Plasmodium Vivax Among Duffy Negative Population in Cameroon.

NCT05058885 | Unknown

• 1 other identifier: TMA2020CDF-3171.
• Study Type: observational
• Target: 900
• Locations: 1 country
• Sites: 1

Brief Summary

Although Plasmodium vivax (P. vivax), one of the five malaria species causing parasites, has the widest geographical distribution, it is rare in sub-Saharan Africa due to the absence of a red blood cell receptor (Duffy antigen) in black Africans. Duffy-negative individuals are, for the most part, therefore refractory to P. vivax infection and the Duffy-negative phenotype is found at highest frequencies in Africa, whereas it is relatively rare elsewhere. P. vivax has however, been observed as single infections in up to 5% of Duffy-negative febrile patients in one health facility in Dschang, a region of low malaria transmission in Western highlands of Cameroon. Whereas in the littoral South West and Southern forest of Cameroon characterised by high malaria transmission, areas, there are contrasting molecular evidence of human P. vivax infection. While important, the significance is limited from an epidemiological point of view, concerning the source, transmission, distribution range of P. vivax. There is thus a challenge in the true estimation of malaria burden, as well as the attributable parasite species in infections occurring in the low transmission areas of Western Cameroon. As a consequence, our understanding of the local epidemiology of malaria in Western Cameroon warrants formal investigation. The current proposal is a multi-centre observational study. Its purpose is to characterise the malaria species composition and particularly exposure and burden of P. vivax across malaria endemic settings in Cameroon. It will use multiplex serological methods based on quantitative suspension array on finger-stick blood samples collected from febrile patients of ages 1-100 during two malaria transmission seasons in different eco-climatic regions in Cameroon.

Conditions

Malaria, Vivax; Malaria,Falciparum; Malaria

Keywords

Serology,; Vivax; Malaria; Duffy-negative; Cameroon

Outcome Measures

Primary Outcomes (2)

• Proportion of P. vivax exposed patients in different eco-climatic settings in Cameroon

  A cut-off for seropositivity will be determined based on the mean of log MFI values plus three standard deviations of the seronegative controls. Separate cut-off values will be generated for each of the studied antigens. By so doing, participants will be classified as seropositive or seronegative depending on whether their antibody levels lie above or below the cut-off values. The seroprevalence will be calculated for each antigen, as the proportion of seropositive individuals of the total study population, per study site, and overall.

  June 2022-June 2023

• Species ratio among febrile patients infected with Plasmodium spp in geo-ecological regions of Cameroon.

  This will be defined as the ratio of each of identified species by serology to the total species observed for the particular region and, if required, for the overall study sites.

  June 2022-June 2023

Secondary Outcomes (2)

• Vector type, abundance, infectivity and anthropophily

  June 2022-December, 2023.

• Entomological innoculation rate of vivax mosquitoes

  June 2022-December, 2023.

Eligibility Criteria

• Age: 1 Year+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

n each selected health facility, children 1 year and above, and adult of both gender will be eligible for participation. Those who provide written consent/assent will be recruited in the study and be seen only once. All eligible and consenting individuals including women, children and other vulnerable persons will be part of the study as risk of infection with Plasmodium vivax, and malaria in general is the same for everyone living in Cameroon. Appropriate (ethical) measures will be taken when including vulnerable persons and children

You may qualify if:

• Patient must be febrile (temperature \>37.50 C or history of fever within 24 hours of arrival to the hospital)
• Patient must be aged 1 year or older
• Both males and females alike
• The patient must be able to sign a consent/assent form
• The patient must be seeking care and be suspected of malaria infection

You may not qualify if:

• Eligible patient who refuses consent to study procedures
• Patient withdraws consent before or during the start of study procedures
• Patient, who, for any reason, refuses that sensitive data should not be processed.

Sponsors & Collaborators

• University of Dschang: lead
• Barcelona Institute for Global Health: collaborator
• University of Yaounde 1: collaborator

Study Sites (1)

Dschang Health District

Dschang, West Region, Cameroon

RECRUITING

Biospecimen

Retention: SAMPLES WITH DNA

Finger-stick blood spots on Whatman n3 filter papers.

MeSH Terms

Conditions

Malaria, Vivax; Malaria, Falciparum; Malaria

Condition Hierarchy (Ancestors)

Protozoan Infections; Parasitic Diseases; Infections; Mosquito-Borne Diseases; Vector Borne Diseases

Central Study Contacts

Innocent Ali, PhD

CONTACT

+237677021275; dr.alinn@gmail.com

Jules Roger Kuiate, PhD

CONTACT

+237699679135; jrkuiate@yahoo.fr

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Senior Lecturer

Study Record Dates

• First Submitted: September 17, 2021
• First Posted: September 28, 2021
• Study Start: May 2, 2022
• Primary Completion: June 30, 2024
• Study Completion: June 30, 2024
• Last Updated: April 13, 2023

Record last verified: 2023-04

Locations

CA (1)