Clinical trial NCT02769013: Assessing the Effect of Neglected Tropical Diseases on Plasmodium Falciparum Transmission in an Area of Co-endemicity
Official title: Assessing the Effect of Neglected Tropical Diseases on Plasmodium Falciparum Transmission in an Area of Co-endemicity
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Malaria Transmission
Keywords: Schistosoma haematobium plasmodium falciparum transmission
Lead sponsor: University Hospital Tuebingen
Sponsor class: OTHER
First posted: 2016-05-11
Enrollment: 380
Sex: ALL
Minimum age (years): 6
Maximum age (years): 30
Standard ages: CHILD
ADULT
Accepts healthy volunteers: yes
Observational model: CASE_CONTROL
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: 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.

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

Detailed description: 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.

Eligibility criteria: 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

Primary outcomes:
measure: Number of participants with Plasmodium falciparum gametocytes and/or asexual blood stages
timeFrame: 15 months
Secondary outcomes:
measure: Number of participants with positive serum antibodies specific to the asexual and gametocyte stages of Plasmodium falciparum.
timeFrame: 15 months
measure: Percentage of mosquitoes attracted to Schistosoma-infected participants to non-infected individuals in a wind-tunnel assay.
timeFrame: 15 months
Other outcomes:
measure: Proportion of Plasmodium infected Anopheles mosquitoes per individual per night
timeFrame: 3 months
Locations:
city: Lambarene
country: Gabon
facility: Ayôla Akim ADEGNIKA
state: Albert Schweitzer Hospital
city: Kumasi
country: Ghana
facility: KCCR
Study officials:
affiliation: CERMEL, Lambarene, GABON
name: Ulysse ATEBA NGOA, Dr.
role: PRINCIPAL_INVESTIGATOR
affiliation: KCCR, Kumasi, Ghana
name: Oumou MAIGA, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Dejon-Agobe JC, Edoa JR, Honkpehedji YJ, Zinsou JF, Adegbite BR, Ngwese MM, Mangaboula A, Lell B, Woldearegai TG, Grobusch MP, Mordmuller B, Adegnika AA. Schistosoma haematobium infection morbidity, praziquantel effectiveness and reinfection rate among children and young adults in Gabon. Parasit Vectors. 2019 Dec 10;12(1):577. doi: 10.1186/s13071-019-3836-6.