lack of intermixing is reflected in their relatively homogeneous cultural, linguistic and genetic profiles. We have determined the electrophoretic variation at 26 red cell enzyme, serum protein and haemoglobin loci in the Watut Anga, a splinter group occupying the Upper Watut Valley of Morobe Province. Their genetic profile reveals the lack of a number-of variants, such as PGM2*10 and MDH*3, known to exhibit high frequencies in other highland populations. The average heterozygosity in the Watut is also much lower when compared with other Papua New Guinean populations. Their present numerical strength notwithstanding, it appears that the Angan populations have experienced population bottlenecks in their evolutionary history which may have accentuated their genetic divergence from other Papua New Guinean populations.     

Associations between anthropometric variables and reproductive performance in a Papua New Guinea highland population

Associations between anthropometric variation and reproductive performance have important ecological and evolutionary implications. Bivariate associations between measures of reproductive performance (live births and offspring still living at the time of interview) and 24 anthropometric variables were examined in 150 females, aged 21–44 years, from the Eastern Highlands district of Papua New Guinea. Where significant linear or curvilinear associations with age existed, the reproductive and anthropometric variables were age-corrected. Linear, quadratic and cubic regressions were computed for each bivariate regression of age-corrected reproductive variable on age-corrected anthropometric trait. Positive linear regressions were found in the cases of body weight, triceps skinfold and head breadth. Positive cubic regressions were found in the cases of upper arm circumference, calf circumference, bicondylar femur and wrist breadth. It is suggested that these associations may reflect important ecological factors which influence both anthropometric and reproductive variation. U-shaped associations were found in the cases of wrist breadth and bicondylar femur. Inverted U-shaped associations were found for stature, sitting height, bizygomatic diameter and morphological face height. These curvilinear associations may be interpreted in terms of natural selection, and suggest that stature and sitting height may be undergoing stabilizing selection in this population.     

Immunoglobulin allotypes and response to tetanus toxoid in Papua, New Guinea.

The data indicates that Papuans with the Austronesian haplotype Gmf,a;b produce significantly higher levels of tetanus specific antibody, than Papuans without this haplotype, suggesting that response to tetanus toxoid in man is associated with the Gm phenotype of the individual. Km (1) status was not related to response.     

Ethnic and environmental factors affecting fetal growth in Papua New Guinea

We studied 738 live singleton births in Papua New Guinea to examine the contribution of ethnic origin and environmental factors to birth weight and gestation. Maternal history, examination and post-partum anthropometry, infant anthropometry and clinical gestational assessment were performed, and placental blood slides and histology were examined. Mothers from Highlands provinces who delivered on the coast had larger babies (mean birthweight 3.34 SD 0.48 kg) than either indigenous coastal mothers (mean 3.10 SD 0.51 kg) or those migrating to Port Moresby from other coastal regions (mean 3.14 SD 0.51 kg). This was due to a combination of longer gestation and better intrauterine growth (assessed by birthweight standard deviation scores). Gestation was slightly longer in Highlands mothers delivering on the coast compared with those delivering in the Highlands, but birthweight standard deviation scores were unchanged. Malarial infection of the placenta was almost never found. Stepwise regression analysis showed that parity, maternal height, Highlands origin and maternal body mass index (weight/height2) were all significant predictors of birthweight standard deviation score, while maternal body mass index and Highlands origin were predictors of gestational length. We conclude that Highland mothers have a tendency to deliver heavier babies, and do not demonstrate the fetal growth-retarding effects of altitude seen in other races. Although the incidence of low birthweight was only 7.1% in our study, we found that indices of maternal nutrition were predictors of birth weight.     

