The Lancet published this article on January 24: Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. It's caused some online consternation because it says the index case of this outbreak was not the dealer at the seafood market. I feel some of that consternation too. Here's the passage in question, with my bolding:
27 (66%) patients had direct exposure to Huanan seafood market (figure 1B). Market exposure was similar between the patients with ICU care (nine [69%]) and those with non-ICU care (18 [64%]). The symptom onset date of the first patient identified was Dec 1, 2019. None of his family members developed fever or any respiratory symptoms. No epidemiological link was found between the first patient and later cases.So the unlucky dealer was just the first death in this outbreak. The real index case seems to have been an innocent bystander, who caught the coronavirus from an unknown source and failed to pass it on to any of the other 40 cases in this cohort.
Presumably this case was hospitalized and tested like all the others, but as a total amateur I'm naively surprised that the case vanishes from the rest of the report. We don't even know if he is alive, dead, or still in hospital. They couldn't find an epidemiological link to the other 40 cases, and apparently they have no idea where and how he might have been infected.
But his symptoms began on December 1, presumably weeks before the dealer fell ill, and the world didn't know about the outbreak until the very end of the month.
It's a tribute to Wuhan's healthcare system that, in the winter flu season in a city of 11 million, doctors noticed this one case, tested it, and found something new. They may well have thought it was a one-off, for a week or two, until other cases including the dealer and his wife turned up. But they did tie later cases to that unusual December 1 case, and linked them all into a 41-case cohort.
I have to wonder: What the hell happened to the index case? And why didn't the authors of this crucial report deal with the outcome of that case, or try to find its origin? If Huanan Market was just one source out of two or more, we are in a very different outbreak from the one we thought we were.
Again, I'm a total amateur. Maybe I haven't read the Lancet report properly, and the explanation is painfully obvious to a knowledgeable person. If so, I'd be grateful if one of the professionals would point out that explanation.
Postscript: A commenter points out that I was mistaken when I said "they did tie later cases to that unusual December 1 case, and linked them all into a 41-case cohort." Good point. The researchers didn't "tie later cases" to the first one, but they do seem to have lumped him in with the rest of the later cases.
Another commenter links to a FluTrackers article suggesting that the virus strains found in the first 41 cases appear to have had a common ancestor as recently as November 2019. That certainly agrees with the first case showing symptoms on December 1.
Rereading the article and scanning the supplementary material, I find no reference to case #1 apart from that one sentence: no discussion on where or how he might have contracted that newly mutated coronavirus, what his specific symptoms were, what treatment he received, or when he recovered (a graph suggests that he did recover, unlike the Huanan dealer, who began showing symptoms on December 10). But he is certainly the survivor the authorities should be interviewing repeatedly about his whereabouts in the second half of November.
