MOSQUITOS, MAGGOTS, LEECHES, CENTIPEDES AND BEDBUGS
Mosquitos are flies (their name means "little fly" in Spanish). They first appeared bout 170 million years ago during the age of the dinosaurs, and today they are found in virtually every part of the world. The species that causes yellow fever and malaria are believed to have diverged about 150 million years ago.
There are 3,500 species and subspecies of mosquito, three fourths of which live in the tropics. Once they have left the larval stage, mosquitos typically live 7 to 10 days. Some females live as long as 30 days. If the weather is too hot, mosquitos quickly dehydrate and die. [Sources: Lewis Nielsen, National Geographic, September 1979; David Schwartz, Smithsonian; David Zimmermann, Smithsonian]
Mosquitos are though to transmit more diseases than other creature. They carry over 80 different diseases, including malaria, yellow fever, encephalitis and dengue fever. There are more than 500 known mosquito-borne viruses, but not all of them have harmful affects on humans.
Mosquitos fly at a speeds around 3mph. The buzzing noise produced by mosquitos is generated by wings flapping at a rate of 200 to 500 beats a second. Mosquitos can cover long distances. Some have been captured 100 miles out at sea. They are most vigorous in temperatures above 80°F. They get sluggish at 60°F and disappear when the temperatures drop below 50°F. The can hibernate through the winter and spring back to life when the temperatures warm.
On a day to day basis both sexes feed on flower nectar and fruit juices like other insects. These are the only things that males feed on. Females need protein-rich blood to produce viable eggs. They extract blood not just from humans but from a variety of creatures and are attracted by the body heat, carbon dioxide and the lactic acid and folic acid in the sweat of prey, which they can detect more than a 100 feet away.
Websites and Resources on Health and Diseases: Centers for Disease Control and Prevention cdc.gov/DiseasesConditions ; Disease Pictures hardinmd.lib.uiowa.edu/pictures ; World Health Organization (WHO)statistics and data who.int/research ; World Health Organization (WHO) disease outbreak alert who.int/csr/disease ; Third World Traveler thirdworldtraveler.com/Disease/diseases ; Health Map healthmap.org ; Medline Plus medlineplus/healthtopics ; Merch Manuals (detailed info many diseases) merckmanuals.com/professional/index ; Health Images Directory healthline.com/directory/images
Book: Mosquito: A Natural History of Our Most Persistent and Deadly Floe by Andrew Spielman and Michael D'Antonio (Hyperion, 2001)
Mosquito Mating and Young Mosquitos
Females may go through several cycles of mating, feeding, and egg laying. A stomach full of blood signals the female to start producing eggs. Females mate just once, storing the sperm in special pouch to fertilize several batches of eggs. Each batch requires a new meal of blood. The male dies soon after mating. After ejaculating sperm some mosquitos produces a kind of plug which seals the female's orifice and prevents other males from impregnating the female.
Some species of mosquito lay their eggs directly in water. Others lay them in a dry area expected to flood. In places with human populations, mosquitos often lat their eggs in bird baths, pet dishes, puddles, small pots, potted plants, and old tires. Mosquitos take advantage of every bit of standing water to lay their eggs. That is why there are so many mosquitos in tundra regions, which floods after the spring thaw. Scientists in the Canadian Arctic have recorded attack rates of 9000 bites a minute, enough to cause a person to lose half his blood supply in two hours and cause death.
Generally, within a few days after the eggs are laid they hatch, releasing larvae that swim around, breath through snorkels and survive off organic material. After molting for the fourth time, which occurred about a week after hatching, the larvae becomes pupa which do not eat and float around the water. A few days later the pupa skins break open and a mosquito emerges and flies away and is ready to mate and start the cycle over again.
Mosquitos, Blood and Disease
aegypti Only female mosquitos bite. They are capable of carrying three times their body weight in blood. They need the protein and nutrient-rich hemoglobin in the blood to nourish their eggs. One good feeding provides enough nutrients for 75 to 500 eggs. Males have no interest in blood.
To extract blood a female places its proboscis (a long tube that extends from the mouth) in the skin and penetrates the skin with a mandibles that flip out of her mouthpart like switchblade. When the skin is pierced a pair of tubes called fascicles enters the body to search for blood. A mosquito’s proboscis looks like a solid spike but is actually a composite of cutting blades and feeding tubes, powered by two tiny pumps. After taking position on a female drills through layers of epidermis and fat until she reaches blood-filled micro-capillaries and the starts to drink.
