Chikungunya Death Risk Factors in Brazil, in 2017: A case-control study

Background In 2016/2017 we had a major epidemic of chikungunya (CHIK) in Brazil, with many deaths. We evaluated to factors associated with deaths from CHIK that occurred in the city of Fortaleza, Brazil. Methods A matched case-control study was conducted (1:2), by sex, age (+/- 5 years) and neighborhood. Cases were CHIK deaths that occurred between January 1 and December 31, 2017, in Fortaleza, Brazil, and which were laboratory confirmed. Controls were laboratory confirmed CHIK patients occurring in the same neighborhood and in the same period, but which did not progress to death. Results 82 cases of CHIK and 164 controls were included. Considering the clinical history, significant associations were found between other chronic heart diseases (OR 3.8; CI: 1.53-9.26) and chronic kidney disease (OR 12.77; CI: 2.75-59.4). In the multivariate analysis of the variables related to signs and symptoms, fever (OR: 19.23 CI: 1.73-213.78), abdominal pain (OR: 3; 74 CI: 1.06-13.16), apathy (OR: 11.62 CI: 2.95-45.82) and dyspnea (OR: 50.61; CI: 12.37-207.18) were identified with greater likelihood of death from CHIK. It also stood out that altered blood glucose was associated with cases with a worse prognosis (OR: 13.5; CI: 1.3-135.0). Among the laboratory findings, only lymphocytes and albumin were not associated with greater likelihood of death. Conclusion The factors related with deaths were chronic kidney disease and previous heart disease, presence of fever, abdominal pain, apathy, dyspnea and arthritis and laboratory findings such as leukocytosis, leukopenia, thrombocytopenia, neutropenia and lymphopenia.