On this page
Cholera kills by draining water and salt from the body faster than a person can replace it. In 1971 an Indian doctor faced that problem in its worst form: crowded refugee camps, a cholera outbreak, and not enough intravenous fluid. His answer was a drink. Here is who Dilip Mahalanabis was, what he did in the camps, the science of why it worked, and what a student can learn from how he worked.
Who was Dilip Mahalanabis?
According to a 2024 profile in Cureus by Kawalkar and colleagues, Mahalanabis was born on 12 November 1934 in Kishoregunj, now in Bangladesh. He took his medical degree from Calcutta Medical College in 1958 and trained further in London. In the 1960s he worked on oral rehydration at the Johns Hopkins University International Center for Medical Research and Training in Kolkata.
He was not working alone. A review in the Indian Journal of Medical Research (2024) describes how teams in Dhaka, including David Nalin and Richard Cash, had shown by 1968 that oral glucose-salt solutions could keep cholera patients hydrated in hospital. What was not yet known was whether the method would hold up outside a well-run ward.
What happened in the 1971 refugee camps?
During the Bangladesh war, millions of refugees crossed into India. The Cureus profile describes the camp at Bangaon: by mid-June 1971 it held about 350,000 people, cholera arrived with the monsoon, and intravenous saline was nowhere near enough.
Mahalanabis chose to treat with a drink. His mixture used glucose, common salt and baking soda (sodium bicarbonate). Potassium was left out because it was scarce. His team packed measured amounts into plastic bags in the library of the Johns Hopkins centre, each with instructions for dissolving it in water. At the camp, staff gave IV fluid to the most severely ill, while patients who could drink got the oral solution, with relatives keeping them drinking.
A 2022 review by David Nalin, one of the Dhaka researchers, reports the result: a case fatality rate of 3.6% among about 3,700 patients treated, compared with an estimated 30% in the camps in general. The team published the work as Oral fluid therapy of cholera among Bangladesh refugees in the Johns Hopkins Medical Journal in 1973.
How big a difference is 3.6% against 30%?
Work it through for 3,700 patients.
At 3.6%: 0.036 × 3,700 = 133.2, so about 133 deaths.
At 30%: 0.30 × 3,700 = 1,110 deaths.
The gap is roughly 977 people, from one camp team in one outbreak.
The rough comparison shows why the report mattered. Nalin writes that the success in the camps helped win strong support from WHO, UNICEF and USAID for a global oral rehydration programme.
Why does a sugar-salt drink work?
Nalin explains the mechanism: glucose and sodium ions are carried across the lining of the intestine together, which increases the absorption of salt, and water follows by osmosis. He describes this glucose-sodium co-transport as the science behind a 1978 Lancet editorial, "Water with sugar and salt", which said that the discovery that "glucose accelerates absorption of solute and water" was "potentially the most important medical advance this century".
Nalin also stresses that the drink alone was not the whole answer. What mattered was a method that kept intake ahead of output, which in the camps meant paramedics and family members keeping patients drinking.
If you want the story of the toxin itself, read our post on Sambhu Nath De and the cholera toxin. For the earlier fight against cholera through clean water, see John Snow's cholera map.
Does oral rehydration still matter today?
Yes. The WHO fact sheet on diarrhoeal disease calls diarrhoea the third leading cause of death in children aged 1 to 59 months, killing around 443,832 children under 5 each year. It describes ORS as a mixture of clean water, salt and sugar that costs a few cents per treatment, and recommends zinc tablets alongside it.
Recognition for Mahalanabis came late. The Cureus profile lists the Pollin Prize in 2002 and Thailand's Prince Mahidol Award in 2006. He died in 2022, and the Government of India's Padma Awards list for 2023 names him first among the Padma Vibhushan recipients, posthumously, for medicine.
What can a student take from how he worked?
Trust evidence over habit. Nalin notes that the prevailing wisdom was that drinking would make acute diarrhoea worse. The Dhaka trials said otherwise, and he acted on the data.
Design for the real setting. A method that needs trained nurses and drips fails when there are too few of both. He redesigned the process so that relatives could do much of the work.
Count and report. Writing up 3,700 patients with deaths recorded is what turned a field decision into evidence that others could check.
Understand the mechanism. Knowing why glucose helps sodium absorption is what makes the recipe sensible rather than a folk remedy.
If osmosis and transport across cell membranes still feel hazy, the Fermi Concept Library has every concept in physics, chemistry, biology, mathematics and computing, each with its own lesson, so you can fill that one gap.
Next step: read the WHO fact sheet's section on treatment and explain to someone at home, in two sentences, why ORS contains both salt and sugar.
