[4] Public health officials credited the lessons learned from the San Francisco outbreak with saving lives, and swiftly implemented preventative measures, including hospitalization of the sick and all their contacts, a neighborhood quarantine, and a large-scale rat eradication program.

[4] At the time, Los Angeles, being the largest city on the West Coast and the fifth-largest in the country, was growing on an economy primarily reliant on its flourishing tourism industry, a "land boom," and a new harbor.

[10][15] Many papers rarely bothered to report on the area and when they did it was to describe crime or recount comical tales of citizens chasing chickens around Clara Street.

A physician initially diagnosed Lajun's pneumonic plague as a venereal disease (sexually transmitted infection), due to his enlarged lymph node.

[18] As Lajun's condition worsened, he developed extreme symptoms such as bloody sputum, causing physician to believe it converted into pneumonic form.

[19][20][21] Dr. Porter initially diagnosed Lajun's plague as a venereal disease, or sexually transmitted infection, due to his enlarged lymph node.

[25] On October 26, Guadalupe Flores died and received an autopsy by pathologist Lawrence Parsons, who misruled his cause of death as double pneumonia.

No bacterial culture was conducted to correctly identify the cause of his pneumonia as Yersinia pestis, the causative agent of the pneumonic plague.

[32] That same day, brothers Mike and Jose Jiminez also fell ill and vacated 742 Clara Street, the residence of the Samaranos, exposing the rest of the district to the plague.

The Samaranos' children, Alfredo, Gilberto, Raul, and Roberto, along with six others, were hospitalized and diagnosed with meningitis, despite their skin turning black, a pathognomonic symptom of the plague.

[2] Thirteen more cases of an unknown disease were admitted, all of whom developed cyanosis and hemoptysis, or bloody sputum,[4] the former of which is indicative of low oxygen saturation of tissues near the skin surface.

Mulford Company laboratories in Philadelphia, a 3,141-mile journey which would require automobile transport to Mineola, New York then a flight by mail plane to Los Angeles with a stopover in San Francisco.

[39] The guards ruled vigilantly in the quarantined district and shot stray dogs, cats, chickens, and more in an attempt to eradicate animals that could potentially be plague-infected.

Recommend federal aidCumming then alerted Senior Surgeon James Perry, who was then stationed in San Francisco, to confidentially investigate the outbreak, attempting to avoid gratuitous involvement in state and municipal affairs.

[43] A temporary laboratory was constructed by the Los Angeles City Health Department in the quarantined area to quickly identify new cases.

Los Angeles authorities racially quarantined Mexican homes outside of the Macy Street District as well as majority African American, Chinese, and Japanese neighborhoods.

Before the antiserum was used on Mary Costello, she endured intravenous injections of mercurochrome because it was believed that the compound was a way of sterilizing the body's infected blood and other maladies.

That same day, El Heraldo de México became the first local newspaper to transparently report on the outbreak, revealing that the plague spread by rat fleas, not pneumonia, was its cause.

[3] On November 14, a man named Martin Hernandez, who did not live anywhere near the Macy Street District, died of the plague; his case was not reported to any authorities.

Because it is highly infective and can be stored in large quantities, there is a concern that it could be dispersed in a form that is resistant to desiccation or foreign environmental conditions.

[56] The pneumonic plague primarily affects the lungs, and common symptoms include fatigue, fever, and pneumonia, the latter of which in turn can cause chest pain, coughing, hemoptysis (bloody sputum), and shortness of breath.

[59] The pneumonic plague is diagnosed after evaluation by a healthcare worker and a laboratory test of the patient's blood, lymph node aspirate, or sputum confirms infection.

[52] Currently, the pneumonic plague is diagnosed after evaluation by a healthcare worker and a laboratory test of the patient's blood, lymph node aspirate, or sputum confirms infection.

[4] A vaccine to the plague was first developed in 1897 by Waldemar Haffkine who demonstrated that a heat-killed culture of Y. pestis protected rabbits from infection and was later tested in humans in India.

As cases piled up, a telegram sent on October 31 recommended federal aid for the city of Los Angeles, replacing the terms "pneumonic plague", "death", and "situation" with code "ekkil", "begos", and "ethos", respectively.

Secretary of the State Board of Health doctor Walter Dickie conducted a test on a guinea pig with a lymph node sample taken from Jesus Lajun before he died.

Due to cramped and often illegal living conditions, rats were prevalent in majority Hispanic neighborhoods, cultivating the belief that the plague was an ethnic trait, as exemplified in a University of California, Los Angeles professor who claimed that Mexicans have a tendency to "huddle together" and therefore spread disease.

Health officials blamed the plague outbreak on Mexicans' supposed ignorance of proper hygiene, despite actually being the fault of notoriously inferior living conditions and poverty in the Macy Street District.

Some health officials even blamed the outbreak itself entirely on Mexican Americans, which Feldinger argues reinforced the pro-segregation views widely held at the time.

The city lifted houses 18 inches above the ground and ripped off their siding to allow stray cats and dogs to eat infected rats.