Chikungunya Outbreak in Bangladesh (2017): Clinical and hematological findings
Authors: Anwar Saeed , Mourosi Jarin Taslem , Khan Fahim , Ullah Mohammad Ohid , Vanakker Olivier M. , Hosen Mohammad Jakir 
Published: May 2019

A massive outbreak of Chikungunya occurred in Bangladesh during the period of April-September, 2017 and over two million people were at risk of getting infected by the virus. A prospective cohort of viremic patients was constituted and analyzed to define the clinical, hematological and long-term aspects of this outbreak. A 35-day long comprehensive survey was conducted in two major, neighboring cities, Dhaka and Mymensingh. One-hundred and eighty-seven clinically proven Chikungunya cases were enrolled in the cross-sectional cohort study. Additionally, a smaller group of 48 Chikungunya patients was monitored for post-infection effects for 12 months. Clinical data revealed that a combination of fever and arthralgia (oligoarthralgia and/or polyarthralgia) was the cardinal hallmark (97.9% of cases) of the infection. Hematological analysis showed that, irrespective of age groups, hemoglobin level significantly decreased and erythrocyte sedimentation rate remarkably increased in Chikungunya confirmed patients. However, the majority of the patients had a normal range of whole WBC and platelet counts; RBC counts for mid aged (40 – 60 years) and senior (61+ years) patients (especially in the females) were beyond the reference values. The post-infection study revealed that children had an early recovery from the infection compared to the adults. Moreover, post-infection weakness, successive relapse of arthralgic pain and memory problems were the most significant aftereffects, which had an impact on daily activities of patients. This study represents a comprehensive overview of clinical and epidemiological features of the 2017 outbreak of Chikungunya in Bangladesh as well as its chronic outcomes till the 12th month. It provides insights into the natural history of this disease which may help to improve management of the Chikungunya patients.

Author summery

The clinical profile, epidemiology and the economic impacts during the acute phase of Chikungunya infection has been studied quite rigorously. However, studies regarding the hematological features and chronic consequences are very limited. In this study, a dataset of 187 clinically proven chikungunya patients were analyzed for the clinical and hematological features at acute phase of the infection. Additionally, the long-term consequences till month 12 after the infection were studied for a smaller group of 48 patients. Clinical data revealed that a combination of fever and joint pain (arthralgia) was the cardinal hallmark in the acute phase of the infection. Hematological analysis showed that, hemoglobin levels of the patients were significantly reduced and erythrocyte sedimentation rate increased remarkably. Also, RBC counts for mid-aged and older patients were beyond the reference values. The post-infection consequence study unveiled that children recovered better from the infection compared to the adults. Further, post-infection weakness, successive relapse of joint pain and memory problems were the most significant aftereffects. Overall, the infection had moderate to severe impact on daily activities of the respondents. This study provides insights into the clinical and hematological aspects of Chikungunya infection during the acute phase as well as describes an account for its chronic outcomes which puts forward to the knowledge for clinicians and epidemiologists regarding the infection diversity and to help improved patient management.