The Pasteur Institute in Madagascar is under fire from the Malagasy government after a number of false positives were found in samples submitted for Covid-19 testing. The government had the original samples retested, and only five positive cases were found.
The Institute, which received the samples on 6 May, admitted that samples sent to its laboratory for analysis could have been contaminated.
It had originally announced that 67 cases were positive.
The samples were sent to the Charles Mérieux Center for Infectious Disease, a research centre in Antananarivo, where only five samples came back positive.
A sample of an exceptional viral load could contaminate an entire series, according to André Spiegel, director of the Institut Pasteur.
He says unintentional contamination could have affected the entire chain, from taking samples at the hospital to their arrival at the institute.
Spiegel said that tests are carried out only on samples brought to the centre from the Malagasy Ministry of Health.
He said that the Institut Pasteur conducted an internal investigation, but did not find any issues with the diagnostic process.
The government ministry is also looking in to the matter of contamination.
According to the African Centres for Disease Control and Prevention, Madagascar has 283 positive Covid-19 cases.