Roundworms

Roundworms (Also known as Nematodes) includes Ascarids, Hookworms, Stongyloids, Heartworms, and Whipworms

Wow, where do I start? I guess I’ll just focus on those roundworms that can cause disease in humans which are passed through animals (zoonotic). Many pets have their own kind of roundworms that are not passed to humans. The safest bet here is to worm all your pets and livestock regularly and wash your hands after exposure to dirt or feces of ANY kind! And the thing is? Your doctor does not know your history and even you may have forgotten what you played with, that you loved the beach and sand, or were exposed via dirt or cleaning something. This is why I’m writing so much about symptoms and signs in these pages. Sometimes you have to do your own investigative work to convince the doctors which tests to do or to try a prophylactic worming.

Optimally, it’s best to get an identification as to which type of worm to treat so that it can be treated correctly. So, a fecal sample, urinalysis, ELISA blood test or some type of biopsy can be important tests. And hopefully the lab will have a parasitologist on staff and that the parasite worms will show up in the testing. . .

We were taught in our parasitology classes that if you took everything away from the world and left only roundworms, we would be able to see a perfectly formed planet kind of like a skeleton made of roundworms. There are that many roundworms in our soil.

Roundworm statistics: There are over 20,000 classified species of nematodes. This group of parasites have survived for over 370 million years on the Earth and can measure anywhere from less than one mm. up to eight meters in length. The soil can contain as many as 100 million nematodes/sq. m. and many species live 15 to 39 years or longer

Pictures of two species of intestinal roundworms. Roundworms (depending on the species) can be tiny like in the left picture, look like bean sprouts or Top Ramen like in the right picture, or can be a couple of feet long (like in pig roundworms which can be passed to humans through their feces).

Symptoms of intestinal roundworms in general include: Fevers, cough, wheezing, stomach problems, diarrhea, constipation, abdominal cramping, appendicitis, gas, bloating, increased cramping (menstrual), heart palpitations, pain in the lower right quadrant that comes and goes (spasms in the ileocecal valve), itchy anus’, dry lusterless hair with split ends, seizures, pica appetite (often for sugar), clear mucous strands in the stool (yes you should be looking at it each time you go! And yes, I will ask you what it looks like if you ever consult with me.) People and animals with lots of parasites also have big bellies and lots of diameter below the belly button caused from the intestines losing their tone. Most times worms can be diagnosed by looking at the bowel contents under a microscope or doing a blood test, but not always.

Prevention: worm your animals (pets and livestock regularly), don’t use pig feces for human food gardens (pig roundworms pass to humans), wash your hands regularly especially after playing or working with pigs and before you eat, don’t eat raw or pickled fish (esp. herring and squid),

Roundworm—Angiostongylus causes Angiostrongyliasis which affects the abdomen but can migrate to the nervous system causing headaches, stiff neck and back, meningitis, seizure and paresthesia. They can also get into the eyes causing vision disturbances. Angiostrongylus is passed by snails, slugs, planaria, fish, land crabs and rats. Make sure you thoroughly wash greens and cook your snails before eating them. Diagnosis is through muscle or tissue biopsy.

Roundworm—Anisakis causes Anisakiasis is caused by Anisakis marina giving acute abdominal pain, peritonitis and bloody diarrhea. People and animals get the parasite by eating raw, pickled or lightly salted fish or squid. Treatment is with surgery or endoscopic removal. There are medications as well that have been used with some success.

Roundworm—Ascaris causes Ascariasis. The pig roundworm, passed through feces, is called Ascaris suum and can be passed to humans. Symptoms include respiratory distress, coughing, fever, colic, vomiting and diarrhea. People working around swine are very susceptible and if vegetables are not washed thoroughly a person can ingest the eggs and be host to the adult worms. A similar organism is found in the clouded leopard and causes subcutaneous abscesses in humans.

Roundworm—Ancylostoma braziliense, the common dog/cat hookworm, causes Cutaneous Larval Migrans, but other species in the roundworm family Ancylostoma, Uncinaria, Bunostomum (cattle hookworm), Gnathostoma (dog, cat and pig roundworm), Capillaria (rodent, dog, cat and poultry whipworm) and Stongyloides can also cause cutaneous larval migrans. Picture of an Ancylostoma egg in a fecal floatation:

Symptoms include itchy, red serpentine lesions and secondary bacterial infections (from scratching). The soil and sandy beaches get contaminated with feces from infected dogs or cats so sunbathers, fishermen, hunters, gardeners, construction workers, pest exterminators, children and anyone with skin, but one human can pass it to another human as well or from one spot to another area on the same body. Here are some pictures of cutaneous larval migrans in a human:

Treatment includes Thibendazole, sedatives and anti itch products. I’ve used clove flea shampoo with success for some of these cases. The trick is to worm stray animals and/or keep them off the local beaches. Duck poop also harbors a parasite that may contaminate swimming holes (Swimmer’s itch).

