Disease surveillance is an information-based activity involving the collection, analysis and interpretation of large volumes of data originating from a variety of sources. This is the basic premise of EPIDEMIOLOGY

What is Epidemiology : Scientific study of the spread and control of diseases

SIGNIFICANCE :

• In the years to follow, epidemiology became a key discipline to prevent and control infectious diseases (and in present context for non communicable diseases as well).
• The application of principles of epidemiology is possible through systematic collection and timely analysis, and dissemination of data on the diseases. This is to initiate action to either prevent or stop further spread, a process termed as disease surveillance.

Historical success :

• In the years to follow, epidemiology became a key discipline to prevent and control infectious diseases (and in present context for non communicable diseases as well).
• The application of principles of epidemiology is possible through systematic collection and timely analysis, and dissemination of data on the diseases. This is to initiate action to either prevent or stop further spread, a process termed as disease surveillance.

• In 1854, when a deadly outbreak of cholera affected Soho area of London, John Snow (1813-1858), a British doctor and epidemiologist, used the health statistics and death registration data from the General Registrar Office (GRO) in London, to plot on a map of the area, the distribution of cholera cases and deaths. He observed that a majority of cases and deaths were in the Broad Street area, which received supply from a common water pump, supporting his theory that cholera was a waterborne, contagious disease.
• The collection of health data and vital statistics by the GRO had improved over the previous decade-and-a-half due to untiring efforts put in by another medical doctor, William Farr (1807-1883). Based upon the data on the time, place and person distribution of cholera cases and deaths, supplemented by a map, Snow, on September 7, 1854, could convince the local authorities in London to remove the handle of the water pump, which they reluctantly did. The cholera outbreak was controlled in a few weeks. It started the beginning of a new era in epidemiology.

IN INDIA

• A major cholera outbreak in Delhi in 1988 and the Surat plague outbreak of 1994
• Government of India launched the National Surveillance Programme for Communicable Diseases in 1997.
• In wake of the SARS outbreak, in 2004, India launched the Integrated Disease Surveillance Project (IDSP).
• Focus – Increase government funding for disease surveillance, strengthen laboratory capacity, train the health workforce and have at least one trained epidemiologist in every district of India.
• With that, between 2004 and 2019, nearly every passing year, more outbreaks were detected and investigated than the previous year. It was on this foundation of the IDSP (which now has become a full fledged programme) that when COVID-19 pandemic struck, India could rapidly deploy the teams of epidemiologists and public health experts to respond to and guide the response, coordinate the contact tracing and rapidly scale up testing capacity.
• The disease surveillance system and health data recording and reporting systems are key tools in epidemiology; however, these have performed variably in Indian States, be it seroprevalence-survey findings or the analysis of excess COVID-19 deaths.
• As per data from the fourth round of sero-survey, Kerala and Maharashtra States could identify one in every six and 12 infections, respectively; while in States such as Madhya Pradesh, Uttar Pradesh and Bihar, only one in every 100 COVID-19 infections could be detected, pointing towards a weak disease surveillance system.
• The estimated excess deaths are also higher in those States which have weak disease surveillance systems and the civil registration and vital statistics (CRVS) systems.

ISSUES

• In a well-functioning disease surveillance system, an increase in cases of any illness would be identified very quickly. An example is Kerala, arguably the best performing disease surveillance system amongst the India States, as it is picking the maximum COVID-19 cases; it could pick the first case of the Nipah virus in early September 2021.
• On the contrary, cases of dengue, malaria, leptospirosis and scrub typhus received attention only when more than three dozen deaths were reported and health facilities in multiple districts of Uttar Pradesh, began to be overwhelmed. The situation is not very different in States such as Madhya Pradesh and Haryana, where viral illnesses, most likely dengue, are causing hospitalisation but not being correctly identified or are being reported as mystery fever.

WAY FORWARD

• A review of the IDSP by joint monitoring mission was conducted in 2015
• Steps suggested : Increasing financial resource allocation, ensuring adequate number of trained human resources, strengthening laboratories, and zoonosis, influenza and vaccine-preventable diseases surveillance.
• Government resources allocated to preventive and promotive health services and disease surveillance need to be increased by the Union and State governments.
• Workforce in the primary health-care system in both rural and urban areas needs to be retrained in disease surveillance and public health actions. The vacancies of surveillance staff at all levels need to be urgently filled in.
• Laboratory capacity for COVID-19, developed in the last 18 months, needs to be planned and repurposed to increase the ability to conduct testing for other public health challenges and infections. This should be linked to create a system in which samples collected are quickly transported and tested and the reports are available in real time.
• Emerging outbreaks of zoonotic diseases, be it the Nipah virus in Kerala or avian flu in other States as well as scrub typhus in Uttar Pradesh, are a reminder of the interconnectedness of human and animal health. The ‘One Health’ approach has to be promoted beyond policy discourses and made functional on the ground.
• Dedicated focus on strengthening the civil registration and vital statistics (CRVS) systems and medical certification of cause of deaths (MCCD). These are complementary to disease surveillance systems and often where one is weak, the other is also functioning sub-optimally.
• Ensure coordinated actions between the State government and municipal corporation to develop joint action plans and assume responsibility for public health and disease surveillance. The allocation made by the 15th Finance Commission to corporations for health should be used to activate this process.