Swarming hornet attacks: shock and acute kidney injury-a large case series from Vietnam

Background. Social hornets attack victims in swarms in Asia, Africa and the Middle East. The venom consists of multiple proteins with myotoxin, haemotoxin, vasodilatory and anticoagulant effects. Methods. We reviewed the records of 65 patients at Cho Ray Hospital (Ho Chi Minh City, Vietnam) attacked by swarms of the lesser banded hornet, Vespa affinis. Patients were divided into four groups. Groups A and B presented within 3 days of attack and C and D after 3 days with or >50 stings, respectively. Results. Varying degrees of acute kidney injury (AKI) were seen in 38 (58.5%) patients in all groups. Twenty nine required renal replacement therapy. AKI was likely to be myoglobin and toxin induced with a clinical course consistent with acute tubular injury. The prognosis for renal recovery is excellent in those who survive. Seven patients (one from Group A and six from Group B) developed non-anaphylactic shock which led to four deaths. The predominant finding in Groups C and D who sought delayed tertiary care is renal failure. Conclusions. This cases which illustrate the varied effects of hornet venom and the need to be vigilant for shock within the first 2 days and persistent AKI beyond 3 days or attack.