Pulmonary involvement in Mycoplasma pneumoniae infection in families.

The transmission rate and the clinical and pulmonary manifestations of serologically proven mycoplasma infections were reviewed in 34 patients from 11 families consisting of 30 children and adolescents aged 1 to 18 years, and four parents aged 30 to 41 years (total number of family members = 59:37 children, 22 adults). Twenty-seven of the 37 children had pulmonary involvement (73%). The total infection rate was 58%, and the infection rate in children 81%. The roentgenologic findings in children with pneumonia showed no pathognomonic features. The most common X-ray finding was bronchopneumonia (48%). Pulmonary infiltrates occurred in six children (20%) under four years of age. Three of the children (10%) had severe clinical and/or radiological manifestations. These findings depict a pattern of mycoplasma infection that is different from previous reports, i.e. high pulmonary infection rates in families, the occurrence of pneumonic infiltrations in young children and a quite severe clinical and radiological course in some of the patients.