Once the a capillary is pierced by the fascicles, two powerful pumps inside the female’s head draw out the blood. Mosquito's saliva contains hundreds of chemicals, including anticoagulants that prevent the blood form clotting and compounds that dilate the capillaries to increase flow. A mosquito often draws its own body weight in blood in one feeding.
Mosquitos have an efficient anticoagulant in their saliva. When mosquitos bite they deposit a protein that keeps the blood from coagulating as they drink it. The body responds by producing histamines to fight off the invaders. It the histamines that cause the skin to swell, turn red and itch.
Speed is critical. The mosquito usually lands, finds the blood and sucks it less than two seconds. Those that linger to long are often swatted and killed. Weighted down by the blood it usually flies some place to rest. There are still things about the process that scientists don’t understand. For example friction should make sucking blood through a feeding tube with an infinitesimally small diameter impossible.
Japanese medical researchers have been able to reduce the pain of an injection by using hypodermic needles edged with tiny serrations, like those on a mosquito’s proboscis, minimizing nerve stimulation.
gambiae For protection from insects use an insect repellant with at 30 percent DEET (some people recommend 95 to 100 percent), wear long pants and long sleeve shirts, treated with "Coulston's Duranon Tick, spray, and sleep under an insecticide-impregnated insect netting. Periodically check your body for ticks. If a tick penetrates your skin, remove the entire tick with tweezers or a tick removal kit by grasping the head and slowly backing it out.
Disease-carrying mosquitos, like most mosquitos, generally bite at night between dusk and dawn, and are particularly fierce around sunset. An exception to this rule are mosquito that carries dengue fever. They generally bite in the day. Mosquitos generally go for the lower extremities of the body. People with a high skin temperature and high moisture-transpiration rates sometimes attract more mosquitos.
The best way to avoid disease-carrying mosquitos and insects is avoid the places where the diseases are known to exist. The Center of Disease Control can provide information on countries and regions where diseases are found. Rural areas are generally more risky than urban areas. Local people can often provide information on specific risky places in their area.
The best way to avoid mosquitos is to: 1) stay inside when they are most active (in the late afternoon, early evening, and early morning); 2) sleep under a mosquito net (tucked under the mattress and treated with an insecticide); 3) cover as much of your body with clothing as possible, wearing long sleeve, light-colored, loose-fitting clothing; 4) use a repellant and your skin and a toxicant on your clothing; and 5) stay in hotels that are well-screened or air-conditioned, if screens are insufficient ask for mosquito netting. Fans and mosquito coils are also effective in keeping mosquitos away. Sandals should be avoid and pants should be tucked into socks in places with lots of ticks. White or light clothing makes ticks easier to spot.
Many Africans who live malaria-endemic areas use nets but still get the disease. Many people in hot countries don't like them because the keep out the breeze.
DEET and Permethrin
Use a DEET insect repellents on your skin. DEET is a strong chemical that interferes with the tiny sensory hairs and pits in the antenna and body it uses to detect carbon dioxide.. DEET is toxic if ingested; stings eyes severely; and can blister the skin in high concentrations. Repellents with 30 to 35 percent DEET are good. They the usually only last for around five hours. Higher concentrations, such a 95 percent to 100 percent, don’t add any more protection but they last longer. Aerosol insecticides and mosquito coils help to clear rooms but they sometimes contain DDT. Non-DEET repellants generally work 1½ hours or less.
The Centers for Disease Control and Prevention recommend products containing DEET, picaridin, IR3535 and the oil of lemon eucalyptus. They say put some on you clothes for greater protection. If you wear sun screen, apply the insect repellant on top of it.
Use a spray or repellent with Permethrin or Permanone (such as Coulston's Duranon Tick Repellent) on your clothes, shoes, tents, camping gear and bed netting. Permethrin often maintains its potency through ten or more washing. It bonds tightly with cotton fabric and It is effective enough to knock out a mosquito by the time sticks its probe through the cloth and it aims it towards the victims skin.
Some people are turned off by the odor of DEET and the chemical os not suited for all ages. Alternatives include the chemical Picaridin and the plant-based oil of lemon eucalyptus.
