Funding for this research was provided by:
Deutsche ForschungsGemeinschaft (GZ:MO 1071/12-1 AOBJ: 620617)
Received: 23 May 2019
Accepted: 3 December 2019
First Online: 10 December 2019
Change Date: 5 June 2021
Change Type: Update
Change Details: Following publication of the article, it was brought to our attention that Tamirat Gebru Woldearegai had been erroneously omitted from the author list; the article has since been corrected.
Change Date: 21 June 2021
Change Type: Correction
Change Details: A Correction to this paper has been published:
Change Details: https://doi.org/10.1186/S13071-021-04815-1
Ethics approval and consent to participate
: The original study was approved by the institutional ethics committee of CERMEL, Lambaréné, Gabon (Reference number: CEI-CERMEL 009/2014). For this analysis, no additional intervention was made. The study was conducted in line with the Good Clinical Practice (GCP) principles of the International Conference on Harmonization (ICH) [CitationRef removed] and the Declaration of Helsinki [CitationRef removed].
: Not applicable.
: The authors declare that they have no competing interests.