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Sunday, January 26, 2014

విషపు చెట్టు.

Most Amazing Places on Earth


From the air, the Great Blue Hole of Belize resembles an otherworldly maw, intent on drinking down the surrounding Lighthouse Reef Atoll. In reality, the 1,000-foot (305-meter) wide hole is simply a sinkhole in the ocean. Geologists believe that an underlying cave system collapsed under increased pressure some 10,000 years ago due to rising sea levels.
The dark hole descends 412 feet (126 meters), terminating in lightless depths where a lack of oxygen prevents most forms of life from thriving. Divers rarely plunge these depths, however, as most are content to explore the stalactite-rich caverns accessible from depths of some 130 feet (40 meters) below the surface.
From hidden depths to towering vistas, these are just 10 of Earth's countless geologic wonders -- each more than a rival for anything dreamed up for fiction and fantasy. We live on a spectacular planet; you just have to open your eyes to it.
Explore the links on the next page to learn even more about Earth's amazing geology.


The hill country of Kentucky's Green River Valley certainly has its charms, but beneath its gentle woodlands there is an underworld. More than 390 miles (628 kilometers) worth of caves worm through the rocky depths, making Mammoth Cave the largest known cave system in the world.
For more than 10 million years, waters from the Green River have cut through the soft limestone, riddling it with all manner of cave formations. A visitor may pass through a lengthy passageway and
into a vast cathedral. Vertical shafts descend into darkness while stalagmites, stalactites and bizarre crystal formations speak to the immensity of geologic time.
Yet Mammoth Cave is not just a place of minerals, stones and tourists. It also boasts an impressive ecosystem of cave flora and fauna, encompassing more than 130 documented species.


When an enormous column of rock towers 1,267 feet (386 meters) above the surrounding landscape, people take notice. That's why Teddy Roosevelt declared Devils Tower America's first national monument, and Steve Spielberg decided to land a UFO on top of it in "Close Encounters of the Third Kind. Long before either man thrust the natural landmark into the spotlight, more than 20 Native-American tribes held the site sacred -- including the Lakota people who dubbed it "Bear Lodge."
While its exact origins are unclear, many geologists believe the enormous column of igneous rock is an intrusion: a column of molten rock pushed up from the inner Earth through sedimentary rock layers. It's unclear whether the intrusion cooled before or after it breached the surface, but the vertical furrows indicate that cooling and contraction took place.
Geologists suspect the northeastern Wyoming tower formed more than 50 million years ago and remained buried beneath the ground up until roughly 2 million years ago [source: SERC]. Today, Devils Tower is a popular tourist destination, and licensed climbers can even scale the monolith for an unforgettable view.

You want a fantastic real-world locale? It's hard to improve upon the fairy chimneys of Cappadocia in central Turkey. Here, tall spires of stone dot the landscape like some manner of bizarre growth. What's more, early Christians carved countless storerooms, stables and domiciles into the fairy towers from the 4th to the 11th century.
To understand the formation of these stone spires (also known ashoodoos), look at the accompanying photograph. The fairy chimneys you see here were once part of a massive slab of earth covered in a layer of hardened volcanic ash called tuff. Over time, the erosive forces of wind and water wore away much of the underlying soft material, leaving only slender towers with caps of tuff.
The early Christians went so far as to carve whole monasteries and underground cities out of the stone in Cappadocia. Today, many such chambers are still in use -- some as guesthouses for visiting tourists.


Madagascar is truly a lost world. Cut off from the rest of the world, the island's lemur population thrived (they don't exist anywhere else on the planet, except in captivity), and a host of unique life forms evolved in relative isolation. Yet Madagascar's geology also stands apart from the rest of the world's -- especially the region known as Tsingy de Bemaraha.
Here, visitors encounter a forest of upturned limestone daggers. This painful-looking landscape, also known as karst topography, results from long-term dissolution of soluble limestone bedrock. Formerly a massive slab of rock, rainwater has whittled it down into multiple, individual towers of stone. The Tsingy de Bemaraha National Park protects a 600-square-mile (1,554-square-kilometers) region of stone and vegetation.
The inhospitable nature of the tisngy serves to protect a host of creatures, many of which avoided discovery by humans until the 21st century.