Roundworm—Ancylostoma duodenale or Necator americanus causes Hookworm Disease. Symptoms include abdominal pain, iron-deficiency anemia, heart problems and stunted growth, but there also may be no symptoms. Eggs are discarded into the feces of animals or humans which hatch in the soil. These infective larvae can now penetrate the skin (usually through bare feet), and get into the lungs through the lymph and blood system. Here are some hookworm egg pictures from a fecal flotation:

Roundworm—Capillaria causes Capillariasis. Three species affecting humans are Capillaria hepatica (liver) C. phillipinensis (intestinal) or C. aerophila (pulmonary). There are lots of symptoms with this one depending on the species, for example; enlarged liver and spleen, intermittent fever, nausea, vomiting, diarrhea, edema, and fluid in the abdomen. The intestinal form can cause abdominal pain, sporadic diarrhea, and weight loss. The pulmonary form can cause asthma, cough, fever, mucoid or bloody discharges being coughed up. You can get this from just about any infected animal—especially carnivores like dogs, cats, fox and even some birds or fish. Don’t eat raw fish. Rats seem to be heavily contaminated with this parasite.

Roundworm—Dioctophyma renale causes Dioctophymiasis. Symptoms of this disease in the human include renal dysfunction, blood in the urine and kidney spasms. Urinalysis will reveal the eggs of D. renale but if the parasite is male, it can burrow into the abdomen and must be removed surgically. Eating raw or undercooked fish, frogs or crawfish livers can cause the disease. Here is a picture of a D. renale egg in the urine:

Roundworm—Dirofilaria causes Heartworm which is a form of Filariasis. Filariasis, is defined as disease caused by the presence of filariae in the tissues of the body and is caused by nematodes (roundworms) that inhabit the lymphatics and subcutaneous tissues.

Eight main species of roundworms infect humans: Dipetalonema does not affect humans, but Wuchereria bancrofti and Brugia malayi cause lymphatic Filariasis (also known as elephantiasis), and Onchocerca volvulus causes onchocerciasis (river blindness). The other five species are Loa loa, Mansonella perstans, M. streptocerca, M. ozzardi, and Brugia timori. (The last species also causes lymphatic filariasis.) Picture of a Dirofilaria in blood samples. To diagnose one of these types of worms you can use blood tests, antigen testing, other lab tests like ELISA, or you can determine which species it is by identify the adults.

Symptoms include painful swellings under the skin, lymph duct inflammation, enlarged and painful testicles and fever. Heartworm symptoms include fatigue after exercise; cough and ascites (build up of fluid in the abdomen). These worms are passed by mosquitoes and the black fly Simulium.

Treatment of heartworm (if heartworm doesn’t kill the animal first) is with diethylcarbamazine or Ivermectin. Prevention is really important and it’s also really important to get your dog tested for heartworm BEFORE giving it the preventative because if the wormer or preventative kills the worms off too quickly, the animal may have an anaphylactic reaction and die. It’s a bad deal.

Roundworms—Dracunculus medinensis and D. insignis cause Dracunculiasis. An adult worm releases larvae into a water source which are ingested by Cyclops (common in lakes). The animal or human ingest the water and the larvae develop into adult worms. A little blister erupts, usually in the lower extremities and is accompanied by fever, nausea, diarrhea and generalized itching before more blisters break out. Sepsis is common. Sometimes you can see the worm move in the lesion. Gross. Most cases are in Africa and India but there have been a few cases in the eastern United States in dogs, wild carnivores and raccoons. Most animals can harbor the parasite. Treatment includes niridazole and diethylcarbamazine. Um. . .I won’t describe how you get the worm out of the body. Google it. It’s gross! The right picture shows a worm poking its head out of the lump. Ewww. Don’t swim in dirty water—especially in foreign countries!

