Hurricane victims face new microbial threat: mold

As if it wasn’t bad enough already…

Mold now forms an interior version of kudzu in the soggy South, posing health dangers that will make many homes tear-downs and will force schools and hospitals to do expensive repairs.

It’s a problem that any homeowner who has ever had a flooded basement or a leaky roof has faced. But the magnitude of this problem leaves many storm victims prey to unscrupulous or incompetent remediators. Home test kits for mold, for example, are worthless, experts say.

Don’t expect help from insurance companies, either. Most policies were revised in the last decade to exclude mold damage because of “sick building” lawsuits alleging illnesses. Although mold’s danger to those with asthma or allergies is real, there’s little or no science behind other claims, and a lot of hype.

Even for those whose homes were spared the worst of the devastation, the mold problem might be too great for them to be habitable again. As anyone who’s dealt with mold clean-up knows, it’s a huge pain in the ass, and if you miss just a little bit it can come back with a vengeance.

Emergence of canine influenza

Canine flu strikes in Westchester county, NY.

A NEW strain of influenza that began infecting dogs in Florida early last year has recently struck hard in the Westchester area, forcing the temporary closure of two kennels after more than 100 dogs being boarded there became ill, veterinary officials say.

Gracelane Kennels in Ossining underwent decontamination after a viral illness infected dogs. Eddie Loga hoses down a run at the kennel. Although prepared for the less-virulent kennel cough, boarding sites have been blindsided by the new virus.

At least one of the dogs has since died. The two sites, Gracelane Kennels in Ossining and a branch of Best Friends Pet Care in Chestnut Ridge in Rockland County, have undergone decontamination procedures.

The symptoms mimic those of bordetella, a less virulent illness commonly known as kennel cough, for which all dogs must be vaccinated before they are boarded. Health officials fear that this similarity has contributed to underreporting of the spread of the new illness, both locally and nationally.

There is not yet any vaccine for the new virus, which is believed to have jumped from horses to dogs last year.

This once again shows how badly we need good surveillance for zoonotic diseases. Here we have an influenza strain that’s already jumped species, is likely causing more illness than is being attributed to it, and has been shown to be potentially lethal in the new population. I’ve no doubt that similar events are happening all the time, and we’re missing them–and therefore, missing chances to intervene before they become established in the new population. But I guess, why pay for public health funding, when there’s wars to be fought?

Edited to add: Previous article.

The virus, which scientists say mutated from an influenza strain that affects horses, has killed racing greyhounds in seven states and has been found in shelters and pet shops in many places, including the New York suburbs, though the extent of its spread is unknown.

How many dogs die from the virus is unclear, but scientists said the fatality rate is more than 1 percent and could be as high as 10 percent among puppies and older dogs.

They say it’s killed greyhounds in Iowa as well…first I’ve heard of it. Which again underscores that folks in veterinary public health need to be in better touch with those of us in human public health as well.

Dobzhansky and anthrax

The Washington Post today reminds us that there has been little progress in uncovering the source of the 2001 anthrax attacks. [1]

First, a disclaimer. I’m not an “evolutionary biologist,” per se. I have what is I swear the longest job title ever–molecular infectious disease epidemiologist. As such, I often get asked, “what’s the relevance of evolution to your work?” Or, I’ll read editorials such as Dr. Skell’s recently in The Scientist [2] questioning the use of evolutionary theory in experimental biology, and be disheartened. Yet the method of investigating the anthrax attacks shows once again just how relevant evolutionary theory is to all areas of biology, and how Dobzhansky’s famous “Nothing makes sense…” comment once again ring true.

There are several clues regarding the 2001 attack (for those unfamiliar with the story, the background can be found here) [3]. Some are in the packaging of the material: the writing on the envelope, the location of the postmark, the mailbox where the letters were dropped. Others are in the processing of the anthrax: the spores were finely milled, so as to be more easily aerosolized. Finally, there are clues in the bacteria themselves: in their genetic makeup. Early on, they looked at the molecular profiles of the anthrax and compared them to known strains, zeroing in on the Ames anthrax strain.

This is a good thing, because the Ames strain is fairly rare in nature–making it more likely that the anthrax was obtained from a laboratory. The problem with anthrax, however, is that as a species, it is very homogeneous: there isn’t a lot of variation in the DNA sequence. Fingerprinting techniques like pulse field gel electrophoresis (PFGE), which uses restriction enzymes to cut the bacterial chromosome into smaller pieces to be run out on agarose gels, work well for pathogens like E. coli and Staphylococcus aureus, but isn’t nearly as useful in anthrax due to the low level of sequence diversity. This makes it necessary to use more sensitive techniques to identify the bacterium, bringing us back to the characterization of the 2001 bioterrorist strain as the Ames anthrax strain.

What is the “Ames strain,” exactly? In a 2001 Science article [4], it was noted that

Over the past 2 decades, the U.S. Army Medical Research Institute of Infectious Diseases [USAMRIID] in Fort Detrick, Maryland, sent the Ames strain to several research labs. And as it was passed around and grown in different labs, it may well have accumulated minute new changes.

Researcher Martin Hugh-Jones noted, “The Ames strain can be many different things. A very detailed fingerprint could reveal very very minor variations.”

Therefore, it’s the accumulation of these mutations–from a common ancestor, the original “Ames strain” (sound familiar?)–that may allow for a more specific determination of the origin of the 2001 strain, shedding light on the most notable biocrime in recent history. I’ve not seen a published comparison of the whole genome sequences of the various Ames strains, but that seems like the logical way to proceed in this (apparently stalled) investigation–go right back to that “useless” evolutionary biology to save the day.

References

[1] Lengel, A. “Little progress in FBI probe of anthrax attacks.” Washington Post. September 16, 2005.
[2] Skell, PS. 2005. “Why do we invoke Darwin? Evolutionary theory contributes little to experimental biology.” The Scientist. 19:10.
[3] http://en.wikipedia.org/wiki/2001_anthrax_attack
[4] Enserink, M. 2001. “Taking anthrax’s genetic fingerprints.” Science: 294; 1810-2.