The bubonic plague is an ancient disease caused by fleas that carry Yersinia pestis, the bacterial cause of the plague to a common black or brown house rat (also called a ship rat or plague rat).  When a rat dies, fleas leave to find another living rat and if there is no rat a human will be another host.  The origin of the plague thought to have originated from Himalayan borderlands between India and China.  It was generally believed that plague escaped its Asian confines in the 6th century and marched westward.  The Justinian plague lasted from 542 CE to around the middle of the 8th century.  The buboes are tell-tale signs of the plague and lymph nodes swell to the size of an egg or even an orange.  Infection can be septicemic or it can reach the lungs which is called pneumonic.  Emperor Justinian contracted the disease but survived and the plans for uniting western and eastern portions of the Roman Empire were shattered due to reduced manpower.  The overall mortality estimated at 100 million for the two centuries the plague persisted.

The Jews were blamed for the Black Death and the first use of the maritime quarantine was in 1377 in the Venetian colony of Ragusa.  The Boards of health oversaw isolation of the sick quarantine of exposed individuals, management of medical and burial services along with record keeping.  Networks of spies were made to provide an intelligence surveillance system.  The first permanent plague hospital was opened by the Republic of Venice in 1423 on the small island of Santa Maria di Nazareth.  The initial outbreak of the modern plague was in Yunnan province of China in 1855.  By 1894, plague spread to Hong Kong killing over 2400 in two months and then it spread to India by 1896.  In a 30 year period, more than 12 million died in India, Pakistan, Bangladesh, and China.  British Indian Plague Commission proved rat’s role in transmission but assumed that rat to rat transmission occurred through rats eating their fallen comrades.  They speculated that poor sanitation was to blame so their response was draconian.  This included extreme isolation of victims and contacts, clothing and cadavers were burned, and houses were fumigated and slums razed.  In 1899, the plague reached the Hawaiian islands.  The first evidence of the disease was found in Honolulu’s Chinatown on Oahu.  The Board of Health’s solution was to burn down any buildings in Chinatown suspected of containing a source of the disease.  The original plan was to burn down only a few targeted buildings but the fire got out of control causing many of Chinatown’s homes to be destroyed with an estimated 4,000 people left homeless.  Australia suffered 12 major plague outbreaks between 1900 and 1925 originating from shipping.  Research by Australian medical officers Thompson, Armstrong and Tidswell contributed to understanding the spread of Yersinia pestis to humans by fleas from infected rats.

The plague was first introduced into the United States in 1900 by rat-infested steamships from affected areas, mostly from Asia.  Epidemics occurred in port cities.  The last urban plague epidemic in the U.S. occurred in Los Angeles from 1924 through 1925.  Plague then spread from urban rats to rural rodent species, and became entrenched in many areas of the western U.S.  Plague mostly occurs as scattered cases in rural areas.  Most human cases in the U.S. occur in two regions which are Northern New Mexico, northern Arizona, and southern Colorado, California, southern Oregon, and far western Nevada.  During plague epizootics, many rodents die, causing hungry fleas to seek other sources of blood.  People and animals that visit places where rodents have recently died from plague are at risk of being infected from flea bites.  Dogs and cats bring plague-infected fleas into the home.  Flea bite exposure results in primary bubonic plague or septicemic plague.  Humans can become infected when handling tissue or body fluids of a plague-infected animal.

Plague is now commonly found in sub-Saharan Africa and Madagascar, areas which now account for over 95% of reported cases.  Political upheaval coupled with drastic cuts in foreign assistance crippled basic government services. Millions of people were in poverty, hundreds of health clinics were closed, investments in clean water and infrastructure nose-dived, hygiene is poor.  Burial practices involve unburying the dead to consult with them when necessary.  Plague victims must be buried immediately to prevent spread of disease.  Families anticipating not being able to bury family members will decide not to bring their relatives to a hospital at all.  Options for rural population: city hospital or traditional healers, who use hand mirrors to seek advice from ancestors.  Healers have used spit to “cure” patients and claim they can fix any ailment.  In villages, people keep their cattle, chickens, and crops inside their homes to keep them from being stolen.  This attracts rats, which carry the fleas.  In the rainy season, outbreaks occur.  The rat populations decrease but flea counts increase.