Lymphatic filariasis in Papua New Guinea: prospects for elimination

Lymphatic filariasis is a significant public health problem in several Pacific island countries. Papua New Guinea is one of the most populous countries in this region, and 39% of its residents are estimated to be infected with Wuchereria bancrofti. The Ministries of Health of the 22 islands and territories in the Pacific region are committed to taking action against lymphatic filariasis. Accordingly, a regional collaborative effort aimed at the control of filariasis has been organized under the auspices of a program referred to as PacELF. The main objective of PacELF is to eliminate filariasis as public health problem in the Pacific region by the year 2010, 10 years before global elimination of this infectious disease has been targeted. This contribution describes the epidemiology and ecological features of filariasis and prospects for its elimination in Papua New Guinea. The frequencies of microfilaremia, chronic lymphatic disease, and acute filarial morbidity in Papua New Guinea are higher than in many other endemic countries of the Pacific, Africa, and South America. All possible combinations of these three manifestations of filariasis exist. They occur independently of each other, and there is no association between chronic lymphatic disease and microfilarial status. Anopheles punctulatus mosquitoes are the main vectors throughout the country. Transmission intensity is heterogeneous and a major determinant of local patent infection and morbidity rates. Annual transmission potential and annual infective biting rates are positively associated with the village-specific microfilarial rate, mean intensity of microfilaremia, and prevalence of leg edema. Children and adults have similar worm burdens, assessed by circulating filarial antigen levels, in areas of high transmission, whereas worm burdens increase with age in areas of lower transmission. Intensity of exposure to infective third-stage larvae (L3) is significantly correlated with filarial antigen-specific lymphocyte proliferation and cytokine production, possibly by a mechanism that alters APC function. Historical evidence suggests that residual insecticide spraying conducted for malaria control in some parts of the country interrupted transmission of W. bancrofti as it did in the Solomon Islands. Prospects for eliminating lymphatic filariasis in Papua New Guinea are good and may be achieved by the end of the second decade of the twenty-first century if an integrated control approach using mass drug administration with vector control is adopted.     

Size relationships among permanent mandibular molars in Aboriginal Australians and Papua New Guinea Highlanders.

Size relationships among crown units of permanent mandibular molars were investigated in two Sahul-Pacific samples: Aboriginal Australians (Yuendumu) and Papua New Guinea Highlanders (Wabag). Measurements of first, second, and third molars (M1, M2, and M3), including overall mesiodistal and buccolingual diameters as well as the mesiodistal and buccolingual diameters of the trigonid and talonid, were obtained from dental casts using a sliding caliper. Molar reduction was noted in talonid dimensions within both samples, but the trigonid mesiodistal diameter was not reduced in M2 or M3 compared with M1, indicating that the later-developing crown unit (talonid) was more reduced than the early-developing unit (trigonid). M2 was most reduced in size mesiodistally of the three molars, but its buccolingual diameter was not reduced. M3 was the most reduced tooth in trigonid buccolingual diameter. The percentage sexual dimorphism values were greater for the size of the talonid than for the trigonid, indicating that male values exceeded those for females by a greater amount in the later-developing crown unit. Crown dimensions were larger generally in the Aboriginal Australians from Yuendumu than in the Papua New Guinea Highlanders from Wabag, with differences being more evident in M2 and M3 than M1, especially in talonid dimensions. The trigonid, which develops early both phylogenetically and ontogenetically, tended to be relatively stable in size, whereas the later-forming talonid displayed size reduction when comparisons were made both within and between groups.     

Comparative in situ hybridisation study of juvenile laryngeal papillomatosis in Papua New Guinea and Australia.

A comparative study of cases of juvenile laryngeal papillomatosis from Papua New Guinea (n = 3) and Brisbane, Australia (n = 9) was carried out. In situ hybridisation reactions for human papillomavirus (HPV) types 6 and 11 occurred in 11 cases. All three cases from Papua New Guinea and eight from Australia gave positive signals. A negative reaction was observed in one Australian case. The intensity of the reaction was strong in seven cases, moderate in one, and weak in three. An equivocal reaction was also noted with probes for types 16 and 18, and types 31, 33, and 35 in two cases from Australia and one from Papua New Guinea. It is concluded that as similar staining patterns and intensities occurred in cases from both areas, the aetiology is the same. The equivocal reactions noted in three cases were probably due to cross hybridisation rather than multiple infection.     

