Vigilance wanting

A systematic evaluation of the surveillance system for identifying Japanese Encephalitis cases is the need of the hour

Published - August 25, 2013 03:01 pm IST

A research paper published in Emerging Infectious Diseases suggests that it is the low-quality of Acute Encephalitis Syndrome (AES)/Japanese Encephalitis (JE) surveillance data that provides little evidence to support development of prevention and control measures and estimate the effect of interventions. This jeopardises health of vulnerable populations and results in a waste of public health resources.

Despite the high profile of AES, importance of surveillance data for guiding these initiatives has not been sufficiently realised and translated into action, the paper said. JE and AES kills thousands of children and results in high morbidity in eastern Uttar Pradesh, and Bihar predominantly, and 15 other States across the country.

According to Dr. Manish Kakkar, senior public health specialist at Public Health Foundation of India (PHFI), who along with his infectious disease team, conducted the study in Kushinagar district of Uttar Pradesh, “at the crux of the debate, lies quality surveillance for AES, including laboratory testing, which is necessary for understanding the epidemiology and etiology of AES, planning interventions, and developing appropriate policy measures. There has to be a serious and concerted effort to address this by having a systematic evaluation of the AES/JE surveillance system first, followed by providing adequate laboratory support”.

AES is a clinical condition caused by infection with Japanese Encephalitis virus (JEV) or other infectious and non-infectious causes. A confirmed etiology is generally not required for the clinical management of AES. So far, surveillance for JEV infection in India has focused on identifying AES cases rather than JE cases since this approach is seen to be more feasible, given the limitations of public health resources.

From the 1970s until around 2010, JEV infection was considered to be the leading cause of AES in the traditional JE belt of India, which includes Kushinagar district. However, because of a large number of JE cases of unknown etiology, AES patterns alone have not suggested a clear picture of the epidemiology of the disease.

The study looked at different aspects of AES surveillance, by reviewing AES surveillance data for January 2011–June 2012 from Kushinagar. They examined the completeness and quality of AES surveillance data from the district where JEV is highly endemic. The inferences about AES epidemiology and etiology would be useful for policy planners and program implementers. Accordingly, the data were cleaned, incidence determined, and demographic characteristics of cases and data quality analysed.

A total of 812 AES case records were identified, of which 23 per cent had illogical entries. In some instances, the dates were illogical (e.g., dates of symptom onset and sample collection following and preceding the dates of hospital admission, respectively). Records for laboratory results (available for JE but not AES) of 82 per cent of AES cases in 2011 and 100 per cent in 2012 were “awaited”. Similarly, vaccination history for 84 per cent of AES cases in 2011 and 100 per cent in 2012 were “unknown”. So, inferences about the epidemiology and etiology of AES could not be made.

Dr. Kakkar pointed out that the study had found that a substantial contributor to the ambiguity about the etiology of AES could be the fact that surveillance data for AES had not been analysed, to assess reasons for increased cases and other reported causes. Also, the current AES/JE surveillance system had a complicated specimen referral and reporting system at the district level, and the available line lists suggested that data indeed was of low quality.

Gaps in surveillance capacity that were identified in this study indicate the need for a systematic evaluation of the AES/JE surveillance system in Kushinagar and constitute key lessons that need to be incorporated.

The government has tried to address some of these concerns through focused efforts such as the formation of a multi-sectoral and inter-ministerial National Encephalitis Control Programme. The National Vector Borne Diseases Control Programme (NVBDCP) developed guidelines for AES surveillance to promote need for a strong surveillance system as a critical component for control activities. The NVBDCP also built the capacity of the health workforce to provide better clinical management, extending referral diagnostic facilities by upgrading the existing Baba Raghav Das (BRD) Medical College facilities and setting up a National Institute of Virology field unit; and establishing a dedicated surveillance unit in the Department of Preventive and Social Medicine at BRD Medical College to provide improved surveillance and outbreak response.

However, in spite of the high profile of AES and subsequent interventions, the importance of surveillance data for guiding these initiatives has not been realised or translated to action.

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