A Cluster of Severe Myositis with Rhabdomyolysis Identified During the Zika Virus Outbreak in Thiruvananthapuram, India, 2021

Abstract

Abstract Background: A cluster of patients with severe myositis and rhabdomyolysis was identified in a tertiary care hospital during the Zika virus (ZIKV) outbreak in Thiruvananthapuram district of Kerala state, India, 2021. We report their clinical features, laboratory investigations and virological studies. Materials and Methods: An electronic medical record based retrospective analysis of these cases was done. Clinical details, laboratory investigations including virological investigations were noted. Results: 11 patients with severe myositis and rhabdomyolysis were admitted in July-August 2021. Most patients developed severe rhabdomyolysis with acute kidney injury. Virological investigations were available in six patients. ZIKV RNA was detected by reverse transcription polymerase chain reaction in urine sample of one patient. Four patients tested positive for anti-ZIKV immunoglobulin M (IgM) antibodies by ELISA. Among the four patients who tested positive for ZIKV by ELISA, two tested positive for anti-dengue IgM antibodies by ELISA; while in the other two, the test was equivocal. PRNT90 assay performed in all six patients showed flaviviruses cross-reactive neutralizing antibodies. Conclusion: Our observations point toward a possible association between ZIKV disease and severe myositis. Further epidemiological and virological studies are warranted.