Roundworm—Enterobius vermicularis (Pinworms or Seatworms) causes Enterobiasis. The severity of disease depends upon the worm load, since most nematodes cannot multiply in their host. The picture on the right shows what you see on a positive pinworm scotch tape test under the microscope (after staining) and upon an endoscopic rectal exam (right picture):

This particular worm is only passed to humans via humans by fecal-oral route. The eggs can also stick to bed sheets or become airborne. Adults mature and settle in the small intestine, colon and cecum. The females sneak out at night and lay eggs around the perineal areas. Symptoms usually include an itchy anus but they can also cause problems with the gut such as abdominal pain and appendicitis. Diagnosis is with the Scotch Tape Test. You stick a piece of tape, sticky side to the skin, on the anal area then tape it to a microscope slide which is stained and viewed to find the eggs. The adult female pinworm is about 10 millimeters long, the male pinworm is much smaller. In the old days, physicians used to tell the parents to sneak into the child’s room at night with a flash light, spread the child’s legs and turn the flash light on to see if they could see the worms coming out of the anus. Gross! Can you imagine how many emotional problems were caused from that ordeal! These days you’d probably be labeled as a pervert! Treatment Enterobius vermicularis can be treated with several antihelminthic drugs, e.g. pyrantel pamoate, pyrvinium pamoate or mebendazole.

Roundworm—Strongyloides (also called Threadworms) cause Strongyloidiasis. These roundworms are passed through fecal contaminated soil and water. Larvae in the soil penetrate the skin. Here is a picture of a Strongyloides worm in a fecal floatation.

Common animals that act as host to this species include humans, dogs, foxes, cats, primates, rodents, horses and raccoons. A fecal sample is necessary to identify the eggs. Symptoms are not that evident, but can include itching at the point of entry, coughing, nausea and vomiting, abdominal pain, straining to defecate and weight loss. This is a common cause of colic in horses and one main reason why horse owners should worm their horses as least every quarter (rotating the types of wormers so the parasites don’t get resistant to the same wormer given time and time again.) Feeding in feeders or where the hay does not contact the soil is also important. Treatment is with thiabendazole or mebendazole.

Roundworm—Thelazia: Thelaziasis is caused from Thelazia species of roundworms. This one likes the eyes. Flies feed on lacrimal secretions and inadvertently act as vectors in transferring the larvae into the eye. Symptoms include conjunctivitis (pinkeye) photophobia (sun sensitivity) and tearing. Corneal scarring can happen with chronic infection. You can actually see the worm move across the visual field. Treatment is by removing the worm surgically and controlling flies.

Roundworm—Trichinella: Trichinosis is caused by the roundworm Trichinella.

Trichinella larvae are passed to humans and other animals by eating meat that has been improperly cooked. The larvae penetrate the stomach and intestines and find a resting spot as they embed within the muscles. Above is a picture of a muscle biopsy containing a Trichinella worms. I had a couple cases of this in some forestry employees. Someone shot a cougar and made jerky out of it and shared it with their entire office. Five people came down with the disease. Very painful. It can also be passed by the meat of pork, bear, seals, rats, dog, cats and many other wild animals. Diagnosis is by ELISA blood test and muscle biopsy. Treatment is with thiabendazole and steroids to help with the inflammation of the muscles where the larvae embed. Prevention includes thoroughly cooking all meat including meat scraps fed to other animals.

Roundworm—Trichostongylus: Trichostrongyliasis is caused by the roundworm species of Trichostrongylus, Haemonchus and Ostertagia. This one is common in cattle and other ruminants and can be passed through the fecal-oral route. Some people get infected because they use cattle dung as a heat source. Symptoms of Trichostongylus are not as obvious as with some of the other roundworm species and include diarrhea, abdominal pain, and lack of appetite or weight loss. Treatment is with Pyrantel Pamoate.

Roundworm—Toxocara: Visceral Larval Migrans or Ocular Larval Migrans is caused by Toxocara canis and cati (dog, cat and wild felid roundworms), Baylisascaris (passed by raccoons—uh. . .this one can also migrate to your brain and kill you!) and Gnathostoma. It is not the same worm that causes Toxoplasma although it has a similar name. Symptoms include: fever, cough, skin rash diarrhea, vomiting, pneumonitis and general icky feeling. With eye involvement there may be retinoblastoma, strabismus and blindness. Transmission is through contaminated dirt or plants and by eating undercooked and contaminated fish, meat and poultry. Treatment is with diethylcarbamazine, albendazole, or mebendazole. Prevention is through proper hygiene, cooking, and routine worming of pets. Cutaneous larva migrans should not be confused with visceral and ocular larva migrans, which are due to the ingestion of the eggs of the parasite Toxocara canis or Toxocara cati. Children with pica or people eating unwashed raw vegetables have the greatest risk of acquiring visceral and ocular larva migrans. Picture of Toxocara canis in a fecal sample:

Roundworm, Toxoplasma: Toxoplasma cati or T. gondii, are one-celled protozoa. Common Sources of Infection—Raw and undercooked meat, water contaminated with the eggs and cat feces. Symptoms: Causes blindness in children. Most healthy individuals do not show symptoms of toxoplasmosis, but when they do occur they may appear to be a viral infection: enlarged lymph nodes, muscle pains, and fever. Diagnosis and Prevention of Toxoplasma: Diagnosis is usually made by comparing symptoms of the patient with laboratory tests, such as seeing the protozoa in tissue or finding antibodies specific to Toxoplasma in the patient's blood serum. Prevention is the best option to prevent spread of Toxoplasma. Pregnant women must take care to cook her foods well to kill all cysts present in meat. Hand washing after working outside in the soil will help, and pregnant women should not change or being around cat litter. Freezing also will kill oocysts. Fresh produce should be peeled, or at least washed well. Treatment: Sulfa drugs or a homeopathic made of Toxoplasma kills the parasite. We use Epstein Barr drops and Parasite/Amoeba/Protozoa drops in our practice. This one is more common in AIDS patients and those with severely challenged immune systems. Here are a couple pictures of Toxocaris leonina eggs in a cat fecal floatation.

Toxoplasma Life Cycle: Toxoplasma has a complicated life cycle and is an organism capable of infecting many mammals and birds, but its main host is the cat. Only in the cat is the full life cycle of the parasite able to be completed. Initially the cat may get infected from capturing and eating an infected mouse or bird. The meat of the infected animal has pockets of a special form of Toxoplasma called bradyzoites, which are released from the meat into the cat's small intestine soon after ingestion. The parasite grows and multiplies within the cells lining the cat's intestine. This phase of the life cycle is called the intestinal phase, and eventually results in the formation of oocysts. These are released by large numbers into the cat's feces but are not infectious at first. After a day or so in the environment they mature or sporulate into infectious oocysts, which then are not only resistant to chemicals and drying, but also can infect whatever mammal happens to eat them. They can persist in the environment for months and be carried about by rain, wind, earthworms, and insects (another good reason for routine worming!) They may eventually end up on produce or on pastures where different grazing animals may ingest them as they graze. They might also get into irrigation water to be used to water produce which may be for human consumption.

The other life cycle phase is the extra-intestinal, as it involves the parasite leaving the intestine (as the motile form called tachyzoites) and entering other cells within different organs in the body. The parasite forms a special cyst called the zoitocyst within the animal's muscle, brain, lymph node or other tissue. Within these cysts the bradyzoites can persist for many years, often without harming the host, as long as the host has a healthy immune system. It is also this extra-intestinal phase that is so harmful to the human fetus, as the motile form of the parasite may cross the placenta to infect the fetus. This may result in spontaneous abortion or either a stillborn or physically and/or mentally handicapped child.

The cat may have either of these life phases present or both, shedding oocysts while also having zoitocysts within its tissues. All other infected animals (including humans) only have the extra-intestinal phase present. Healthy individuals may have the dormant cysts present in their body and show little signs of infection for many years. The parasite also may be triggered to multiply and spread when something lowers the immunity of the host (HIV infection, chemo-therapy treatment, or some other combination of factors).

The fetus within its mother is still growing and developing its immune system, so it is more vulnerable in the early stages of its life, when the immune system is not yet developed. An infection to the fetus during the last trimester may not be as devastating to the fetus as some immune system functioning is present.

One wonders why we don’t pick up Toxoplama more often—especially for those of us who own cats. Could it be that we build up immunity to this organism if our immune system is functioning? It would seem to make sense as serologic surveys show that 7-94% of various populations are infected with the organism and are usually symptomatic. The disease occurs worldwide.

If an infection is found, there are antibiotics which can be taken, so early diagnosis is especially urgent for those pregnant or immunocompromised. Children as well are at risk.

Schistosomiasis, also known as bilharziasis, swimmer’s itch or snail fever, is a primarily tropical parasitic disease caused by the larvae of one or more of five types of flatworms or blood flukes known as schistosomes. All five species are contracted in the same way, through direct contact with fresh water infested with the free-living form of the parasite known as cercariae. The building of dams, irrigation systems, and reservoirs, and the movements of refugee groups introduce and spread schistosomiasis. Eggs are excreted in human urine and feces and, in areas with poor sanitation, contaminate freshwater sources.

The eggs break open to release a form of the parasite called miracidium. Freshwater snails become infested with the miracidium, which multiply inside the snail and mature into multiple cercariae that the snail ejects into the water. The cercariae, which survive outside a host for 48 hours, quickly penetrate unbroken skin, the lining of the mouth, or the gastrointestinal tract. Once inside the human body, the worms penetrate the wall of the nearest vein and travel to the liver where they grow and sexually mature. Mature male and female worms pair and migrate either to the intestines or the bladder where egg production occurs. One female worm may lay an average of 200 to 2,000 eggs per day for up to twenty years. Most eggs leave the blood stream and body through the intestines. Some of the eggs are not excreted, however, and can lodge in the tissues. It is the presence of these eggs, rather than the worms themselves that causes the disease.

