Clinical differences between influenza A (H1N1) virus and respiratory infection between the two waves in 2009 and 2010

Long Term Respiratory Follow-Up for COVID-19 Patients a Multicenter Study

BACKGROUND

The first wave of the COVID-19 pandemic initiated officially in October 2020. Since then several observations have been made regarding the disease and its symptoms.

PATIENTS AND METHODS

We included eighty seven in our observational study. Our main aim was to investigate their long term respiratory follow-up in correlation with their initial radiological and laboratory findings and values. The nose swab PCR test for COVID-19 was used for diagnosis. Patients were monitored at 3 and 6 months after their hospital reception whereas basic parameters of health condition (smoking, PO2, SPO2, WBC, CXR, CRP, intercurrent findings, days of nursing, colchicine administration) in joint with gender and age were recorded.

RESULTS

Males seem more susceptible to the viral disease than females in a ratio 1,8:1. The parameters FEV1 and FVC (as % relative changes) were not affected, apart from the DLCO to which CRP (in loge+1 transformation) and SPO2 showed a statistically significant effect.

CONCLUSION

None of these patients were intubated, or admitted to the intensive care unit. The respiratory function is affected by the virus and the effect is reversed within the first three months. Males are more affected and the radiological and laboratory findings are associated with the respiratory functions.

Comparison of clinical presentation and laboratory values at admission between PCR-confirmed influenza A H1N1 infection and influenza-like disease, South-East Austria

PURPOSE

Reliable and rapid diagnosis of influenza A H1N1 is essential to initiate the appropriate antiviral therapy and preventive measures. As PCR assays are time-consuming and rapid antigen tests have a limited sensitivity, official influenza case definitions are used in many clinical settings. These, however, are based exclusively on clinical criteria and have only a moderate potential to differentiate between influenza and other febrile diseases. Only limited data on the differences in clinical and laboratory parameters between influenza and non-influenza febrile diseases are available to date.

METHODS

This was a retrospective case-negative control series that was conducted in Styria, southeast Austria. We analyzed the differences in clinical presentation and laboratory admission parameters between patients with PCR-confirmed H1N1 influenza infection (n = 199) and those with influenza-like disease and negative influenza PCR results (ILD group; n = 252).

RESULTS

In the multivariable analysis lower C-reactive protein (CRP) level, lower white blood cell (WBC) count, fever, wheezing, cough, and the absence of nausea or sudden onset remained significant predictors of H1N1 influenza in adult patients (n = 263). Lower CRP level, lower WBC count, and cough remained significant predictors in pediatric patients (<16 years; n = 188).

CONCLUSION

Lower CRP level, lower WBC count, and cough were significant predictors of H1N1 in both the adult and pediatric patient group. These data may help to develop an improved case definition for suspected H1N1 infection which combines clinical findings and easily available laboratory parameters.