Clinical manifestations, therapy and outcome of pandemic influenza a (H1N1) 2009 in hospitalized patients

Abstract

Background/Aim. Increasing number of epidemiological and clinical studies to date showed that the pandemic influenza A (H1N1) 2009, by its characteristics, significantly differs from infection caused by seasonal influenza. Therefore, the information about clinical spectrum of manifestations, risk factors for severe form of the disease, treatment and outcome in patients with novel flu are still collected. Methods. A total of 98 patients (mean age 32 ? 15 years, range 14-88 years) with the signs and symptoms of novel influenza were treated in the Clinic for Infectious and Tropical Diseases, Military Medical Academy. There were 74 (75.5%) patients with suspected influenza A (H1N1) 2009, 10 (10.2%) with the likelihood and 14 (14.3%) with the confirmed influenza. In all the patients we registered the basic demographic data, risk factors for severe disease, symptoms and signs of influenza, laboratory tests and chest radiography. We analyzed antiviral therapy use and disease outcome (survived, died). Results. The average time from the beginning of influenza A (H1N1) to the admission in hospital was 3 days (0-16 days) and from the moment of hospitalization to the Intensive Care Unit (ICU) admission was 2 days (0-5 days). There were 49 (50.0%) patients, 20-29 years of age and 5 (5.1%) patients older than 65. A total of 21 (21.4%) patients were with underlying disease, 18 (18.4%) were obese, 19 (19.4%) were cigarette smokers. All of the patients had fever, 81 (82.6%) cough, while dyspnea and diarrhea were registered in ? of the patients. In more than 75% of the patients laboratory tests were within normal limits. The realtime polymerase chain reaction (PCR) test for identification of influenza A (H1N1) 2009 was positive in 14 (77.8%), while pneumonia was verified in 30 (30.7%) of the patients. Six (6.1%) patients, mean age of 45 ? 14 years (31-59 years) were admitted to the ICU, of whom five (5.1%) had Adult Respiratory Distress Syndrome (ARDS). Risk factors were registered more frequently in the patients with acute respiratory failure (14.2% vs 4.9%, p < 0.05). A total of 67 (68.4%) patients received oseltamivir, 89 (90.1%) was applied to antibiotics and 64 (65.3%) were treated with a combined therapy. Antiviral therapy was applied to 43 (43.3%) patients in the first 48 hours from the onset of the disease, of whom only one (3.4%) developed ARDS. Fatal outcome was noted in 2.0% of the patients (2 of 98 patients) and in 33.3% of the patients treated in the ICU. Conclusion. Novel influenza A (H1N1) is most commonly manifested as a mild acute respiratory disease, which usually affects young healthy adults. A small number of the patients develop severe illness with acute respiratory failure and death. Patients seem to have benefit from antiviral therapy especially in first 48 hours.Uvod/Cilj. Vise epidemioloskih i klinickih studija do sada pokazalo je da se pandemijska influenca A (H1N1) 2009 po svojim karakteristikama znacajno razlikuje od infekcije izazvane virusom sezonske influence. Zato se i dalje prikupljaju informacije o klinickom spektru ispoljavanja, faktorima rizika od tezih oblika bolesti, terapiji i ishodu kod obolelih od novog gripa. Metode. U Klinici za infektivne i tropske bolesti Vojnomedicinske akademije leceno je 98 bolesnika sa novim gripom, prosecne starosti 32 ? 15 godina (14-88 godina). Broj bolesnika sa sumnjom na grip A (H1N1) 2009 bio je 74 (75,5%), sa verovatnim gripom 10 (10,2%), a sa potvrdjenim gripom 14 (14,3%). Kod svih bolesnika registrovani su osnovni demografski podaci, faktori rizika od tezeg oblika bolesti, simptomi i znaci gripa, laboratorijski nalazi i radiografija grudnog kosa. Analizirana je primenjena antivirusna terapija i ishod bolesti (preziveli, umrli). Rezultati. Prosecno vreme od pocetka gripa A (H1N1) 2009 do prijema u bolnicu bilo je 3 dana (0-16 dana), a do prijema u jedinicu intenzivne nege (JIN) 2 dana (0-5 dana). U zivotnom dobu od 20-29 godina bilo je 49 (50,0%) bolesnika, a ? 65 godina 5 (5,1%) bolesnika. Osnovne bolesti imao je 21 (21,4%) bolesnik, gojaznih je bilo 18 (18,4%), pusaca cigareta 19 (19,4%). Povisenu telesnu temperaturu imalo je svih 98 bolesnika, kasalj 81 (82,6%), dispneju i dijarealni sindrom ? bolesnika. Vise od 75% bolesnika imalo je laboratorijske nalaze u granicama normale. Real-time polymerase chain reaction (PCR) test za identifikaciju virusa influence A (H1N1) 2009 bio je pozitivan kod 14 (77,8%) bolesnika. Pneumonija bila je verifikovana kod 30 (30,7%) bolesnika. U JIN bilo je primljeno 6 (6,1%) bolesnika, prosecne starosti 45 ? 14 godina (31-59 godina), od kojih je akutni respiratorni distres sindrom (ARDS) imalo 5 (5,1%). Faktori rizika registrovani su cesce kod bolesnika sa akutnom respiratornom insuficijencijom (14,2% prema 4,9%, p < 0,05). Oseltamivir je dobijalo 67 (68,4%), antibiotike 89 (90,1%), a kombinovanu terapiju 64 (65,3%) bolesnika sa novim gripom. U prvih 48 sati od pocetka gripa oseltamivir bio je primenjen kod 43 (43,3%) bolesnika, od kojih je samo jedan (3,4%) razvio ARDS. Smrtni ishod zabelezen je kod 2,0% bolesnika (2 od 98 bolesnika), odnosno kod 33,3% bolesnika lecenih u JIN. Zakljucak. Novi grip ispoljava se uglavnom kao blaga akutna respiratorna bolest, od koje najcesce obolevaju mladje odrasle osobe. Mali broj bolesnika razvija teske forme bolesti. Antivirusna terapija moze biti od velike koristi, posebno kada se sa njenom primenom otpocne u prvih 48 sati od pocetka bolesti.