Email updates

Keep up to date with the latest news and content from Malaria Journal and BioMed Central.

Open Access Methodology

Studying fitness cost of Plasmodium falciparum infection in malaria vectors: validation of an appropriate negative control

Ibrahim Sangare12, Yannis Michalakis2, Bienvenue Yameogo1, Roch Dabire1, Isabelle Morlais23 and Anna Cohuet12*

Author Affiliations

1 Institut de Recherche en Sciences de la Santé-Direction Régionale de l’Ouest, Bobo Dioulasso, Burkina Faso

2 Institut de Recherche pour le Développement, Unité MIVEGEC (IRD 224-CNRS 5290-UM1-UM2), BP 64501, Montpellier Cedex 5, 34394, France

3 Laboratoire de Recherche sur le Paludisme, Organisation de Coordination pour la lutte contre les Endémies en Afrique Centrale, Yaoundé, BP 288, Cameroon

For all author emails, please log on.

Malaria Journal 2013, 12:2  doi:10.1186/1475-2875-12-2

Published: 2 January 2013

Abstract

Background

The question whether Plasmodium falciparum infection affects the fitness of mosquito vectors remains open. A hurdle for resolving this question is the lack of appropriate control, non-infected mosquitoes that can be compared to the infected ones. It was shown recently that heating P. falciparum gametocyte-infected blood before feeding by malaria vectors inhibits the infection. Therefore, the same source of gametocyte-infected blood could be divided in two parts, one heated, serving as the control, the other unheated, allowing the comparison of infected and uninfected mosquitoes which fed on exactly the same blood otherwise. However, before using this method for characterizing the cost of infection to mosquitoes, it is necessary to establish whether feeding on previously heated blood affects the survival and fecundity of mosquito females.

Methods

Anopheles gambiae M molecular form females were exposed to heated versus non-heated, parasite-free human blood to mimic blood meal on non-infectious versus infectious gametocyte-containing blood. Life history traits of mosquito females fed on blood that was heat-treated or not were then compared.

Results

The results reveal that heat treatment of the blood did not affect the survival and fecundity of mosquito females. Consistently, blood heat treatment did not affect the quantity of blood ingested.

Conclusions

The study indicates that heat inactivation of gametocyte-infected blood will only inhibit mosquito infection and that this method is suitable for quantifying the fitness cost incurred by mosquitoes upon infection by P. falciparum.

Keywords:
Plasmodium falciparum; Vectors; Infection cost; Negative control; Fitness