Assessing the effect of neglected tropical diseases on Plasmodium falciparum transmission in an area of co endemicity.

The project is divided in three different work packages that cover the life cycle of P. falciparum :

1. In Work Package 1 (WP1) the investigators will assess whether S. haematobium infection increases the human reservoir of P. falciparum by increasing the carriage rate and incidence of P. falciparum gametocytaemia as well as by increasing the proportion and incidence of subject with sub-microscopic P. falciparum infection. The investigators will also determine whether this increase in gametocyte carriage is a consequence of an impairment of the immune response of helminth infected subjects to P. falciparum.
2. In Work Package 2 (WP2) the investigators will determine whether the transmission of the sexual forms of P. falciparum from the human host to mosquito is increased in S. haematobium infected subjects compared to uninfected controls. Moreover the investigators will study whether the immunological changes induced in S. haematobium infected subjects lead to a decrease of the transmission reducing activity of IgG specific to Pfs48/45 and Pfs230 (both capable of blocking/impairing further development of P. falciparum in the mosquito gut).
3. Finally in Work Package 3 (WP3) the investigators will assess whether S. haematobium infection affects the transmission of P. falciparum from the mosquito to the human host. This effect will be determined indirectly by assessing whether S. haematobium infected subjects are more attractive to mosquitoes.

Inclusion Criteria:

• Subjects aged from 6 to 30 years
• Without severe or moderate disease
• Agreement to be enrolled in the study (written informed consent or consent by the legal representative and assent)
• Living in the study area for at least 1 year

Exclusion Criteria:

• Anaemia with haemoglobin less than 8g/dl
• Know sickle cell disease
• Macroscopic haematuria
• Any other know severe disease

The study population are subjects aged from 6 to 30 years since both adults and children have been shown to be a reservoir of P. falciparum. Participants will be recruited in two African villages located in Gabon (lambarene) and Ghana Asokwa submetropolitan area in Kumasi, Ghana. Settings in the two locations are different and represent a rural area with very high infectious pressure from helminths infection (S. haematobium and geohelminths) as well as year-round transmission of malaria in the Central African rain forest (Lambaréné) and a more densely populated area in West Africa with pronounced seasonal variation in malaria transmission and high endemicity of S. haematobium but very little other helminthiases due to well-implemented mass treatment campaigns.