November 14, 2018

Portions of Maine Should Be On The Lookout for Wildlife Diseases

Last week outdoor writer George Smith told his readers that they should be aware that Chronic Wasting Disease (CWD) in bearing down on Northwestern Maine as the disease has been found only 100 miles from the Maine border with Quebec, Province. CWD is a debilitating disease for deer as it causes, as the name suggests, deer to “waste away” and die. While not pleasant to see or harvest a fulling infected CWD deer, eating the meat is not harmful to humans…but not everyone cares to eat it and will not risk doing so.

But, this isn’t the only threat Mainers should be made aware of. Today I posted a recent study that showed certain strains of Echinococcus worms carried and spread by wild and domestic canids (dogs). The study sampled wolves, coyotes, red, and arctic foxes in both Quebec Province and the State of Maine and found the human-contagious parasite in Northern and Western Maine near the Canadian border.

Some good news is that the more harmful strain of Echinococcus, E. multilocularis, was not found in any of the canids sampled, although it has been found in portions of Ontario and moving east.

I’ve written much about this disease over the past years, falling mostly on deaf ears. Even when the Maine Department of Inland Fisheries and Wildlife (MDIFW) first reported that they had found the disease in Moose in Maine (2014), after initially posting something about it on their website, they quickly scrubbed it. In an email I sent to Commissioner Woodcock asking him what the Department intended to do about this troubling discovery, the response I got was, “nothing at this time.”

So when? It’s been 4 years.

Canid species are definitive hosts of the Echinococcus eggs and are passed through their feces into the environment of which wild ungulates – moose, deer, elk, caribou, etc. – ingest the tiny spores which in turn form cysts on their lungs, liver and other organs. While not deadly to these animals directly, cysts can affect the capacity of lungs and the function of the liver making these animals more susceptible to predators.

Humans, on the other hand, are at risk from the same ingestion of spores. This can happen from close examination of wolf, coyote, fox scat when the spores are released into the air and a person can inhale or ingest eggs that have gotten on their skin or clothing. They can also ingest eggs by drinking infected water. These eggs are extremely viable in various environmental conditions.

The most common way of becoming infected is when dog owners allow their dogs to run free in areas where wild canines, infected with the disease, live and roam. Dogs, as dogs do, can eat infected carrion, getting eggs on their mouth, face, and fur, passing it on to people, including children (think dogs licking children’s faces). Dogs also will eat or roll in wild canine feces, bringing the eggs with them back home and into the house if people allow their free-ranging dogs to live with them in their houses.

The study that I linked to in a previous posts exclaims that what is needed is that more effort is taken to educate and warn those who might be at risk, including trappers, hunters, and anyone with free-ranging dogs living in known infected areas.

Perhaps it is time for MDIFW to step up to the plate and inform the public what they know and begin an education program. They may be concerned about the spread of Chronic Wasting Disease, as they should, because it can destroy our already fragile deer herd, but what about protecting people? That should be of higher priority than protecting the deer…shouldn’t it?

For Maine, the E. canadesis strain (G8 and G10) are of the most threat to us. The report defines the spread of this disease into Maine as “rapid.” Now is the time to begin the education process, to teach people about restraining their dogs and or talking to their vets to make sure they are getting the proper and timely worm treatments. The simplest and quite effective thing people can do is to wash their hands frequently.

Detection of the cysts, Hydatid cysts, in humans is difficult. If detected, treatment is expensive and dangerous. Part of the reason detection is difficult is because doctors aren’t looking for it because nobody is telling them the incidents of Hydatid disease is on the increase. These people prefer to scoff at the notion of any health risk in order to protect their precious wild dogs.

It’s time to make some changes that will help reduce the risk of infection of humans.