Short History of Mosquito Repellents
anopheles Over the centuries a variety of concoctions with things like vanilla, eucalyptus sassafras, cloves, citronella, and pennyroyal have been touted as effective insect repellents. Geoponika , a collection of classical Greek agricultural writings published in the A.D. 6th, recommended using salt alum to get rid of flies and bats and was tied to tall trees kept locusts away.
Researchers sometimes check the mosquito concentration in a given area by rolling up their pant legs and counting how many times they get bitten in a certain length of time. Scientists measuring the effectiveness of repellants count number of mosquitos that bite per minute when an forearm is exposed to mosquitos inside a tank. One scientist told Smithsonian magazine, "It isn't difficult to find substances that repel insects. What's difficult is finding a truly useful repellant” that lasts a long time against a variety of pests under a variety of conditions and doesn’t harm people.
Shortly after World War II, researcher who had tested over 20,000 compounds in an effort to find sometime to protect U.S. servicemen in the Pacific from insect-borne diseases, discovered a chemical that deterred all known insect pests twice as long as any previous compounds. The new chemical, N.N. dieth-meta -toluamide (later called "DEET") was added in 1957 to a new insect repellant called Off! and three years later to Cutter’s. The drug was tested by men who stuck their arms into tanks filled mosquitos.
DEET is the most widely used insect repellant in the world. For a long time scientists weren’t sure how DEET worked. In 2008 , a team at Rockefeller University in New York lead by Leslie Vosshall announced in the journal Science they discovered that it affects the mosquito’s nose by blocking a highly-specific molecular pathway that tells the insect’s brain what it is smelling. In particular, it interferes with he ability of the mosquito to smell 1-octen-3-ol—a telltale ingredient of human breath—and lactic acid, one of the smellier sweat component. Researchers Walter Leal and Zainukabeuddin Syed didn’t agrees with this conclusion. They argue that mosquitos simply dislike the stuff. They came to this conclusion by using several different delivery systems that responded to different senses—of which smell was just one—and found that mosquitos were turned off to them in every case.
A toxicant known as permethrin and by the trade name Permanone Tick Repellant was developed in the early 1980s.
Mosquitos seem to prefer some humans over others: children over adults, blondes over brunettes and blacks more than whites and aggressively go after some people and leave others alone. It is still not known why this is so. Scientist thinks that this because some people give off chemicals that attract them and others gives off chemical that repel them. Scientists in British took the body odor off people that turned mosquitoes off and applied it to people who attracted mosquitos and found that the body odor repelled the mosquitos.
Mosquito Eradication, See Malaria
Maggots as a Cure
Doctors are increasingly taking a serious look at maggots (flesh-eating fly larvae) as a treatment for severely wound and ulcerated legs because the treatment has proven to be effective, easy and cheap. Maggots are very good at cleaning festering, gangrenous wounds. They are used on diabetics and other people who have a hard time getting wounds to heal by pressing them into dying flesh with wire-mesh bandages. Greenfly larvae are given patients who are assured that the maggots will not burrow into their skin. Maggots are especially effective fighting the super bug antibiotic-resistant staphylococcus aureus.
Maggots eat dead tissues and killing bacteria that could block the healing process. The use of maggots was common in the 19th century and early 20th century but fell out of favor after antibiotic were invented. The practice was revived out of concerns of patient using too many antibiotics.
Among the cultures that have that have used maggots have been Aboriginals in Australia, hill tribes in Burma and the ancient Mayans. Napoleon’s doctor commented on their effects. In World War I doctors discovered that soldiers that had been left untreated had healthy, pink flesh under their maggot-infested wounds. Their efforts to promotes maggots as a form of treatment was dismissed after antibiotics became widely embraced.
Dr. Thomas Stuttaford wrote in the Times of London, “The value of maggots in removing irretrievably wound-damaged tissue came into its own in World War I...In trench warfare, wounded soldiers often had to lie in no man’s land for hours, sometimes a day or two, until they could be brought back by patrols after dark...My father , who was a doctor for three years in the trenches, said he always reassured the casualties whose wounds were playing host to maggots that, disgusting as they looked, they would hasten the healing of the their wounds....Claims that maggots may have antiseptic action that destroys bacteria are quite possibly true but more important is that they remove the decaying flesh that makes a wonderful culture on which bacteria flourish.”