Nearly 1,000 feet (305 meters) beneath Mexico's Naica silver mine you'll find a chamber of unearthly wonder. Here in Cueva de los Cristales (the Cave of Crystals), 36-foot (11-meter) obelisks of solid crystal lay heaped about like fallen pillars in a dilapidated temple.
This subterranean forest of wonders boasts the largest known gypsums (soft minerals made of hydrate calcium sulfate) on Earth. For roughly half a million years, the hidden chamber was nothing short of a crystal incubator. For starters, nearby magma deposits heat the cavern to temperatures of up to 112 degrees Fahrenheit (44 degrees Celsius). And to top things off, the entire space was flooded with mineral-rich waters up until very recently.
The chamber was discovered in 2000, after mining operations pumped it dry. Today, only a few visitors risk heatstroke to witness the crystals' beauty firsthand.


Earth's vast, barren expanses are often as awe-inspiring as its highest peaks and deepest valleys. Just consider the Bolivian Uyuni Salt Flats, or Salar de Uyuni, a 4,000-square-mile (10,360-square-kilometer) plane of what appear to be hexagonal tiles. This extraordinary high-altitude landscape stretches among the snow-peaked Andean mountains, and if you happen to visit during the rainy season, you're in for quite a sight.
When the rains sweep down onto the Uyuni Salt Flats, the entire expanse becomes an immense reflecting pool. The water on the salt flats never reaches a depth of more than 6 inches (15 centimeters), so it offers visitors the unique sensation of walking on the surface of a mirror -- all amid a desolate silence.
The unique landmark is actually the remnant of a prehistoric lake and currently ranks as the largest salt flat in the world.

You'll find no shortage of breathtaking vistas on the Greek peninsula, but the Meteora rock formations truly take the cake. These massive sandstone fingers seem to emerge as much from a dream as from the plains of Thessaly. Towering as high as 2,044 feet (623 meters) above lush landscape below, the steep peaks of Meteora are a perfect setting for a secluded monastery.
Monks and nuns have called Meteora's peaks and caverns home for centuries. Hermits scaled the daunting peaks as early as the 10th century and, according to legend, St. Athanasios Meteorites rode an eagle to the top in the 1300s to found Great Meteoron, the largest of the region's six secluded monasteries.
The monasteries remain active to this day, though some peaks remain rather isolated destinations. Up until 1925, visitors could only reach Ayia Triada (aka Hagia Triada) monastery via rope ladders and baskets. Today, it boasts a 140-step staircase hewn into the rock.

Conflict is the meat of great storytelling. You might prefer such tropes as man-versus-nature or man-versus-blue-aliens, but the best geological drama often unfolds when tectonic plates duke it out, especially continental plates. Travel to Iceland, however, and you'll find a most curious occurrence on the boundaries of the North American and European plates.
Adjacent to Lake Thingvalla, you'll find Silfra Crack. Filled with crystal-clear, glacial meltwater, this narrow slit plunges 66 feet (20 meters) into the Earth. It makes for a rather chilly descent, but sight-seeking divers make the pilgrimage each year to dive between the continents. Experienced cave divers can explore depths of more than 148 feet (45 meters) by swimming into the Silfra cave system.
Visitors frequently describe the Silfra diving experience as one of floating weightlessly through space. The glacial waters filter through miles of volcanic rock before emptying into the crack.

In "Avatar," a noble, indigenous people fight to protect their sacred landmarks against an invading culture. If you're pining for that sort of drama, then look no further than Australia's Uluru-Kata Tjuta National Park. Here you'll find mighty Uluru, one of the largest geologic monoliths in the world.
Dubbed "Ayers Rock" by Europeans, the 5.8-mile (9.4-kilometer) wide slab of arkose (a type of sandstone) resonates with sacred significance for the Anangu people. Aboriginal paintings pepper its base, as well as caves and waterholes held sacrosanct in the spiritual tradition of Tjukuritja. While the Anangu have visited the site for roughly 22,000 years, they only regained legal ownership of the land in 1985 after a century of European rule.

