Philipp Mathé1, Daniel Z Egah2, Janis A Müller3, Nathan Y Shehu2, Emmanuel T Obishakin4, David D Shwe5, Victor C Pam6, Mark O Okolo2, Christopher Yilgwan7, Simji S Gomerep6, Jonas Fuchs1, Ibrahim Abok6, Kenneth I Onyedibe2, Ewa J Olugbo8, Samson E Isa6, Salamatu S Machunga-Mambula9, Caleb J Attah10, Jan Münch3, Stephen Oguche6, Marcus Panning11. 1. Institute of Virology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany. 2. Department of Medical Microbiology, Jos University Teaching Hospital, Jos, Nigeria. 3. Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany. 4. Biotechnology Department, National Veterinary Research Institute, Vom-Jos, Nigeria. 5. Department of Medicine, Jos University Teaching Hospital, Jos, Nigeria. 6. Department of Obstetrics and Gynaecology, Jos University Teaching Hospital, Jos, Nigeria. 7. Department of Paediatrics, Jos University Teaching Hospital, Jos, Nigeria. 8. University of Jos, Jos, Nigeria. 9. University of Abuja, Abuja, Nigeria. 10. Department of Paediatrics, Federal Medical Center, Keffi, Nigeria. 11. Institute of Virology, Medical Center - University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany. Electronic address: marcus.panning@uniklinik-freiburg.de.
Abstract
BACKGROUND: Zika virus (ZIKV) has been known for decades in Africa but contemporary data is lacking at large. OBJECTIVES: To describe the seroepidemiology of ZIKV in North Central Nigeria. STUDY DESIGN: We performed a cross-sectional study at six health care facilities in North Central Nigeria from January to December 2016. Detection of ZIKV antibodies was done using an anti-ZIKV recombinant non-structural protein 1 (NS1)-based ELISA. A colorimetric assay to detect ZIKV neutralizing antibodies was used on ELISA reactive and randomly selected ELISA non-reactive samples. ZIKV real-time RT-PCR was done on a subset of samples. RESULTS: A total of 468 individual samples were included with almost 60% from pregnant women. Using NS1-based ELISA, an anti-ZIKV positive rate of 6% for IgM and 4% for IgG was found. Pregnant women showed anti-ZIKV positive rates of 4% for IgM and 3% for IgG. None of the ZIKV antibody positive samples tested ZIKV RT-PCR positive. An association with male sex was found for anti-ZIKV IgG ELISA positivity (prevalence ratio 3.49; 95% confidence interval: 1.48-8.25; p = .004). No association with pregnancy, yellow fever vaccination or malaria was found for anti-ZIKV IgM or IgG positivity. ZIKV neutralizing antibodies were detected in 17/18 (94%) anti-ZIKV NS1 positive/borderline samples and in one sample without detectable ZIKV NS1 antibodies. Partial ZIKV E gene sequence was retrieved in one sample without ZIKV antibodies, which clustered within the West African ZIKV lineage. CONCLUSIONS: Our results show a largely ZIKV immunologically naïve population and reinforce the importance of ZIKV surveillance in Africa.
BACKGROUND:Zika virus (ZIKV) has been known for decades in Africa but contemporary data is lacking at large. OBJECTIVES: To describe the seroepidemiology of ZIKV in North Central Nigeria. STUDY DESIGN: We performed a cross-sectional study at six health care facilities in North Central Nigeria from January to December 2016. Detection of ZIKV antibodies was done using an anti-ZIKV recombinant non-structural protein 1 (NS1)-based ELISA. A colorimetric assay to detect ZIKV neutralizing antibodies was used on ELISA reactive and randomly selected ELISA non-reactive samples. ZIKV real-time RT-PCR was done on a subset of samples. RESULTS: A total of 468 individual samples were included with almost 60% from pregnant women. Using NS1-based ELISA, an anti-ZIKV positive rate of 6% for IgM and 4% for IgG was found. Pregnant women showed anti-ZIKV positive rates of 4% for IgM and 3% for IgG. None of the ZIKV antibody positive samples tested ZIKV RT-PCR positive. An association with male sex was found for anti-ZIKV IgG ELISA positivity (prevalence ratio 3.49; 95% confidence interval: 1.48-8.25; p = .004). No association with pregnancy, yellow fever vaccination or malaria was found for anti-ZIKV IgM or IgG positivity. ZIKV neutralizing antibodies were detected in 17/18 (94%) anti-ZIKVNS1 positive/borderline samples and in one sample without detectable ZIKVNS1 antibodies. Partial ZIKV E gene sequence was retrieved in one sample without ZIKV antibodies, which clustered within the West African ZIKV lineage. CONCLUSIONS: Our results show a largely ZIKV immunologically naïve population and reinforce the importance of ZIKV surveillance in Africa.