Patients Hospitalized with pH1N1 Influenza in an Academic Community Medical Center

Abstract

Background:The emergence of a novel strain of pandemic influenza (pH1N1) in 2009 presented significant challenges to health care facilities worldwide. In our academic community medical center in suburban Philadelphia, we noted our first pH1N1 diagnosis in September 2009. We sought to assess the impact of pH1N1 disease on our hospitalized patient population.Methods:We prospectively collected clinical and epidemiological data on 29 consecutive patients that were admitted to our hospital with a primary or secondary diagnosis of influenza from October 1-November 30, 2009. Data were obtained through care of the patients and chart review.Results:Prominent symptoms on admission included fever, hypoxia, cough, myalgias, and diarrhea, with leukocytosis and neutrophilia. Pre-existing medical conditions included asthma, pregnancy, immunosuppressive therapy, and sickle cell disease. All but 5 of the patients were under 60 years of age. Three patients had culture-documented bacterial or mycoplasma infections. All but two of the patients received oseltamivir. Six required admission to the intensive care unit but only one patient died.Conclusions:Our population of hospitalized patients with novel pH1N1 influenza demonstrated many of the features that have been associated with pH1N1 disease in other populations. Most of the patients were women and none of the patients died directly as a complication of influenza. We observed a cluster of patients with a tetrad of features comprising a history of asthma, obesity, female gender, and African-American race. Individuals with this constellation of factors should be specifically targeted for pH1N1 vaccination.

VOC breath profile in spontaneously breathing awake swine during Influenza A infection

“…Different intranasal virus loads in the animals can be explained through individually different immune response after intranasal virus application. While other studies describe lymphopenia 16 or neutrophilia 17 in humans as well as lymphopenia and granulocytosis in ferrets during Influenza A infection 18 , we did not see any changes in white blood cell counts of the swine in this study. Since swine in this study did not show any clinical symptoms neither, it might be tempting to speculate that their immune response was by nature lower than reactions in humans or ferrets.…”

Influenza in Asthmatics: For Better or for Worse?

“…Although environmental pollutants are known to complicate asthma ( 127 ) and influenza ( 128 ), information on tobacco smoke exposure was only provided in a small number of these reports (Figure 4 ). In addition, as noted in our compilation of the previous literature, most patients had more than one underlying condition (Figure 4 ), although this was only considered by some authors ( 98 , 111 , 114 , 129 , 130 ). Complex interactions between asthma and other underlying conditions, including obesity ( 131 ), diabetes ( 132 ), and cardiac disease ( 133 ) for example, are only beginning to be elucidated.…”

“…While the majority of these individuals were otherwise healthy ( 108 ), approximately 40% [and as many as 78% ( 98 )] of the hospitalized patients had at least one underlying medical condition (Figure 4 ). Since other respiratory viruses (RSV and RV) clearly induce asthma exacerbations ( 109 , 110 ), it came as no surprise when asthma was identified as a risk factor associated with hospitalization in both children and adults during the 2009 pandemic ( 104 , 111 , 112 ). Multiple investigations surrounding this pandemic reported on the incidence of co-morbidities that have been identified by the Advisory Committee on Immunization Practices (ACIP) to increase the risk of influenza morbidity.…”

“…Therefore, the impact of steroid treatment during the 2009 influenza pandemic is ambiguous and may have enabled the likelihood of infection/complications or protection against severe influenza. Since patients with asthma and COPD were found among those admitted to the ICU ( 111 , 114 , 116 , 117 , 136 , 147 ), and among those that died ( 98 , 100 ), it is clear that the interaction between asthma and pH1N1 was complex, and may have been altered by asthma phenotype and endotype as suggested by animal studies described below.…”

Glucocorticosteroids enhance replication of respiratory viruses: effect of adjuvant interferon

“…These infections place patients at increased risk of severe lung disease, often requiring hospitalization12. For example, during the 2009 IAV H1N1 pandemic, pneumonia occurred chiefly in persons who had exacerbations of pre-existing asthma or COPD34. It is as yet unclear why this patient group is susceptible to viruses and go on to develop life-threatening lower airway infections.…”