Human herpesvirus-8 and other viral infections, Papua New Guinea.
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We studied residents of remote villages and the capital (Port Moresby) of Papua New Guinea to determine the distribution of human herpesvirus-8 (HHV-8) infection. Our data suggest that HHV-8 has been endemic on the island for a long time and that the epidemiologic pattern of HHV-8 is more similar to that of herpes simplex virus-2 than hepatitis C virus. (+info)
Hypoxaemia in acute respiratory and non-respiratory illnesses in neonates and children in a developing country.
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AIMS: To determine, in sick neonates and children requiring admission to a hospital in the highlands of Papua New Guinea: (1) the incidence and severity of hypoxaemia; (2) the proportion with hypoxaemia who do not fulfil criteria for acute lower respiratory infection (ALRI); and (3) the power of clinical signs to predict hypoxaemia, according to age and disease category. METHODS: Age dependent normal values for transcutaneous oxygen saturation (SpO(2)) were established in 218 well neonates and children in Goroka. A total of 491 sick neonates and children were then studied on presentation to the paediatric department at Goroka Hospital. RESULTS: A total of 257 sick neonates and children (52%) were hypoxaemic. Hypoxaemia was present in 179/245 (73%) with clinical criteria for ALRI; 79/246 (32%) with non-ALRI illnesses (including meningitis, septicaemia, severe malnutrition, low birth weight, birth asphyxia, and congenital syphilis) were also hypoxaemic. For children aged 1 month to 5 years with ALRI, the clinical signs best predicting hypoxaemia were cyanosis, respiratory rate >60, poor feeding, or reduced spontaneous activity; in those without ALRI the best predictors were cyanosis, respiratory rate >60 per minute, and inability to feed, but the positive predictive value was much lower than for children with ALRI. For neonates cyanosis was predictive of hypoxaemia, but tachypnoea or inability to feed were not. CONCLUSIONS: Hypoxaemia is an under recognised complication of non-ALRI illnesses in children and in sick neonates in developing countries. Use of algorithms with high sensitivity for the recognition of hypoxaemia, and protocols for administration of oxygen to neonates, and to children with non-ALRI illnesses, might substantially reduce case fatality. (+info)
Etiology of child mortality in Goroka, Papua New Guinea: a prospective two-year study.
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OBJECTIVE: To collect accurate data on disease- and microbial-specific causes and avoidable factors in child deaths in a developing country. METHODS: A systematic prospective audit of deaths of children seen at Goroka Hospital in the highlands of Papua New Guinea was carried out. Over a 24-month period, we studied 353 consecutive deaths of children: 126 neonates, 186 children aged 1-59 months, and 41 children aged 5-12 years. FINDINGS: The most frequent age-specific clinical diagnoses were as follows: for neonates--very low birth weight, septicaemia, birth asphyxia and congenital syphilis; for children aged 1-59 months--pneumonia, septicaemia, marasmus and meningitis; and for children aged 5-12 years--malignancies and septicaemia. At least one microbial cause of death was identified for 179 (50.7%) children and two or more were identified for 37 (10.5%). Nine microbial pathogens accounted for 41% of all childhood deaths and 76% of all deaths that had any infective component. Potentially avoidable factors were identified for 177 (50%) of deaths. The most frequently occurring factors were as follows: no antenatal care in high-risk pregnancies (8.8% of all deaths), very delayed presentation (7.9%), vaccine-preventable diseases (7.9%), informal adoption or child abandonment leading to severe malnutrition (5.7%), and lack of screening for maternal syphilis (5.4%). Sepsis due to enteric Gram-negative bacilli occurred in 87 (24.6%). The strongest associations with death from Gram- negative sepsis were adoption/abandonment leading to severe malnutrition, village births, and prolonged hospital stay. CONCLUSIONS: Reductions in child mortality will depend on addressing the commonest causes of death, which include disease states, microbial pathogens, adverse social circumstances and health service failures. Systematic mortality audits in selected regions where child mortality is high may be useful for setting priorities, estimating the potential benefit of specific and non-specific interventions, and providing continuous feedback on the quality of care provided and the outcome of health reforms. (+info)
A recombinant blood-stage malaria vaccine reduces Plasmodium falciparum density and exerts selective pressure on parasite populations in a phase 1-2b trial in Papua New Guinea.
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The malaria vaccine Combination B comprises recombinant Plasmodium falciparum ring-infected erythrocyte surface antigen and 2 merozoite surface proteins (MSP1 and MSP2) formulated in oil-based adjuvant. A phase 1-2b double-blind, randomized, placebo-controlled trial in 120 children (5-9 years old) in Papua New Guinea demonstrated a 62% (95% confidence limits: 13%, 84%) reduction in parasite density in children not pretreated with sulfadoxine-pyrimethamine. Vaccinees had a lower prevalence of parasites carrying the MSP2-3D7 allelic form (corresponding to that in the vaccine) and a higher incidence of morbid episodes associated with FC27-type parasites. These results demonstrate functional activity of Combination B against P. falciparum in individuals with previous malaria exposure. The specific effects on parasites with particular msp2 genotypes suggest that the MSP2 component, at least in part, accounted for the activity. The vaccine-induced selection pressure exerted on the parasites and its consequences for morbidity strongly argue for developing vaccines comprising conserved antigens and/or multiple components covering all important allelic types. (+info)
The role of trade-offs in biodiversity conservation planning: linking local management, regional planning and global conservation efforts.