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Molecular Characterization of Echinococcus granulosus Cysts in North Indian Patients: Identification of G1, G3, G5 and G6 Genotypes

“Cystic echinococcosis (CE) caused by the Echinococcus granulosus, is a major public health problem worldwide, including India. The different genotypes of E. granulosus responsible for human hydatidosis have been reported from endemic areas throughout the world. However, the genetic characterization of E. granulosus infecting the human population in India is lacking. The aim of study was to ascertain the genotype(s) of the parasite responsible for human hydatidosis in North India.”<<<Read More>>>

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Spotlight on Nasty Parasites: Echinococcus granulosus

Did you know that some dogs might have a tapeworm in their small intestine that can cause the development of large cysts in people’s livers, lungs, and brains? This is not very common in the United States currently, though there are cases reported periodically (2), but in some areas of the world it is a huge problem. An infection that can spread from animals to humans or vice-versa is called a zoonotic infection.<<<Read the Rest>>>

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Human Hydatid Disease: A Warning to Trappers and Hunters

HYDATID DISEASE
(Echinococcosis)
By Dave Miller

The disease is the result of an infection caused by tapeworms of the family Taenidae. Of importance, is that the dormancy of this can be up to 50 years. It was previously most common in South & Central America, Middle East, China, and Western North America.

It has now arrived in the Northeast.

This is of equal importance to trappers and hunters alike in Maine and the rest of the Northeast.
Although, some of us in the trapping community have been aware of the disease for a number of years and I was planning to write an article on it eventually, I have moved up its importance. This is based on the fact that IF&W has done research on it and just made the fact that is here public. Some of us assumed it would get here in the near future, but was not aware it had already actually arrived. IF&W presented it publically during Lee Kantar’s recent February presentation of his annual report on moose and deer to the legislature’s IFW Committee. I think trappers along with hunters should have been made aware of it immediately upon its discovery in Maine, considering our possible expose to it.

There are three different forms of echinococcosis found in humans, each of which is caused by the larval stages of different species of the tape worm genus Echinococcus. They are cyctic echinococcosis (the most common), alveolar echinococcosis and the third is polycystic echinococcosis. We are concerned with the first one here caused by echinococcus granulsus.

The first article I have in reference to the disease is part of an Outdoorsman article published about 40 years ago. At that time most readers of the Outdoorsman were from Northwestern Canada and Alaska where the cysts were present in moose and caribou. That article included statistics on the number of reported human deaths resulting from the cysts over a 50 year period. It also addressed the decline in deaths, once outdoorsmen learned what precautions were needed to prevent humans from infection.

It has been reported that in Alaska alone, over 300 cases have been reported in humans since 1950 as a result of canines (primarily wolves) contaminating the landscape with billions of the worm eggs in their scat (feces). The invisible eggs are ingested by wild and domestic animals, and sometimes by humans. It is made airborne by kicking the scat or picking it up to see what the animal has been eating. It can also be spread by wind over large areas. The eggs are very hardy and survive through extreme temperatures and weather for very long periods. The egg hatches in the digestive system of the intermediate host, producing larva.

Once ingested this larvae develops from the egg stage, penetrates the intestinal walls, and moves into the capillary beds (liver, lungs & brain) where they develop into large cysts full of tiny tapeworm heads. It settles there and turns into a bladder-like structure called a hydatid cyst. The cysts eventually kill the infected animals (humans) unless diagnosed and removed surgically. After the death of the intermediate host, its body (animals) is consumed by carnivores suitable as its final host. In their intestines, the protoscolices (the inner layer of the cyst wall that buds and protrudes into the fluid sac) turns inside out, attach and give rise to adult tapeworms, completing its life cycle.

It is important that outdoorsmen (hunters & trappers in particular) know not to kick or touch the scat of canids. Also, the wearing of rubber gloves when field dressing game and/or while fur handling is of upmost importance to prevent infection from the blood and/or internal organs. It must be noted that the tapeworm affects many other mammals from your dog and horse to rodents. For those collecting and using the anis glands for scent making – be forewarned of the direct contact with the scat.

The announcement of a tiny tape worm who’s name most of us can’t pronounce, that had never been reported south of the U.S. and Canadian border is now infecting elk, deer, moose, and even humans is being rapidly spread cross thousands of square miles. It is believed this has resulted from the introduction of the Gray Wolf to our western mountains. The tape worm has been reported in elk, deer, and mountain goats over large areas out west.

Even Sweden and Finland have reported the westerly spread of the disease into their moose herds from from Russian wolves. The Russian wolf population is currently increasing dramatically to the point they are hiring hunters/trappers to reduce the wolf population.

