Flu child: is it underestimated?

The probability of being hit by the flu was three times higher in children than in young adults and the disease is underestimated in the child population in terms of both frequency and impact, have warned of specialists.

Thus, a U.S. study on children under five years shows that infection with influenza virus is identified in a minority of cases. When it is confirmed by laboratory tests, it appeared that the diagnosis had been before that in only 28% of inpatients and 17% of those seen in installed.

The flu affects children of all ages, those of school age, however, being the most exposed. For example, in France in 2003, the viral infection has reached nearly 3.5 million children under the age of 14 years. In general, younger people are affected two weeks before the rest of the population and epidemic period a child of 3 is reached, against only one in 10 adults. Similarly, within a family, the incidence of influenza is two times higher in a school-age child with his parents.

Propagators of virus

The children are, moreover, a major reservoir of virus and play an essential role in the spread of influenza. In fact, in this population, the virus multiplies and spreads faster longer than in adults. Children may be contagious for longer than 7 days after the onset of signs and therefore play a central role in the spread of influenza. In families where the children are in school, the risk of exposure is twice as high and 36% of households with a child appear ill see at least one case of infection.

In addition, the diagnosis is not always easy for young children and the clinical signs vary with age.

Before the age of one year, influenza infection is asymptomatic or discrete in 45% of cases, with temperatures often low or even normal. The cough is more rare, but more common pharyngitis than in older children. Bronchopneumonia with dyspnea touched nevertheless more than 37% of infants during the epidemic of 1995-1996, difficult to distinguish bronchiolitis respiratory syncytial virus (RSV).

Between 1 and 4 years, the diagnosis is more difficult because the symptoms are misleading, not breathing, as observed in more than half of the cases in this age or in gastrointestinal disorders of abdominal pain drowsiness, nausea, vomiting or diarrhea in 40% of cases.

Between 4 and 14 years, clinical signs similar to those of adults, with a sudden onset of fever over 39.5 ° C in 30-40% of cases associated with a runny nose in 75% of children. It describes the classic V influenza: drop in temperature after 36 to 48 hours (between 37 and 37.5 ° C), and then back the 3 or 4th day at 39 to 39.5 ° C. Chills, body aches, cough, headache and anorexia are associated. The healthy child heals in a week.

Some complications to know

The affinity of influenza virus in the respiratory tract may increase the risk of complications such as bronchitis or exacerbation of asthma. Acute otitis media is the most common complication and can reach nearly 40% of children seized for three years.

Before the age of 5 years, fever poorly tolerated can lead to seizures and flu can be complicated in older children with encephalitis, a Guillain-Barré syndrome (peripheral nerve responsible for limb paralysis, the face or respiratory muscles may require a self-limiting respiratory assistance, several weeks to months), or benign acute myositis (muscle damage).

The child is more vulnerable he is younger, more than 1% is hospitalized due to a severe form, which is in France nearly 35,000 hospitalizations lasting on average 4 to 5 days.

The limits of vaccination

If vaccination is the best way to prevent the flu, it still has its limits. On the one hand, the vaccination schedule is loaded until the age of 18 months or the vaccine should be injected with two doses of primary vaccination followed by an annual booster and despite a rigorous procedure the vaccine strains selected may not be close enough to the circulating viral strain during the epidemic. On the other hand, immunity in the child does not appear optimal.

However vaccination is capable of preventing influenza in 60-90% of children and to reduce by 70% the number of missed school days. In France, the rate of coverage, however, remains low during the 2004-2005 season, only 5% of healthy children were vaccinated and 19% of children with asthma.

* The antiviral Tamiflu (oseltamivir) can, in turn, reduce the duration of influenza (1.5 days), and the severity of symptoms and reduce the risk of complications (40% decrease of ear). It is indicated for children from one year to the prophylaxis and for the treatment of influenza and is available in capsules or oral suspension. It should be administered within 48 hours after contact with a person or flu symptom onset and confirmation of influenza. Because of other winter epidemics affecting the child (VRS rotavirus), the use of rapid diagnostic tests proves of great interest. Finally, adverse reactions taking Tamiflu * are possible, such as nausea, vomiting and abdominal pain (less than 10% of cases).