Animals

Those of you who follow our Facebook page have noted several recent stories on the zoonotic disease front. New human cases were reported of the influenza A (H3N2) variant, a swine virus that thus far appears to cause mild disease and has limited-to-no transmissibility from human-to-human (virtually all cases have been among those with direct pig contact, often at summer fairs). Meanwhile, an avian H3N8 strain was reported to be the cause of a recent fatal outbreak of pneumonia among New England harbor seals—whenever an avian strain demonstrates adaptation to a mammalian host, it is cause for concern. This development further stresses the importance of open and transparent work to understand the key features of virulent influenza strains that predict human infection and transmission (in other words, lift the “voluntary moratorium”). Finally, we have a very provocative report suggesting that rabies virus exposure, at least in remote communities in the Peruvian Amazon, may not always result in infection and death. Rabies is notorious for having a human fatality rate approaching 100%, with very few reports of survival after clinical infection. It is surprising, then, to find evidence for nonlethal rabies virus infection among those with bat exposure and no history of vaccination. Too soon, really, to determine if this finding is explained by unique genetic-immunologic characteristics of this remote population, or if there are other mechanisms of nonlethal exposure that have not yet been identified.

While we are on the topic, I’d like to plug my favorite blog about infections in animals, Worms and Germs, by Drs. Scott Weese and Maureen Anderson of the Ontario Veterinary College's Centre for Public Health and Zoonoses.

Novel H3N2 Influenza in Iowa: More bad news from pig country

PIGS: Portugal, Italy, Greece and Spain

When it rains, it pours.  Dr. Patricia Quinlisk, medical director for the Iowa Department of Public Health, announced today that a novel H3N2 influenza A strain had infected three Iowa children.  Evidence points to one child transmitting the virus to the other two. There have been seven prior cases of this strain, all in the US (Maine, Indiana and Pennsylvania) and all apparently linked to animal exposure, which makes the Iowa cases unique. All but one case has been in children under 10 years old, suggesting prior year exposure to H3N2 might be protective. Perhaps it's ironic that this novel swine strain was first transmitted from human-to-human right here in pig country.

Sources: Des Moines Register 11/22/2011 and Winnipeg Free Press 11/22/2011

Addendum: Iowa just added 2,300 jobs, which I think is about double our human population.  I think two job seekers family members (update:  actually just in for Thanksgiving) from other states even moved in with Dan this past weekend.  Getting crowded here, which might be increasing the flu transmission.

Actual update on the virus: "In these ten most recently reported cases, the virus has been a swine H3N2 virus with the M segment gene borrowed from the 2009 H1N1 virus. Essentially a hybrid – a new reassortant virus - that until this summer had not been seen before." source: Avian Flu Diary

Swine flu & conflict of interest

There is an interesting editorial in this month's Journal of Public Health that looks at conflicts of interest with regards to the swine flu pandemic. The author briefly describes some examples of organizations that manage financial and intellectual conflicts quite well. It's worth reading and the full text can be viewed here.

Swine flu mortality estimate

The New York Times reports this morning that CDC has revised its estimate of deaths due to swine flu in the US at 4,000. The revision now will make the swine flu mortality estimate more comparable to the mortality estimate for seasonal flu, which on average is about 36,000 persons yearly in the US.

Swine flu and the blood supply

The Wall Street Journal reports today that blood banks are facing shortages of blood products because blood drives have had fewer donors due to illness from swine flu. On top of that, donors are instructed to call the blood donation center if they develop illness in the few day period following donation and the blood is destroyed.

I'll beat a dead horse...

See here for CNN's coverage of the swine flu mask debacle, which is well written and a primer for anyone who hasn't been following the debate.

H1N1 myopia not uniquely American

I've blogged before about the H1N1 frenzy in US hospitals. Today I was accompanied on Infectious Diseases Consultation Service rounds by the Chief of Infectious Diseases at one of India's largest hospitals. He was lamenting the fact that such a large proportion of his time recently has been spent on H1N1 planning. And he brought it all into perspective when he said "I'm more worried about the 30 patients with cholera in my Emergency Department."

Is the H1N1 vaccine the new smallpox vaccine?

