| diversity in the immunodominant determinants of the circumsporozoite protein of plasmodium falciparum parasites from malaria-endemic regions of papua new guinea and brazil. | to determine the nature and extent of variation in the t cell sites of the plasmodium falciparum circumsporozoite (cs) protein, a candidate antigen in the development of a malaria vaccine, we cloned and sequenced 69 recombinant clones of the cs protein gene representing 18 and 17 p. falciparum isolates from infected individuals from madang, papua new guinea (png), a holoendemic malaria region, and paragaminos and jacunda, brazil, relatively low endemic regions, respectively. as previously known, ... | 1992 | 1281968 |
| chemoprophylaxis against malaria in papua new guinea: a trial of amodiaquine and a combination of dapsone and pyrimethamine. | a placebo-controlled chemoprophylaxis trial was carried out in 1980 in 318 semi-immune school children in the madang area of papua new guinea, where there was a high prevalence of strains of plasmodium falciparum resistant to 4-aminoquinolines. since prophylaxis with amodiaquine at 5 mg/kg weekly had failed, amodiaquine at a dose of 10mg/kg weekly and maloprim (half a tablet or one tablet depending on body weight, which gave ranges of dapsone of 1.7-3.3mg/kg and pyrimethamine 0.2-0.4 mg/kg) week ... | 1992 | 1341089 |
| human antibody responses to epitopes on the plasmodium falciparum gametocyte antigen pfs 48/45 and their relationship to infectivity of gametocyte carriers. | antibodies in human sera recognizing epitopes i, iia, iii, and iv on the plasmodium falciparum gametocyte antigen pfs 48/45 have been investigated by competitive enzyme-linked immunosorbent assay. more than one-third of the residents of three villages in madang, papua new guinea responded to epitopes i, iia and iii, with little variation by village or with time. there was a bimodal distribution of positive sera by age, with the highest proportion of responders in the 5-9- and greater than 20-yea ... | 1992 | 1377881 |
| gametocyte sex ratios as indirect measures of outcrossing rates in malaria. | the frequency of recombination between unlike genotypes is central to understanding the generation of genetic diversity in natural populations of malaria. here we suggest a way of investigating the problem which could complement conventional biochemical approaches to the population genetics of malaria. sex allocation theory is one of the most successful areas of evolutionary biology. a well-supported prediction is that progressively less female-biased sex ratios are favoured with more outcrossin ... | 1992 | 1641238 |
| antibody responses to plasmodium falciparum gametocyte antigens during and after malaria attacks in schoolchildren from madang, papua new guinea. | sera from 49 school children in madang, papua new guinea with malaria and follow-up sera from 40 of these cases were tested by competitive elisa for antibodies capable of inhibiting binding of eight monoclonal antibodies (moabs) to plasmodium falciparum gametocytes. the proportion of sera inhibiting each moab ranged from 31.2% to 85.7%. at follow-up, the proportion of inhibitory sera decreased for 3 moabs, did not change significantly for 4 moabs and increased for one moab. when sera were groupe ... | 1991 | 1712931 |
| malaria and glucose 6-phosphate dehydrogenase deficiency in populations with high and low spleen rates in madang, papua new guinea. | previous studies in madang have demarcated 2 groups of women, one with high spleen rates (hs group) and the other with low spleen rates (ls group). an association between glucose 6-phosphate dehydrogenase (g6pd) deficiency and low spleen rates was investigated in 196 hs and 106 ls group men. prevalence was 12.2 and 9.4%, respectively. parasite and spleen rates were lower in deficients in the hs group. differences in prevalence between hs group villages were observed which may be related to the i ... | 1990 | 2179119 |
| failure of chloroquine prophylaxis for falciparum malaria in pregnant women in madang, papua new guinea. | six hundred and twenty pregnant women, living under conditions of year-round transmission of malaria in a rural coastal area of madang, papua new guinea (png), were followed while attending mobile antenatal clinics and receiving chloroquine prophylaxis (300 mg base weekly). whole blood chloroquine concentrations measured by elisa from samples collected at delivery indicated a high level of drug compliance in regular attenders. susceptibility is increased in primigravidae to plasmodium falciparum ... | 1990 | 2184784 |
| consequences of maternal anaemia on outcome of pregnancy in a malaria endemic area in papua new guinea. | the prevalence of anaemia during pregnancy was investigated in relation to parasite and spleen rates of pregnant women living in a defined study area in rural madang, papua new guinea. the effects in pregnancy of anaemia, iron deficiency and malaria on the foetus were investigated. there is a high prevalence of anaemia in this population, with 44% of primigravidae and 29% of multigravidae having severe anaemia [haemoglobin (hb) less than 8 g dl-1] after 28 weeks gestation. the odds ratio for sev ... | 1990 | 2184786 |
