To epidemiologists, does “index case” and “patient zero” both mean the same thing? That the patient is the very first person to contract the virus before it got to other people (used as a pinpoint)?

167 views

To epidemiologists, does “index case” and “patient zero” both mean the same thing? That the patient is the very first person to contract the virus before it got to other people (used as a pinpoint)?

In: 39

3 Answers

Anonymous 0 Comments

It was never a zero. The label was actually patient “Oh” like the letter. It stood for outside. as in the case came from outside of the state that was doing the investigation.

>William Darrow, the CDC investigator who was eventually able to expand the Los Angeles cluster to connect forty cases in several cities, has repeatedly maintained that the study was always meant to investigate the transmissibility, and never the origin, of the newly recognized syndrome. He acknowledged in a 2008 interview that the term “patient O”—the letter “O” abbreviating the patient’s “Out[side]-of-California” residential status—evolved within the CDC to become the numerical “patient 0.” Nevertheless, Darrow downplayed the more capacious definitions associated with the word “zero”:

[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4046389/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4046389/)

It’s become a slang but isn’t used in epidemiology, which I do for a living.

The index case is first case noticed that started the investigation. It doesn’t have anything to do with who got it first. Pathogens don’t usually leave easy traces. So finding the true first person to catch a virus is practically impossible.

I use evolutionary analysis to compare virus genomes and given enough samples you can come up with a timeline of how the virus is evolving. You can place the pathogen roughly along that timeline but you would need extraordinary luck to find the true person where a particular mutation took place. Even then you wouldn’t be able to tell if the mutation happen in them or if it happened in a previous case. It can take some time for a mutation to come to prominence in a pathogen population.

You are viewing 1 out of 3 answers, click here to view all answers.