Medical researchers are building India’s first map of infectious diseases, one patient at a time

These days, doctors at the Hosanagara Taluk Hospital in Karnataka are asking patients who come in with a fever a few extra questions. If a patient tests positive for dengue, the doctors visit his or her home and inspect the surrounding area for signs of the mosquito-borne virus. The patient’s village along with his immunisation record and other relevant information then goes into a national database. This database is slowly growing with information on infectious diseases across the country and the people suffering from them.

This is all part of a project to study infectious diseases in India, their causes, prevention and cure, and – in a first – to build an interactive heat map of these diseases. A heat map is the representation of data in the form of a map or diagram, with different colours indicating the intensity of the subject they represent.

Epidemiologists, bioinformatics experts, virologists, entomologists, biotechnologists, scientists, social scientists, software experts and students from various institutions across India have come together for the project.

As a first step, data about dengue in the taluks (sub-districts) of Karnataka will be shared on the map, which will go online this month. Dengue is an under-reported disease in India. The map will have information about the density of patients in a particular area, its demography, socio-economic status, immunisation and climatic data, clinical classification of the four types of dengue virus that cause infection, the medicines sold for dengue in that area, and other viruses found there. The map is roughly modelled on the infectious diseases heat map of the United States.

Interactive heat map

Sudhir Krishna, professor with the Cellular Organisation and Signalling group at the National Centre of Biological Sciences in Bengaluru, brought the project team together. “We have created a consortium that is working towards building a digital heat map for India in infectious disease,” he said. “The current focus point for a variety of reasons is dengue and using a sub-set of Karnataka taluks, we do have a first graphic created by the Manipal Virus Centre.”

The team intends to update the map regularly and make it interactive to allow users to post data on it. There will be around four levels of filters that will verify such data. “We want the map to be a one-stop resource for all infectious diseases in India,” said Krishna. “Of course, we may expand our vision later and add non-infectious diseases such as cancer and others.

Dr G Arunkumar, professor and head of the Manipal Centre for Virus Research that is part of the heat map project, said, “We have no structured public health system in India. As of now, whatever evidence and data we have, it is not user-friendly to policymakers.”

According to him, the heat map will help address many problems – the overuse of antibiotics, disease cases not being properly documented, and the wilful blindness of health departments.

“By actually seeing data in the heat map, denial among policymakers and health department officials will come down and [this] will lead to policy changes,” he said. “We may be able to identify hotspots in the areas affected by disease and implement prevention strategies.”

The group is also exploring using next-generation sequencing technology to identify viruses, study the processes by which they have evolved to be able to infect humans, and build a virus data map. “We are involving the Postgraduate Institute of Medical Education and Research at Chandigarh for a fungi database and another institution for a bacteria database,” said Arunkumar. “We are also interested in the molecular epidemiology of bacteria. For example, how did shigella become resistant to drugs in some villages?”

Shigella is a group of bacteria that causes a diarrhoea-like infection called shigellosis, and spreads through contaminated food. The infection is treated with fluoroquinones and cephalosporins, two classes of antibiotics. In recent years, medical researchers have documented cases of shigella infection in villages of Karnataka’s Gulbarga district that are resistant to treatment with these antibiotics.

Meanwhile, Dr Guruprasad Madigeshi, a virologist at the Translational Health Science and Technology Institute, will start mapping the characteristics of viruses causing diseases in India. “In addition, we will also study the properties of antibodies against dengue,” said Madigeshi.

Dr Satish Rao from Medical College, Kolar is also part of the project and interested in developing dengue biomarkers – entities in the blood of infected patients that help in diagnosis. “Data in an excel sheet is not interesting and people don’t read it,” he said. “However, everyone will be interested in looking at an interactive map that will let us know more about dengue, influenza, malaria and so on. This health heat map will have big data mapped out in a graphical way for it to be interesting to lay people as well as experts in the area.”

The team is collecting data from state-run primary health centres as well as private institutions. According to Arunkumar, 27 sites in 13 districts in 10 states will be covered. “Samples reach Manipal within 24 hours to 48 hours through special courier service,” he said. “The idea is to empower the local hospital to test and evaluate the disease.”