Measurement of malarial infectivity of human populations to mosquitoes in the Madang area, Papua New Guinea

Parasitology ◽  
1988 ◽  
Vol 96 (2) ◽  
pp. 251-263 ◽  
Author(s):  
P. M. Graves ◽  
T. R. Burkot ◽  
R. Carter ◽  
J. A. Cattani ◽  
M. Lagog ◽  
...  
Keyword(s):  
Papua New Guinea ◽  
Human Population ◽  
New Guinea ◽  
Human Populations ◽  
Prevalence Rates ◽  
Anopheles Farauti ◽  
Gametocyte Carrier ◽  
Average Proportion ◽  
The Mean ◽  
Blood Meals

SummaryThe 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 rearedAnopheles farautiwere 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 feeding on a human would pick up infection was 0·013±0·005. In the second approach mosquitoes were fed on identifiedPlasmodium falciparum, P. vivaxandP. malariaegametocyte carriers. The results indicated that 46% of gametocyte carriers were infectious and that the mean probability of a mosquito becoming infected after feeding on a gametocyte carrier was 0·151±0·029. Gametocyte prevalence rates in all ages measured over 18 months in three villages averaged 3·3%P. falciparum, 4·0%P. vivaxand 0·7%P. malariae, totalling 8·0±0·7%. Combining gametocyte prevalence rates with the probability of a mosquito becoming infected from a gametocyte carrier, the probability of a mosquito becoming infected following a blood meal on a member of the human population was estimated to be 0·012±0·003.

scholarly journals Human impacts and Anthropocene environmental change at Lake Kutubu, a Ramsar wetland in Papua New Guinea

2021 ◽  
Vol 118 (40) ◽  
pp. e2022216118 ◽  
Author(s):  
Kelsie E. Long ◽  
Larissa Schneider ◽  
Simon E. Connor ◽  
Niamh Shulmeister ◽  
Janet Finn ◽  
...  
Keyword(s):  
Mineral Resource ◽  
Environmental Change ◽  
Papua New Guinea ◽  
Human Impacts ◽  
Wetland Management ◽  
New Guinea ◽  
Ecosystem Dynamics ◽  
Resource Extraction ◽  
Human Populations ◽  
Ramsar Wetland

The impacts of human-induced environmental change that characterize the Anthropocene are not felt equally across the globe. In the tropics, the potential for the sudden collapse of ecosystems in response to multiple interacting pressures has been of increasing concern in ecological and conservation research. The tropical ecosystems of Papua New Guinea are areas of diverse rainforest flora and fauna, inhabited by human populations that are equally diverse, both culturally and linguistically. These people and the ecosystems they rely on are being put under increasing pressure from mineral resource extraction, population growth, land clearing, invasive species, and novel pollutants. This study details the last ∼90 y of impacts on ecosystem dynamics in one of the most biologically diverse, yet poorly understood, tropical wetland ecosystems of the region. The lake is listed as a Ramsar wetland of international importance, yet, since initial European contact in the 1930s and the opening of mineral resource extraction facilities in the 1990s, there has been a dramatic increase in deforestation and an influx of people to the area. Using multiproxy paleoenvironmental records from lake sediments, we show how these anthropogenic impacts have transformed Lake Kutubu. The recent collapse of algal communities represents an ecological tipping point that is likely to have ongoing repercussions for this important wetland’s ecosystems. We argue that the incorporation of an adequate historical perspective into models for wetland management and conservation is critical in understanding how to mitigate the impacts of ecological catastrophes such as biodiversity loss.

Assessing Survival Rates of Anopheles farauti (Diptera: Culicidae) from Papua New Guinea

10.2307/4393 ◽  
1985 ◽  
Vol 54 (3) ◽  
pp. 1003 ◽  
Author(s):  
J. D. Charlwood ◽  
M. H. Birley ◽  
H. Dagoro ◽  
R. Paru ◽  
P. R. Holmes
Keyword(s):  
Papua New Guinea ◽  
Survival Rates ◽  
New Guinea ◽  
Anopheles Farauti

Comparative performance of cattle and buffalo on the Sepik Plains, Papua New Guinea

1977 ◽  
Vol 17 (87) ◽  
pp. 550 ◽  
Author(s):  
JH Schottler ◽  
A Boromana ◽  
WT Williams
Keyword(s):  
Growth Rate ◽  
Papua New Guinea ◽  
Water Buffalo ◽  
New Guinea ◽  
Comparative Performance ◽  
Mineral Supplementation ◽  
Calf Mortality ◽  
The Mean ◽  
Native Pastures