You may recall the ambitious public health campaign several years ago to vaccinate over 400,000 Americans against smallpox. It was a huge failure, meeting only about 10% of its target. A new paper in Biosecurity and Bioterrorism, reporting on a national survey done in June 2009, suggests that the H1N1 vaccine may be headed for the same fate. Respondents were asked whether they would be willing to receive an H1N1 vaccine approved under Emergency Use Authorization by the FDA. Only 9% of the sample reported that they were willing to receive the vaccine. Although it is important to note that the soon-to-arrive H1N1 vaccine is not being released under Emergency Use Authorization, I suspect that the public won't make the distinction. Interestingly, willingness to receive the vaccine was lower in higher income groups and those with higher educational attainment. Moreover, over half of those individuals who get the seasonal flu vaccine yearly reported they would not take the H1N1 vaccine. (Anecdotally, we are hearing the same from many of our healthcare workers who regularly accept the seasonal vaccine). What should be most worrisome to the CDC is the survey's finding that a sizable fraction of the population does not trust the government's messages or its competence to manage the H1N1 epidemic.

Let's get a grip....

For this hospital epidemiologist it looks like this will turn out to be another week consumed by H1N1. The number of questions regarding who to test, who to treat, how to isolate, and which mask to wear seem to be accelerating. And in the midst of this pandemonium, there is something discomforting about all of this that makes me wonder whether my reality testing is intact. Whenever I get those feelings, I head for the data so that I can determine if I have lost my mind. So below are two important graphs from the most recent data release from CDC (week ending September 5):

In a nutshell, outpatient visits for influenza like illness are higher than expected for this time of year, while deaths due to pneumonia and influenza are lower than expected. That's right--lower than expected! Thus, we have lots of people with mild disease. We're acting as if this has never happened before, and as Dan noted in an email to me earlier today, that we have to create a zero-risk environment for this mild infection. Meanwhile, the usual work we do to prevent important healthcare associated infections with high attributable mortality is set aside, so we can respond to the H1N1 "emergency." But in a world of 24/7 news and daily CDC teleconferences, is it any wonder that we find ourselves in this situation?

OK, I'd like to write more but it's time to get ready for my next H1N1 meeting...

New predictions for H1N1 activity

There's a very interesting new paper in BMC Medicine that uses sophisticated modeling to predict influenza activity for the upcoming flu season. Here is what the model predicts for the US:

• The peak of flu activity will occur between late September and early November
• At the peak of the epidemic, 1% of the population (3 million people) will become infected daily
• By October 15, the US will have had 5-30 million cases of influenza
• Each person infected with influenza will infect on average 1.75 other people

Unfortunately, the model predicts that the arrival of the H1N1 vaccine will be too late to have a great effect on the epidemic. However, the model also predicts that if 30% of cases could be treated with antivirals, the peak of the epidemic could be shifted forward in time by about 4 weeks, in which case the vaccine would have a much greater impact.

We'll know soon how accurately the model predicted reality. 

A must-read for germophobes

For those of you who are really worried about swine flu, today's New York Times has an interesting article and video of Ariel Kaminer, the Arts and Leisure editor, going about the city in full personal protective equipment--a jumpsuit, mask, gowns and goggles.

Photo:  Patrick Andrade for the New York Times

Potential new option for treatment of severe swine flu

A new case report in Lancet documents the first use of IV zanamivir in a patient with respiratory failure from H1N1. Sequential testing of the H1N1 viral load in bronchoalveolar lavage fluid suggests that the novel therapy was effective after trials of oral oseltamivir and nebulized zanamivir were not. Of course, as I teach our first year medical students in their epidemiology course, case reports are prone to over-interpretation. Nonetheless, given the dearth of therapeutic options for patients with severe manifestations of H1N1, this new option deserves further study.

H1N1 on campus: Club Swine

The front page of this morning's New York Times has an article about quarantine dorms for students with swine flu on college campuses. I have been receiving calls from our University Health Service and will spend several more hours this week working with university administrators on additional planning for swine flu. A number of questions keep circulating in my mind: How much of this planning activity is driven by continuous media reports? Would this have happened 10 years ago? Could our time be used more wisely? How much planning can be done for a disease that is so unpredictable?

So to ensure that my reality testing is intact, I again reviewed the latest CDC surveillance data. In a nutshell, here are how things stand:

• Since mid-April there have been 9,079 hospitalizations and 593 deaths (in a typical flu season there are on average 226,000 hospitalizations and 36,000 deaths)
• During this influenza season there have been 111 flu-related deaths in children, over half of which were due to seasonal strains (in a typical season there are on average 92 deaths in this group)
• Only 1 of 10 national regions currently has an elevated incidence of outpatients with influenza-like illness (ILI)
• For the most recent week reported (ending August 29), the proportion of deaths attributable to pneumonia and ILI were below baseline levels
• 97% of subtyped viruses in the most recent reported week were H1N1

