INFLUENZA IN CHILDREN - LESSONS OF 2009

Abstract

In 2009 global influenza H1N1 virus has spread, so far the damage was done less, as was expected. Pandemic started in developed countries, influenza was not so dangerous for older people, as 1918 - the latter already had immunity, antiviral drugs worked, and most of patients had not felt very severe symptoms. Influenza H1N1 was recorded in 214 countries of the world, 1 483 520 cases of influenza registered and 18 036 deaths of pandemic influenza cases were confirmed in the laboratory. 59 thousand Lithuanian adults and children had flu symptoms from October 2009 to March 2010. Laboratory confirmed 810 A (H1N1) influenza cases, 23 deaths were recorded. Children morbidity data are not anounced yet. 545 children having clinical symptoms of influenza, were treated in Clinic of children diseases of Kaunas University of medicine and in the II Clinical hospital of Kaunas from 06.11.2009 to 22.12.2009. 16 children required supervision at intensive care unit, six children died due to suspected pandemic influenza or its complications, laboratory confirmed H1N1 virus in two of them. Clinical symptoms of influenza in Kaunas children were similar to the WHO declared pandemic flu symptoms. Fever was reported in 99.45 proc., cough - in 80.37 proc., runny nose - in 45.32 proc., headache – in 26,97 proc., sore throat - in 18.17 proc. of cases. Specific symptoms of pandemic H1N1 influenza - vomiting and diarrhea were registered as well (5,32 proc., and 8.81 proc. of children respectively). 18,7 proc. of children had signs of cytopenia: leukopenia - 11.7 proc., granuliopenia - 9.1 proc., thrombopenia - 12.5 proc. of children. These children more often had bacterial infection (11.1 proc.) in comparison with children without cytopenia (1.9 proc. χ2 = 16.4, p < 0.05). The most frequent complication - pneumonia, was diagnosed in 134 (24.59 proc.) hospitalized children. Severe flu complications, usually manifesting in respiratory system and causing respiratory failure, shock, and lethal option are possible. Therefore in February 2010 WHO updated recommendations for high-risk patients, who should get antiviral treatment as soon as possible. Inhaled zanamivir and oral oseltamivir were approved for the treatment of influenza and prevention in children. Antiviral medications, started within 48 hours from onset, reduces disease severity and duration. This year's experience showed, that antiviral therapy may be beneficial, even started later. 225 children (41.3 proc.), treated in both Kaunas hospitals received oseltamivir. When children with influenza are complicated by bacterial infection, antibacterial therapy is essential and can be vital. 249 (53,9 proc.) children at Kaunas hospitals were treated with antibiotics. Importance of vaccination to protect against seasonal and pandemic influenza, is undeniable. However, only 6 (1,1 proc.) children, hospitalized at KMU Children clinic and the II Kaunas hospital were vaccinated against seasonal flu. Experts say, that the possibility of the second pandemic influenza wave more likely. In this case, the vaccination question also remains relevant.