scholarly journals Nonrandom Selection and Multiple Blood Feeding of Human Hosts by Anopheles Vectors: Implications for Malaria Transmission in Papua New Guinea

2021 ◽  
Author(s):  
John B. Keven ◽  
Michelle Katusele ◽  
Rebecca Vinit ◽  
Daniela Rodríguez-Rodríguez ◽  
Manuel W. Hetzel ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Papua New Guinea ◽  
New Guinea ◽  
Blood Feeding ◽  
Specific Marker ◽  
Blood Samples ◽  
Targeted Interventions ◽  
Multiple Blood ◽  
Genetic Profiles ◽  
Blood Meals

Nonrandom selection and multiple blood feeding of human hosts by Anopheles mosquitoes may exacerbate malaria transmission. Both patterns of blood feeding and their relationship to malaria epidemiology were investigated in Anopheles vectors in Papua New Guinea (PNG). Blood samples from humans and mosquito blood meals were collected in villages and human genetic profiles (“fingerprints”) were analyzed by genotyping 23 microsatellites and a sex-specific marker. Frequency of blood meals acquired from different humans, identified by unique genetic profiles, was fitted to Poisson and negative binomial distributions to test for nonrandom patterns of host selection. Blood meals with more than one genetic profiles were classified as mosquitoes that fed on multiple humans. The age of a person bitten by a mosquito was determined by matching the blood-meal genetic profile to the villagers’ genetic profiles. Malaria infection in humans was determined by PCR test of blood samples. The results show nonrandom distribution of blood feeding among humans, with biased selection toward males and individuals aged 15–30 years. Prevalence of Plasmodium falciparum infection was higher in this age group, suggesting males in this age range could be super-spreaders of malaria parasites. The proportion of mosquitoes that fed on multiple humans ranged from 6% to 13% among villages. The patterns of host utilization observed here can amplify transmission and contribute to the persistence of malaria in PNG despite efforts to suppress it with insecticidal bed nets. Excessive feeding on males aged 15–30 years underscores the importance of targeted interventions focusing on this demographic group.

scholarly journals Mapping routine malaria incidence at village level for targeted control in Papua New Guinea

2019 ◽  
Vol 14 (2) ◽  
Author(s):  
Daniela Rodríguez-Rodríguez ◽  
Seri Maraga ◽  
Sharon Jamea-Maiasa ◽  
Anthony Tandrapah ◽  
Leo Makita ◽  
...  
Keyword(s):  
Papua New Guinea ◽  
Malaria Incidence ◽  
New Guinea ◽  
Malaria Surveillance ◽  
Targeted Interventions ◽  
Surveillance And Response ◽  
Animated Maps ◽  
Response Systems ◽  
Study Sites ◽  
Video Format

Malaria surveillance and response-systems are essential for identifying the areas most affected by malaria and for targeting interventions and optimising resources. This study aimed to assess whether the visualisation of routinely collected health facility data linked to village of residence provides evidence for targeting control interventions in four sentinel health facilities in Papua New Guinea. A video format was used to visualise the dynamics in case incidence over time and space alongside photographs illustrating the context of the data collection in the study sites. Incidence changes overtime were illustrated in animated maps. Despite limitations, this approach appeared useful in sites with very few remaining cases or with increasingly marked heterogeneity. Villages that could benefit from targeted interventions or investigations were identified.

scholarly journals Malaria parasite immune evasion and adaptation to its mosquito host is influenced by the acquisition of multiple blood meals

2019 ◽  
Author(s):  
Hyeogsun Kwon ◽  
Rebekah A. Reynolds ◽  
Maria L. Simões ◽  
George Dimopoulos ◽  
Ryan C. Smith
Keyword(s):  
Blood Meal ◽  
Blood Feeding ◽  
Parasite Development ◽  
Protein Meal ◽  
Infected Blood ◽  
Adult Lifespan ◽  
Multiple Blood ◽  
The Impact ◽  
Immune Detection ◽  
Blood Meals

AbstractA minimum of two blood meals are required for a mosquito to acquire and transmit malaria, yet Anopheles mosquitoes frequently obtain additional blood meals during their adult lifespan. To determine the impact of subsequent blood-feeding on parasite development in Anopheles gambiae, we examined rodent and human Plasmodium parasite infection with or without an additional non-infected blood meal. We find that an additional blood meal significantly reduces P. berghei immature oocyst numbers, yet does not influence mature oocysts that have already begun sporogony. This is in contrast to experiments performed with the human parasite, P. falciparum, where an additional blood meal does not affect oocyst numbers. These observations are reproduced when mosquitoes were similarly challenged with an artificial protein meal, suggesting that parasite losses are due to the physical distension of the mosquito midgut. We provide evidence that feeding compromises the integrity of the midgut basal lamina, enabling the recognition and lysis of immature P. berghei oocysts by the mosquito complement system. Moreover, we demonstrate that additional feeding promotes P. falciparum oocyst growth, suggesting that human malaria parasites exploit host resources provided with blood-feeding to accelerate their growth. This contrasts experiments with P. berghei, where the size of surviving oocysts is independent of an additional blood meal. Together, these data demonstrate differences in the ability of Plasmodium species to evade immune detection and adapt to utilize host resources at the oocyst stage, representing an additional, yet unexplored component of vectorial capacity that has important implications for transmission of malaria.

