Influenza A H1N1 Pandemic Infection In Onco-Hematologic Patients

Epidemiological, virological and clinical data about H1N1 pandemic infection in immunocompromised patients are needed.

To describe a series of onco-hematologic patients with H1N1 pandemic infection who required hospitalization.

Review from institutional database and electronic patients charts. Specific diagnosis defined as a positive nasal swab PCR. Flu syndrome defined as fever, cough and/or sore throat; severe respiratory disease as fever higher than 38°C, cough and dyspnea.

From July 24^th to September 30^th 2009, 114 patients were investigated; 18 (15.8%) was confirmed and 9 were onco-hematologic patients. Hematological diseases were: chronic myeloid leukemia (3), lymphoma (3), amiloidosis (2) and myelofibrosis (1) – 2 with previous TCTH (for amiloidosis and myelofibrosis). Clinical manifestations in table 1. One patient died (11.1%). Two patients had received chemotherapy in the last 4 weeks. Radiological findings were mainly interstitial (4) and interstitial-alveolar (1). Lymphocytes less than 1000 cel/mm³ were detected in 3 patients; the patient who died had 1000 lymphocytes/mm³. Three patients required ICU; 1 of 2 who required mechanical ventilation died. Time between symptoms onset and start of oseltamivir in table 2; mean therapy length was 6.1 days (3-10 days); 3 days in the case of obit. Prolonged viral shedding was investigated in 3 patients - 1 negative (5 days after first oseltamivir dose) and 2 positive (5 and 7 days after).

We did not include outpatients because in our country most of the time PCR was available only for those requiring hospitalization, despite of clinical suspicion and oseltamivir prescription. An important challenge recognized was atypical clinical presentation including acute respiratory distress without fever, leading us to consider that we probably lost opportunity to make diagnosis in some other cases. For both reasons, we were not able to know the real impact of H1N1 pandemic infection among onco-hematological patients. We recognize however that, among our hospitalized patients, mortality rate was low as reported recently in hematological cancer patients.

No relevant conflicts of interest to declare.