Uluru is the visible tip of a much larger rock slab that extends deep into the Earth. In ages past, this tip was underground as well, but hundreds of millions of years of erosion have reduced the surrounding landscape. Uluru gets its red complexion from clay and rusted iron minerals within the sandstone. At dusk and dawn, the monolith takes on even darker, crimson hues.


Friday, January 24, 2014

Why brush twice a day...?

Why brush twice a day? 

There are several answers to this question. We brush, floss, and rinse repeatedly every day to reduce the bacterial load in the mouth, prevent disease development, avoid halitosis, remove stains, and remove food particles, among others. All these answers are true, valid, and accurate, but they do not drill down to the bottom line, bare bones, one ultimate reason.

Understanding the real reason for repetitive home care begins with the mechanism of biofilm formation. Biofilm develops in a precise sequence of bacterial species stacking on top of one another. It happens the same way over and over, every time biofilm starts building up. The first bugs congregating on a newly forming biofilm are always the same gram-positive aerobes, Streptococcus and Actinomyces. The most important feature of these early colonizers is that they are not pathogenic.

In other words, they cannot cause periodontitis. In fact, they are considered favorable or beneficial and are associated with healthy gingiva. Remember, a healthy gingival sulcus is not sterile or devoid of bacteria. It is, rather, populated by the right types of bacteria, namely the early colonizers.
If a newly developing biofilm is not eliminated or at least adequately dismantled, the later-arriving periodontal pathogens have a chance to come on board the biofilm. The periodontal bugs are always among the later colonizers.

This is certainly an evolutionary adaptation, for if the highly virulent periodontal bugs were the initial colonizers, the body would have a lower likelihood of surviving. The bugs cannot land on the biofilm until the conditions are appropriate and it is their turn. Holding them back gives the immune system a fighting chance to keep the pathogens in check.

Prior to joining the biofilm, the periodontal pathogens are freely floating around in the mouth. In a free-floating state, they cannot cause disease. Bacteria must be attached to the gingival epithelium to cause gum disease. No attachment, no disease, period.

When the biofilm is not brushed away, the perio pathogens start piling on. In approximately three to 12 weeks, they will become the predominant species. If the patient is genetically susceptible to periodontitis, it may ultimately develop.

Putting this all together, the primary reason for repetitive daily home care has to do with the properties of biofilm formation. Since the early colonizers are not pathogenic, we want to have these in place as often as possible. We want the virulent, disease-causing periodontal pathogens to be in the nonattached, free-floating position as often as possible. Those early bugs cannot cause periodontitis.

Development of periodontitis requires a genetically susceptible individual, an active chronic inflammatory response, and a sufficient number of the gram-negative anaerobic periodontal pathogens in the gingival sulcus in direct contact with the gingival epithelium.

So, on a clinical level, how do we maximize the favorable, early colonizers and minimize the later-colonizing periodontal pathogens? We do this by forcing the biofilm to keep starting over. We accomplish this by removing it as often as reasonably possible.

Every time we knock down the biofilm with our home-care efforts, we make it start over. Every time it starts over, the early bugs are the same favorable, nondisease-causing ones — and they cannot cause periodontitis, ever.
The ultimate reason for brushing twice a day is to keep making the biofilm start over and over and over, because every time it starts over, we have just the early arriving good bacteria on the biofilm. When this situation exists on a daily basis, the later-colonizing periodontal pathogens are kept in a holding pattern, circling around in the mouth without a place to land. This is where we want them, since they cannot cause disease in a nonattached position.

Frequent, effective home care is critically important, since periodontal diseases have local effects in the oral cavity and global effects around the rest of the body. Failure to prevent periodontitis development condemns the patient to a lifetime of disease management, since it is a noncurable condition. The oral contribution to the total inflammatory burden is significant, and the total inflammatory burden increases the risk for systemic diseases.
Brushing twice a day protects the patient’s general health. And the patient’s well-being is the reason we go to work every day.

Dr. Richard Nagelberg has practiced general dentistry in suburban Philadelphia for more than 28 years. He is a speaker, advisory board member, consultant, and key opinion leader for several dental companies and organizations. He lectures extensively on a variety of topics centered on understanding the impact dental professionals have beyond the oral cavity. In-office consultations are available. Contact him at

Wednesday, January 22, 2014

Arthritis (Joint pain ) Natural Remedy.


