Long-term respiratory follow-up of H1N1 infection

Abstract

BackgroundThe first case of 2009 pandemic influenza A (H1N1) virus infection was documented in our Hospital on 10th August 2009.Metdods and findingsReal-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) testing was used to confirm the diagnosis. All patients were treated with oseltamivir from the first day of hospitalization. Upon admission 12/44 had local patchy shadowing in their chest x-ray and additionally antibiotic regimen was added to these patients as pneumonia was suspected based on clinical evidence. In total 44 patients were hospitalized 15/44 had asthma, 6/44 COPD, 5/44 leukemia. Lung function was evaluated with forced vital capacity, forced expiratory volume in 1 sec and diffused carbon monoxide upon discharge and every 3 months, until 6 months of observation was completed after discharge. The purpose of this retrospective cohort study was to evaluate whether influenza A (H1N1) had an impact on the respiratory capacity of the infected patients.ConclusionsAn improvement of pulmonary function tests was observed between the first two measurements, implicating an inflammatory pathogenesis of influenza A (H1N1) to the respiratory tract. This inflammation was not associated with the severity or clinical outcome of the patients. All patients had a mild clinical course and their respiratory capacity was stable between the second and third measurement, suggesting that the duration of respiratory inflammation was two months. Early treatment with antiviral agents and vaccination represent the mainstay of management.

Health costs from hospitalization with H1N1 infection during the 2009–2010 influenza pandemic compared with non-H1N1 respiratory infections

“…Importantly, not only are influenza viruses highly contagious, but they can also mutate, developing resistance to standard treatment 9–11. The incidence, clinical characteristics, and factors affecting patient outcome of the first wave have already been described 12–16…”

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.…”

Pulmonary function in patients with pandemic H1N1

“…The present study found that 54.54% of the patients had associated comorbidities, the most present being systemic arterial hypertension and diabetes. Zarogoulidis et al (20) in his study with 44 patients did not ind a signi icant number of associated comorbidities, and when present, the most related were lung diseases, cardiac coronary disease and diabetes. Lenzi et al (21) showed that out of 1,827 patients who used Oseltamir on average 2.3 days after the beginning of the symptoms, 11% (201) evolved to death.…”

“…Similar to our indings, Toufen et al (11) in his study followed-up 4 patients with Severe Acute Respiratory Syndrome (SARS) at the time of hospitalization for In luenza A (H1N1) who required invasive mechanical ventilation, two months after discharge a lung function exam was completed demonstrating a restrictive pattern in 3 patients and after 6 months the condition remained for 2 patients. Zarogoulidis et al (20) also discovered abnormal results in lung function immediately after discharge, he veri ied that FVC and FEV1 were reduced, after 3 months there was improvement which remained similar 6 months after discharge. Liu et al (29) (26) evaluated 37 patients with SARS and who remained under mechanical ventilation.…”

“…Paredes and Cevallos (2) and Zarogoulidis et al (20) demonstrated that image exams, such as radiographs, aid in the diagnosis of lung damage. During hospitalization patients with In luenza A (H1N1) presented extensive regions of lung damage, generally with a ground-glass opacity pattern or consolidations.…”