Analysis for malaria transmission dynamic between human and mosquito population, part II: Effective infection rate using new technique

Malaria transmission blocking immunity has been found to operate against two distinct phases of development of malaria parasites in the mosquito midgut: (i) against the extracellular gametes and newly fertilized zygotes shortly after ingestion by a mosquito of parasitized blood and (ii) against the zygotes during their subsequent development into ookinetes. Immunity is antibody-mediated and stage-specific. A set of three proteins, synthesized in the gametocytes, expressed on the surface of the gametes and newly fertilized zygotes and subsequently shed during later transformation of the zygotes, has been identified as the target antigens of anti-gamete fertilization blocking antibodies. A single protein, synthesized and expressed on the zygote surface during its development to ookinetes, has been identified as the target of antibodies which block the development of the fertilized parasites in the mosquito. Immunization of hum an populations against gamete or zygote antigens, while not directly protecting an immunized individual from inflection, would reduce the transfer of malaria within the population. Such immunity, in addition to reducing the overall rate of malaria transmission, would, if combined with a vaccine against the asexual (disease-causing) stages, reduce the chance of selection of parasites that are resistant to the asexual vaccine by preventing their entry into the mosquito population.

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Numerical treatment of optimal control theory applied to malaria transmission dynamic model

Quality & Quantity ◽

10.1007/s11135-020-01092-5 ◽

2021 ◽

Author(s):

E. A. Bakare ◽

S. Hoskova-Mayerova

Keyword(s):

Optimal Control ◽

Control Theory ◽

Malaria Transmission ◽

Dynamic Model ◽

Optimal Control Theory ◽

Numerical Treatment ◽

Transmission Dynamic

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Entomological determinants of malaria transmission in Kayin state, Eastern Myanmar: A 24-month longitudinal study in four villages

Wellcome Open Research ◽

10.12688/wellcomeopenres.14761.3 ◽

2019 ◽

Vol 3 ◽

pp. 109

Author(s):

Victor Chaumeau ◽

Bénédicte Fustec ◽

Saw Nay Hsel ◽

Céline Montazeau ◽

Saw Naw Nyo ◽

...

Keyword(s):

Malaria Transmission ◽

Infection Rate ◽

Malaria Vectors ◽

Bed Nets ◽

Biting Rate ◽

Multiple Species ◽

Few Data ◽

Greater Mekong Subregion ◽

Very High ◽

Human Biting Rate

Background: The Thailand-Myanmar borderland is an area endemic for malaria where transmission is low, seasonal and unstable. The epidemiology has been described but there is relatively few data on the entomological determinants of malaria transmission. Methods: Entomological investigations were conducted during 24 months in four villages located in Kayin state, on the Myanmar side of the Thailand-Myanmar border. Anopheles mosquitoes were identified by morphology, and molecular assays were used in order to discriminate between closely related sibling species of malaria vectors. Plasmodium infection rate was determined using quantitative real-time PCR. Results: The diversity of Anopheles mosquitoes was very high and multiple species were identified as malaria vectors. The intensity of human-vector contact (mean human-biting rate= 369 bites/person/month) compensates for the low infection rate in naturally infected populations of malaria vectors (mean sporozoite index= 0.04 and 0.17 % for P. falciparum and P. vivax respectively), yielding intermediary level of transmission intensity (mean entomological inoculation rate= 0.13 and 0.64 infective bites/person/month for P. falciparum and P. vivax, respectively). Only 36% of the infected mosquitoes were collected indoors between 09:00 pm and 05:00 am, suggesting that mosquito bed-nets would fail to prevent most of the infective bites in the study area. Conclusion: This study provided a unique opportunity to describe the entomology of malaria in low transmission settings of Southeast Asia. Our data are important in the context of malaria elimination in the Greater Mekong Subregion.

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Entomological determinants of malaria transmission in Kayin state, Eastern Myanmar: A 24-month longitudinal study in four villages

Wellcome Open Research ◽

10.12688/wellcomeopenres.14761.1 ◽

2018 ◽

Vol 3 ◽

pp. 109 ◽

Cited By ~ 6

Author(s):

Victor Chaumeau ◽

Bénédicte Fustec ◽

Saw Nay Hsel ◽

Céline Montazeau ◽

Saw Naw Nyo ◽

...

Keyword(s):

Malaria Transmission ◽

Infection Rate ◽

Malaria Elimination ◽

Malaria Vectors ◽

Bed Nets ◽

Biting Rate ◽

Multiple Species ◽

Few Data ◽

Greater Mekong Subregion ◽

Human Biting Rate

Background: The Thailand-Myanmar borderland is an area endemic for malaria where transmission is low, seasonal and unstable. The epidemiology has been described but there is relatively few data on the entomological determinants of malaria transmission. Methods: As part of a pilot study on Targeted Malaria Elimination, entomological investigations were conducted during 24 months in four villages located in Kayin state, Myanmar. Anopheles mosquitoes were identified by morphology, and molecular assays were used in order to discriminate between closely related sibling species of malaria vectors. Plasmodium infection rate was determined using quantitative real-time PCR. Results: The biodiversity of Anopheles entomo-fauna was very high and multiple species were identified as malaria vectors. The intensity of human-vector contact (mean human-biting rate= 369 bites/person/month) compensates for the low infection rate in naturally infected populations of malaria vectors (mean sporozoite index= 0.4 and 1.7 /1,000 mosquitoes for P. falciparum and P. vivax respectively), yielding intermediary level of transmission intensity (mean entomological inoculation rate= 0.13 and 0.64 infective bites/person/month for P. falciparum and P. vivax, respectively). We estimated that 65% of the potential infective bites are not prevented by mosquito bed nets because of outdoor and early biters. Conclusion: This study provided a unique opportunity to describe the entomology of malaria in low transmission settings of Southeast Asia. Our data are important in the context of malaria elimination in the Greater Mekong Subregion.