| the relationship between splenomegaly and antibody to the circumsporozoite protein of plasmodium falciparum in two groups of women with high and low enlarged spleen rates in madang, papua new guinea. | the objective of this study was to determine the prevalence of antibodies recognizing the circumsporozoite (cs) protein of plasmodium by an enzyme-linked immunosorbent assay, in 2 subpopulations of women with significantly different enlarged spleen rates but similar exposure to malaria, on the north coast of papua new guinea. antibody levels of immunoglobulin g (igg) antibody to cs protein in the high and low spleen rate groups were similar (56.2% and 55.1%) but there was a significant differenc ... | 1990 | 2189244 |
| association between hla type and antibody response to malaria sporozoite and gametocyte epitopes is not evident in immune papua new guineans. | hla-a,b,c and dr types were determined for 46 adults living in the madang area of papua new guinea. sera from these individuals were tested by elisa for antibodies against: (i) sonicated schizont extract of plasmodium falciparum; (ii) circumsporozoite repeat regions of p. falciparum and p. vivax; and (iii) epitopes on the 230 and 48/45 kd gametocyte antigens of p. falciparum. all sera were from highly immune individuals and reacted strongly to the schizont antigen. the proportions responding to ... | 1989 | 2482146 |
| small area variation in prevalence of an s-antigen serotype of plasmodium falciparum in villages of madang, papua new guinea. | cross-sectional and longitudinal village-based studies of the transmission dynamics of an s-antigen serotype of the asexual erythrocyte stages of plasmodium falciparum have been carried out in madang, papua new guinea (png). sera collected from village residents were screened for circulating s-antigen of the fc27 serotype by enzyme-linked immunosorbent assay (elisa). the prevalence of the fc27 s-antigen was found to vary between villages at a given point in time, as well as within a village over ... | 1989 | 2653060 |
| newborn splenic volumes vary under different malaria endemic conditions. | ultrasound was used to measure newborn splenic dimensions and calculate the volumes in a malarious and a non-malarious region of papua new guinea. the median splenic volume of infants born in madang, where malaria transmission is high throughout the year, was 5.2 cm3/kg, while that of infants born in goroka, where malaria is not endemic, was 2.6 cm3/kg. the cause of this difference is unknown, but possible explanations include fetal exposure to malaria antigens in utero and the high incidence of ... | 1989 | 2665658 |
| differential antibody responses to plasmodium falciparum and p. vivax circumsporozoite proteins in a human population. | papua new guineans exposed to hyperendemic malaria in the madang area showed different antibody responses to plasmodium falciparum and plasmodium vivax sporozoites despite comparable entomological inoculation rates. although there was a significant trend of increasing prevalence of anti-p. falciparum circumsporozoite (cs) protein immunoglobulin g (igg) with age, there was no significant increase in the antibody units of igg recognizing p. falciparum cs proteins. antibodies recognizing p. vivax c ... | 1989 | 2666443 |
| diversity of antigens expressed on the surface of erythrocytes infected with mature plasmodium falciparum parasites in papua new guinea. | antigens were detected on the surface of erythrocytes from children with acute falciparum malaria in madang, papua new guinea. these parasite-induced erythrocyte surface antigens (piesa) were serotyped with convalescent sera from children and hyperimmune sera from adults in parasite infected cell agglutination assays (picas) and by inhibition of binding of infected cells to melanoma cells. extensive serological diversity of piesa was demonstrated. a significant correlation between serotypes defi ... | 1989 | 2679156 |
| two populations of women with high and low spleen rates living in the same area of madang, papua new guinea, demonstrate different immune responses to malaria. | specific malaria and total igm antibody responses were measured in 2 linguistically distinct coastal papua new guinean populations living in the same endemic malarious area, but exhibiting different adult female spleen rates (51% and 30%), in order to establish whether the higher spleen rates in the former group were due to hyper-reactive malarious splenomegaly (hms). malaria parasite rates were comparable, and geometric mean titres of igg malaria antibody were the same, in both groups, indicati ... | 1989 | 2694494 |
| human malaria transmission studies in the anopheles punctulatus complex in papua new guinea: sporozoite rates, inoculation rates, and sporozoite densities. | malaria sporozoite rates and inoculation rates were measured over periods up to 25 months in the different anopheline species biting humans in 13 villages in madang province, papua new guinea. analysis of three members of the anopheles punctulatus complex, 68,458 an. farauti, 36,779 an. koliensis, and 11,667 an. punctulatus caught in landing catches was made using monoclonal antibody based elisas to detect sporozoites of plasmodium falciparum and p. vivax. sporozoite rates ranged from 0%-5.5% in ... | 1988 | 3044151 |
| in-vivo susceptibility of plasmodium falciparum to cholorquine in pregnant and non-pregnant women and in-vitro response of p. falciparum to chloroquine and mefloquine in madang province, papua new guinea. | | 1988 | 3072818 |
