Is poliomyelitis in the tropics provoked by injections?

In the tropics and sub-tropics, poliomyelitis is characterized by a high non-seasonal case-rate, very young victims and a predominance of leg paralysis following injections. It is proposes that this could be caused by infection of immunosuppressed infants with poliovirus of low virulence following mal-nutrition, infections with malaria and measles and treatment by injections. Vaccination policies are briefly reviewed and the complete safety of inactivated and oral poliovaccines in the tropics is queried on theoretical grounds. Even if injections are coincident with and not causal of paralysis, it may be difficult to persuade parents of this .