• duration (days)and severity (grade mild, severe) of different symptoms (clear nasal discharge, coloured nasal discharge, nasal obstruction, cough, throat pain, ear ache, fever, headache, diarrhea) [ Time Frame: within the first three weeks after enrolment ]
• number of days the child is using the following symptomatic drugs (pain killers, nasal vasoconstrictors, nasal corticosteroids, asthma drugs, antihistamines) [ Time Frame: within the first three weeks after the enrolment ]
• number of days the child is not at school and that the parents are not at work [ Time Frame: within the first three weeks after enrolment ]

The purpose of this study is to find out whether the children with respiratory infection and the presence of pathogenic bacteria (S. pneumoniae, H. influenzae or M. catarrhalis) in the nasal middle meatus benefit from antimicrobial treatment.

Acute sinusitis is one of the most common disease in children requiring antimicrobial treatment. The diagnosis and treatment outcomes of acute sinusitis are contradictory, and better diagnostic criteria are needed. In adults with acute maxillary sinusitis, bacterial culture results obtained from the nasal middle meatus are comparable to those obtained from sinus puncture and aspiration. In children, the presence of pathogenic bacteria (S. pneumoniae, H. influenzae or M. catarrhalis) in the nasal middle meatus during respiratory infection predicts longer duration of signs and symptoms of common cold.

In this randomized placebo-controlled study, the effect of the antimicrobial treatment (amoxicillin-clavulanate) is examined in children with pathogenic bacteria (S. pneumoniae, H. influenzae or M. catarrhalis) in the nasal middle meatus during respiratory infection. The duration of the symptoms and speed of recovery is recognized by daily symptom-diary, the results are compared between the treatment groups.

• Acute Respiratory Infection
• Sinusitis

• Drug: placebo
• Drug: amoxicillin clavulanate acid

• Placebo Comparator: placebo Ora-Plus (registered trademark) mixture with an strawberry sweetening agent to make the placebo mixture similar in appearance and taste to active drug
• Active Comparator: amoxicillin-clavulanate acid

Inclusion Criteria:

• acute respiratory infection with nasal symptoms (nasal obstruction or discharge)
• seeking medical help from health centre for the respiratory symptoms
• pathogenic bacteria (S pneumoniae, H influenzae or M catarrhalis) identified from right or left nasal middle meatus in the endoscopically taken swab culture sampling taken by a study investigator (all microbiological analyses are done by the National Public Health Institute´s microbiological laboratory in Oulu)

Exclusion Criteria:

• otitis, tonsillitis or other disease requiring antimicrobial treatment
• respiratory infection within 4 weeks of screening
• antimicrobial treatment within 4 weeks of screening
• allergy to penicillin or amoxicillin