Researchers have found that maggot treatment for a severe, festering wounds can reduce the duration time of the treatment from weeks to days and cut the cost from $4,400 to $600. A study by maggot-supplier Zoobiotoc published in the Journal of Wound Care found that an ulcerated leg could be treated effectively with12 boxes of maggots, each containing 300 maggots. To treat the same wound with hydrogel, the common treatment for leg ulcers, cost $4,400.
bed bug Bed bugs are wingless insects that hide in the creases of mattresses, carpets and bedroom furniture and crawl out at night to suck the blood of human victims while they sleep. Victims wake up and find large, bloody, itchy welts on their skin.
Bed bugs are parasites that feed on the blood of humans, bats and chickens. Adult bedbugs can live up to a year without eating, which makes them especially hard to kill. A single female can lay enough eggs to infest an apartment. Evidence of bed bugs includes small dark spots on the mattress (possibly bed bug excrement), blood stains and unexplained bites on the skin.
After World War II, better household hygiene and the use of strong pesticides help eliminate them from the United States. But in recent years they have made a comeback there in part because the pesticides that brought them under control are now deemed to be too dangerous to use and the high number of international travelers that bring the bugs back from their trips. The good news about bed bugs is that they do not transmit any disease.
Removal of bed bugs can be very expensive. In the United States, it can cost between $500 and $1,000 to treat an office, apartment or house. The treatment by a professional usually involves a heavy dose of sprayed steamed chemicals to kill the insects. Trained dogs that cost about $8,000 to $10,000 each are often employed to search for bed bugs. If you want to try to do it yourself you can scrub mattresses, vacuum the carpets and caulk places where you think the insects might be hiding. If an insufficient job is done they can come back.
Bed bugs are expected to displace cockroaches and termites as the leading domestic pest insect in the United States soon if they haven’t already.
Websites : bedbugger.wordpress,om
bed bug life cycle
Bed Bug Sex
Bed bugs have a rather gruesome means of reproduction. The male has a sharp, pointed sword-like penis. He bypasses the females genitalia and thrust this needle-like penis through the body wall of the female’s abdomen into her body cavity and injects his sperm, which migrates to the ovaries and fertilizes the eggs. Female bed bugs suffer a 25 percent higher mortality rate than males as a result of infections introduced through the wounds. Females mate after the eat when their bodies have swelled up to 30 percent larger than normal size and they are unable to escape from the males.
Mike Siva-Jothy, a bed bug expert at the University of Sheffield, told the Times of London, “This is a bizarre reproductive rite. This is so extreme it has only evolved once, The consequences of this form of mating is females die sooner, males are basically killing the females.”
Female bed bugs are only known creature in the animal kingdom to possess an immune organ. The organ produces a wave of white blood cells as a line of defense against sexually-transmitted infections caused by males. When bed bug have sex the females suffer nasty wounds that easily become infected. Their immune organ is being studied as a way of producing a strong immune response of fight diseases such as malaria.
Ticks and Lice
Ticks are blood-sucking creatures related to spiders. They evolved from spiders and became parasites. They have eight short legs, powerful jaws and special sense organs at the end of their front legs that enable them to locate a host by detecting odors and humidity.
Ticks wait on leaves, stems and grass for a host to pass by. This may seem likely a inefficient way of locating a host. Ticks are very patient. Some species can go for seven years between meals.
Once it finds a host, a tick digs through the hair to the skin , cuts an incision with its pincers and, holding on with its teeth, inserts its grooved snout, covered with backward-pointing hooks, through which it sucks blood. It will gorge itself for several hours or days and may swell from the size of rice grain to the size of a large marble. If it is mature, it will drop off and breed.
Ticks have powerful proteins and efficient anticoagulants in their saliva. The slow-feeding ixodid tick alternatively sucks blood and inserts its saliva in the wound, using proteins that deactivate the host’s immune system, preventing inflamation and immune system responses. A bite that otherwise would cause itching or pain remains unnoticed allowing the tick to continue feasting on blood. The rapid-feeding Argasis tick produces proteins in its saliva that prevent the blood from clotting so it can feast quickly on its host and drop off and make an escape.
You can avoid lice by washing yourself, your hair, and your clothes frequently. If you are worried have a friend examine your hair for lice eggs which usually laid near the base of the hairs. They can be redirected with an insecticide shampoos such as Lorexanne, Suleo and Pormula PCT (Delva).
Leeches are segmented, hermaphroditic worms. There are 650 known species of them. Some are quite specialized. One lives exclusively in the nostrils of Saharan camels. Another feed only on earthworms. Yet another feed on fishes found in freezing polar waters. Horse leeches can reach a length of eight inches. The largest species is found in the Amazon basin. It reaches a length of 18 inches and has an six-inch proboscis. .