| a longitudinal study of splenomegaly in pregnancy in a malaria endemic area in papua new guinea. | 582 pregnant women living in a defined population were examined for splenomegaly when attending monthly rural antenatal clinics in madang province, papua new guinea, in an area with all-year malaria transmission. 712 non-pregnant women of child-bearing age from the same population were examined as controls. in non-pregnant women who later became pregnant spleen rates increased in early pregnancy. peak spleen rates in early pregnancy occurred before 16 weeks gestation for all gravida classes. the ... | 1988 | 3252585 |
| congenital malaria in papua new guinea. | the incidence of malarial infection in pregnant women at delivery, their corresponding infants and umbilical cords and a control group of non-pregnant women were investigated in the madang region of papua new guinea. anti-malarial antibody titres were measured in maternal and paired cord sera. parasitaemia occurred in 18/73 (24.7%) of non-pregnant females compared with 15/51 (29.4%) of pregnant females. malarial parasites were found in 7/48 (14.6%) cord blood samples and in 4/52 (7.7%) samples o ... | 1988 | 3256983 |
| measurement of malarial infectivity of human populations to mosquitoes in the madang area, papua, new guinea. | the proportion of blood meals taken on humans which are infectious to mosquitoes in the madang area, papua new guinea was estimated by two methods. in the first, laboratory reared anopheles farauti were fed on individuals of all ages at village surveys. the results showed that 3.8% of people were infectious and that the mean percentage of mosquitoes which became infected by feeding on these people was 37.9%. from the average proportion of mosquitoes infected, the probability that a mosquito feed ... | 1988 | 3374964 |
| small-area variations in the epidemiology of malaria in madang province. | | 1986 | 3529703 |
| cerebral malaria in children: a retrospective study of admissions to madang hospital, 1980. | a review was undertaken of sixty-eight children admitted with cerebral malaria to madang hospital, madang, papua new guinea (png) in 1980. children with cerebral malaria were significantly older than those with uncomplicated malaria, and older than children admitted with other conditions causing fits or coma. the nutritional status of children with cerebral malaria did not differ from that of children admitted with other diagnoses. the cerebrospinal fluid was normal in 80% of children with cereb ... | 1982 | 6764075 |
| acute malaria in children in madang: endemicity, clinical presentation and treatment. | much of the present knowledge of the status of malaria in papua new guinea stems from a few studies carried out in the past. in the present situation there are many areas of uncertainty not least the effects of poor acceptance of residual spraying programmes and the emergence of chloroquine-resistant falciparum malaria. new anti-malarials are being developed, new methods of vector control may become useful and immunization may soon become possible. in order to assess the impact of these measures ... | 1981 | 7039178 |
| chloroquine-resistant plasmodium falciparum malaria in madang children. | | 1981 | 7039179 |
| mating patterns in malaria parasite populations of papua new guinea. | description of the genetic structure of malaria parasite populations is central to an understanding of the spread of multiple-locus drug and vaccine resistance. the plasmodium falciparum mating patterns from madang, papua new guinea, where intense transmission of malaria occurs, are described here. a high degree of inbreeding occurs in the absence of detectable linkage disequilibrium. this contrasts with other studies, indicating that the genetic structure of malaria parasite populations is neit ... | 1995 | 7569897 |
| dynamics of malaria parasitaemia associated with febrile illness in children from a rural area of madang, papua new guinea. | active community and self-reporting surveillance techniques have been used to describe the dynamics of febrile illness and associated malaria infection in children aged 2 to 15 years from a rural area of madang province, papua new guinea (png). both history of fever and fever in association with parasitaemia appeared to be reliable indicators of malaria morbidity in this endemic area. parasite density was observed to be a major determinant of mild malarial disease at both the population level an ... | 1994 | 8036670 |
| alpha+-thalassemia protects children against disease caused by other infections as well as malaria. | in the south west pacific region, the striking geographical correlation between the frequency of alpha+-thalassemia and the endemicity of plasmodium falciparum suggests that this hemoglobinopathy provides a selective advantage against malaria. in vanuatu, paradoxically, alpha+-thalassemia increases the incidence of contracting mild malaria in the first 2 years of life, but severe disease was too uncommon to assess adequately. therefore, we undertook a prospective case-control study of children w ... | 1997 | 9405682 |