Late-childhood-onset spinal muscular atrophy in three Melanesian families in Papua New Guinea

Late-childhood-onset spinal muscular atrophy (SMA) with rapid progression from proximal to distal muscle groups and leading to severe incapacity or death in adolescence or early adult life, was studied in two Melanesian families in Papua New Guinea. Probable SMA with cardiomyopathy was observed in a 12-year-old boy in a related family. The pattern of inheritance in the study group did not conform to any of the conventional Mendelian modes and it was conjectured that the disease was expressed in heterozygote carriers of the SMA gene only when an allelomorphic activator gene was present.     

Persistent high intestinal lactase activity in Papua New Guinea. Lactose absorption curves in two populations

Thirty adolescent males, aged 16-19 years, all of Huli, Mendi or Dunai descent, sampled at Tari in Southern Highlands of Papua New Guinea, and 29 children aged between 9 and 15 years, all speakers of Daga and sampled at Agaun in the Milne Bay Province, have been tested for persistent high intestinal lactase activity. Three persons at Tari and five at Agaun were found to be lactose absorbers. There is reasonably convincing evidence that all five absorbers at Agaun descend from a common ancestor five generations ago, but there is no such suggestion for those tested at Tari. Gene flow from Caucasoids who penetrated both areas is possible. The presence of lactose absorbers in peoples who are not traditional users of fresh milk suggests that the culture historical hypothesis may not give a completely adequate explanation for the establishment and conservation of the lactose polymorphism in man.     

Two decade trends in birth weight and early childhood growth in Papua New Guinea

At present, little is known about patterns of early growth and development in foraging and small-scale horticultural populations. Moreover, still less is known about secular changes in growth in these populations. Data collected in 1967, 1976, and 1989 are presented for birth weight and subsequent growth to 5 years among Au forager-horticulturalists of Papua New Guinea. Despite the launching of health campaigns over the last two decades aimed at bettering the nutritional status of the Au, the data show that average birth weight has remained stable and low at just over 2600 g. Weight- and length-for-age also show no significant changes among traditional Au over the last 20 years, and remain on average, at just below the U.S. 5th percentile. Evidence for the start of a positive secular trend in birth weight and subsequent growth is seen, however, among a small group of Au children residing in households that have a source of wage income. These individuals show an increase of 150 g in birth weight, and over the subsequent 5 years of growth average 93 g heavier and 2.6 cm taller than Au children in traditional households. In addition to providing baseline data on child growth in a forager-horticulturalist society, the findings provide evidence for a secular trend newly underway, and suggest that health promotion campaigns alone without socioeconomic development may be insufficient in effecting change in growth status in rural communities. Am. J. Hum. Biol. 10:483–493, 1998. © 1998 Wiley-Liss, Inc.     

HTLV-I antibody studies in villagers in East Sepik Province,Papua New Guinea

Summary Serum samples collected in 1984 during a malariometric survey of two villages in the East Sepik Province of Papua New Guinea were tested for antibodies to HTLV-I. None of the villagers showed any symptoms suggestive of retrovirus infection. Eighteen of the 186 (9.5%) sera tested at that time were found to be positive. Blood samples were subsequently obtained from fifteen of the eighteen positives and subjected to analysis by enzyme-linked immunosorbent assay (ELISA), radioimmuno assay (RIA), radioimmunoprecipitation assay (RIPA), and Western blot (WB). Fourteen of the fifteen gave a positive ELISA response, but none were unequivocally positive by p 24 RIA. All sera tested were reactive togag antigens by WB, but gave indeterminate results currently accepted criteria. Notably absent from the WB profiles of all of the study subjects was an antibody response to HTLV-I envelope protein gp 46. It is possible that these antibody responses are directed against a variant of HTLV-I or to a novel retrovirus which possesses core antigens similar to those of HTLV-I but has different envelope antigens. Until a virus is isolated, or the viral genome is identified in infected lymphocytes, the possibility remains that the response may be due to factors unrelated to retrovirus infection.