When joint cartilage wears away, bone rubs against bone, causing osteoarthritis. Sounds painful? It is.

Osteoarthritis seriously impairs the quality of life for 27 million Americans. Given that osteoarthritis is so disabling, painful, and common, lots of quack “cures” are out there, from shark cartilage to copper jewelry to snake venom.

But here are 13 natural remedies that research suggests may actually help ease arthritis pain.

Weight loss

The best remedy—maintaining a healthy weight, and losing weight if necessary—is not the easiest.

Still, every pound you pare off means 4 pounds less pressure on your knees, says Laura Robbins, senior vice president of education and academic affairs at the Hospital for Special Surgery in New York City.

Some people will see their symptoms disappear if they lose 10 to 20 pounds, says Roy Altman, MD, a rheumatologist and professor of medicine at the University of California, Los Angeles.



Physical activity is essential for people with osteoarthritis, whether it means walking around your apartment if you’re a fragile older person or swimming laps if you’re in better shape.

People used to think that exercise made arthritis worse, but the opposite is true—unless you’re pounding the pavement. (Runners with knee osteoarthritis should cut down on mileage, try to cross-train, and run on softer surfaces like tracks and dirt paths.)

Exercise programs should include both aerobic exercise—like walking, swimming, or biking—and strengthening exercises, such as isometric and isotonic exercises, Dr. Altman says.


Many people find that acupuncture helps relieve pain and disability due to arthritis; several studies have found benefit from the procedure.

“Several trials show acupuncture to be helpful for many people with osteoarthritis,” says Dr. Altman. “It’s not helpful in everybody.” 


There is some evidence that suggests that glucosamine alleviates arthritis pain, but the type of glucosamine matters.

“There continues to be a lot of controversy about it. There’s a fair amount of data that glucosamine sulfate is beneficial, but glucosamine hydrochloride is not,” Dr. Altman says. “Almost all of the products that are sold here in the United States are glucosamine hydrochloride. There are no trials demonstrating that glucosamine hydrochloride benefits people with osteoarthritis.”

In the studies that did find benefit for glucosamine sulfate, Dr. Altman says, patients took 1,500 milligrams once a day, which resulted in better absorption in the body than splitting the dose.


Early research found that this supplement was promising when combined with glucosamine. However, more recent studies indicate it’s not effective.

Although some studies suggest that chondroitin sulfate slows arthritis progression, it hasn’t been shown to help symptoms, says Dr. Altman. Studies that found the supplement helpful used 800 milligrams or 1,200 milligrams daily.

“They’re really pretty safe,” Dr. Altman says of the supplements. “The one thing about them is there’s no major side effects. They’re fairly well tolerated.”

Other supplements

Other supplements have shown promise, but the evidence just isn’t that strong, says Dr. Altman.

Industry-funded studies have found benefits for avocado soybean unsaponifiables (ASU), which are made from avocado and soybean oils, in patients with hip and knee arthritis. But such studies aren’t as reliable as those funded by groups that don’t stand to gain financially.

There’s some evidence that rose hips and highly concentrated ginger could be helpful, Dr. Altman says.

Although fish oil has anti-inflammatory properties, more research is needed.

Topical remedies

Strong-smelling mentholated rubs and creams may make your skin tingle, but many have limited value for osteoarthritis, says Dr. Altman.

However, there are some creams now available that have proven benefit, he adds. Diclofenac gel, sold in the U.S. as Voltaren Gel or Pennsaid by prescription (but available over the counter in Europe), is a nonsteroidal anti-inflammatory drug that can ease osteoarthritis pain in the knees, ankles, feet, elbows, wrists, and hands. It hasn’t been evaluated in osteoarthritis of the spine, hip, or shoulder. (Dr. Altman is a consultant for Novartis, the maker of Voltaren Gel.)

Capsaicin cream

Capsaicin cream can also relieve osteoarthritis pain, and it’s available without a prescription.

It’s made from the substance that gives chili peppers their heat.

Nobody knows how it works, although one theory is that the cream relieves pain by depleting the nerve ending of pain-impulse-transmitting chemicals known as “substance P” and calcitonin gene-related protein, Dr. Altman says.