| resistance of plasmodium falciparum malaria to amodiaquine, chloroquine and quinine in the madang province of papua new guinea, 1990-1993. | the in vivo response of plasmodium falciparum parasites to amodiaquine or chloroquine was assessed in children with symptomatic malaria attending different health facilities in the madang area. among the 27 subjects who were completely followed up, 4 (15%) were infected with parasites fully susceptible and 23 (85%) with parasites exhibiting some degree of resistance. out of the latter group, 52% were of ri level, 26% rii and 22% riii. 14 subjects out of 42 (33%) failed to clear their parasitaemi ... | 1996 | 9522846 |
| red cell morphology and malaria anaemia in children with southeast-asian ovalocytosis band 3 in papua new guinea. | southeast-asian ovalocytosis (sao) was diagnosed in children from madang, papua new guinea, by detection of the sao band 3 gene variant using the polymerase chain reaction. sao band 3 was present in 16/241 (6.6%) children living in the community and 32/389 (8.2%) children with acute plasmodium falciparum malaria (p=0.42). sao band 3 was detected in 8.2% (23/281) of alpha+-thalassaemia homozygotes, 9.4% (20/214) of heterozygotes and 2.4% (2/85) of children with a normal alpha-globin genotype (p=0 ... | 1998 | 9633878 |
| causes of preterm delivery and intrauterine growth retardation in a malaria endemic region of papua new guinea. | to identify causes of preterm delivery and intrauterine growth retardation (iugr) in a malaria endemic region of papua new guinea. | 1998 | 9828741 |
| age- and species-specific duration of infection in asymptomatic malaria infections in papua new guinea. | the burden and duration of asymptomatic malaria infections were measured in residents of the malaria endemic village of gonoa, madang province, papua new guinea. plasmodium falciparum, p. vivax and p. malariae infections in people aged 4 years to adulthood were compared. frequent sampling at 3-day intervals for up to 61 days allowed assessment of individual episodes of infection. statistical assessment of p. falciparum detection revealed a periodicity consistent with synchronous replication of t ... | 2000 | 11085245 |
| antibodies to plasmodium falciparum glycosylphosphatidylinositols: inverse association with tolerance of parasitemia in papua new guinean children and adults. | 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 glycosylphosp ... | 2002 | 12183552 |
| 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 geographica ... | 2004 | 14695625 |
| molecular analysis of plasmodium falciparum from drug treatment failure patients in papua new guinea. | a study was conducted in papua new guinea to analyze plasmodium falciparum drug resistance polymorphisms in patients presenting with resistant malaria. one hundred ninety-nine p. falciparum-positive patients were recruited at two sites, madang and maprik. exposure to the 4-aminoquinolines chloroquine and amodiaquine was uniformly high, at 84% overall. however, 59% of these were taken in various combinations of sulfadoxine/pyrimethamine and/or primaquine and/or quinine. two markers for 4-aminoqui ... | 2004 | 15031512 |
| [interpreteation of immunochromatographic tests with hrp-2 antigen in children under 5 years in an area of high risk of malaria transmission in papua new guinea]. | the immunochromatographic tests with hrp-2 antigen (histidine-rich protein) vision biotech pf rapid malaria test was performed in 291 children under 5 years presenting fever or history of fever (malaria presumptive cases) admitted to children out-patient department of the modilon hospital in madang, in a high malaria risk area of papua new guinea. the results of the tests were compared to the results of the parasitic examination of the peripheral blood with light microscopy (thick and thin smear ... | 2004 | 16859025 |
| low efficacy of amodiaquine or chloroquine plus sulfadoxine-pyrimethamine against plasmodium falciparum and p. vivax malaria in papua new guinea. | because of increasing resistance to 4-aminoquinolines in papua new guinea, combination therapy of amodiaquine (aq) or chloroquine (cq) plus sulfadoxine-pyrimethamine (sp) was introduced as first-line treatment against uncomplicated malaria in 2000. the purpose of this study was to monitor in vivo efficacy of the current standard combination therapy against plasmodium falciparum and p. vivax malaria. studies were conducted between 2003 and 2005 in the simbu, east sepik, and madang provinces in pa ... | 2007 | 17984359 |
| southeast asian ovalocytosis is associated with increased expression of duffy antigen receptor for chemokines (darc). | the duffy antigen receptor for chemokines (darc or fy glycoprotein) carries antigens that are important in blood transfusion and is the main receptor used by plasmodium vivax to invade reticulocytes. southeast asian ovalocytosis (sao) results from an alteration in rbc membrane protein band 3 and is thought to mitigate susceptibility to falciparum malaria. expression of some rbc antigens is suppressed by sao, and we hypothesized that sao may also reduce fy expression, potentiallyleading to reduce ... | 2009 | 19927622 |
| plasma plasmodium falciparum histidine-rich protein-2 concentrations do not reflect severity of malaria in papua new guinean children. | in areas of unstable malaria transmission, plasma plasmodium falciparum histidine-rich protein 2 (pfhrp-2) concentrations parallel total parasite biomass and thus infection severity. however, where transmission is more intense, plasma pfhrp-2 might not reliably predict complications and mortality. | 2011 | 21216895 |