AIMS: To evaluate the association of acute organophosphate (OP) poisoning with 
chronic sensory and motor neurological impairment.
METHODS: This study concerns the third of a series of three examinations of hand 
strength and vibration thresholds in a two year period after acute OP poisoning 
among 48 Nicaraguan men. The first two examinations were performed at hospital 
discharge and seven weeks after poisoning, and the present examination two years 
later. Twenty eight cattle ranchers and fishermen who had never experienced 
pesticide poisoning were examined as controls, also three times over the two 
year period. The poisonings were categorised as caused by "non-neuropathic" OPs 
and "neuropathic" OPs, each subdivided in moderate and severe poisonings.
RESULTS: Men poisoned with OP insecticides had persistent reduced hand strength. 
We previously reported weakness at hospital discharge for OP poisoned in all 
categories that worsened seven weeks later for those severely poisoned with 
neuropathic OPs. Strength improved over time, but the poisoned were still weaker 
than controls two years after the poisoning, most noticeably among the subjects 
most severely poisoned with neuropathic OPs. Also, index finger and toe 
vibration thresholds were slightly increased at the end of the two year period, 
among men with OP poisonings in all categories, but patterns of onset and 
evolvement of impairment of vibration sensitivity were less clear than with grip 
and pinch strength.
CONCLUSIONS: Persistent, mainly motor, impairment of the peripheral nervous 
system was found in men two years after OP poisoning, in particular in severe 
occupational and intentional poisonings with neuropathic OPs. This finding is 
possibly due to remaining organophosphate induced delayed polyneuropathy.