Table 3
Author, date and countryPatient groupStudy type (level of evidence)OutcomesKey resultsStudy weaknesses
Clark RF et al, 1993, USA54 patients who attended with crotalid (rattlesnake) envenomations observed for signs of infectionProspective observational studyPresence of infection3% patients without antibiotics developed an infection, compared with 22% (2/9) who were receiving antibioticsFollow up involved telephone consultation as well as direct observation
Data available for 41Very small numbers
Kerrigan KR et al, 1997, Ecuador114 patients–59 randomly assigned to receive antibioticsPRCTPresence of infection as shown by abscess formation10.2% of treated patients developed abscesses compared with 5.5% of the untreated p=0.558No blinding
Not controlled for other variables, for example, antivenin administration or surgical debridement
Initiation of antibiotic treatment delayed
Blaylock RS, 1999, South Africa363 patients presenting with snake bites–both venomous and non-venomous (12%) (310 files available) requiring admission to hospital with swellingProspective trial% receiving antiobiotics84.8% of patients received no antiobioticsNot PRCT
?Comparable groups
Compared the length of stay in the two groups, (antibiotics v no antibiotics) further subdivided and analysed depending on main symptomatology–swelling, weaknessNo difference in length of stay between the groups–this is interpreted as reflecting no difference in infection rateExtrapolation and interpretation of results is controversial
Very little raw result data provided