Now back to the situation on college campuses. If you consider that students are likely infectious one day before onset of symptoms, that some symptomatic individuals will ignore recommendations and continue with their normal daily activities, and that social distancing is essentially abnormal behavior in college, does it make sense to attempt to control transmission of swine flu by setting up quarantine dorms? Could it be that doing so may prolong the outbreak on any given campus? Since in the vast majority of students the acuity of disease is about the same as a bad cold, does any of this make sense? If we knew that a vaccine would be available tomorrow, then quarantining students might be a reasonable idea, but since the vaccine is weeks away at best, it's likely that any college community with disease activity today will already have high levels of H1N1 antibody by the time the vaccine arrives.

When the H1N1 epidemic is over it would be interesting to know the opportunity cost for hospital infection control programs. Since these programs run with fixed resources, which in most hospitals are likely inadequate at baseline, diversion from our normal work to plan, and plan, and plan some more for H1N1, is likely to result in more healthcare associated infections.

IOM & face masks: Efficacy vs effectiveness

Yesterday's report from the IOM on respiratory protection for healthcare workers against H1N1 was quite disappointing. Unfortunately, IOM evaluated the question from the standpoint of efficacy (how well an intervention works in an ideal setting) rather than one of effectiveness (how well an intervention works under real world conditions). Effectiveness takes into account compliance, which is likely to be an issue when levels of disease activity rise and healthcare workers spend more of their day wearing a mask. But more importantly, the current supply of N95 masks appears to be insufficient for them to be used when encountering all patients with suspected swine flu. I don't disagree with IOM's conclusion that N95 masks are more protective then standard masks, but to ignore logistics and practicality when making a recommendation is of little help to those of us in the trenches. I received several emails yesterday from hospital epidemiologists at academic medical centers who stated they would not follow the IOM recommendation but continue with SHEA's recommendation (i.e., use of a standard mask except for aerosol generating procedures).

CDC press conference

Well, I got nothin' from that.......the CDC apparently doesn't want to talk about the IOM report until they have more time ("days to weeks") to study it. I can summarize it for them, if it would help: we think health care workers should wear properly fitted N95 masks while providing care to patients with known or suspected novel H1N1 infection. Also,.......more studies are needed.

There.

IOM report out

And a CDC press conference is about to begin. As expected, the IOM endorsed the use of N95s for care of patients with suspected H1N1.....

IOM report

Looks like it will be later today or tomorrow before we know the details of the IOM recommendations to CDC regarding personal protective equipment for care of patients with suspected novel H1N1. I’ll wait to comment until those details are available. If, as expected, IOM supports the current CDC position, it will be interesting to see how the state departments of public health will react, at least in states that have gone with the WHO guidance until now. It will also be interesting to see if future CDC guidance for seasonal flu includes recommendations for N95 masks—or will we have to individually assess each individual influenza strain in the future, to determine exactly what PPE is required?

Wow

Just heard through the grapevine that the IOM is going to support the CDC guidance about respiratory protection for novel H1N1....which means using an N95 for all patient contact when H1N1 is suspected (i.e. everyone with febrile respiratory illness!). I'm in clinic right now, but I'm sure Mike and I will have much more to say about this later......

Refusal to care for H1N1 patients?

I hope this doesn't become a trend. A recent entry on the Emerging Infections Network listserve describes ICU nurses refusing to care for very sick H1N1 patients, requesting reassignment for fear of contracting the virus. From the listserve responses so far, this appears to be a rare phenomenon, fortunately.

This is an interesting counterpoint to the finding Mike previously highlighted, of healthcare workers suggesting that they would refuse the vaccine! It is often interesting how people perceive risk, and what behaviors they choose to reduce that risk. Education will be key throughout this respiratory virus season—provide healthcare workers with the information and tools they need to protect themselves, and support them fully after any documented exposure. For those with valid concerns about the consequences of H1N1 acquisition (e.g. pregnancy, other high-risk condition), I believe counseling about risk, and case-by-case accommodation (including potential reassignment) is the correct approach.

Hong Kong Healthcare Workers: We're Not Gonna Take It

A new study in the BMJ, which surveyed a large number of healthcare workers in Hong Kong, found that less than half of them would accept the swine flu vaccine. This is particularly interesting given that the survey was performed in May 2009 at the height of the panic about the disease and also because Hong Kong was the epicenter for the SARS epidemic several years ago. The investigators believe the findings are applicable in other countries. Reasons given for refusing the vaccine are familiar--fear of side effects and questions of efficacy.