Risk of severe malaria associated with parasite positivity, number of clones and antibodies to schizont extract in three-monthly visits before admission.

Conditional logistic regression adjusted for log number of visits including 42 risk sets where the case was no older than 2 years and 3 months at the time of severe malaria episode and thus had samples until three months before the admissiona.a. excluding 13 risk sets with children with longer time since their last visit (4–47 months).b. adjusted for log number of visits in the period before the severe admission of the cases and respective periods in the controls.c. including PCR and microscopy results.d. including only risk sets where PCR results were available (n = 41).e. antibodies to schizont extract detected in at least one of the three most recent visits before admission in the cases and corresponding time in the controls, including 40 risk sets where samples for antibody analysis were available.