West Nile Virus Information

Frequently Asked Questions - West Nile Virus

Below are answers to frequently asked questions about the West Nile virus received by the Texas Department of Health (TDH). Answers to more than 50 frequently asked questions received by the national Centers for Disease Control and Prevention can be found at http://www.cdc.gov/ncidod/dvbid/westnile/q&a.htm

Q. Can dogs, cats and other pets get the West Nile virus?

A. Yes. But they rarely, if ever, get sick. No cases of West Nile disease have been confirmed in dogs and cats. The virus can infect many species of animals, but few actually get the disease. Most infections have been identified in birds, but West Nile virus has been shown to infect dogs, cats, horses, and domestic rabbits, as well as bats, chipmunks, skunks, and squirrels.

Q. Is there a vaccine for dogs and cats?

A. No.

Q. How many human cases have there been in the United States? How many deaths?

A. In 1999, 62 cases of severe disease, including 7 deaths, occurred in the New York area. In 2000, 21 cases were reported, including 2 deaths in the New York City area. In 2001, there were 66 human cases of severe disease and 9 deaths. No reliable estimates are available for the number of cases worldwide of West Nile encephalitis, the disease caused by the West Nile virus.

For the latest up-to-date information, go to http://www.cdc.gov/ncidod/dvbid/westnile/surv&control04Maps.htm.

Q. How many human cases have there been in Texas? How many deaths?

A. The first human death in Texas occurred on August 16th, 2002. For the latest up-to-date information on human cases in Texas, see the TDH West Nile Virus home page at http://www.tdh.state.tx.us/zoonosis/diseases/arboviral/westnile

More information about West Nile virus in Texas can be found at http://www.tdh.state.tx.us/zoonosis/diseases/arboviral/westnile.

Q. What is the risk of someone becoming infected with West Nile?

A. The risk is very low. Even in areas where the virus is circulating, very few mosquitoes are infected with the virus. Even if the mosquito is infected, less than 1% of people who get bitten and become infected will get severely ill. The chances you will become severely ill from any one mosquito bite are extremely small.

Q. Where in Texas has the virus been found?

A. For the most up-to-date information, go to http://www.tdh.state.tx.us/zoonosis/diseases/arboviral/westNile.

Q. Where does the virus live? Do birds or mosquitoes get it first?

A. Birds get it first. The virus is in their bloodstream. Mosquitoes become infected when they feed on infected birds. The infected mosquitoes can then transmit West Nile virus to humans and animals while biting to take blood. The virus is located in their salivary glands and, during blood feeding, the virus can be injected into the animal or human, where it can multiply, possibly causing illness in the animal or human.

Q. Is TDH doing spraying around the state to kill mosquitoes?

A. No. Vector control is up to the Mosquito Control Districts and local health departments.

Q. In addition to being infected by the West Nile virus, what else can cause bird "die-offs"?

A. Chemical spills, pesticides, drought, severe weather, and other diseases.

Q. What's an arbovirus?

A. Any of various RNA viruses which are the causative agents of encephalitis, yellow fever, and dengue and which are transmitted chiefly by arthropods, such as insects.

Q. What kind of laboratory tests are done to identify the West Nile virus?

A. Various tests can be done. The type of test will vary among mosquitoes, chickens, humans, and horses. The type of test also depends on the kind of samples available (blood serum, cerebrospinal fluid, brain tissue, etc.). Samples may be tested to find antibodies to West Nile virus, or there may be an attempt to isolate virus particles from the sample. Tests that can be done include Hemagglutination-Inhibition, IgM-Capture, Plaque-Reduction Neutralization, virus isolation, and PCR. More details are available in the Response Guide at http://www.tdh.state.tx.us/zoonosis/diseases/arboviral/westnile.

Q. Is there a human vaccine?

A. No, but several companies are working towards developing a vaccine.

Q. Can a human get the virus twice?

A. We don't think so. It is assumed that a person would develop a natural immunity to future infection by the virus, and that this immunity would be lifelong. However, this immunity may wane in later years.