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 Vector composition, abundance, biting patterns and malaria transmission intensity in Madang, Papua New Guinea: assessment after 7 years of an LLIN-based malaria control programme

2022 ◽  
Vol 21 (1) ◽  
Author(s):  
John B. Keven ◽  
Michelle Katusele ◽  
Rebecca Vinit ◽  
Daniela Rodríguez-Rodríguez ◽  
Manuel W. Hetzel ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Papua New Guinea ◽  
Malaria Control ◽  
New Guinea ◽  
Control Programme ◽  
Transmission Intensity ◽  
Bed Nets ◽  
Malaria Control Programme ◽  
Malaria Transmission Intensity ◽  
Vector Abundance

Abstract Background A malaria control programme based on distribution of long-lasting insecticidal bed nets (LLINs) and artemisinin combination therapy began in Papua New Guinea in 2009. After implementation of the programme, substantial reductions in vector abundance and malaria transmission intensity occurred. The research reported here investigated whether these reductions remained after seven years of sustained effort. Methods All-night (18:00 to 06:00) mosquito collections were conducted using human landing catches and barrier screen methods in four villages of Madang Province between September 2016 and March 2017. Anopheles species identification and sporozoite infection with Plasmodium vivax and Plasmodium falciparum were determined with molecular methods. Vector composition was expressed as the relative proportion of different species in villages, and vector abundance was quantified as the number of mosquitoes per barrier screen-night and per person-night. Transmission intensity was quantified as the number of sporozoite-infective vector bites per person-night. Results Five Anopheles species were present, but vector composition varied greatly among villages. Anopheles koliensis, a strongly anthropophilic species was the most prevalent in Bulal, Matukar and Wasab villages, constituting 63.7–73.8% of all Anopheles, but in Megiar Anopheles farauti was the most prevalent species (97.6%). Vector abundance varied among villages (ranging from 2.8 to 72.3 Anopheles per screen-night and 2.2–31.1 Anopheles per person-night), and spatially within villages. Malaria transmission intensity varied among the villages, with values ranging from 0.03 to 0.5 infective Anopheles bites per person-night. Most (54.1–75.1%) of the Anopheles bites occurred outdoors, with a substantial proportion (25.5–50.8%) occurring before 22:00. Conclusion The estimates of vector abundance and transmission intensity in the current study were comparable to or higher than estimates in the same villages in 2010–2012, indicating impeded programme effectiveness. Outdoor and early biting behaviours of vectors are some of the likely explanatory factors. Heterogeneity in vector composition, abundance and distribution among and within villages challenge malaria control programmes and must be considered when planning them.

scholarly journals Malaria transmission dynamics surrounding the first nationwide long-lasting insecticidal net distribution in Papua New Guinea

2016 ◽  
Vol 15 (1) ◽  
Author(s):  
Lisa J. Reimer ◽  
Edward K. Thomsen ◽  
Gussy Koimbu ◽  
John B. Keven ◽  
Ivo Mueller ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Papua New Guinea ◽  
New Guinea ◽  
Transmission Dynamics

scholarly journals Risk factors and knowledge associated with high unintended pregnancy rates and low family planning use among pregnant women in Papua New Guinea

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Elizabeth Peach ◽  
Christopher Morgan ◽  
Michelle J. L. Scoullar ◽  
Freya J. I. Fowkes ◽  
Elissa Kennedy ◽  
...  
Keyword(s):  
Family Planning ◽  
Pregnant Women ◽  
Papua New Guinea ◽  
Unintended Pregnancy ◽  
Male Partner ◽  
New Guinea ◽  
Targeted Interventions ◽  
Male Partner Involvement ◽  
Unintended Pregnancies ◽  
Partner Involvement

AbstractUnintended pregnancy is a major driver of poor maternal and child health in resource-limited settings. Data on pregnancy intention and use of family planning (FP) is scarce in Papua New Guinea (PNG), but are needed to inform public health strategies to improve FP accessibility and uptake. Data from a facility-based cross-sectional sample of 699 pregnant women assessed prevalence and predictors of unintended pregnancy and modern FP use among pregnant women in East New Britain Province, PNG. More than half (55%) the women reported their pregnancy as unintended. Few (18%) reported ever having used a modern FP method, and knowledge of different methods was low. Being single, separated or divorced (AOR 9.66; 95% CI 3.27–28.54), educated to a tertiary or vocational level (AOR 1.78 CI 1.15–2.73), and gravidity > 1 (AOR 1.43 for each additional pregnancy CI 1.29–1.59) were associated with unintended pregnancy; being accompanied by a male partner to ANC was associated with a reduced unintended pregnancy (0.46 CI 0.30–0.73). Factors associated with modern FP use included male partner involvement (AOR 2.26 CI 1.39–3.67) and gravidity > 1 (AOR 1.54 for each additional pregnancy CI 1.36–1.74). FP use also varied by the facility women attended. Findings highlight an urgent need for targeted interventions to improve FP knowledge, uptake and access, and male partner involvement, to reduce unintended pregnancies and their complications.

scholarly journals Treatment of pigs with endectocides as a complementary tool for combating malaria transmission by Anopheles farauti (s.s.) in Papua New Guinea

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Cielo J. Pasay ◽  
Laith Yakob ◽  
Hannah R. Meredith ◽  
Romal Stewart ◽  
Paul C. Mills ◽  
...  
Keyword(s):  
Malaria Transmission ◽  
Papua New Guinea ◽  
New Guinea ◽  
Anopheles Farauti
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