Fifty female Brahman-cross cattle and 50 water buffalo were run on the infertile native pastures of the Sepik lowland plains, Papua New Guinea; half the buffalo, and all the cattle, received mineral supplementation (phosphate, Ca, Cu and Co). After the beginning of the experiment all animals were able to maintain, but not improve, their weights. The liveweights attained were everywhere less than those attained on more fertile pastures elsewhere in Papua New Guinea, the discrepancy being greater for cattle than for buffalo. Supplementation improved both the mean liveweight of buffalo and the growth rate of the calves. Calf mortality was 18 per cent in both species. Despite the longer gestation period, the buffalo produced nearly 50 per cent more calves than the cattle; buffalo more often than not conceived while still lactating, whereas cattle did so only rarely. There was some evidence of a long-term improvement in fertility as a result of supplementation. It is concluded that under these difficult conditions buffalo are a better proposition than cattle.

Breast-feeding and sexual abstinence in Papua New Guinea

1984 ◽  
Vol 16 (4) ◽  
pp. 451-461 ◽  
Author(s):  
William K. A. Agyei
Keyword(s):  
Papua New Guinea ◽  
Breast Feeding ◽  
New Guinea ◽  
Sexual Abstinence ◽  
Urban Mothers ◽  
Mother And Child ◽  
Child Spacing ◽  
The Mean ◽  
Rural Mothers

SummaryData collected in Papua New Guinea between November 1979 and March 1980 show that the main reason for prolonged breast-feeding and sexual abstinence is to ensure the welfare of the mother and child (which is indirectly a means of child spacing). The mean period of breast-feeding for the rural mothers is 21·8 months and for the urban mothers is 20·7 months. The mean duration of sexual abstinence for the rural male respondents is 21·4 months and for the female is 20·2 months. The figures for their urban counterparts are 19·5 months and 16·6 months respectively.

NEST PROVISIONING IN THE MUD-DAUBER WASP SCELIPHRON LAETUM (F. SMITH): BODY MASS AND TAXA SPECIFIC PREY SELECTION

Behaviour ◽  
1999 ◽  
Vol 136 (2) ◽  
pp. 147-159 ◽  
Author(s):  
Matthew Jebb ◽  
Mark Elgar
Keyword(s):  
Field Experiment ◽  
Papua New Guinea ◽  
Body Mass ◽  
Prey Selection ◽  
Larval Instar ◽  
New Guinea ◽  
Spider Species ◽  
Volumetric Capacity ◽  
The Mean ◽  
Nest Provisioning

AbstractThe mud dauber wasp Sceliphron laetum (F. Smith) lays a single egg in a mud chamber that is provisioned almost exclusively with orb-weaving spiders. In Madang, Papua New Guinea, the wasps provision their chambers with between three and nine spiders that weigh between 0.01 and 0.28 g and are from at least twelve species. The number of spiders placed in each chamber is negatively correlated with the mean mass of each spider. A field experiment revealed that females cease provisioning after capturing a certain mass of spiders, rather than simply filling each chamber to its volumetric capacity. Furthermore, the wasps select different spider species according to the provisioning sequence. In general, wasps avoid provisioning the early larval instar with species of Gasteracantha, perhaps because the newly emerged wasp larvae cannot penetrate the hard integuments of these spiders.

scholarly journals Infectivity of symptomatic malaria patients to Anopheles farauti colony mosquitoes in Papua New Guinea

2020 ◽  
Author(s):  
Lincoln Timinao ◽  
Rebecca Vinit ◽  
Michelle Katusele ◽  
Tamarah Koleala ◽  
Elma Nate ◽  
...  
Keyword(s):  
Light Microscopy ◽  
Plasmodium Vivax ◽  
Papua New Guinea ◽  
Venous Blood ◽  
New Guinea ◽  
Anopheles Farauti ◽  
Symptomatic Malaria ◽  
Membrane Feeding ◽  
Transmission Studies ◽  
Mosquito Infection

AbstractDespite being a weak point in their life cycle, transmission of Plasmodium parasites from humans to mosquitoes is an understudied field of research. Direct membrane feeding assays (DMFA) are an important tool, allowing detailed mechanistic malaria transmission studies from humans to mosquitoes. Especially for Plasmodium vivax, which cannot be cultured long-term under laboratory conditions, implementation of DMFAs requires proximity to P. vivax endemic areas. In the present study, we investigated the infectivity of symptomatic Plasmodium infections to Anopheles farauti colony mosquitoes in Papua New Guinea (PNG), a country with one of the highest rates of Plasmodium vivax in the world. A total of 182 DMFAs were performed with venous blood collected from symptomatic malaria patients positive by rapid diagnostic test (RDT). DMFAs resulted in mosquito infection in 20.9% (38/182) of cases. The parasite species in the blood feeds were determined retrospectively by expert light microscopy and quantitative real-time qPCR. Based on light microscopy, 9.2% of P. falciparum and 42% of P. vivax human infections resulted in mosquito infections. Infections containing gametocytes detected by microscopy led to mosquito infections in 58.8% of P. vivax and 8.7% of P. falciparum infections. Based on qPCR, 10% of P. falciparum and 43.6% of P. vivax lead to a successful mosquito infection. Venous blood samples from symptomatic P. vivax patients were more infectious to An. farauti mosquitoes in DMFAs compared to P. falciparum infected patients. The capacity to perform DMFAs in a high-burden P. vivax setting creates a unique opportunity to address critical gaps in our understanding of P. vivax human-tomosquito transmission.