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Stability and Time-Scale Analysis of Malaria Transmission in Human-Mosquito Population

International Journal of Systems Science and Applied Mathematics ◽

10.11648/j.ijssam.20170201.11 ◽

2017 ◽

Vol 2 (1) ◽

pp. 1 ◽

Cited By ~ 1

Author(s):

Kodwo Annan

Keyword(s):

Malaria Transmission ◽

Time Scale ◽

Mosquito Population ◽

Scale Analysis

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Natural Malaria Infection in Anopheline Vectors and Their Incrimination in Local Malaria Transmission in Darién, Panama

10.21203/rs.3.rs-48458/v1 ◽

2020 ◽

Author(s):

Rolando Torres-Cosme ◽

Chystrie Rigg ◽

Ana Maria Santamaria ◽

Vanessa Vazquez ◽

Carlos Victoria ◽

...

Keyword(s):

Malaria Transmission ◽

Infection Rate ◽

Control Strategies ◽

Natural Infection ◽

Transmission Dynamics ◽

Baited Traps ◽

New Information ◽

Mosquito Pool ◽

Elevated Frequency ◽

Species Being

Abstract BackgroundMore than 85% of the malaria cases in Panama occur in characteristically poor, rural and indigenous regions like Darien Province. Vector diversity, vector infection rate and spatial distribution are important entomological parameters of malaria transmission dynamics. Their understanding is crucial for the development of effective disease control strategies. The objective of this study was to determine the composition of Anopheles species, their natural infection rate and their geographic distribution to better understand the malaria transmission dynamics in Darién, Panama.MethodsAnopheline mosquitoes were captured during the rainy and dry season of 2016. We selected five communities where adult anophelines were collected using CDC light-traps, and through protective human-baited traps. Detection of natural infection and Plasmodium genotype in collected mosquitoes were detected via nested PCR through the amplification of Plasmodium 18s rRNA and the circumsporozoite protein gene, respectively.ResultsA total of 1,063 mosquitoes were collected, and nine Anopheline species were identified, with the predominant species being: An. (Nys.) darlingi (45.0%) and An. (Nys.) albimanus (42.6%). Among these mosquitoes, An. (Nys.) albimanus has historically presented an elevated frequency and abundance in all Panamanian regions. Natural infection with P. vivax was detected in a mosquito pool from the community Pueblo Tortuga (0.6%), three mosquito pools from Marraganti (1.7%), two pools from Bajo Chiquito (1.1%) and three pools from Alto Playona (1.7%). For An. (Nys.) darlingi mosquitoes, we detected seven positive pools from the community Bajo Chiquito (4.0%), two pools from Marraganti (1.1%) and two pools from Alto Playona (1.1%). This study was able to detect the P. vivax allelic variant VK210 in infected mosquitoes.ConclusionThe results from this study provide new information on the transmission dynamics associated with anopheline vectors in the Darién region. This is the first report of natural P. vivax infection in An. (Nys.) darlingi and its incrimination as a potential malaria vector in Panama. Additional studies are necessary to expand our knowledge and determine crucial parameters in malaria transmission in Darién, which in turn will aid the National Malaria Program in attaining an adequate malaria control strategy towards malaria elimination.

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Studies on the Schistosomes of Domestic Animals in Iran: I. Observations on Ornithobilharzia turkestanicum (Skrjabin, 1913) in Khuzestan

Journal of Helminthology ◽

10.1017/s0022149x00023865 ◽

1973 ◽

Vol 47 (2) ◽

pp. 165-180 ◽

Cited By ~ 10

Author(s):

J. Massoud

Keyword(s):

Infection Rate ◽

Domestic Animals ◽

Economic Importance ◽

Prepatent Period ◽

Pathological Response ◽

New Technique ◽

Recovery Rates ◽

Different Types ◽

A New Technique ◽

Large Animals

O. turkestanicum infection was found to be uniformly distributed in the northern and central parts of Khuzestan (cattle, 30%, sheep, 15%; goats, 7% and buffaloes, 2%). In the southern part of Khuzestan the infection rate was very low. A new technique was devised for exposing large animals by leg immersion in a cercarial suspension in a polythene bag and good infections were obtained by this method. The prepatent period of O. turkestanicum infection in different types of animals varied from 43–46 days. The recovery rates of adult worms were 37.6% in calves, 33.9% in sheep, 22.5% in goats and 9.6% in a buffalo. O. turkestanicum produced a milder pathological response in ruminants than did S. bovis, but is nevertheless of considerable economic importance in Khuzestan.

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