Molecular Analysis of Influenza A(H3N2) and A(H1N1)pdm09 Viruses circulating in the Democratic Republic of Congo, 2014.

ABSTRACT

BACKGROUND: Very little is known about influenza viruses circulating in the Democratic Republic of Congo (DRC). We aim to characterize genetically and antigenically Influenza A(H3N2) and A(H1N1)pdm09 viruses circulating in the country. METHODS: From August to December 2014, specimens were collected from patients with influenza like-illness (ILI) or severe acute respiratory infection (SARI) in various surveillance sites. Specimens were tested using real time reverse transcription polymerase chain reaction (RT-PCR) method for the detection of influenza viruses. Positive influenza samples with a cycle threshold (Ct) <30 were genetically and antigenically characterized. RESULTS: 32 samples tested were found positive to influenza A with Ct <30. At CDC Atlanta, 28 out of 32 samples (88%) were tested positive for influenza A virus, including 26 seasonal influenza A viruses subtype H3N2 and 2 pandemic influenza A viruses subtype H1N1pdm 2009. The majority of influenza A(H3N2) viruses were antigenically related to the A/Switzerland/9715293/2013 vaccine virus, while two influenza A(H1N1)pdm09 isolates were antigenically characterized as A/California/07/2009-like. All A(H3N2) and A(H1N1)pdm09 virus isolates characterized were sensitive to oseltamivir and zanamivir. CONCLUSION: Two genetically distinct influenza subtypes were co-circulating in the DRCongo. Effective measures against influenza have been suggested.