Experience for S-OIV of Admission Pediatric Patient with S-OIV at YUMC, 2009 / 영남의대학술지

The clinical picture in severe cases of pandemic (H1N1) 2009 influenza is markedly different from the disease pattern seen during the epidemics of seasonal influenza as many of those affected were previously healthy young people. Current predictions estimate that during a pandemic wave, 12~30% of the population will develop clinical influenza (compared with 5~15% for seasonal influenza) with 4% of those patients requiring hospital admissions and one in five requiring critical care. Until July 6, 94,512 people have been infected in 122 countries, of whom 429 have died with an overall case-fatality rate of <0.5%. Most of the confirmed cases of S-OIV (Swine- Origin Influenza A Virus) infection have been characterized by a self-limited, uncomplicated febrile respiratory illness and 38% of the cases have also included vomiting or diarrhea. Efforts to control these outbreaks are based on our understanding of novel S-OIV (Swine-Origin Influenza A Virus) and the previous influenza pandemics. So, this review covers the experience with S-OIV (Swine-Origin Influenza A Virus) for the admission and background data and the clinical presentation, diagnosis and treatment of H1N1 in pediatric patient with S-OIV (Swine-Origin Influenza A Virus) at YUMC, 2009.

Swine Origin Influenza (Swine Flu).

Swine origin influenza was first recognized in the border area of Mexico and United States in April 2009 and during a short span of two months became the first pandemic. The currently circulating strain of swine origin influenza virus of the H1N1 strain has undergone triple reassortment and contains genes from the avian, swine and human viruses. It is transmitted by droplets or fomites. Incubation period is 2 to 7 days. Common clinical symptoms are indistinguishable by any viral respiratory illness, and include fever, cough, sore throat and myalgia. A feature seen more frequently with swine origin influenza is GI upset. Less than 10% of patients require hospitalization. Patients at risk of developing severe disease are – younger than five years, elderly, pregnant women, with chronic systemic illnesses, adolescents on aspirin. Of the severe manifestations of swine origin influenza, pneumonia and respiratory failure are the most common. Unusual symptoms reported are conjunctivitis, parotitis, hemophagocytic syndrome. Infants may present with fever and lethargy with no respiratory symptoms. Diagnosis is based on RT PCR, Viral culture or increasing neutralizing antibodies. Principle of treatment consist of isolation, universal precautions, good infection control practices, supportive care and use of antiviral drugs. Antiviral drugs effective against H1N1 virus include: oseltamivir and zamanavir. With good supportive care case fatality is less than 1%. Preventive measures include: social distancing, practicing respiratory etiquette, hand hygiene and use of chemoprohylaxis with antiviral drugs. Vaccine against H1N1 is not available at present, but will be available in near future.

Novel swine-origin H1N1 influenza / 소아과

Since its identification in April 2009, a swine-origin H1N1 influenza A virus (S-OIV) which is a reassortment of gene segments from both North American triple-reassortant and Eurasian swine influenza has been widely spread among humans in unexpected rapidity. To date, each gene segment of the 2009 influenza A (H1N1) outbreak viruses have shown high (99.9%) neucleotide sequence identity. As of July 6, 94,512 people have been infected in 122 countries, of whom 429 have died with an overall case-fatality rate of <0.5%. Most confirmed cases of S-OIV infection have been characterized by self-limited, uncomplicated febrile respiratory illness and 38% of cases have also included vomiting or diarrhea. Standard plus droplet precautions should be adhered to at all times. Tests on S-OIV have indicated that current new H1N1 viruses are sensitive to neuraminidase inhibitors (oseltamivir). However, current less virulent S-OIV may evolve into a pathogenic strain or acquire antiviral resistance, potentially with more severe clinical consequences. Efforts to control these outbreaks would be based on our understanding of novel S-OIV and previous influenza pandemics.