Q. I've heard of " suspect cases," " positive cases," " confirmed cases," and " probable cases." What does it all mean?

A. Infections with West Nile virus may, or may not, produce illness. A few people who get ill may seek medical care. Those with severe enough disease that has the appearance of West Nile and similar viruses may have blood or spinal fluid sampled for testing.

Testing of samples has two main components:

• Samples may be tested for antibodies to West Nile and other viruses. A positive result indicates that the patient may have been exposed to the virus, but does not prove that the virus is still in the patient.
• Samples may also be tested to find the actual virus. This type of test is more difficult, takes much longer, and may not be successful. A negative test does not prove that the virus did not cause the illness.

Here are definitions of the terms you asked about:

Suspect: A patient with symptoms similar to West Nile might be considered a suspect by their physician. Since they would also be suspect for a multitude of others diseases with similar signs, they are not counted or reported by Texas.

Positive case: Many laboratories can test for West Nile and may find positive results. These results are often cross-reactions with other conditions and may not represent a true West Nile positive. Only those results that meet the case definitions for "Confirmed" or "Probable" will be reported as "cases."

Confirmed: A febrile illness associated with neurologic manifestations ranging from headache to aseptic meningitis or encephalitis, plus at least one of the following:

• Isolation of WN virus from or demonstration of WN antigen or genomic sequences in tissue, blood, cerebrospinal fluid, or other body fluid;
• Demonstration of IgM antibody to WN virus in cerebrospinal fluid by IgM-capture enzyme-linked immunoassay (EIA);
• A > 4-fold serial change in plaque-reduction neutralizing test (PRNT) antibody titer to WN virus in paired, appropriately timed serum or cerebrospinal fluid samples;
• Demonstration of both WN virus-specific IgM (by EIA) and IgG (screened by EIA or HI and confirmed by PRNT) antibody in a single serum specimen.

Probable case: Symptoms identical to that for a confirmed case plus one or more of the following:

• Demonstration of serum IgM antibody against WN virus (by EIA);
• Demonstration of an elevated titer of WN virus-specific IgG antibody in convalescent-phase serum (screened by EIA or hemagglutination inhibition (HI) and confirmed by PRNT).

Health Risks Associated with Wildlife as Pets

Many people have contact with wild animals and, especially if the animals are young, are tempted to take them home as pets. Baby animals are often cute, cuddly and responsive to attention. The temptation to remove them from their natural environment can be very strong, but before you try to make a pet out of a wild animal, please consider the following:

Most wild animals will not live very long in our normal household surroundings. Baby animals that do survive will undergo a drastic behavioral change as they become adults. They often become very aggressive and continually try to escape back to the out-of-doors. A tailor-made pet does not result from declawing, descenting, neutering or removing fangs from a wild animal. In addition, attempting to return such animals to the wild when their behavior becomes intolerable is actually a death sentence.

The dietary requirements of most wild animals are different from domestic pets. An improper diet can result in serious nutritional deficiencies such as rickets and other crippling conditions.

Most wild animals are normally most active at night. This perfectly normal behavior can be very disruptive to persons trying to sleep and attempts to change it may be very frustrating to the animal itself.

Many diseases which affect people can be carried even by healthy-looking wild animals. Rabies is one such disease and others include leptospirosis, tularemia and plague. Preventive vaccines against these diseases are not approved for use in wildlife.

Most wild animals are protected by various federal and state laws and permission from the proper authorities must be obtained before keeping a wild animal.

When you are tempted to take home a wild animal for a pet, ask yourself these questions:

* Is what I am doing legal?
* Am I willing to risk the health, and possibly the life, of myself and my family?
* Am I willing to risk destroying the animal?
* Am I willing to change my lifestyle to conform to the animal's natural and unalterable behavior?

If you cannot truthfully answer "yes" to each question, do not attempt to keep a wild animal as a pet.

Identified

The 2 unidentified birds are Brown-headed cowbirds.
One is not doing well, nor is the Mockingbird.
The other Chimney Swift died late yesterday afternoon.
Suspecting West Nile according to the symptoms.

Released today:

Released the 4 Sparrows and the Inca Dove this morning.

