41 children with
pneumonia (proven by X-ray) and 271 children with
upper respiratory tract infections were examined for
bacterial antigens (Haemophilus influenzae type b and pneumococci) in serum and urine. In patients with
pneumonia blood cultures, deep nasal swabs and antibody assay in serum (against Mycoplasma pneumoniae and Chlamydia) were made. In 271 patients with an
upper respiratory tract infection also a deep nasal swab for bacterial cultures was performed. In 29 of 41 patients with
pneumonia latex agglutination test was positive (in 15 patients for Haemophilus
antigen, in 14 patients for pneumococcal
antigen). Coagglutination test was positive in 6 patients (in 1 patient for Haemophilus
antigen, in 5 patients for pneumococcal
antigen). In 12 patients
latex agglutination was negative; there were other causes of
pneumonia (partially
viral infections). In 5 of 271 patients with an
upper respiratory tract infection (
purulent otitis media)
latex agglutination was positive (4 times for Haemophilus, once for pneumococcal
antigen). Bacteriological investigations confirmed the results of
latex agglutination test in serum and urine. To avoid false positive reactions we recommend heating of serum to 65 degrees C, of urine to 100 degrees C for 5 min. Urine should be concentrated 25 times (there were 3 times more positive results than with unconcentrated urine).