New World leeches tend to track their hosts through the water. Old World leeches stalk their prey on land. Most species of leech like be near water.. They are found in ponds, wetland and tropical rainforests. In many places they appear in the rainy season and disappear in the dry season. Leeches are good swimmers. They swim like eels, except with their tails forward.
Leeches feed on other live animals, ether swallowing worms, snails of insect larvae or attaching themselves to a host and sucking their blood. A typical leech is one is one to 4 inches long and has suckers at each end of its body and has three jaws, arranged in a "Y," with sawlike teeth. It’s “brain” is a collection of 32 nerve bundles located in the middle of its body. If enough hosts are available a leech can live for five years.
Websites and Resources: Leech Pictures mongabay.com/topics/new/leeches ; Leeches USA medical suppliers leechesusa.com ; Leech Videos videos.howstuffworks.com/discovery ; Removing a Leech wildmadagascar.org/overview/leeches ; Leech fact Sheet australianmuseum.net.au/Leeches ; Wikipedia article Wikipedia ;
Leeches are elongated and somewhat flattened. The suckers at the front and back of their body enables them to "inch" about by alternatively attaching and releasing suckers and extending and contracting their bodies." The suckers also allow them to grip their's host's skin while they drink blood.
Leeches can absorb oxygen through their body walls in both water and air. They were once placed in jars and used like barometers to predict the weather. When the parametric pressure fell, suggesting a strong possibility of rain, the leeches swim to the surface.
Leeches have pimple-like sense organs that can detect the heat of potential hosts and have stomachs that extend almost the entire lengths of their bodies. A leech can swell out its highly elastic body as if fills with blood with the help of numerous small sacs on its sides can increase with capacity.
Hermaphroditic leeches copulate on land by wrapping around each other, secreting mucus. Afterwards secrete a cocoon to house the fertilized eggs, which are deposited in damp soil. After two to four weeks about 15 to 20 inch-long baby leeches hatch and begin their quest for fresh blood. Under ideal conditions, a leech can produce 1,200 offspring its five-year lifetime.
Leeches deliver an anesthetic, an antibiotic and chemicals that dilate blood vessels. Leeches fasten themselves with their hind suckers and suck the blood through little holes which they make in the skin with their 300 or sharp teeth with their tripartite jaw. Ducts between the teeth release compounds into the leech’s saliva that anesthetize the wound, prevent clotting and dilate vessels to increase blood flow. In some cases blood will continue to ooze up to 48 hours after the leech has been removed.
A leech typically needs 20 to 40 minutes to feed. When it is done it often increases in size tenfold. Some species swell up to the size of a cigar and prevent half a cup of blood from coagulating. One leech meal may last several months and take up to 18 months to completely digest. In that time the leech does little more than lie around and reproduce.
Leeches detect warmth, motion and shadows and drop off branches or find hosts from the ground. In the case of humans, they usually crawl up a host's leg from the ground and attach themselves to the first area of flesh the come to, usually above the socks. Leeches like earlobes, and burrowing between toes. They are capable of climbing on hammock strings to reach their victims. When leeches are full of blood they fall and the bleeding gradually stops Normally people stop bleeding after 10 minutes, but sometimes continue bleeding for up to 10 hours.
Some areas more infested than others. It is not unusual for people traveling in rain forests to pick off 20 leeches or more a day. To deter leeches keep moving and apply insect repellant to your shoes and socks and roll up your socks over you pants. Some people wear pantyhose to keep away leeches. In spite of leeches, many forest dwellers go barefoot Their advise with leeches is to "surrender what they want to them. If they feel happy, you will too."
Leeches can be detached by exposing them to a flame or sprinkling them with salt or alcohol. The methods employed regular visitors to swamps and rain forests is to burn it off with a lighter simply by holding the lighter next to the leech until in falls off. The bites don't hurt or itch but there is a possibility of infection if the a portion of the leach remain in the body. The bleeding can go on for 24 hours.
History of Leeches and Healing
For centuries physicians used leeches under the mistaken belief that they world help balance a patients’s body fluids or “humors.” George Washington is said to have died after doctors used leeches to drain huge quantities of blood during his illness.
Leeches were used by the pharaohs as a means or reducing blood pressure and were depicted on Egyptian tombs dated at 1500 B.C. Using leeches for bloodletting probably originated in ancient China and India.
