Clostridium tetani is the etiological agent of tetanus. This bacterium is a spore forming anaerobic rod, that inhabit the soil. Before 1970 it causes 200 to 300 deaths per year in Costa Rica. Afterwards the disease was practically controlled and nowadays there are less than 3 cases by year and no cases in infants were observed. The last case in an infant tetanus that occurred in Costa Rica was in 1989; some relevance characteristics of its clinical story, which end was fatal, aimed this report, this is an example of facts that never would occur. He was a 50 day old child that had diarrhea and vomiting 3 days before admission, his grandfather gave him antibiotic injection at home. The child was admitted to hospital with muscular spasms and dead 24 hours later. We presume an infected needle was the entrance door for the Clostridium tetani spores. This case represents a lesson for the antiseptic management of needles. We should always keep tetanus in mind because its agent is a normal inhabitant in our soils and vaccination does not eliminate it from the environment.

tetanus infantil; injections