Suspected H1N1 Cases: Clinical Presentations and Autopsy Findings in Cases of Early Death
V Nair, DM Hwang, J Butany. Toronto General Hospital/University Health Network, Toronto, Canada; University of Toronto, Toronto, Canada; Mcmaster University, Hamilton, Canada
Background: H1N1 or Human Swine influenza is a pandemic. A respiratory illness similar to seasonal flu, the morbidity and mortality are higher in some age groups. In cases with no laboratory confirmation, it is essential to rapidly confirm the diagnosis for the public health services(PHS). We were ordered to perform 4 such suspected H1N1 autopsies(April to Sept 09) and present the findings to highlight the clinical spectrum of respiratory disease that can mimic H1N1 and the need for an organized approach to the autopsy.
Design: The 4 autopsy cases with clinical suspicion of H1N1 infection were reviewed. Patient's age, sex, recent travel history, presenting symptoms were recorded. All the autopsy material was studied in detail by light and electron microscopy as well as immunohistochemistry. Appropriate tissues were sent to the public health lab for H1N1 other virus and bacterial testing.
Results: The ages ranged from 32 to 67 years, with three male and one female patient. Two had a history of recent travel(Mexico & China). The presenting symptoms were cough, fever and shortness of breath in all cases, for 1 to 8 days. The tissues in one of the cases were positive for HINI on PCR and DNA sequencing of H genes. The lungs in this case showed bilateral diffuse alveolar damage involving all lobes with edema and patchy hemorrhage. There was also evidence of bilateral bronchopneumonia with gram positive cocci. The lungs in other cases showed confluent bronchopneumonia, pulmonary hemorrhages and diffuse alveolar damage.Death in one of the cases was attributed to septic shock secondary to an unsuspected acute appendicitis.
Conclusions: The major changes in the positive case, were in the lungs and were by themselves not differentiable from any other cause of DAD eg SARS. There was superimposed bacterial bronchopneumonia. Cultures from other cases were negative for H1N1 and seasonal flu.The autopsy provided a rapid answer(under 24 hours) making it possible for the PHS to take further steps as necessary. Cases with a clinical suspicion of H1N1 should have an autopsy and all cultures obtained. All the cases had significant changes in the lung. At this time H1N1 cases appear to have a nonspecific pathology, not independently predictive of H1N1. Reliance on molecular studies, for a definitive answer, is therefore essential.
Monday, March 22, 2010 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 6, Monday Morning