The micro-erythrocyte sedimentation rate as a screening test for bacteraemia in young children with non-focal infections.

The micro-erythrocyte sedimentation rate (micro-ESR) was evaluated in 349 patients without focal signs of infection with bacteraemia, bacteraemia/malaria, malaria (218) and fever of undetermined origin(100). There were significant differences between the diagnoses in their mean micro-ESR uncorrected for anaemia (F ratio = 3.66, p = 0.013 for one way analysis of variance). The sensitivity of uncorrected micro-ESR > 20mm/hr for bacteraemia was moderate (53%) and specificity was low (32%); for bacteraemia/malaria sensitivity was high (88%) but specificity was also low (33%). The positive predictive value of micro-ESR > 20mm/hr was low for bacteraemia (3%) and bacteraemia/malaria (6%) whereas the negative predictive value was high for bacteraemia (94%) and very high for bacteraemia/malaria (98%). We conclude that a low micro-ESR (< 20mm/hr) may be helpful in ruling out bacteraemia, especially bacteraemia/malaria, in young febrile children without focal signs.