Describe the epidemiological transition with reference to India.

The Epidemiological Transition

• The classical three stages described by Omran:
• 1. The age of pestilence and famine — high and fluctuating mortality dominated by epidemics, famine and infection; life expectancy low (about 20 to 40 years); and population growth slow and unstable
• 2. The age of receding pandemics — mortality falls progressively as epidemics become less frequent, chiefly through improved nutrition, sanitation and living conditions; life expectancy rises to about 50; and, because fertility remains high while mortality falls, population growth accelerates
• 3. The age of degenerative and man-made diseases — mortality falls further and stabilises at a low level; cardiovascular disease, cancer, diabetes, mental illness and injuries predominate; and life expectancy exceeds 70
• Later authors added a fourth stage — the age of delayed degenerative diseases, in which cardiovascular deaths are postponed to later life by treatment and prevention rather than avoided, so people live longer with chronic disease and disability
• A fifth stage is sometimes proposed — the age of emerging and RE-emerging infection, reflecting HIV, antimicrobial resistance, drug-resistant tuberculosis, and pandemic influenza and coronaviruses, which show that the transition is not a one-way street
• The drivers of the transition — improved nutrition, sanitation and water, which did most of the early work; immunisation and antibiotics; rising income and education; the demographic transition and consequent population ageing; urbanisation; and lifestyle change — tobacco, diet, physical inactivity and alcohol
• The INDIAN situation is the important part of this answer, and it does not follow the classical sequence
• India shows a protracted, polarised and overlapping transition, and each of those three words carries meaning:
• Protracted — the shift has been slow and incomplete rather than the clean succession seen in the West
• Polarised — different states and social groups are at different stages simultaneously; KERALA and Tamil Nadu resemble middle-income countries in their disease pattern, while parts of the central and eastern states remain in an earlier stage
• Overlapping — India carries the triple burden: unfinished communicable disease (tuberculosis, malaria, diarrhoea, HIV); a rapidly rising burden of non-communicable disease; and injuries, particularly road traffic
• The nutrition transition runs alongside it — producing the double burden of malnutrition, with undernutrition and stunting coexisting with obesity and diabetes, sometimes within the same household
• The consequence for the health system is the central point — India cannot simply replace its communicable disease services with non-communicable ones, as the classical model would suggest; it must run both at once, with the resources of a low-middle-income country
• The implications for planning — a shift from acute, episodic care to continuing, long-term care; strengthening primary care for chronic disease, which is what the Health and Wellness Centres are intended to do; primordial and primary prevention through policy on tobacco, salt, sugar, trans fats and air quality; affordable essential medicines for lifelong treatment; financial protection, since chronic disease impoverishes families through sustained out-of-pocket cost; palliative care and rehabilitation; services for the elderly; and trained human resources for chronic care
• The warning that should conclude the answer — the transition must not be read as licence to neglect communicable disease. Tuberculosis remains India’s largest single infectious killer, antimicrobial resistance is worsening, and COVID-19 demonstrated how rapidly an infectious threat can dominate everything else
• India transition is protracted, polarised and overlapping, and each of those three words should be explained rather than listed
• The triple burden is infection, chronic disease and injury, all three carried at once with middle-income resources
• Different states sit at different stages, with Kerala resembling a middle-income country and others an earlier phase
• India must run two health systems at once, since neither burden has finished and the classical model does not apply
• The double burden of malnutrition coexists, with stunting and obesity sometimes in the same household
• The fifth stage is emerging infection, which shows the transition is not a one-way street
• COVID-19 demonstrated that reversal is possible, and is the reason communicable disease services cannot be dismantled
• Delayed degenerative disease means living longer with illness, since cardiovascular death is postponed rather than avoided
• Chronic care needs continuing rather than episodic services, which is what Health and Wellness Centres are meant to provide
• Chronic disease impoverishes through sustained cost, which makes financial protection central rather than peripheral
• Primordial prevention by policy is the cheapest response to the non-communicable burden, through tobacco, salt and air quality
• Tuberculosis remains the largest infectious killer in India, which is the warning that should close the answer