Epidemiological Description of the Influenza Virus Infection Period During the First Four Months of 2016 in a Teaching Third Level Hospital in Mexico City

Abstract

Background. The Influenza virus period in Mexico City is a risk of morbility and mortality. In this year there was saturation of health services so is important to know the factors that determined this period. Objective. Describe the epidemiological characteristics of the infected by influenza virus hospitalized patients in a teaching third level hospital in Mexico City during the first four months of 2016. Methods. Observational, prospective and analytical study from 1 January 2016 to 30 April 2016. Inclusion criteria: any age patient who were admitted to hospitalization with a diagnosis of influenza virus infection by molecular tests. Statistical analysis: description of frequencies and odds ratio calculation. Results. In the study period were done 1711 molecular tests and 1264 (73%) were positive to Influenza virus. 224 patients required hospitalization. Demographic characteristics: male 46.4%, average age 60.8, average days from beginning of symptoms to medical attention 3.4, average days of hospitalization 11, frequency of symptoms: fever 68.3%, cough 68.3%, odynophagia 17.4%, dysnea 40.6%; complications: interstitial pneumonia 4.9%, ICU treatment 5.8%, deaths 4.9%; baseline risk factors: pregnancy 3.6%, DM2 10.3%, cardiopulmonary disease 37.5%, cancer 8%, HIV 0.9%, overweight 32.6%, obesity 12.9%, no Influenza vaccination in the 3 months prior 83%. Distribution of Influenza virus typification: Influenza AH3/N2 29%, AH1N1 25%, A w/o subtypification 15%, B 31%. Mortality risk factor analysis: age > 65 OR 4.34 (p < 0.05), interstitial pneumonia OR 26.7 (p < 0.05), average days from beginning of symptoms to medical attention 4.8. ICU risk factor analysis: DM2 OR 4.5 (p < 0.05), overweight/obesity OR 5.8 (p < 0.05), age>65 OR 3.68 (p < 0.05), interstitial pneumonia OR 25 (p < 0.05), average days from beginning of symptoms to medical attention 6.07. Conclusion. Despite the previous sensibilization, still patients take more than 3 days to get medical attention, what is associated with mortality and complications. The low rate of vaccination is alarming, and it was observed that during this period all patients that were vaccinated 90% had AH3N2 infection. As infection disease practitioners, we have to insist on general population vaccination, as well as preventive campaigns regarding risk of dissemination, given that 90% of these patients acknowledged close contact with another confirmed case.