Lin and colleagues recently described in Clinical Infectious Diseases, the detection of anti-H7N9 antibodies in the first exported (from mainland China) human case of H7N9.
The 53-year old male case in Taiwan (described previously) harboured a virus that was not fully susceptible to oseltamivir/zanamivir/peramivir 6-days after initiation of oseltamivir.
This resistance was associated with high viral load in nasopharyngeal and sputum (not spilling over into serum specimens) and slow clearance of virus.
Whether the virus already had these mutations or developed them in the patient during treatment, could not be determined but both types of viral sequences could be detected in samples using 2nd generation next-generation sequencing techniques.
The patient developed antibodies to H7N9 after 2-weeks, when viral shedding was dropping.