Ethnicity, occupation and susceptibility to early adverse reaction to snake antivenom in northern Nigeria

Background Early adverse reactions (EARs) are common complications of snakebite antivenom (ASV) therapy. However, data on ethnic and occupational variation in the risk of EARs in Nigeria are limited. This study investigated the association of sociodemographic factors, particularly ethnicity and occupation, with EARs following ASV administration. Methods In this prospective cross-sectional study, 850 patients with snakebite envenoming were treated with EchiTab Plus-ICP polyvalent antivenom and monitored for EARs from the start of antivenom infusion until 4 h after treatment. Sociodemographic predictors of EARs were evaluated using multivariable binary logistic regression. Results EARs occurred in 240 (28.2%) participants, comprising 99 anaphylactic, 88 skin-only and 53 pyrogenic reactions. Ethnicity–occupation and residence were independently associated with EARs, whereas sex was not. Compared with Fulani non-herders, Fulani herders had significantly higher odds of EARs (adjusted odds ratio [aOR] 3.59 [95% confidence interval {CI} 2.40 to 5.36], p<0.001). Fulani non-herders also had higher odds than non-Fulani non-herders (aOR 2.12 [95% CI 1.34 to 3.34], p=0.001). Urban residence was associated with increased odds of EARs (aOR 2.16 [95% CI 1.10 to 4.31], p=0.030), while sex was not associated with the outcome. Conclusion Fulani ethnicity, herding occupation, and urban residence were independently associated with an increased risk of EARs following ASV administration.