Outbreak of pandemic 2009 influenza A/H1N1 infection in the hematology ward: fatal clinical outcome of hematopoietic stem cell transplant recipients and emergence of the H275Y neuraminidase mutation

Abstract

We report an outbreak of pandemic 2009 influenza A/H1N1 virus (2009 H1N1) infection that occurred in the hematology ward of our institution during the 2010-2011 influenza season. A total of seven hospitalized patients with hematologic tumors, including five recipients of hematopoietic stem cell transplantation (HSCT), successively developed rapid influenza detection test (RIDT)-positive influenza A; four patients had laboratory-confirmed 2009 H1N1 infection. Three HSCT recipients required mechanical ventilation support and two were admitted to the intensive care unit; they died of progressive respiratory failure despite receiving available anti-viral drugs. We implemented outbreak-control measures including transferal of RIDT-positive patients to a single-patient room and chemoprophylaxis with oseltamivir. We note that the H275Y neuraminidase mutation was detected in respiratory specimens from three patients, who were administered therapeutic or prophylactic dosages of oseltamivir. The present report demonstrates that the nosocomial 2009 H1N1 outbreak in the hematology ward led to fatal clinical outcomes and the emergence of a resistant virus at a markedly high rate.

A multicenter evaluation of pandemic influenza A/H1N1 in hematopoietic stem cell transplant recipients

“…, who noted that increased mortality may occur with nosocomial acquisition. Iloka and colleagues also reported 3 deaths in 5 HSCT recipients who acquired infection nosocomially. Patients with nosocomial infection may have a greater mortality, as they are likely to have other co‐morbidities that lead to an overall greater burden of illness.…”

Assessment of Influenza Virus Hemagglutinin Stalk-Based Immunity in Ferrets

“…These antibodies can be used for prophylactic and therapeutic treatments of influenza virus infections. Although the large amount of MAb needed for treatment might preclude the use of the antibodies in the general population, this approach might be useful for the therapy of severe influenza cases, especially when drug-resistant viruses in an immunocompromised host are involved (57)(58)(59)(60)(61)(62)(63). We therefore wanted to evaluate MAb 6F12 in a prophylactic setting in the ferret model.…”

Characterization of Human Influenza Viruses in Lebanon during 2010-2011 and 2011-2012 Post-Pandemic Seasons

“…Nonetheless, the rate of oseltamivir resistance is much higher among high-risk groups such as immunocompromised patients, and clusters of high community transmission rates have been reported [25,27]. Hurt et al [28] reported a significant increase in the frequency H275Y oseltamivir-resistant H1N1p viruses in a community in Australia.…”