The 2 Chimney Swifts are not doing well, they stopped chattering and taking food.

1 of the 3 unidentified birds passed away 10 minutes ago. Metabolic bone disease.

Noon update: 1 of the Chimney swifts didn't make it, the other one is still refusing to eat...

New Arrivals and Updates

Received 3 cottontails, about 2 weeks old, good shape.

Received a juvenile skunk with obvious signs of rabies; referred to animal control.

4 sparrows will need another 3 - 5 days before release; all are doing fine.

Mockingbird juvenile finally opened beak for me to feed after 2 days of forcefeeding.

The 3 not identified birds are filling in feathers: black with brown tips and streaks, spotted belly, naked face, no yellow on beak, red legs.

2 Chimney Swifts are opening their eyes; 7 days old.

2 opossums are outside in the new screen room. Since they can't climb, the largest place I had was a plastic dog pool. Filled with sheets and top of dog crate for den, covered with deer netting; they seem to love it.

Doves

Helping some of Mother Nature's most frequently orphaned baby birds
With spring comes baby birds, and for many a few short weeks is a long life. Predators raid the nest, storms blow the nest out of trees, too active babies fall from the nest, and an assortment of other tragedies take lives. Sometimes humans can and do make a big difference in whether or not a baby bird survives.

Why bother? Because it makes a difference of life and death to the little one in trouble; because songbirds are on the decline nationwide and saving one of any species seems to be important, and in this violent world of ours, saving something more fragile than ourselves brings out the best in us. Of that, we cannot get or have enough!

It is against the law in most states to pick-up a baby bird and keep it for more than 24 hours. Unless you are a licensed rehabilitator, you may not have the knowledge and expertise to raise a baby bird, and you probably do not have the time. Baby birds require almost constant attention, feeding, and cleaning from sun-up to sun-down for a minimum of two weeks and usually longer. Finding a rehabilitator is as close as your closest nature center, natural museum, humane society or animal control.

There are various techniques that have proven successful in raising orphaned baby birds of different species. If you are sincerely interested in raising even a few songbirds each season, volunteer to help a local rehabilitator who is overrun at this time every year with hungry mouths, get a rehabilitation license and enroll in a course of two to learn the basics so you can make a real difference in the wildlife in your backyard. Check with continuing education course offerings at your local community college or university, or nature center. Work with an experienced wildlife rehabilitator and or veterinarian who treats injured and orphaned wild creatures or better yet work with both of them to get "hands-on" experience.

Formulas are not listed in order of effectiveness. All have been used, tested, and proven successful.

These are by no means the only nutritionally sound feeding formulas. These are just some of those that the North American Wildlife's Health Care Center's rehabilitation network have used repeatedly.

Baby mourning dove feeding formula
North American Wildlife Health Care Center's dove formula

Wild doves nest up to five and six times yearly. During each nesting period, babies blow out of nests during storms, perch perilously on the nest's edge, and fall to the ground before their wings will carry them into flight.

If the young dove is too young to eat grass seeds and grain off the ground, it will have to have human help to survive.

A successful feeding formula includes

1/2 cup soaked chicken starter or turkey starter, or wild game bird starter and grower,
1/4 cup Hi-Protein baby cereal
1 tsp. Brewers' yeast (supplies Vitamin-B complex)
1 tsp. Vionate (vitamins)
1 jar baby egg yolk or 4 oz. egg yolk (hard-boiled)
1 tsp unflavored gelatin
1/4 tsp. wheat germ flakes
1/4 tsp. powder
1 tsp. dyne (stat) balances electrolytes, and supplies needed vitamins and minerals. Check with your "vet". Many refer to the product as STAT.

Baby doves need to be fed no more than five to six times in a 24 hour period. They have a large crop that stores food.

Warm only what is to be fed each feeding, and keep the remaining refrigerated.

Feed until the crop feels like a soft balloon inflated. Do not feed until the crop feels stretched and tight.

Baby dove feeding formula #2
The Brukner Nature Center Primer of Wildlife Care and Rehabilitation by Patti L. Raley 2nd edition.

