Echoviruses diagnosed in two Children presenting with Acute Flaccid Paralysis (AFP): An Illustration of the Evolving role of the Zambian AFP Surveillance Programme in the Absence of Polio

Abstract

Background: The Enteric Cytopathic Human Orphan virus commonly referred to by  the acronym ECHO virus has been known to cause acute flaccid paralysis (AFP). Zambia has since 1993 run a national AFP surveillance program to primarily detect and confirm poliomyelitis cases. Through this program other enteroviruses have  been confirmed to be associated to the non-polio cases. We describe two patients with acute flaccid paralysis presenting like poliomyelitis and yet are non-polio cases associated with ECHO virus.
Case reports: In March 1995, a 2 year old male from Misisi compound, presented at the UTH with muscle weakness and paralysis of sudden onset. Aside from the acute flaccid paralysis presenting in both legs and arms, the child had no other signs of  symptoms of significance. Laboratory investigations using the WHO polio laboratory network standard protocols revealed the  presence of ECHO 7 virus. In April 1995, a 4 year old girl from Kamwala South in Lusaka presented at the UTH with symptoms and signs of AFP of asymmetrical presentation affecting the Left upper and lower limbs, fever and sore throat. Two stool  specimens collected for laboratory analysis revealed the presence of Echovirus untyped.
Discussion: AFP is a neurological condition primarily suspected as a poliomyelitis commonly seen in children below 15 years defined by sudden onset of weakness and floppiness affecting usually one or more limbs. Laboratory analysis has revealed
other viruses including the Echovirus being associated with acute flaccid paralysis. This case series reveals Echovirus 7 and Echovirus untyped as being associated with AFP cases that presented to the UTH initially suspected to be poliomyelitis.
Conclusion: The clinical manifestations and laboratory results provide evidence of ECHO virus causing acute flaccid paralysis similar to that caused by polio virus. The last wild polio cases circulating in Zambia were in 2001. It is important that Zambia continues to investigate other causes of AFP for clinical decision making, scientific documentation and policy guidance.