Influenza A pandemics: clinical and organizational aspects: the experience in Chile.

Recently, the World Health Organization declared a pandemic mediated by the novel A H1N1 influenza virus. Soon after the first report from Mexico, the disease arrived in Chile, where it spread quickly from south to north, mimicking cold weather progression through the country. Between May and September 2009, 366,624 cases of H1N1 were reported; 12,248 were confirmed by real-time reverse-transcription polymerase chain reaction and 1562 were hospitalized. One hundred thirty-two deaths were attributable to the infection, creating a death rate of 0.78 per 100,000 inhabitants. Common comorbidities were present in 59%, including obesity, chronic obstructive pulmonary disease, hypertension, type II diabetes, and congestive heart failure. Nine percent were pregnant. Severe disease developed early; the median time to admittance was 5 days, and the most common clinical manifestations were cough, fever, dyspnea, and myalgia. Mean acute physiology and chronic health evaluation II and sequential organ failure assessment scores were 14 and 5, respectively. Highlighted laboratory data were lactate dehydrogenase and creatine kinase elevation, leukocytosis in 50%, elevated creatinine in a 25%, and thrombocytopenia in 20%. Severe respiratory failure requiring high-frequency oscillatory ventilation and extracorporeal membrane oxygenation as sophisticated modes of respiratory support was seen in 17%. Acute renal failure occurred in 25% of the intensive care unit patients, with death rates near 50%. Health systems reinforced outpatient guards with extra staff and extension of the duty schedules. Antivirals were supplied free for medically diagnosed cases. Admissions for severe cases were prioritized, reconverting hospital beds into advanced care ones; a central coordination station rationed their assignment. Recommendations for small hospitals include adding ventilators, using videoconferences, providing tutorial activity from experts, developing guidelines for disease management, and outlining criteria for transport.