Genetic Association Mapping of Malaria Resistance in Anopheles Gambiae

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT00850655

Enrollment

Registered

2009-02-25

Start date

2008-03-31

Completion date

2015-03-31

Last updated

2016-10-26

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Malaria

Brief summary

This is a study of the genetics of malaria transmission by the mosquito vector in Africa, Anopheles gambiae. The study focuses on the mosquito vector, not the human subjects infected with malaria. DNA extracted from infected mosquitoes will be analyzed genetically by microsatellite and single-nucleotide polymorphisms (SNPs) to identify mosquito genes that control mosquito resistance to malaria parasites.

Detailed description

A standard diagnostic blood smear from a drop of blood will be carried out on 20 study subjects once per month. One malaria-positive subject from among the 20 will be asked to donate 5cc of blood, also no more frequently than once per month. The blood will be placed in a water-jacketed heated membrane feeding device that will be positioned on top of a cage of mosquitoes. The mosquitoes are attracted to the warmth and drink the blood through the artificial skin-like membrane. The goal of the research is to study the infected mosquitoes. No studies will be carried out on the human subjects. The point of human subjects involvement is to obtain the naturally malaria-infected blood for feeding of mosquitoes. After blood feeding, the mosquitoes are held in an environmental chamber for one week, at which time they are dissected to count numbers of malaria parasites developing on the mosquito stomach wall. This number constitutes the quantitative phenotype, and we extract genomic DNA from the carcass for genetic marker typing, which constitutes the genotype. Genetic linkage analysis identifies markers near genes that control parasite number, thus resistance or susceptibility to parasite infection.

Interventions

None listed

Study design

Observational model

ECOLOGIC_OR_COMMUNITY

Time perspective

CROSS_SECTIONAL

Eligibility

Sex/Gender

ALL

Age

5 Years to 10 Years

Healthy volunteers

Inclusion criteria

* 5-10 years old, and general good health

Exclusion criteria

* Outside age group * Specific diagnosable health problems * General poor health

Design outcomes

Primary

Measure	Time frame	Description
mosquito infection	one week	Protocol involves non-invasive blood draw from participant screened by finger-prick for infection with malaria. Drawn blood (0.5cc) is placed in artificial membrane feeder for feeding of mosquitoes. Primary outcome is infection of mosquitoes, detectable one week after blood feeding.

Countries

United States

Outcome results