Electrical energy can be used to help ease pain and swelling in arthritic joints in a couple of different ways. Physical therapists often employ transcutaneous electrostimulation, or TENS, which involves placing electrodes around the affected joint and delivering electromagnetic pulses through the skin.

And there’s electroacupuncture, in which the provider uses needles at acupuncture points that are attached to electrodes to pass an electric charge through the acupuncture needles.

There’s some evidence that both approaches can help provide at least short-term pain relief and also ease joint stiffness.


Chiropractic therapy won’t help with osteoarthritis. But what it is useful for, says Dr. Altman, is treating the muscle spasms that often accompany the condition.

For example, if you have acute lower back pain, chiropractic manipulation can break up the muscle spasm and scar tissue, easing the pain.

Heat and cold treatments can also be helpful for easing these muscle spasms, which aren’t only painful, but can interfere with sleep.

Physical therapy

Most of the time you don’t need to see a physical therapist, Dr. Altman says. Still, in some cases physical therapy can be invaluable.

For example, a person who is so weak that he or she has trouble getting out of a chair can benefit from physical therapy, and possibly even have PT adminstered at home.

But the therapist should be experienced in treating osteoarthritis. “Many physical therapists are used to treating stroke patients or sports injuries or other things where they’re used to pushing people a lot,” Dr. Altman says. “Physical therapy for osteoarthritis needs to be more gentle.”

Assistive devices

Shoe inserts, canes, splints, braces, and other devices that can help redistribute your weight to take the load off an arthritic joint or hip can be very beneficial, says Dr. Altman.

They are particularly helpful, for example, if someone has become knock-kneed or bow-legged as a result of having arthritic knees; unloading braces can help restore normal weight distribution, reduce pain, and prevent your arthritis from getting worse.

While evidence for the benefits of shoe wedges is mixed, according to Dr. Altman, some people will find them helpful, especially if they have leg length discrepancies greater than a half-inch.

Monday, January 20, 2014

Top 25 Amazing Animal Facts.



houseflyHouseflies don’t allow their short lifespans (14 days) to hinder their musical abilities. They always hum in the key of F.


ostrich runningOstriches can run faster than horses, and the male ostriches can roar like lions.


batBats are the only mammals that can fly, but wouldn’t it be awesome if humans could fly too?


KangarooKangaroos use their tails for balance, so if you lift a kangaroo’s tail off the ground, it can’t hop.


spider on faceOn average, there are 50,000 spiders per acre in green areas. Bet you’ll think twice before going outside now – unless you’re this guy.


tiger cubsTigers not only have stripes on their fur, they also have them on their skin. No two tigers ever have the same stripes.


Steve IrwinHere’s a tidbit that might be useful if you plan on becoming the next Steve Irwin: To escape the grip of a crocodile’s jaw, push your thumb into its eyeball – It will let you go instantly.


fleaFleas can jump up to 200 times their height. This is equivalent to a man jumping the Empire State Building in New York.


evil catA cat has 32 muscles in each ear. All the better for them to eavesdrop on your conversations and plot your demise.


elephantsElephants can smell water up to 3 miles away. They are also one of the three mammals that undergo menopause – the other two being humpback whales and human females.


koalaKoala bears almost exclusively eat only eucalyptus leaves and nothing else.


beaverBecause beavers’ teeth never stop growing, they must constantly gnaw on objects to keep them at a manageable length. Their teeth would eventually grow into their brain if they didn’t maintain them.


swarm of antsBeware an ant uprising! There are one million ants for every human in the world. These resilient creatures also never sleep and do not have lungs.


oysterOysters can change gender depending on which is best for mating. Talk about successful adaptation.


Butterflies have two compound eyes consisting of thousands of lenses, yet they can only see the colors red, green and yellow.



snailDon’t try this at home, but a snail can grow back a new eye if it loses one.


turtleYou can tell a turtle’s gender by the noise it makes. Males grunt and females hiss.


giraffeGiraffes have no vocal cords and their tongues are blue-black in color.


squirrelYou might want to thank a squirrel the next time you enjoy the shade of a tree. Millions of trees are accidentally planted by squirrels that bury nuts and then forget where they hid them.

