Re: H275Y oseltamivir resistant Influenza A (H1N1) strains in northern Greece during the post pandemic influenza season 2010-2011
Retrospective: 2 cases of Oseltamivir-resistant in Greece in 2009-2010
Gioula G, Melidou A, Exindari M, Papoutsi N, Chatzidimitriou D, Dotis J, et al. Oseltamivir-resistant influenza A pandemic (H1N1) 2009
virus in northern Greece. Hippokratia. 2011; 15: 272-274.
Abstract
Resistance to oseltamivir was observed to influenza A pandemic (H1N1) 2009 virus strains, isolated from two patients
in North Greece. Investigations showed resistant viruses with the neuraminidase (NA) 275Y genotypes. Pandemic A
(H1N1) 2009 virus should be closely monitored for emergence of resistant variants. Hippokratia 2011; 15 (3): 272-274
Clip:
In the present study, we report virologic investigation of the emergence of oseltamivir resistance in two viruses from two patients in Northern Greece. A 7.5 year old girl with Dravet syndrome, hypothyroidism, hypogammaglobulinemia of IgG2 subclasses and psychomotor retardation had a fever and difficulty in breathing on January 1, 2010. On January 3, 2010, physical examination showed a temperature of 38,5?C, a blood pressure of 116/75mmHg, a pulse rate of 94 beats/min, and a oxygen saturation of 85% at room air. Due to status epilepticus on the same day the patient was intubated and was submitted to the pediatric intensive care unit for mechanical ventilation and further treatment.
She was started receiving oseltamivir (Tamiflu) at day 4 after the initial symptoms had started, but despite the therapy, her health condition deteriorated due to Pseudomonas aeruginosa pneumonia. Two months ago, the girl was vaccinated against seasonal influenza and pneumoniococci
but failed to vaccinate against the pandemic influenza A (H1N1).
Diagnosis of pandemic influenza A (H1N1) 2009 virus was established 4 days after the initial symptoms had started at January 5, 20101. 17 days later, her clinical condition gradually improved and she was transferred from the PICU to the pediatric clinic. Oseltamivir was discontinued after 20 days. Her hospitalization lasted for 1 month; no illness was reported among her family members.
The virus in the above specimen had the H275Y mutation in the
neuraminidase gene, known to confer resistance to oseltamivir.
Furthermore, haemagglutinin sequencing of the HA1 region of the above strain
(A/Thessaloniki/225/10) revealed another common variation, D222G, which has been observed to severe and fatal cases, as well as, mild cases of pandemic virus infections.
Clip:
The second case was identified through routine surveillance, rather than active antiviral susceptibility testing because of treatment failure in a severe case. The patient was a 13.5 year old previously healthy girl, who did not receive oselatmivir and developed mild ILI symptoms.The patient experienced cough, sore throat and headache with fever (39.5?C). Her symptoms started 3 days before the specimen collection and the laboratory confirmed the presence of 2009 pandemic influenza A (H1N1) virus by real-time RT-PCR, on October 2. One week later, her
fever resolved and she was asymptomatic. No illnesses were identified among close contacts potentially exposed during her staying at home. Laboratory testing detected H275Y mutation as well.
Open access:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3306038/pdf/hippokratia-15-272.pdf
