Predictors of virologically confirmed poliomyelitis in India, 1998-2000

As we progress toward eradication of polio, a growing proportion of cases of acute flaccid paralysis (AFP) reported are due to causes other than polio. AFP surveillance data from India for 1998-2000 were analyzed to determine the sensitivity and specificity of signs and symptoms present at initial case investigation and of residual weakness (which is used to classify AFP cases) for virologically confirmed poliomyelitis. Sensitivity was highest for age of <5 years (93%-97%) and residual weakness (74%-96%). Residual weakness was more sensitive among children aged <5 years. Cases of AFP in patients aged <5 years who have fever and asymmetrical paralysis are most likely to be confirmed as poliomyelitis. In countries with suboptimal surveillance for AFP, these results may help to prioritize investigation of AFP cases. The high sensitivity of residual weakness demonstrates the importance of 60-day follow-up examination for all patients with AFP, particularly those for whom the initial case investigation was inadequate or delayed.