Epidemic anthrax in the eighteenth century, the Americas - Anthrax Perspectives

Emerging Infectious Diseases, Oct, 2002 by David M. Morens

Anthrax has been described as a veterinary disease of minor importance to clinical medicine, causing occasional occupational infections in single cases or clusters. Its potential for rapid and widespread epidemic transmission under natural circumstances has not been widely appreciated. A little-known 1770 epidemic that killed 15,000 people in Saint-Domingue (modern Haiti) was probably intestinal anthrax. The epidemic spread rapidly throughout the colony in association with consumption of uncooked beef. Large-scale, highly fatal epidemics of anthrax may occur under unusual but natural circumstances. Historical information may not only provide important clues about epidemic development but may also raise awareness about bioterrorism potential.

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In late 2001, anthrax bioterrorist attacks in the United States prompted considerable commentary on how little is generally appreciated about the transmissibility of Bacillus anthracis. Textbooks have long described anthrax as a veterinary disease of minor medical importance, attributing most human infections to occupational exposures, now less common in industrialized nations. Because anthrax is usually recognized in single cases or small clusters, its potential for rapid and broad dissemination to humans under natural circumstances has not been widely appreciated. Such a potential would have implications for both epidemics and bioterrorism. (1)

An obscure report claims that an explosive 1770 epidemic of what was called charbon killed 15,000 persons in Saint-Domingue (modern Haiti). The brief description of this epidemic, written by historian Michel-Placide Justin (1), is unknown to most physicians and historians. The epidemic began shortly after an earthquake near Port-au-Prince on June 3, 1770, devastating the city and much of the western end of the island. With bakeries, stores, storehouses, and many or most of the buildings and homes in major towns destroyed, and with the consequent escape of slaves who typically obtained, transported, and prepared food for themselves and the colonists, famine was a serious threat. Trade regulations in force at the time specifically restricted importation of meats or salted fish. Justin describes the situation as follows:

"... The unfortunate slaves in the north of Saint-Domingue therefore experienced the most frightful famine. The dependencies of Fort Dauphin, that of Gros-Morne, [and] of Jean Rabel, were devastated. Codfish being entirely unavailable, the Spaniards, whose hattes [presumably a form of the Spanish "hato", meaning "cattle ranch"] or pastures were being thinned out daily by a terrible epizootic ["epizootie"], sought to salt or smoke all their ill or dead animals; and they [then] brought them into French establishments. These meats, known as tassau in the colonies, which the Negroes avoided eating when they could get [uncontaminated] salted beef and codfish, spread to the slaves the communicable agent ["germe"] of the disease with which they [the meats] were infected ["infectees"]: A type of epidemic disease ["peste"], called anthrax ["charbon"], spread throughout all the neighboring dwellings of the Spaniards or the routes they frequently used, and in those where the Negroes had bought this tassau. Within six weeks, more than 15,000 white and black colonists perished of this terrible disease, and its ravages did not stop until the government, the magistrates, and the inhabitants themselves had joined all of their efforts to repel the scourge introduced into the colony by Spanish greed.

"But the numerous and rapid deaths caused by the disease were not all: at least 15,000 Negroes perished of hunger, and the escape of slaves increased in the northern dependency, causing serious fear for the security of the colony ..." (1)

Although sketchy, this report of possible epidemic anthrax contains interesting details. It notes the precipitating circumstances of an ongoing epizootic and a sudden change in diet to uncooked--smoked or salted--beef. The report also discloses that outbreak investigation linked the distribution of contaminated beef to the geographic spread of human disease. These associations appear consistent with intestinal anthrax, a disease associated with high mortality. However, exact means and determinants of gastrointestinal transmission were not described. Salted or smoked meat likely would have been eaten without cooking, as was then the custom. Since anthrax spores are resistant to 140[degrees]F and to a wide range of chemical treatments, the failure of salting or smoking to destroy them would not be surprising.

Apparently the overall mortality in the epidemic was high, although the figure of 15,000 deaths may have been only an estimate. Vital events data from the epidemic were probably obtained by French officials and sent to Paris, but I am not aware that such data, if they still exist, have been identified by historians. Neither attack rates nor case-fatality rates have been documented from this or similar anthrax epidemics in the same era, although eighteenth-century observers were nearly unanimous in indicating a high or universal death rate from intestinal anthrax.