1 cup High Protein dog food softened in water
1/2 cup turkey starter
2 hard-boiled eggs, crumbled
2/3 cooked Roman Meal cereal
1 teaspoon dolomite vitamin/mineral mix berries
Lactobacillus
Combine ingredients thoroughly. Separate into individual portions and freeze until needed. Thawed mix will keep up to three days in refrigerator. Moisten with water or fruit juice to feed with a syringe. Give small amounts of water after each feeding.

Baby dove feeding formula #3
From Wild Animal Care and Rehabilitation, Kalamazoo Nature Center, Fourth edition.

2 tbs. fine ground 8-in-1 Mynah Bird Food
1 tbs high protein baby cereal
1 tbs. wheat germ
1 tbs. corn meal
1 teaspoon hard-boiled or baby food egg yolk
2 to 3 drops balanced avian vitamins.
Grind 8-in-1 Mynah Bird Food or you may use unmedicated chick started in a blender. Combine this with high protein baby cereal, wheat germ, corn meal, egg yolk and vitamins. Mix with water until mixture is thick and soupy. As baby matures add sees such as millet or parakeet seeds. Doves need to be fed only four to five times during daylight hours. Do not overfeed. The crop need to have some food in it always. The crop deflates at night.

MacLeod baby dove feeding formula #4
Leslie MacLeod is the wildlife coordinator for the North American Wildlife Health Care Center, a state and federally licensed wildlife rehabilitator with some 10 years experience.

1 jar baby beef (baby food)
1 tbs. finely (yellow or white)
1 hard-boiled eggs, crumbled (white and yolk),
1/4 tsp. wheat germ flakes, 1/4 tsp. brewers yeast (supplies B-complex vitamins)
1/2 inch ribbon of nutrical squeezed from tube.
Mix with pedialyte until mixture is a medium consistency syrup.
When the baby is at least half feathered, add just a pinch of fine grit to formula to keep the crop working well.

By the time the baby is about 10 days old, feathers are beginning to unfurl in the wings, the diet should be about 80 percent of the above formula with 20 percent made up of very small polished finch seed.

Feed at room temperature. Stores well in freezer for individual portions. Thaw one feeding at a time.

Feed baby no more than five to six times in a 24 hour period. Pigeons and doves beg even when not hungry.

New Screen room for flight practice 

New Arrivals

Daily Chart:

4 sparrows, 1 week old
2 chimney swifts, 2 days old
3 crow size birds, about 1 week, brownish/orange skin, feet
same color, wing feathers black/blue/brown, insect eaters, long legs.
1 cottontail, opened eyes today
2 opossums, 5 months, not releasable, crippled

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Opossums Rescue and Rehabilitation Most opossum babies end up orphaned, because their mother was hit by a car (their only real defense is to play dead...) or killed by dogs. So PLEASE, if you care and you happen to hit an opossum with your car - accidents happen - take a minute and make sure that there are no babies on the animal, because they usually survive a lot within momma's pouch. After all, they are America's only Marsupials. Movies April 13, 5 new arrivals, 6 weeks old (571 KB, mpg) April 17, licking milk from eyedropper (1.3 MB, mpg) April 17, licking milk from eyedropper (1.3 MB, mpg) April 22, eating out of bowl first time (1.3 MB, mpg) April 23, release of 4 months old (1.9 MB, flash) May 4th, outside enclosure (1.3 MB, mpg)

