[Latex and coagglutination test of serum and urine in childhood pneumonia]

Abstract

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).