Humpback Whale

Humpback whaleHumpback whales create the loudest sound of any living creature. And you thought the loudest sound came from that two-year-old you sat next to on your trans-continental flight, didn’t you?


dog noseDogs’ nose prints are as unique as human fingerprints and can be used to identify them.


seahorseThe slowest fish is the seahorse, which moves along at about 0.01 mph.


pigPigs communicate constantly with one another; more than 20 vocalizations have been identified that pigs use in different situations, from wooing mates to saying, “I’m hungry!”


poodleContrary to popular belief, French poodles actually originated in Germany. Maybe you should’ve named her Gretl instead of Fifi.


hummingbirdHummingbirds are the only birds that can fly backwards and their wings can beat at up to 80 times per second.

Parasites & Disease

par•a•site [ˈparəˌsīt]
an organism that lives in or on another organism (its host) and benefits by deriving nutrients at the host's expense.

dis•ease [diˈzēz]
a disorder of structure or function in a human, animal, or plant, especially one that produces specific signs or symptoms or that affects a specific location and is not simply a direct result of physical injury.

Mites (ectoparasitic arachnids)

MItes are tiny eight-legged creatures belonging to the Order Acarina and are related to spiders and ticks. Some mites live freely and others as parasites. Mites can attack plants and animals, carry disease, and cause allergies.Flying squirrels affected by:
Psorergates glaucomys
Euhaemogamasus ambulans
Trembicula micrati
Haemolaelaps megaventralis
Haemogamasus reidi
Androlaelaps fahrenholzi

Lice (ectoparasitic insects)

Lice are wingless, normally flat-bodied insects with short antennae, complex mouthparts and six short legs adapted for clinging to feathers, hair or fur. There are two basic types of lice: chewing lice (skin, feathers, fur) and sucking lice (blood).

Flying squirrels affected by:
Haploplura trispinosa
Nechaematopinus sciuropteri (this is the louse that transmits typhus fever bacterium Rickettsia prowazekii)from southern flying squirrrels to humans)
Enderleineilus replicatus
Microphthirus ucinatus

Fleas (ectoparasitic insects)
Flying squirrels affected by:
Opisodasys pseudarctomys
Epitedia faceta
Orchopeas howardii (this is the flea that transmits typhus fever bacterium Rickettsia prowazekii)from southern flying squirrrels to humans)
Peromyscopsylla catatina
Conorhinopsylla stanfordi
Leptopsylla segnis

Protozoa (endoparasitic, single-celled micro-organisms)
Flying squirrels affected by:
Eimeria parasciurorum
Eimeria dorneyi
Eimeria glaucomydis
Eimeria sciurorumTrypanosoma denysi

Acanthocephala (endoparasitic, bilaterally symmetrical worm-like organisms)
Flying squirrels affected by:
Moroliformis clarki

Nematoda (endoparasitic, (mostly) microscopically small,eelworms, roundworms, threadworms)
Flying squirrels affected by:
Capillaria americana
Citellinema biturcatum
Enterobius sciuri
Syphacia thompsoni
Strongyloides robustus

Cestoda (endoparasitic tapeworms, all of which lack a gut)
Flying squirrels affected by:
Raillietina bakeri


Flying squirrels in North America are considered to be vectors (carriers) of only ONE disease that affects humans, a form of typhus. The Centers for Disease Control in Atlanta, Georgia state that this flying squirrel-specific typhus (Rickettsia prowazekii) is endemic to parts of the eastern United States, but this disease rarely is passed on to humans (since 1976, only 30 cases have been reported, and not all were confirmed to be passed on by flying squirrels).

Typhus synonyms: epidemic typhus, louse-borne typhus fever, typhus exanthematicus, classical typhus fever, European typhus, Brill-Zinsser disease, jail fever

Flying squirrels are NOT associated with rabies, or any other known disease that affects humans. (Message to the Canadian Food Inspection Agency - there has never, ever been a report of a North American flying squirrel ever having contracted monkey pox. Mmmkay?)
This is not to say that flying squirrels can't contract rabies, just that this disease is a very rare occurrence in flying squirrels. The first ever recorded case of rabies involving flying squirrels as the known carrier was in 1961 (Venters H,D, Jennings, W.L., Rabies in a flying squirrel. Public Health Rep. March, 1962;77:200. PMID: 13925340 [PubMed - OldMedLIne for pre-1966). There have been but a few instances since that time, however, there is a much more prevalent transmissable disease that affects southern flying squirrels, namely epidemic typhus.
Epidemic typhus is a potentially severe, but treatable disease once thought to cycle exclusively between humans and body lice. In the mid-1970s, it was discovered that southern flying squirrels were a reservoir for the typhus pathogen,Rickettsia prowazekii.

