Bad summer in U.S. for zoonoses

West Nile, Hantavirus, Plague-

A zoonosis is an infectious disease transmitted between species, especially from animals to humans and vice versa. New strains of influenza are usually a zoonosis having emerged from DNA mixing in geese, pigs, birds and the like, but The Wildlife News is generally  concerned with zooneses like Rocky Mountain spotted fever and Lyme disease in they that come from wildlife.

West Nile Virus, Echinococcosis, Giardia, Hantavirus, Bubonic Plague, Brucellosis, Toxoplasmosis, Rocky Mountain spotted fever, and Lyme disease. It it interesting how there is a politics of these diseases with anti-wolf folks worrying about echinococcosis; ranchers ginning up fear about brucellosis; and outdoor enthusiasts worrying about the rest of the diseases listed above. Folks in these groups try to play up fear or downgrade it in order to accomplish other political objectives.

It is doubtful this year that anyone has been infected by Echinococcosis or brucellosis from wildlife, but it has been a record year for West Nile Virus. It has killed 43 in Texas, and 87 nationwide with at least 1,069 neuroinvasive West Nile cases and 924 non-neuroinvasive West Nile cases. You get it from mosquitoes. The risk overall depends on the number of mosquitoes and the percentage of them that are infected.

In terms of the likelihood of getting seriously ill or dying if you contract the disease, hantavirus is more dangerous (36% mortality) of the two, but there are fewer cases of it. However, this summer has seen an unprecedented level of exposure to hantavirus. It came at Yosemite National Park where the structure of rented, already erected tents (Signature tent cabins) facilitated the tents becoming inhabited by the prime host of hantavirus, the “cute” deer mouse (Peromyscus). So far only 3 people have died, but as many as 6000 (some say 12,000) persons might have stayed or entered the Signature tent cabins where the mice found refuge.  The disease does not always develop quickly after exposure.  Five others are currently sick from it, but there could be more. Story: Yosemite extends hantavirus warning; death toll rises. Reuters.

Overall, since the hantavirus pulmonary syndrome (HPS) was identified (1993), there have been 556 cases reported in the U.S.. The mortality rate was 36%. The most cases have been in Arizona, New Mexico and Colorado. California, Washington, and Montana follow. The secret of staying safe is to keep away from deer mouse droppings, and if you clean droppings up, do not sweep them. This makes the virus airborne. The droppings can instead be disinfected by spraying down the area with bleach.

Every year about 10 or 20 people in the U.S. get the notorious “Black Death” (plague). Mortality is about 15%. The Plague is caused by the pathogen Yersinia pestis which seems to have lost some of its “ummphf” since the says when it killed a quarter or so of the population of Europe.

This summer an Oregon man barely survived an infection he got when his cat bite him while it was choking on an infected mouse. He was trying to save the cat. Oregon man recovering from case of the plague. Posted by Cathy McLain. Seattle Times. Meanwhile a Colorado 7-year old girl is recovering from The Plague transmitted to her by fleas that were on a dead squirrel she examined near Pagosa Springs. Fortunately the physician quickly put her symptoms together with the dead squirrel to make the uncommon, but correct diagnosis. Story. Rare Colorado plague case had Girl Scout near death. By Michael Booth. The Denver Post.

In Missouri a new zoonosis has been identified. So far it has infected two men. They barely survived. Named the “Heartland Virus” it is an addition to the long list of diseases passed to humans and other animals by ticks. This time the tick is the Lone Star tick. Other tick borne diseases are Q-fever, Colorado tick fever, Rocky Mountain Spotted Fever, Lyme Disease,  babesiosis , and  ehrlichiosis. Story from the New York Times. New Virus Tied to Ticks Poses Puzzle for Doctors. By Denise Grady.

Of course, Lyme Disease is the most common zoonosis in the United States. Lyme Disease has been increasing over time, though not in a strictly linear trend. Soon (maybe 2012), we will see at least 50,000 cases reported in a year.

Zoonoses have always been with us. On the other hand the number of new ones seems to be growing.  One hypothesis is that environmental disruptions and population migrations play a key role in animal organisms becoming pathogens in new species. Dengue fever has been spreading north due to climate change. Back at the time of the Black Death (peak in Europe 1348-50) the great kill was set in motion by the opening of new trade routes and the infected fleas were carried to and from ships by fleas on black rats.  Famine also helped create a population more susceptible.

