World Resources 1996-97
(A joint publication by The World Resource Institute, The United
 Nations Environment Programme, The United Nations Development
 Programme, and the World Bank)
(Data edited by Dr. Róbinson Rojas)

2. Urban Environment and Human Health

Box 2.3 The Black Death Revisited: India's 1994 
                   Plague Epidemic

In September 1994, nearly 30 years after the last urban outbreak of plague in India, plague struck Surat, a city in the western part of India (1). The Surat outbreak, which killed 56 people nationwide, did not have the devastating impact originally feared, but it did generate considerable anxiety worldwide while also exacting a heavy economic toll in India (2) (3). It also served as a chilling reminder of how rapid urbanization and deterioration of the urban environment can bring people into contact with forgotten disease vectors.

Plague has long been a scourge of cities. The disease, caused by the bacterium Yersinia pestis , is best known for its role in the Black Death that swept across Europe and Asia in the Middle Ages, killing roughly one fourth of the population of Western Europe--an estimated 20 million people. Yet, its roots may be more ancient still: as early as 1190 BC, Homer referred to a plague-like disease that was associated with the movement of rats into populated areas (4).

The last major epidemic occurred early in the 20th Century in India, where it killed more than 10 million people (5). By the 1970s, although a number of small outbreaks continued to occur around the world, plague as an urban health threat had been largely relegated to the past. Or so the world thought until the Surat outbreak.

TWO TYPES OF PLAGUE

Bubonic plague--the form of plague that ravaged Europe--is transmitted to people through the bite of an infected flea. In urban areas, rats are the primary source of plague-infected fleas. In parts of Asia, Africa, South America, and the United States, wild rodent populations are persistently infected with the plague organism, serving as a natural reservoir for the disease.

However, the outbreak of plague that occurred in Surat was pneumonic plague--a highly contagious form of the disease that kills 100 percent of its victims if left untreated. Pneumonic plague is caused by the same disease organism that causes bubonic plague, but it infects the lungs rather than the lymph system. Since the disease invades the lungs, it can be transmitted to others in close physical contact through exhaled sputum droplets. Crowding and poor sanitation can provide ideal conditions for the spread of this type of plague (6) (7).

Because it is so contagious, and thus easily portable from one location to the next, the pneumonic plague outbreak in Surat caused panic both locally and internationally. In Surat, hysteria followed reports of the rapid and painful deaths of seven people on September 21 and the preliminary diagnosis of plague.

The fear of an epidemic was so intense among Surat residents that within 4 days, one quarter of the populace had fled the city. This exodus fueled anxiety throughout India, with the fear that plague might be transported far and wide by Surat refugees. On September 25, the government brought in a Rapid Action Force of police to stem the exodus and to prevent frightened patients from abandoning the hospitals where they were being treated.

Fortunately, the Surat outbreak was diagnosed quickly, and widespread treatment with tetracycline was begun. About half a million capsules of tetracycline were distributed in Surat alone. The death rate dropped dramatically, from roughly 10 each day from September 21 to 23 to none at all after September 28 (8). Not a single case was confirmed in Bombay, the nearest large city.

WHY AN EPIDEMIC?

Why did plague reemerge in an urban setting after many years of relative quiescence? Evidence points to two principal factors: the squalid conditions in much of Surat and the occurrence of two recent natural disasters in the area. Both of these factors contributed to bringing a plague-infected rat population into contact with the human population of Surat. Even though pneumonic plague does not require rats and fleas for its transmission among humans, the Surat rat population is regarded as the original source of the infection.

A year before the plague incident, an earthquake measuring 6.4 on the Richter scale hit the adjacent state of Maharashtra, killing at least 10,000 people and causing extensive damage (9). Researchers believe that the disturbances and resettlement associated with the earthquake helped bring the wild rodent population inhabiting the forested area near Surat into contact with the domestic rat population, introducing the disease into the local rat population in the process.

Surat's sanitation problems then helped the rat population grow dramatically. Surat, a city of 2.2 million, generates close to 1,250 metric tons of garbage each day, 250 metric tons of which remain uncollected. To make matters worse, floodwaters inundated the city during the 1994 monsoon, particularly in low-lying slum areas near the river. Surat residents complain that nothing was done to remove the great piles of rubbish that remained after the floodwaters receded, offering an ideal habitat for rats.

LESSONS LEARNED

An international response followed in the aftermath of the Surat plague outbreak. The World Health Organization (WHO) announced plans to establish a Disease Intelligence Unit that will function independently when such outbreaks occur to help diagnose the problem quickly. In addition, WHO asked the International Civil Aviation Organization to tighten its health controls at all international airports and to strengthen quarantine measures that seem to have lapsed since the eradication of smallpox.

India has also taken steps to prepare for future plague incidents. In response to the outbreak, medical school course work has been revised to address plague in greater detail. The National Institute for Communicable Disease's plague research unit has been modernized to make diagnosis easier. In addition to activating plague control units all over the country, the national government plans to set up a more sophisticated national surveillance system (10).

This reemergence of plague is a striking reminder that infectious diseases have not been defeated. Malaria has consolidated its strength as a major killer, although it had almost disappeared a few decades ago. Cholera and tuberculosis are donning new faces with drug- resistant strains.

By comparison, the health toll of the Surat plague was relatively minor. It killed just 56 people, whereas the malaria epidemic in Rajasthan in 1994 killed nearly 300 people (11). By any other name, the plague probably would not have caused the kind of panic that it did during this outbreak.

In financial terms, however, the plague's toll was much greater, costing the Indian economy in excess of $600 million. More than 45,000 people canceled their travel plans to India, and the country's hotel occupancy rate dipped to 20 to 60 percent. Many countries stopped air and ship traffic to India altogether. In total, exports from the country suffered a $420 million loss (12).

References and Notes

1. John W. Anderson, "Plague Deaths Recede in Stricken Indian City," Washington Post (September 27, 1994), p. A10.

2. Centers for Disease Control and Prevention, "Update: Human Plague--India, 1994," Morbidity and Mortality Weekly Report, Vol. 43, No. 41 (October 21, 1994), p. 761.

3. Molly Moore, "Plague Turns India into Region's Pariah: Outbreak of Disease Hurts Tourism, Trade," Washington Post (October 2, 1994), pp. A29, A33.

4. Institute of Medicine, Emerging Infections: Microbial Threats to Health in the United States, Joshua Lederberg et al., eds. (National Academy Press, Washington, D.C., 1992), pp. 16-17.

5. Ibid., p. 16.

6. Tom Post et al., "The Plague of Panic," Newsweek (October 10, 1994), pp. 40-41.

7. "The Old Enemy," The Economist (October 1, 1994), pp. 40-41.

8. J.C. Gandhi, "Plague Outbreak in Surat, Gujarat," presentation at the World Health Organization Interregional Meeting on Prevention and Control of Plague, New Delhi, India, March 1995.

9. V.K. Saxena et al., "Earthquake in Maharashtra: Impact Assessment on Communicable Diseases Potential," Journal of Basic and Applied Medicine, Vol. 2, No. 1 (1993), p. 77.

10. Government of India, Report of the Technical Advisory Committee on Plague (Government of India, Delhi, India, 1995).

11. World Health Organization, "India Malaria," Weekly Epidemiological Record, Vol. 69, No. 43 (October 28, 1994), p. 321.

12. Kai Friese, "The Morning After," India Today (October 31, 1994), pp. 30-39.

Table of Contents
Back to Section 2