In the Middle Ages leeches were used as a treatment for headaches and other disease. They became so linked with medicine that the Anglo-Saxon word for doctor and for leech were the same. In 17th and 18th century, leeches were used to treat nosebleeds, laryngitis, kidney infections, mental illness and variety of the ailments. France imported 41 million leeches in 1833.
Leeches and Healing Today
Today, leeches are used to increase circulation in severed limbs that have been reattached which is vital if the limb is survive. When reattaching or transplanting appendages blood-delivering arteries are relatively easy to stitch together because they have thick walls while blood-draining veins are more difficult to deal with because they have relatively thin walls and are frail, often clotting and turning blue after surgery, sometimes killing the new appendage. Leeches suck the blood, helping it circulate, reducing the pressure on veins, buying time for the body to create its own veins. Leeches also let a doctor now how well things are going because they won’t attach unless there is good arterial flow of blood.
The Hirudo medicinalis is the species of leech used most on medicine. It is five to 10 inches long. When it bites, substances in the saliva keeps the blood from clotting and keep blood oozing out for up to 48 hours after the leech has been removed. One woman who had her scalp reattached after it and her hair were pulled into a machine told Discover magazine, “I had them on my neck and back of my head. There was bucket of them in the room with me. Blood was pouring our of my scalp 24 hours a day for a week.”
Leeches are also the sources of new blood thinners and anticoagulants. Scientists have found disease-fighting peptides in leeches that are produced within 15 minutes and diffuse quicker and easier than antibodies. Scientists are also experimenting with producing leech compounds in mustard plants.
Biopharm in Swansea Wales is the main supplier of medical leeches in the world. Leeches are breed and raised on pig bloods. After about six months they stored in a cooling chamber with the temperatures set ast 45°F. They can remain there for up to year without being fed.
Medicinal leeches cost about 30 cents to produce and are sold to doctors in the United States for between $6 and $9. Leeches sold by Leeches U.S.A. are delivered by a Federal Express and cost around $7 a piece.
Companies in France and the Ukraine make face creams for leeches.
Centipedes and millipedes are terrestrial anthropods with many legs, with one pair on each of their many segments. Their heads have biting and antennae. They live primarily in forests in humid areas because they lack waterproof skin and breath through their skin like insects. Centipedes are carnivorous and have venomous claws to kill prey. They can run fast and often found among leaf litter. Millipedes are slower and mostly herbivores
Some rain forest centipedes can reach a size of 12 inches long and have poisonous fangs. Some species can inject enough poison to kill a small bird, mouse of frog. Smaller ones often possess the most poisonous toxin, Some centipedes are brightly colored. Other have dark bodies and legs that are bright yellow.
Segmented creatures like centipedes were the first creatures to walk on the earth. They appeared before insects and some species reached a lengths of two meters. From gills they developed breathing tubes called a tracheae. Some millipedes build their nests out of poop.
Young centipedes start off with just six of legs. As the get older they shed their skin and get a new pair of legs for every segment that is attached.
Four-inch-long poisonous black centipedes with yellow legs are prized ingredients in some oriental medicine concoctions in Korea and some places in China. These disgusting creatures can be quite aggressive. When attacked they rear up and strike like snakes and can run amazingly fast. My wife was bitten on the foot by one that crawled into her bed. Her foot was swollen for about a week.
A sign in front of herb shop in Kyongdong market in Seoul read: "Centipedes: we will roast and grind them for you." A centipede tonic in the shop was prepared according recipe described by Huh Joon, a Chosun dynasty physician who lived from 1546 to 1615. "Describing a man who sold centipede juice on the streets of Seoul, one American wrote in the Korean Times, the man "displays a whole towel that is positively crawling with centipedes the size of tongue depressors. With an enormous pair of tweezers, he picks off the centipedes and drops them in a boiling vat. From a tap at the bottom of the vat, a thick red liquid oozes into glass vials."
Image Source: Centers for Disease Control and Prevention cdc.gov/DiseasesConditions
Text Sources: CDC Health Information for International Travel, U.S. Department of Health and Human Services; National Geographic, New York Times, Washington Post, Los Angeles Times, Times of London, The New Yorker, Time, Newsweek, Reuters, AP, Lonely Planet Guides, Compton’s Encyclopedia and various books and other publications.
© 2009 Jeffrey Hays
Last updated March 2011