Opossum Facts North America's only marsupial (female has a pouch) mammal. The female carries and nurses her young in her marsupium until they are about 2 to 3 months old; then they are carried on her back another 1 to 2 months whenever they are away from the den. Size of a cat; grey to black fur; black eyes; pink nose, feet and tail; black ears; and pointed nose. Solitary and nocturnal: usually slow moving; when frightened and unable to flee may fall into an involuntary shock-like state, "playing 'possum". Hiss or growl and show their 50 sharp teeth when frightened; but, in reality, they are gentle and placid— they prefer to avoid all confrontations and wish to be left alone. Omnivorous: eats insects, snails, rodents, berries, over-ripe fruit, grasses, leaves, and carrion; occasionally will eat snakes, ground eggs, corn or other vegetables. Adaptable; able to live wherever water, food, and shelter exist. At home in trees; uses its prehensile tail to help stabilize position when climbing— it does not, however, hang by its tail. Few live beyond the age of 1 year in the environment; rare reports of living 5 to 10 years in captivity. Killed by many predators: humans (and cars), dogs, cats, owls, and larger wildlife. Opossums are solitary nocturnal animals, but may become diurnal in cold weather. They build the nests in tree hollows and spend most of their time there. Opossums don't hibernate, but remain inactive during severe frosts. Without nests Opossums are unable to survive. Sometimes they choose garages and attics as their temporary quarters because they are pushed out of their natural habitat and forced into closer proximity to people. In the wild Opossums have many predators: dogs, cats, owls, foxes, and other larger wildlife, but mostly Opossums suffer from humans and cars. In danger Opossums can feign death or drool heavily for a predator to think the Opossum is sick and unappetizing. Or they hiss and growl, showing sharp teeth, but it's only a bluff. These gentle and placid animals prefer to avoid confrontations. Opossums have several ways of picking things up. Their back feet have opposable toes like the man's thumb. They can wrap the tail around things or hang on the tail, like monkeys do. They can also use their front feet for picking up things although they don't have opposable thumbs. Opossums don't have their own territory, but they are always on the move in search for food. Females stay in smaller areas while they can care for the youth. Opossums make clicking sounds during mating season or hiss and growl if threatened. Opossums - Habitat Opossums inhabit the United States east of the Rocky Mountains, Central America, and Pacific coastal North America. The Virginia Opossum is the only marsupial found in the North America. In South America and Australia there are about 80 species of Opossums. Opossums lived during the era of dinosaurs - fossil remains have been found from 70 million years ago. Opossums - Reproduction The breeding season for Opossums begins in December and may continue through October with most of the infants born between February and June. Like all marsupials, Opossum females have a well-developed pouch. They produce an average of 7 young, once or twice a year (litters of 17 kids have been reported). At birth, the infants are hairless, embryonic-looking, and weigh about 0.1 grams because the period of gestation is 12-13 days and because they are born at a very early stage in their development. Young Opossums have to make a long and difficult journey from the birth canal into the pouch and latch onto a teat. The mother helps by licking the hair leading into the pouch. There are only 13 teats in the pouch and not all may be functional, so the excess infants will not survive. The young open the eyes at around 60-70 days and are weaned at about 100 days of age. Then they are often carried as they cling onto the mother's back. After separation from the mother, littermates may share common dens for some time. Very few young Opossums survive to become adults. Opossums are considered to be furbearers, but they are not taken in large numbers because their pelt has little value. Opossums are nature's sanitation engineers; they eat road-kill, carrion, rotting fruits, and pests. Also Opossums are of great interest for scientists since they are the only marsupials in America, while Australian marsupials are driven to extinction by more modern mammals. Weight: 9-13 lbs (4-6 kg). Some species reach only 300 gr. Length: 15-20 inches (38-50 cm). Some species are 10-12 inches. Life Span: 1-2 years in the wild, up to 10 years in captivity. Opossums - Conservation In the wild Opossums are closely linked with the ecology of the forests. Devastating fires destroy nest-sites and cause great declines in Opossums populations. Tall, straight trees favored by wild Opossums are highly valued for the production of timber. The technique of tree removing is very detrimental for all animals, including Opossums. The population crash has already begun and extinction of some species of Opossums in the South America and Australia is possible. Opossums - Diet Opossums don't have any methods for storing food or energy so they need stable food sources and that's why their diet is so varied. Opossums feed mostly on carrion. Other food sources for the Opossum include garbage, grass, leaves, insects, frogs, small birds and rodents, snakes, and earthworms. Opossums like to treat themselves with berries, seeds, flowers, and fruits and their favorites are persimmons, apples, and corn. Photos Opossum with 3 legs, birth defect Dwarf Opossum with big 3-legged sister 6 Opossums a minute before release