Two elite flu reporters, Helen Branswell (Canadian Press) and Declan Butler (Nature), both noted yesterday the dearth of clinic information on the serious and fatal swine flu cases. First Butler:
Clinical researchers have been slow to respond to the 2009 flu pandemic, lament researchers writing in today’s Lancet. “Public health officials, virologists, epidemiologists, and policy makers have done well in responding to a rapidly emerging and complex problem. By contrast, the clinical research community’s response has been delayed and modest, ” writes Jeremy Farrar, a researcher in Ho Chi Minh City, Vietnam and colleagues from Vietnam, the US and Mexico.
They deplore the “lack of information” on the pathogenesis and clinical aspects of those with severe illness, and argue that trials and other clinical research are urgently needed to better understand the disease, and learn of necessary tweaks to treatment regimes. What research is being done isn’t being published fast enough, add Farrar et al., contrasting this with the speedy publication by researchers in other disciplines who have published in fast-tracked journal articles, or shared on public wikis – eg here – in advance of formal publication. Clinical researchers need to “catch up,” they conclude, “To do otherwise would be unethical.” (Declan Butler, The Great Beyond [Nature blog])
I don’t know the slowness is “unethical.” Clinicians in the midst of an outbreak have their hands full managing critically ill patients. Papers don’t write themselves. They require time, effort and spare energy, three things not so abundant in such circumstances.
Branswell offers a view what those circumstances look like and a few hospitals:
In a typical flu season, the Winnipeg hospitals where Dr. Anand Kumar works might see one, maybe two life-threatening cases of viral pneumonia caused by influenza.
So seeing 10, 15 and more flu patients in those same hospitals’ intensive care beds in June is still a shock, suggests Kumar, a critical care specialist who works at three different hospitals in the city.
“You just don’t see this many of them,” Anand says of the patients, struggling to survive swine flu infections.
“You don’t see rows and rows of patients on ventilators because they have respiratory failure, a viral pneumonia kind of thing. It’s unusual.” (Helen Branswell, Canadian Press)
We have no idea how representative this is of ICUs in areas with a lot of circulating swine flu, but this is without dobut an unsettling description. The data aren’t available to calculate hospitalization rates or case fatality rates with any confidence, but the contrast with a regular flu season in this description certainly gives one pause.
At any rate, the clinical spectrum of underlying pathology has not yet been described. It sounds much like the patients that go sour fast are taken down by a rapidly progressive primary viral pneumonia (where the influenza virus infects the cells of the lower respiratory tract). What role, if any, a dysregulated innate immune response (“cytokine storm”) or secondary bacterial infections play we don’t yet know.
I expect we’ll see some published case series relatively soon. Branswell reports the doctors she interviewed have some in preparation. They will almost certainly receive expedited review and publication, as would be appropriate. We’re just two months from initial cases, so it’s not surprising there’s a lot we don’t know about what is happening. But in the same time the virus has spread around the world, continues to circulate during summer months in the northern hemisphere and has established a foothold in the southern hemisphere, at the start of its flu season.
The world of public health is fastening its seat belts. It could be a rough ride. But flu is unpredictable, so you never know. Maybe it will surprise us pleasantly, this time. But I doubt it.