The Bubonic Plague

 
    Bubonic plague is caused by the bacteria Yersinia pestis. This bacteria primarily infects rodents and evolved in the grasslands of central Asia where it was vectored among burrowing rodents by fleas. Occasionally throughout history, the fleas were transported to cities in China or Mesopotamia and spread great epidemics among the rodents and people there. Between 1345 and 1360 the epidemic known as the Black Death in Europe killed an estimated one-quarter of the world’s known human population, which at that time was about 24 million.

    The plague bacteria has now become naturalized among burrowing rodents (e.g., prairie dogs and ground squirrels) in the American southwest, among gerbils in South Africa, and among marmots in Siberia and Manchuria. Human exposure is usually from the bite of Xenopsylla cheopis, the oriental rat flea. When the flea bite introduces the bacteria into the blood stream, the lymph glands become infected and swollen (buboes). These buboes release a discharge, and infection (septicemia) spreads in the blood stream throughout the body. This is the bubonic plague. Untreated, the case fatality rate today is about 50%, although primary septicemia is invariably fatal. Early in its development, the disease can be treated with tetracycline and fatality rates can be reduced.

    As the infection spreads through the body, there may be a secondary involvement with the lungs. Bacteria in the lungs occasionally reach such levels that aerosolized droplets of sputum may spread the infection to another person. This is known as pneumonic plague, which, freed of its connection to fleas, is highly contagious among people. There is an incubation period of about two to six days before a person develops symptoms or becomes infectious.

    International law (International Health Regulations, Class I) requires governments to notify the World Health Organization and adjacent countries within 24 hours of the first case of plague in any area previously free of the disease, including newly reactivated cases among rodents (Benenson 1990). Patients with bubonic plague (and no cough) must be isolated and their clothing and premises treated with insecticide. Those with pneumonic plague must be isolated with strict precautions against airborne spread until antibiotic therapy has been completed. International regulations require that prior to departure on an international voyage from an epidemic area, suspect travelers be placed in isolation for six days; on arrival of a suspect vehicle, it may be disinfected and travelers may be kept under surveillance for a period of not more than six days.

 
 

Case Study: Bubonic Plague in India

 
     The city of Surat is located in western India near the Indian Ocean and has a population of 1.8 million people (see Figure 5). Its major industries include diamond polishing, diamond exporting, and the production of textiles, yarn, dyes, and other chemicals. These industries employ the inhabitants of the city as well as a large number of migrant laborers from nearby states. 

 

    In the first week of August 1994, health officials reported an unusually large number of deaths of domestic rats in Malma village in Maharashtra state, about 150 kilometers southeast of Surat. Three weeks later when the public health officials visited the village, the first case of suspected bubonic plague was diagnosed.

    On September 21, 1994, the Deputy Municipal Commissioner of Health (DMCH) in Surat received word that a patient had just died from a chest complication that "seemed" to be a case of pneumonic plague. The DMCH immediately informed his superiors and alerted the medical community in the area where the suspected plague victim resided. Later the same day, a worried caller informed the DMCH of more than ten deaths among the residents of Ved Road in Surat city and of another 50 patients who were seriously ill and had been admitted to the local hospital. By 11:30 p.m. four medical teams were assisting residents of Ved Road. Once patients were identified, family members were given a prophylactic dose of tetracycline, and their homes and surroundings were dusted with pesticides. The team then explained the seriousness of the situation to the local community and asked them to report any case of suspected fever, blood-stained sputum, breathlessness, chest pain, sore throat, or even persistent cough. Two victims were taken for post mortem analysis and another nine suspected cases were shifted to an isolation ward in the New Civil Hospital. Local physicians were told to refer all suspected cases of pneumonic plague to new Civil Hospital.

    Rumors spread quickly that the deaths were the result of poisoning of the city's water supply. Citizens became concerned, and communication lines were jammed by the large number of telephone calls. The administration of Surat sent vans equipped with public address systems around the city to deny the rumor, to ask people to stay calm, and to explain that the deaths were thought to be the result of the plague. This announcement, according to press reports, resulted in extreme responses among members of the public.