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Biodiversity conservation planning requires trade-offs, given the realities of limited resources and the competing demands of society. If net benefits for society are important, biodiversity assessment cannot occur without other sectoral factors "on the table". In trade-offs approaches, the biodiversity value of a given area is expressed in terms of the species or other components of biodiversity that it has that are additional to the components protected elsewhere. That "marginal gain" is called the complementarity value of the area. A recent whole-country planning study for Papua New Guinea illustrates the importance of complementarity-based trade-offs in determining priority areas for biodiversity conservation, and for designing economic instruments such as biodiversity levies and offsets. Two international biodiversity programs provide important new opportunities for biodiversity trade-offs taking complementarity into account. Both the Millennium Ecosystem Assessment and the Critical Ecosystems or "hotspots" programs can benefit from an explicit framework that incorporates trade-offs, in which a balance is achieved not only by land-use allocation among areas, but also by the crediting of partial protection of biodiversity provided by sympathetic management within areas. For both international programs, our trade-offs framework can provide a natural linkage between local, regional and global planning levels. (+info)
Antibodies to Plasmodium falciparum glycosylphosphatidylinositols: inverse association with tolerance of parasitemia in Papua New Guinean children and adults.
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Individuals living in regions of intense malaria transmission exhibit natural immunity that facilitates persistence of parasitemia at controlled densities for much of the time without symptoms. This aspect of immunity has been referred to as malarial "tolerance" and is thought to partly involve inhibition of the chain of events initiated by a parasite toxin(s) that may otherwise result in cytokine release and symptoms such as fever. Antibodies to the candidate Plasmodium falciparum glycosylphosphatidylinositol (GPI) toxin have been viewed as likely mediators of such tolerance. In this study, the relationship between antibodies to P. falciparum GPIs, age, and parasitemia was determined in asymptomatic children and adults living in Madang, Papua New Guinea. The prevalence and intensity of antibody responses increased with age and were lowest in children 1 to 4 years old with the highest-density parasitemias. In children of this age group who were tolerant of parasitemia during the study, only 8.3% had detectable immunoglobulin G (IgG) and none had IgM antibodies to GPI. This suggests that anti-GPI antibodies are unlikely to be the sole mediator of malarial tolerance, especially in children younger than 5 years. Following antimalarial treatment, clearance of parasitemia led to a fall in anti-GPI IgG response in children and adolescents within 6 weeks. As anti-GPI antibodies potentially play a role in protecting against disease progression, our results caution against the treatment of asymptomatic parasitemia and suggest that generation of a sustained antibody response in children poses a challenge to novel antitoxic vaccination strategies. (+info)
Age-acquired immunity to a Plasmodium vivax invasion ligand, the duffy binding protein.
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The interaction between the Plasmodium vivax merozoite Duffy binding protein region II (DBPII) and the human erythrocyte Duffy antigen leads to infection. Highly polymorphic regions of this protein may have arisen as a mechanism to avoid host immunity. To examine whether immunity to P. vivax is directed against these polymorphic regions of DBPII, age-associated changes in the frequency of specific DBPII alleles among 358 P. vivax-positive Papua New Guineans were examined. Although the overall number and diversity of DBPII haplotypes simultaneously infecting an individual decreased with increasing age, only certain alleles at particular loci declined in frequency, indicating preferential immune selection against these alleles. One such polymorphic locus formed part of a B cell epitope, and antibodies from exposed individuals differentially recognized alleles at this locus. Therefore, acquisition of strain-specific age-acquired immunity is partially directed against polymorphic motifs within P. vivax DBPII, suggesting that these polymorphisms are maintained and likely arose under immune pressure in the host. (+info)
Thermovibrio ruber gen. nov., sp. nov., an extremely thermophilic, chemolithoautotrophic, nitrate-reducing bacterium that forms a deep branch within the phylum Aquificae.
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A novel, extremely thermophilic, chemolithoautotrophic bacterium was isolated from the submarine hydrothermal system off the beach of Lihir Island, Papua New Guinea. Cells of the organism were curved rods of about 1.5-3 microm in length and 0.5-0.8 microm in width. The bacterium grew within the temperature range 50-80 degrees C (optimum around 75 degrees C) and was an obligate anaerobe. Molecular hydrogen was used as the sole electron donor by the bacterium, and nitrate or elemental sulfur served as electron acceptors, producing ammonium or H2S, respectively. Complex organic substrates stimulated growth of the bacterium, but they could not be used as the sole energy source. Based on 16S-rDNA-based phylogenetic analyses and on physiological, biochemical and structural characteristics, the novel organism was found to represent a novel genus for which the name Thermovibrio is proposed. This novel genus, together with Desulfurobacterium thermolithotrophum, may represent a new order within the phylum Aquificae. Since cell pellets of the novel bacterium had an intense red colour, the name Thermovibrio ruber is proposed for the novel organism. The type strain of Thermovibrio ruber gen. nov., sp. nov. is ED11/3LLKT (= DSM 14644T = JCM 11468T). (+info)