In a 9-month surveillance of the microbial agents causing acute lower respiratory infections (ALRI) in hospitalized preschool Nigerian children, 24 bacterial isolates were made from 22 (33 per cent) out of 66 blood cultures, including seven (70 per cent) of the 10 cultures from subjects with pleural effusion. Of the 24 positive isolates, Staphylococcus aureus accounted for 14 (58 per cent), Klebsiella pneumoniae for four (17 per cent), Streptococcus pneumoniae and Staphylococcus albus for two (8 per cent) each, and Haemophilus influenzae for only one case. Seven subjects had a mixed aetiology, comprising one bacteraemic case with measles and six with concomitant viral identifications. Sixteen cases, 10 (63 per cent) of whom were malnourished, had two or more pathogens, including 10 with multiple viruses. Bacterial isolates from the throat, were not significantly predictive of the ALRI aetiology. Overt malnutrition, empyema, and anaemia, were significantly commoner in bacteraemic cases (P<0.03,0.01, and 0.05), while rhinorrhoea and crepitations were each associated with the non-bacteraemic ones. (P=0.05 and <0.05). A similar association was shown between rhinorrhoea, wheezing/rhonchi and the mixed aetiological groupl (p<0.05 and 0.05, respectively). The case-fatality in bacteraemic subjects, was 9 per cent and was 2.1 times higher than that for non-bacteraemic cases, in whom a shorter mean duration of admission was recorded. In developing countries, the need for periodic local surveillance of ALRI pathogens, as a prerequisite for evolving rational antimicrobial policies, is emphasized. Our findings underscore the predictive importance of malnutrition as a risk-factor of severe bacteraemic ALRI, frequently associated with multiple pathogens. The relative usefulness of blood culture in identifying bacterial agents of ALRI is discussed. © 1993 Oxford University Press.