    Citizens forced pharmacies across the city to open, and within hours they depleted the entire stock of tetracycline. By the morning of September 22, 1994 the exodus of people from Surat had begun. Because of rumors that Surat would be quarantined, over 300,000 people deserted the city in the next two days. Several doctors and paramedical staff are also alleged to have fled the city. Meanwhile, hundreds began reporting to the Civil Hospital which was almost entirely converted into an isolation ward. At other cities in various parts of India, check points were established at railway stations and airports to monitor incoming Surat inhabitants. Passengers from Surat and neighboring areas were reportedly received, in some cases, by medical teams as a precautionary measure. Likewise, hospitals in a number of cities were alerted for possible arrivals of plague-infected patients.

    The incidence in Surat had large impacts on other major cities of India. In the capital of New Delhi, the lack of public information on how to deal with the spread and contamination of the plague resulted in a rush for surgical masks, tetracycline, and quick remedies. As a precaution, the administration ordered the closure of all schools and public entertainment places. This action alarmed many people; some chose to stay indoors and others who ventured out did so with masks covering their faces.

    It is estimated that as a result of the plague businesses in Surat city incurred losses of over US$260 million because the episode occurred just before the major Hindu festival Deepawali, when business sales usually reach a peak. In addition, one of India's major markets (agricultural exports) was jeopardized by a decision by the United Arab Emirates to suspend all cargo transshipment from India. For example, 500,000 tons of Indian fruit is shipped daily to the United Arab Emirates.

    The incident also resulted in the loss of investor confidence. In London, Global Depository Receipts (GDRs) crashed after the BBC and CNN media agencies reported on the plague situation. In the local stock exchange, agricultural exporters saw their share value tumble. An official tour of India by the Mauritian minister for Tourism was postponed. Foreign journalists and tour operators were offered free travel and hospitality to assess the situation for themselves, but few responded.

    Several countries imposed plague-related travel restrictions on Indian travelers. For example, Indians traveling to the US from plague affected areas had to fill out special forms upon arrival. Aircraft were fumigated on arrival at airports in Rome and Milan and passengers were subjected to special health checks. In Moscow, authorities ordered six-day quarantines for passengers from India and banned travel to India. In addition, an estimated 25% of the passengers between India and the Gulf region who are job seekers were stranded; many had their visas extended but the delays in their departures resulted in a loss of jobs to nationals from other countries.

    Several other decisions and actions influenced societal responses to this event. Health officials in Surat city declared a plague epidemic before it was known if the plague was pneumonic. Authorities are required to report the first cases of plague, but the declaration of an epidemic caused panic. Daily statistics about suspected cases provided by the official agencies added to a mountain of misinformation. The Union Health Minister did not issue any statements to clarify the situation or to calm the country’s or international community's anxieties. Press statements issued by local politicians also did not help the situation. For example, at the time when the plague was considered to be at its peak, the Chief Minister of Gujarat claimed that the plague in Surat was pneumonic and not bubonic, perhaps not realizing that pneumonic plague is more infectious than bubonic plague. To emphasize his point he quoted that "rat fall" (a technical definition indicating large numbers of deaths of domestic rats) in Surat was not very high.

    The local and international media also played an important role in this case. Local newspapers reported highly exaggerated death tolls. Many official press statements were reproduced without assessing the accuracy of the information they contained. International media only added to the confusion. For example, a foreign journalist reported in the Independent, London that efforts to halt the plague were hampered by the Hindu's veneration of the rat!

    Failure of monitoring systems undoubtedly contributed to the spread of the plague. Rat surveillance units that monitor "rat fall" in various districts had been dismantled in 1987 in the state of Maharashtra, where the first case of bubonic plague was reported. Financial constraints and prioritization of limited resources was a major reason for closing the surveillance units. Urban health infra-structure was poorly maintained, and its decay over a period of time resulted in the public’s increased susceptibility to various health hazards. Public health facilities had not kept pace with demand. Because of poor financial capacity, municipal corporations were not able to respond effectively; no emergency plan to deal with such situations had even been prepared.

    As this case study shows, this plague outbreak had severe economic, social, and political impacts. Although the spread of the plague was contained effectively in spatial and temporal terms, societal responses resulted in higher order consequences.