Characteristics of hospitalised patients with 2009 H1N1 influenza in Chile

Abstract

As the pandemic of 2009 H1N1 influenza A virus progressed, more patients required hospitalisation. The objective of this study is to describe the characteristics and clinical course of hospitalised patients with 2009 H1N1 virus infection in Chile.This was a prospective, observational study of 100 consecutive hospitalised patients with RT-PCR-confirmed 2009 H1N1 influenza A, admitted to Puerto Montt General Hospital (Puerto Montt, Chile). Information was obtained regarding contact history, demographics, laboratory values and clinical course.The primary reason for hospitalisation was pneumonia, in 75% of patients. Rapid influenza A test was positive in 51% of patients. Prior exposure to 2009 H1N1 virus was documented in 21% of patients. Clinical failure, documented in 18% of cases, was characterised by respiratory failure and acute respiratory distress syndrome. Failure was more common in patients with obesity, tachypnoea, confusion and multilobar infiltrates.When evaluating a patient hospitalised with influenza-like illness, a negative rapid test for influenza A or negative contact with a suspected case should not alter physicians' considerations regarding the likelihood of 2009 H1N1 virus infection. Patients with 2009 H1N1 virus infection with obesity, tachypnoea, confusion and multilobar infiltrates should be closely monitored since they are at high risk for clinical failure.

Pneumonia associada a influenza A (H1N1)

“…(27) The most common diagnosis was pneumonia, (6,18,19) and the majority of pneumonia-related deaths occurred in young healthy adults with comorbidities. (9,26) In Europe (including Italy), influenza A (H1N1) infection had a milder course than in other countries.…”

“…(28) However, among the severe cases evaluated in the present study, we identified respiratory failure and the need for mechanical ventilation in 19 (70%) and 9 (33%), respectively, findings that are in agreement with those of other authors. (6,8,9,18,19) All of our patients were strictly monitored for the risk of rapid deterioration, especially for increased oxygen demand. (24) Although secondary outcomes, such as the frequency of mechanical ventilation requirement and length of hospital stay, were similar to influenza A (H1N1) infection who were admitted to four infectious disease facilities in Liguria.…”

“…(6,9,12,(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28) Approximately 20-56% of the patients hospitalized with influenza A (H1N1) infection had respiratory failure and required mechanical ventilation. (6,18,19,25) The risk of developing respiratory failure has been significantly associated with scores, at admission, of ≥ 4 on the Sequential Organ Failure Assessment or ≥ 20 on the APACHE II, as well as with lymphocyte counts ≤ 800 mm 3 , interval between symptom onset and initiation…”

Impacto clínico de la influenza A H1N1 pandémica en el hospital de Puerto Montt, Chile

“…Las características clínicas de 100 de estos casos fueron publicadas 5 . El 49% de los casos con RT-PCR (+) tuvo IFD negativa.…”

Infección por virus respiratorios en adultos hospitalizados en un Servicio de Medicina Interna

“…La búsqueda de antígenos en secreción respiratoria por inmunofluorescencia tiene una baja sensibilidad si se compara con métodos de amplificación genómica, requiere una alta carga viral para ser positiva y se ha descrito que tiene baja sensibilidad en adultos con neumonía 6 . En nuestra experiencia durante la pandemia de IA H1N1 de 2009 la IFD tuvo un rendimiento de 51% en nuestro medio 15 . Otra limitación es que no se disponía de métodos diagnósticos para otros virus respiratorios como bocavirus, rinovirus y coronavirus 6 .…”