Atypical Chikungunya virus infections: clinical manifestations, mortality and risk factors for severe disease during the 2005–2006 outbreak on Réunion

Abstract

SUMMARYIn April 2005, an outbreak of Chikungunya fever occurred on the island of Re´union in the Indian Ocean. During winter 2005, six patients developed meningoencephalitis and acute hepatitis due to Chikungunya virus. Our objectives were to determine the incidence and mortality of atypical Chikungunya viral infections and to identify risk factors for severe disease. A hospital-based surveillance system was established to collect data on atypical Chikungunya cases. Case reports, medical records and laboratory results were reviewed and analysed. We defined an atypical case as one in which a patient with laboratory-confirmed Chikungunya virus infection developed symptoms other than fever and arthralgia. We defined a severe atypical case as one which required maintenance of at least one vital function. We recorded 610 atypical cases of Chikungunya fever : 222 were severe cases, 65 affected patients died. Five hundred and forty-six cases had underlying medical conditions (of which 226 suffered from cardiovascular, 147 from neurological and 150 from respiratory disorders). Clinical features that had never been associated with Chikungunya fever were recorded, such as bullous dermatosis, pneumonia, and diabetes mellitus. Hypertension, and underlying respiratory or cardiological conditions were independent risk factors for disease severity. The overall mortality rate was 10 . 6 % and it increased with age. This is the first time that severe cases and deaths due to Chikungunya fever have been documented. The information presented in this article may assist clinicians in identifying the disease, selecting the treatment strategy, and anticipating the course of illness.

Cardiovascular involvement and manifestations of systemic Chikungunya virus infection: A systematic review

“…In retrospective records of severe cases reported by Economopolou A., et al from La Réunion, 89% had previous medical conditions, 78% took medication before the disease (14% NSAIDS) and 14% were alcoholic 11, 23 . Nevertheless, it is notable that risk of severe infection and compromise seems to increase in large outbreaks, as documented in India (2006), where only 25% of cases developed classical CHIKV; and 75% were severe cases where 60% of these had some degree of neurological affectation 10 .…”

“…Cardiovascular compromise is worthy of mentioning because of its usually fatal outcomes 10, 28 . Infection can leds to cardiovascular manifestations, but in addition, patients with existing cardiovascular disease can be decompensated consequently altering its clinical control of disease, then worsening the short-term prognosis; as it has been described with diabetes, lupus; or neurological, renal, pulmonary and cardiovascular insufficiency 9, 11, 23 .…”

“…La Réunion reported an overall outbreak mortality of 10%; heart failure was the attributed cause in 15% of the cases, myocarditis and pericarditis in 5% and acute myocardial infarction in 2%; leaving a remarkable total of 22% mortality due to cardiovascular affectation 11, 15 . Several similar past records raise concerns about a possible cardiac tropism of CHIKV, with clear evidence.…”

“…On the other hand, isolated cases have reported severe acute manifestations, far from the classic expected evolution of the disease, especially in areas with renowned late outbreaks such as India (2006) 1, 10 , La Réunion and Mayotte (France, 2006) 9, 11 , Malaysia (2008), Thailand (2008) 12, 13 and South America (Colombia, Venezuela and later Brazil, from 2014 until now) 14, 15 . As a result, some authors have started to classify the clinical progression of CHIKV into either classical, severe or neurological (neuro-chikungunya) 10, 13 .…”

“…Here, identifying the febrile syndrome is particularly common on a daily basis and, coexists in a great proportion of patients with other morbidities and chronic conditions, that could easily trigger a more severe presentation and clinical picture of the disease 9, 11, 23 .…”