No other animal is known to be a host species. In the past 25 years, 39 cases of flying squirrel suspected typhus in humans has been reported. Most occur during the winter months in flyer trappers and individuals removing nest debris from attics or nest sites. Individuals involved in inspection of red-cockaded woodpecker nest are at risk as flying squirrels frequently usurp their tree cavities.

Between 1962 and 1975, investigators demonstrated the typhus pathogen in southern flying squirrels captured in Florida and Virginia. In the decade after this discovery. a number of cases of typhus were documented among persons living in eastern and southern USA, all of whom had some type of contact with flyers.

In human transmission, body lice become infected while obtaining a blood meal from an infected individual and subsequently shed organisms in their feces before the lice themselves die of the infection. Humans then become infected by direct contact with the louse feces via a mucous membrane or dermal abrasion (usually from scratching irritated skin), or by inhaling infectious material (feces). The typhus incubation period is usually 12-14 days before early symptoms appear e.g. headache, chills, fever, nausea, and muscle aches. Fever is often higher in the evenings and does not get better with aspirin. Another common sign is a flat, red rash (typically on the trunk of the body and spreading to the limbs). Later signs are photophobia (bright light hurting the eyes), stupor, vomiting and leg pain. Severe complications are meningitis, encephalitis, pneumonia, renal failure, or gangrene of the extremities due to microvascular damage.

Typhus can also establish latency and reappear years or decades later in a recrudescent form called Brill-Zinsser disease. These symptoms are often milder, but not always less severe that the initial infection. Fatalities are rare.

Effective treatment consists of tetracycline therapy. Laboratory testing is the only definitive way to diagnosis typhus.

Flying Squirrel Reservoirs:

The isolation of the typhus organism in flying squirrels was discovered while studies were being done on the ecology of Rocky Mountain Spotted Fever in Virginia and Florida in the 1970s. Most cases of typhus in humans have been reported from states within the range of the southern flying squirrel. Studies on the epizootiology of infection in wild populations of flyers indicate that the organism responsible for typhus exhibits a stable pattern of infection in animal populations rather than massive epidemic cycles. Flyers populations experience seasonal fluctuations in infection intensity with peak s during the winter and spring months. most new infections were noted in pups experiencing their first cold season.

During these months, there is a corresponding peak in the organisms that transmit typhus. Flyers carry the Rickettsia for 2 to 3 weeks before becoming ill. Flyers are hosts to 2 of the principle vectors of typhus ... fleas and lice.

Of the 39 cases of flyer-associated typhus, all but one case in California came from the Southern flyers range and most occurred during the winter. While many individuals were seriously ill and most hospitalized, no deaths occurred.


The mechanism of transmission from flyer to humans remain speculative. It is thought that the transmission is by inhalation or by skin or mucous membrane inoculation of infected infectious louse or flea feces. Histories of close contact with flyers or flyer nesting material in the days prior to illness onset exist in all cases.
These contact generally involve removal of flyers from a home or other building, or cleaning of an infested area.

The risk of infection to wildlife biologists and others exposed to flyers appear to be greatest during the colder months of the year and in handling flyers and nest material. Wildlife biologists engaged in red-cockaded woodpecker reintroduction are also at risk as are persons who maintain captive animals.

Prevention and Avoidance:

An individual may reduce his probability of developing the disease by protective measures (e.g. wearing gloves, eye protection. mask) when engaging in risky activity with flyers.

Typhus can be a severe disease and persons who are unable to take tetracycline because of pregnancy or allergic reactions are recommended to avoid handling flyers and flyer nests, or to rigidly adhere to the use of protective barrier equipment. This is also recommended for immunocompromised or immunosuppressed individuals.

Dr. Mary G. Reynolds et al., Viral and Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.