Disease detectives

Usha Albuquerque

In the recent past, India has seen outbreaks of various emerging and re-emerging diseases in different parts of the country whether dengue fever, chikungunya, bird flu, or the more common malaria, typhoid, cholera etc. High pollution and poor air quality levels across north India is adding to our health problems, requiring a sophisticated response for prevention and control of these diseases. 

This is where Epidemiology comes in. It is a study of the distribution and causes of diseases in populations of humans and animals, specifically how, when and where they occur, so as to manage and control the incidence of such epidemics. Epidemiologists attempt to solve, prevent and control these health problems by studying what factors are associated with diseases (risk factors), and what factors may protect people or animals against disease (protective factors).

The science of epidemiology was first developed to discover and understand possible causes of contagious diseases like smallpox, typhoid and polio among humans. It has expanded to include the study of factors associated with non-transmissible diseases like cancer, and of poisonings caused by environmental agents. Epidemiological studies cannot prove that a specific risk factor actually causes the disease but can show that this risk factor is associated with a higher incidence of disease in the population exposed to that risk factor. 

Epidemiologists investigate how diseases affect certain populations, the emergence of viruses in particular countries, or they may track diseases. They can then make predictions about likelihood of the disease occurring, and work out strategies to prevent or limit it.

Work profile 

Epidemiologists often oversee public health programmes, where they investigate the causes of disease. They use their expertise to design research studies, monitoring programmes, and community surveys. Their research involves collecting and analysing various types of data, including blood and tissue samples, interviews, and surveys. They participate in clinical trials to test the effectiveness and safety of drugs and vaccines which could improve the lives of millions of people.

The task of epidemiologists is to reduce public health risks by integrating experiments, risk assessment, statistical analysis, surveys, and interviews to study disease patterns in populations. Epidemiology relies heavily on statistics for establishing and quantifying the relationships between risk factors and disease, and for establishing whether or not there is an excessive amount of a particular disease occurring in a specific geographic area. Epidemiologists are also able to contribute to scientific knowledge by proving or disproving theories on how diseases spread and how best to manage or treat certain diseases. They then write reports to present their findings to governments, medical industries and the general public.

They also advise government agencies on acceptable levels of exposure to environmental contaminants. Public advisories about mercury in fish, high ozone days, and mold exposure are based on their work. The vital work of these professionals helps protect the public from the harmful effects of environmental contaminants.

Job prospects

Epidemiologists work for national, international, public and private organisations involved in the study of patterns of health and disease in populations. Most jobs for epidemiologists are with government, or government funded agencies. Many also work for hospitals, or as faculty members or research staff at colleges and universities, and with science research and development organisations. Epidemiological methods are used increasingly in medical research, public health practice and health care evaluation.  Government and international Organisations like the National Centre for Disease Control, Indian Council of medical Research, World Health Organisation(WHO), United Nations, Médecins Sans Frontières and the Centers for Disease Control (CDC), and other international charities targeting disease outbreaks overseas, regularly recruit epidemiologists and public health experts for field support of projects. The State AIDS Control Societies also provide job openings for Epidemiologists. The work may include outbreak management, helping teams plan appropriate responses, including active case finding, conducting mortality surveys, evaluation and set up of surveillance systems, and also epidemiological support in complex projects to enhance evidence based decision making.

Epidemiologists can also be called upon to provide management, scientific, and technical consulting services in clinical development and research for pharmaceutical companies, and NGOs. A PhD is required for epidemiologists who direct research projects and faculty members at colleges and universities.

While research positions generally involve studying data and reports and lab work, those with government and health support organisations may often have to travel and collect data in the field and conduct environmental investigations. This will include the use of observations, collecting of blood samples and other human tissue samples, surveys, and personal interviews to discover what is causing the spread of disease. Epidemiologists must therefore be excellent listeners, as fact-finding interviews are an important part of their research.

Job opportunities in epidemiology are projected to grow as the incidence and spread of diseases increase. Moreover, advances in the availability and processing of "big data", along with the growing integration of advanced mapping software, will open up new opportunities in this area. 

Today we have so much awareness of factors that cause disease and different kinds of illnesses. Epidemiological studies have been undertaken for so many diseases and epidemics, even with regard to cardiovascular disease, and many factors which influence the development of cardiovascular disease have been found. Such large scale efforts have really paid off because they have provided information about diet and exercise habits that can be used to prevent the development of cardiovascular disease. For this we need to be grateful to epidemiologists who have doggedly conducted extensive studies on a range of factors that contribute to disease and epidemics. Such studies will continue to be required as we work towards a healthy and disease free environment for ourselves and the generations ahead. 

So for those interested in bio-sciences and with a curious and inquisitive mind, this is a career for the disease detective that offers many opportunities!

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Getting in

• The study of epidemiology requires a master's level degree of study, so you can take up an MSc in Epidemiology or Public Health after BSc. The course should ideally cover biostatistics, as much of what epidemiologists do is dependent on interpretation of data particularly that relating to spatial epidemiology, statistical genetics or the quantitative analysis of infectious disease dynamics. 

• Epidemiology courses normally include a study of chronic and infectious diseases, psychology, physiology, biochemistry, genetics, behavioural studies, immunology, toxicology, biostatistics, and health service administration.

• Research and teaching positions in epidemiology require a PhD. 

• Training programmes are being offered by the National Institute of Epidemiology, Chennai and National Centre for Communicable diseases, Delhi. There are also other institutes that offer Master of Public Health in Epidemiology. 

• Some institutes such as SRM University offer an MSc Biostatistics & Epidemiology which focuses on the integration of epidemiology, biostatistics and public health. The course with its focus on bio-statistics equips students with an understanding of statistical theory and epidemiology along with skills in using a range of software packages for statistical analysis and data management. 

• Those getting into this field must have a strong background in science, particularly biology and chemistry. You also need to be good in maths and statistics and be data proficient as you will be working with statistical analysis and data presentation software programmes. Epidemiologists must be critical thinkers with logical and analytical minds, who can analyse their findings, have problem-solving abilities, and ability to take timely decisions. They should be able to work independently or as part of a team and be able to communicate clearly.

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Scope

While tasks vary from role to role, the scope of most epidemiology jobs is to:

• Develop and test hypotheses about populations and communities as they relate to health, disease and lifestyle characteristics over a period of time

• Conduct field, laboratory, and theoretical research

• Analyse data using statistical models

• Review current scientific literature

• Use computer modeling techniques to assess the potential impact of disease and health changes in a given population

• Publish the results of research within the workgroup and in the larger epidemiology community

• Support strategic initiatives for health and wellness

• Produce in-depth technical documents like proposals and presentations for stakeholders and the public

• Design / implement / evaluate quantitative and qualitative epidemiological research methods

• Design and implement surveillance and other data collection systems for disease and outbreak monitoring, including mortality and nutritional surveys

• Be adept in the use of software for epidemiological database and statistical analysis 

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Institute Watch

• National Institute of Epidemiology, Chennai 

• National Centre for Communicable Diseases, Delhi

• Christian Medical College, Vellore

• All-India Institute of Health and Public Hygiene, New Delhi

• Indian Institute of Public Health, Delhi 

• SRM Institute of Science and Technology, Kanchipuram

• MGR Medical University, Chennai