With so many changes taking place in our environment and that of all the organisms on the planet, surveillance for upswings of zoonoses is critical, hardly the sort of activity that should be scaled back to save relatively small amounts of money. Nevertheless budgets for the U. S. Center for Disease Control have been cut and are proposed for more cutting. See, US disease agency in fiscal peril. Proposed budget changes threaten disease prevention and surveillance programmes. Nature.
By Michele Simon. Feds Playing Politics With Food Safety Is Enough to Make You Sick. Huffington Post.

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Update: Lyme disease is associated with the small deer tick, and most people assume that an illness after a tick bite is Lyme disease. It turns out now that other ticks, especially in the Southeast are most likely not deer ticks and the illness not Lyme Disease. Research just published in the journal Zoonoses and Public Health indicates the illness is much more likely  to be spotted fever rickettsiosis or ehrlichiosis.  Even that is not certain, however, because climate change is driving Lyme Disease southward while Lone Star ticks which harbor perhaps as many as ten or so tick borne diseases are moving north. Folks should read this article in Science Daily. Precautions for Tick-Borne Disease Extend ‘Beyond Lyme’. This confusion, of course, makes treating Lyme disease with antibiotics, which is already controversial, more so.

8 thoughts on “Bad summer in U.S. for zoonoses

  1. A neighor’s son (who spent over a month here in Montana) started feeling ill on his way back east. Ended up in an ER in WI. They thought he had an inner ear infection. When he arrived home his doctor ran a series of blood tests and discovered he had West Nile Virus.

    Gonna be a a scary situation for him, good days and bad days, for months to come.

    Posted awhile back that I’d seen very few mosquitoes around this year, compared to previous years but it only takes one infected mosquito to turn your world upside down.

    1. Nancy,

      I remember conversing with you at that time. May the gods help us if West Nile gets up in N MN. If you were brave enough to venture out under the evening skies, mouth breathing was not an option.

      1. West Niles virus has been in N MN for several years killing birds. I have friends who have brought in ravens, crows and blue jays that have been diagnosed with the disease.

  2. Interesting backstopry to the Lyme Disease phenom. A worable vaccine was developed…it was 100 erpcent effective in children and 76 eprcent effective in adults with few adverse side effects. But it was pulled from the market by its maker , GlaxoSmithKline in 2001 after some irrational lawsuits by paranoid people alleging the vaccine caused autoimmune disorders . That was disproven, but GSK never reinstated the vaccine and still holds the patent and manufacturing rights to the vaccine but will not allow it to be produced.

    A quote from the Wikipedia entry on this : ” an editorial in Nature cited the withdrawal of LYMErix as an instance in which “unfounded public fears place pressures on vaccine developers that go beyond reasonable safety considerations. The original developer of the OspA vaccine at the Max Planck Institute told Nature: This just shows how irrational the world can be… There was no scientific justification for the first OspA vaccine LYMErix being pulled.”

    [ expletive deleted ]. I almost lost a good friend to Lyme disease. There are over 12,000 cases diagnosed in the USA each year with many more unreported. The reverse consequences of the mass hysteria about vaccines probably results in unnecessary illnesses or deaths. Quien sabe?

    Ticks 1 Humans 0 . Lawyer still wins either way

    1. I could be wrong. This is just my impression, but when it comes to anti-vaccine political or economic action, I think it is the left-wing more than the right-wing that shows the unscientific paranoid view.

      Am I correct on this?

      1. You could be right Ralph. Would be interesting to know the percentages of left wingers vs. right wingers who rushed to get the H1N1 vaccine.

  3. Years ago my father and I stayed for several days in an old cabin west of Challis near Twin Peaks while hunting Bighorn Sheep. We threw our sleeping bags on the floor as there were no beds.
    Dozens of white footed mice would run all over the cabin and us during the night. I had one run right across my lips during the night. After thrashing around scaring mice away from my bag,I heard one on the old table we were using and turned my flashlight on it. It would come right to the light. I drew my .22 pistol and put it up by the light. The mouse seemed to love the smell of gunpowder. It would grasp the pistol with its’ paws and stick its’ nose down the gun barrel. I didn’t have the heart to shoot it while it was sniffing gun smoke and after sharing a good laugh about it with my father,we went back to sleep.
    Neither of us contracted anything from staying in the cabin with the mice.

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