High prevalence of IgG antibodies to Ebola virus in the Efé pygmy population in the Watsa region, Democratic Republic of the Congo.
Factors related to the natural transmission of Ebola virus (EBOV) to humans are still not well defined. Results of previous sero-prevalence studies suggest that circulation of EBOV in human population is common in sub-Saharan Africa. The Efé pygmies living in Democratic Republic of the Congo are known to be exposed to potential risk factors of EBOV infection such as bush meat hunting, entry into caves, and contact with bats. We studied the pygmy population of Watsa region to determine seroprevalence to EBOV infection and possible risks factors.



Volunteer participants (N = 300) aged 10 years or above were interviewed about behavior that may constitute risk factors for transmission of EBOV, including exposures to rats, bats, monkeys and entry into caves. Samples of venous blood were collected and tested for IgG antibody against EBOV by enzyme-linked immunosorbent assay (ELISA). The χ2-test and Fisher's exact test were used for the comparison of proportions and the Student's t-test to compare means. The association between age group and anti-EBOV IgG prevalence was analysed by a nonparametric test for trend.



The prevalence of anti-EBOV IgG was 18.7 % overall and increased significantly with age (p = 0.023). No association was observed with exposure to risk factors (contacts with rats, bats, monkeys, or entry into caves).



The seroprevalence of IgG antibody to EBOV in pygmies in Watsa region is among the highest ever reported, but it remains unclear which exposures might lead to this high infection rate calling for further ecological and behavioural studies.
National Institute for Biomedical Research, Kinshasa, Democratic Republic of the Congo and, University of Kinshasa, Kinshasa, Democratic Republic of the Congo. sabuemulo@yahoo.fr.|Southern African Centre for Infectious Diseases and Surveillance, Morogoro, Tanzania. sabuemulo@yahoo.fr.
Sabue
0000-0002-2722-2637
S
Mulangu
Institute of Tropical Medicine, Antwerp, Belgium.|Current affiliation: Institute of Tropical Medicine and International Health, Charité - Universitätsmedizin Berlin, Berlin, Germany.
Matthias
M
Borchert
National Institute for Communicable Diseases, Johannesburg, South Africa.
Janusz
J
Paweska
Université de Kisangani, Faculté de Médecine, Département de santé publique, Kisangani, Democratic Republic of the Congo.
Antoine
A
Tshomba
Ministry of Health, Watsa, Democratic Republic of the Congo.
Afongenda
A
Afounde
Ministry of Health, Watsa, Democratic Republic of the Congo.
Amayo
A
Kulidri
National Institute for Communicable Diseases, Johannesburg, South Africa.|Current affiliation: Department of Veterinary Tropical Diseases, University of Pretoria, Pretoria, South Africa.
Robert
R
Swanepoel
National Institute for Biomedical Research, Kinshasa, Democratic Republic of the Congo and, University of Kinshasa, Kinshasa, Democratic Republic of the Congo.
Jean-Jacques
JJ
Muyembe-Tamfum
Institute of Tropical Medicine, Antwerp, Belgium.|Ghent University, Ghent, Belgium.
Patrick
P
Van der Stuyft
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology*; D059552:Caves; D002648:Child; D002685:Chiroptera; D003430:Cross-Sectional Studies; D015023:Democratic Republic of the Congo / Q000453:epidemiology; D029043:Ebolavirus / Q000276:immunology; D004781:Environmental Exposure / Q000706:statistics & numerical data*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D000882:Haplorhini; D019142:Hemorrhagic Fever, Ebola / Q000453:epidemiology* / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D051381:Rats; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D055815:Young Adult
D000914:Antibodies, Viral; D007074:Immunoglobulin G
Ebola virus; IgG Antibody; Pygmy