scholarly journals Probe-based multiplex qPCR identifies blood-meal hosts in Anopheles mosquitoes from Papua New Guinea

2020 ◽  
Author(s):  
John B Keven ◽  
Georgia Artzberger ◽  
Mary L. Gillies ◽  
Rex B. Mbewe ◽  
Edward D. Walker
Keyword(s):  
Papua New Guinea ◽  
Quantitative Pcr ◽  
Blood Meal ◽  
New Guinea ◽  
Molecular Probe ◽  
Conventional Pcr ◽  
Anopheles Mosquitoes ◽  
Mixed Blood ◽  
Host Blood ◽  
Blood Meals

Abstract Background: Determination of blood-meal hosts in blood-fed female Anopheles mosquitoes is important for evaluating vectorial capacity of vector populations and assessing effectiveness of vector control measures. Sensitive molecular methods are needed to detect traces of host blood in mosquito samples, to differentiate hosts, and to detect mixed host blood meals. This paper describes a molecular probe-based quantitative PCR for identifying blood-meal hosts in Anopheles malaria vectors from Papua New Guinea. Methods: TaqMan oligonucleotide probes targeting specific regions of mitochondrial or nuclear DNA of the three primary Anopheles blood-meal hosts, humans, pigs and dogs, were incorporated into a multiplex, quantitative PCR which was optimized for sensitivity and specificity. Results: Amplification of serially diluted DNA showed that the quantitative PCR detected as low as 10-5 ng/ml of host DNA. Application to field-collected, blood-fed Anopheles showed that the quantitative PCR identified the vertebrate hosts for 89% (335/375) of mosquitoes whereas only 55% (104/188) of blood-meal samples tested in a conventional PCR were identified. Of the 104 blood-fed Anopheles that were positive in both PCR methods, 16 (15.4%) were identified as mixed blood meals by the quantitative PCR whereas only 3 (2.9%) were mixed blood meals by the conventional PCR. Conclusions: The multiplex quantitative PCR described here is sensitive at detecting low DNA concentration and mixed host DNA in samples and useful for blood-meal analysis of field mosquitoes, in particular mixed-host blood meals.

scholarly journals A clinical study of kuru patients with long incubation periods at the end of the epidemic in Papua New Guinea

2008 ◽  
Vol 363 (1510) ◽  
pp. 3725-3739 ◽  
Author(s):  
John Collinge ◽  
Jerome Whitfield ◽  
Edward McKintosh ◽  
Adam Frosh ◽  
Simon Mead ◽  
...  
Keyword(s):  
Papua New Guinea ◽  
New Guinea ◽  
Mortuary Practice ◽  
Genetic Studies ◽  
Route Of Transmission ◽  
Incubation Periods ◽  
Jakob Disease ◽  
The Mean ◽  
Age Range ◽  
Codon 129

Kuru is so far the principal human epidemic prion disease. While its incidence has steadily declined since the cessation of its route of transmission, endocannibalism, in Papua New Guinea in the 1950s, the arrival of variant Creutzfeldt–Jakob disease (vCJD), also thought to be transmitted by dietary prion exposure, has given kuru a new global relevance. We investigated all suspected cases of kuru from July 1996 to June 2004 and identified 11 kuru patients. There were four females and seven males, with an age range of 46–63 years at the onset of disease, in marked contrast to the age and sex distribution when kuru was first investigated 50 years ago. We obtained detailed histories of residence and exposure to mortuary feasts and performed serial neurological examination and genetic studies where possible. All patients were born a significant period before the mortuary practice of transumption ceased and their estimated incubation periods in some cases exceeded 50 years. The principal clinical features of kuru in the studied patients showed the same progressive cerebellar syndrome that had been previously described. Two patients showed marked cognitive impairment well before preterminal stages, in contrast to earlier clinical descriptions. In these patients, the mean clinical duration of 17 months was longer than the overall average in kuru but similar to that previously reported for the same age group, and this may relate to the effects of both patient age and PRNP codon 129 genotype. Importantly, no evidence for lymphoreticular colonization with prions, seen uniformly in vCJD, was observed in a patient with kuru at tonsil biopsy.

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