There were plenty of warnings about the spread of this disease by experts. Despite this, various FWS and State Wildlife Departments ignored their warnings. A certain FWS biologist (I have a document that names him – but I won’t here) who was stationed in Alaska and was knowledgeable about the disease was assigned to head up the Northern Rocky Mountain Wolf Recovery Team. He chose not to address or evaluate the impact of wolf recovery on diseases and parasites in the 1993 Draft Environmental Impact Statement (DEIS) provided to the public.

This resulted in alarming a number of experts on pathogens and parasites. One individual (Will Graves) informed the FWS biologist with information including that in Russia wolves carried 50 types of worms & parasites, including Echinococcosis and others with various degrees of danger to both animals and humans. In Graves written testimony in 1993 to the FWS biologist he also cited the results of a 10 year Russia study in which a failure to kill most wolves by each spring resulted in up to 100% parasite infection rate of moose and wild boar with an infection incident of up to 30-40 per animal. Graves’s letter stated that despite the existence of foxes, raccoons and domestic dogs; wolves were always the basic/primary source of parasite infections in the moose and wild boar. He emphasized the toll it could take on domestic livestock, and along with other expert respondents, requested a detailed study on the potential impact wolves would have in regard to carrying, harboring and spreading disease.

In the final 414 page Gray Wolf EIS (FEIS) dated April 14, 1994 only one third of a page addressed Disease and Parasites to & from Wolves (chapter 5 page 55). It stated that “Most respondents who commented on this issue expressed concern about diseases and parasites introduced wolves could transfer to other animals in recovery areas”. Several other statements by the FWS biologist are as simplistic and ignored specific concerns. The FWS implied that Graves “facts” are only his opinion.

Several “other previously unrecognized parasites” in the states where wolves have been introduced have also been found. So our coyotes may well be bringing in new diseases into Maine and the Northeast region.

cyst

lungs1
Cysts found in the lungs of an elk

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Human Echinococcosis Mortality in the United States, 1990–2007

Abstract
Background

Despite the endemic nature of Echinococcus granulosus and Echinococcus multilocularis infection in regions of the United States (US), there is a lack of data on echinococcosis-related mortality. To measure echinococcosis-associated mortality in the US and assess possible racial/ethnic disparities, we reviewed national-death certificate data for an 18-year period.

Methodology/Principal Findings

Echinococcosis-associated deaths from 1990 through 2007 were identified from multiple-cause-coded death records and were combined with US census data to calculate mortality rates. A total of 41 echinococcosis-associated deaths occurred over the 18-year study period. Mortality rates were highest in males, Native Americans, Asians/Pacific Islanders, Hispanics and persons 75 years of age and older. Almost a quarter of fatal echinococcosis-related cases occurred in residents of California. Foreign-born persons accounted for the majority of echinococcosis-related deaths; however, both of the fatalities in Native Americans and almost half of the deaths in whites were among US-born individuals.

Conclusions/Significance

Although uncommon, echinococcosis-related deaths occur in the US. Clinicians should be aware of the diagnosis, particularly in foreign-born patients from Echinococcus endemic areas, and should consider tropical infectious disease consultation early.

Author Summary

Human echinococcosis is a parasitic disease that affects an estimated 2–3 million people and results in an annual monetary loss of over $750,000,000 worldwide. It results in the development of life threatening tissue cysts, primarily in the liver and lung, following accidental ingestion of eggs in infected dog, fox or wild canine feces. Echinococcus parasites have a complex, two-host lifecycle (such as in dogs and sheep) in which humans are an aberrant, dead-end host. The vast majority of cases of human echinococcosis occur outside of the United States (US); however, cases within the US do occur. In this study, the authors examined death certificate data of US residents from 1990–2007 in which echinococcosis was listed as one of the diagnoses at death. The analysis demonstrated 41 echinococcosis-related deaths over the 18-year study period with foreign-born persons accounting for the majority of the deaths. This study helps quantify echinococcosis deaths among US residents and adds further support to the importance of funding echinococcosis prevention research.

<<<Read the Complete Study at National Library of Medicine>>>

In addition, another study involving the presence of cystic echinococcosis in humans was undertaken in Turkey. You can find that information at Research Gate. (Note: You can access the entire study for free but requires a membership form.)

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