Index case

The index case or patient zero is the first documented patient in a disease epidemic within a population,^[1] or the first documented patient included in an epidemiological study.^[2] It can also refer to the first case of a condition or syndrome (not necessarily contagious) to be described in the medical literature, whether or not the patient is thought to be the first person affected. An index case can achieve the status of a "classic" case study in the literature, as did Phineas Gage, the first known person to exhibit a definitive personality change as a result of a brain injury.^[3]

"Patient zero" redirects here. For other uses, see Patient zero (disambiguation).

("Typhoid Mary") was an index case of a typhoid outbreak in the early 1900s. An apparently healthy carrier, she infected at least 47 people while working as a cook. She eventually was isolated to prevent her from spreading the disease to others.^[30]

Mary Mallon

The first recorded victim of was a 44-year-old schoolteacher named Mabalo Lokela, who died on 8 September 1976, 14 days after symptom onset.^[31]

Ebola

64-year-old , a Guangdong doctor, transmitted SARS internationally by infecting other super-spreaders during a stay in the Hong Kong Metropole Hotel in 2003.^[32]^[33]

Liu Jianlun

A baby in the Lewis House at 40 Broad Street, named Frances Lewis, is considered the index patient in the in the Soho neighbourhood of London. (The Ghost Map, Steven Johnson, 2005.)^[34]

1854 cholera outbreak

Édgar Enrique Hernández may be patient zero of the .^[35] He recovered, and a bronze statue has been erected in his honor.^[36] Maria Adela Gutierrez, who contracted the virus about the same time as Hernández, became the first officially confirmed fatality.

2009 flu pandemic

One-year-old is believed to be patient zero in the 2014 Ebola epidemic in Guinea and West Africa.^[37]

Emile Ouamouno

51-year-old Jesus Lujan was the index case of the which killed 33.^[38]

1924 Los Angeles pneumonic plague outbreak

As for the , there are many known "patient zeros" across the world known for different symptoms and stories. Out of Los Angeles, patient zero Gregg Garfield spent 64 days in the hospital, including 30 days of coma-state after contracting the virus on a ski trip. Doctors said he had a 1% chance to live. He survived, but had fingers and toes amputated.^[39]

COVID-19 pandemic

Another patient zero of the COVID-19 pandemic includes an elderly man who was diagnosed on 1 December 2019, someone who had no contact with the . Three other people experienced symptoms in the following days who also did not have contact with the Market.^[40]

Huanan Seafood Wholesale Market

Non-medical usage[edit]

The term is used to identify the first computer or user to be infected with malware on a network, which then infected other systems.^[15]^[41]

Monica Lewinsky has described herself as the "patient zero" of online harassment, meaning that she was the first person to receive widespread public harassment via the internet.^[42]

– person who undergoes an examination or is the subject of a medical genetics study

Proband

– Misinformation about the HIV/AIDS and its spread

Misconceptions about HIV/AIDS

Scapegoating

. orgnet.com. Orgnet. Retrieved 2010-11-03.

"Mapping the Spread of Viruses / Contagions via Contact Tracing"

.

Letter to the New York Review of Books (vol. 35, number 19, December 8, 1988) by Dr. Andrew Moss, Dept. of Epidemiology and International Health, San Francisco, regarding the “patient zero” myth

"". Radiolab. Season 13, Episode 3.