Symptoms of Schistosomiasis infection: Many individuals do not experience symptoms. The first symptom of the disease may be a general ill feeling. Within twelve hours of infection, an individual may complain of a tingling sensation or light rash, commonly referred to as "swimmer's itch," due to irritation at the point of entrance. Other symptoms can occur two to ten weeks later and can include fever, aching, cough, diarrhea, or gland enlargement.

With intestinal Schistosomiasis obstruction of the colon and blood loss can occur. Potbelly look, high blood pressure, enlarged spleen, ascites (build up of fluid in the abdomen), swollen areas in the esophagus and sometimes nervous system can be affected.

With urinary tract Schistosomiasis there is blood in the urine with associated iron deficiency anemia, pain upon urinating, increased frequency of urination, blocked urinary tracts and sometimes bladder cancer.

Diagnosis of Schistosomiasis: Malaria, typhoid and scabies all have to be ruled out as they look very similar to Schistosomiasis. Has the patient traveled to third-world countries? Is the eosinophil white blood count elevated? Are there eggs evident in the urine or feces? Blood in the urine? Don’t hesitate to repeat fecal tests several times as the eggs may not show up for several months. There is an antigen test for the Schistosoma parasite although it may not be readily available in the United States. Ultrasound, CAT scan and MRI may be indicated to detect damage to the blood vessels, liver and to detect polyps and ulcers caused by the parasite.

Treatment of Schistosomiasis: Praziquantel (Biltricide), oxamniquine (intestinal signs), metrifonate (for urinary forms)

Prevention of Schistosomiasis: Water systems must be treated to kill the worms and control snail populations, and sanitation must be improved to prevent the spread of the disease.

Trichuris is present all over the world, but mostly it resides in tropical climates and in places with poor sanitation. We see it in the veterinary world in places that have lots of species of animals or lots of dogs where they do not pick up the poop ever. Symptoms are not present or can include rectal prolapse following bloody diarrhea. Transmission: They are spread through the feces and infect the body via fecal-oral ingestion or the mature eggs. The whipworm can survive six years in the host and lives in the cecum and descending colon (left lower abdomen area) where it embeds in the inner layer of the gut. The adult Trichuris lay eggs for about a year—3000 to 20,000 per day! Diagnosis is through finding the eggs in a fecal floatation or by seeing them in the lining of the gut with an endoscope. Treatment is with Mebendazole, Vermox, Revapol, Vermicol, Vermidil, and Vermin, but Pyrantel pamoate and Combantrin have also been used off label. Off Label means that the Food and Drug Agencies have not tested to see if this is a safe or effective treatment for this particular parasite. Prevention: There are no simple and effective ways of removing whipworm eggs from the soil around your house. However, a contaminated environment can infect your dog over and over again. The best way to combat reinfestation is to make sure your dog's quarters are sunny and dry, since whipworm eggs require moisture. Try to place him in an area of fresh new gravel, pavement or soil.

Salmon Poisoning (Fish Flu) is passed by the Nanophyetus salmonicola fluke present in raw fish (especially Salmon). This fluke sometimes harbors a toxic rickettsial organism inside called Neorickettsia helminthoeca. It is the rickettsial organism that is harmful and potentially fatal to the canid family which includes dogs, foxes, coyotes, and wolves. Salmon poisoning occurs most commonly west of the Cascade mountain. Symptoms, which usually appear within six days after eating the raw fish include: vomiting, lack of appetite, fever (up to 104 degrees F), diarrhea, weakness, extremely swollen lymph nodes and dehydration. If left untreated death usually occurs within two weeks of eating the infected fish.

If you think your animal may have gotten into fish or it wanders the neighborhood and may have gotten into a trash can with fish in it, please tell your veterinarian. Diagnosis is through symptoms and by doing a direct fecal smear of the golden looking diarrhea and seeing the golden-colored eggs in the fresh stool (if we’re lucky). A needle biopsy of the lymph node can also reveal the rickettsial organism.

Treatment includes antibiotics (usually tetracycline), steroids and a tape wormer (I use Cestex. Often symptoms and extensive treatment can be abated if the tape wormer is given within 24 hours of ingesting the fish. Dogs respond very quickly with treatment—usually in only a couple days. Prevention: Keep dogs away from raw fish, fish cleanings, and fish skin. And it’s nice to have a dose of tape wormer with you if you are headed into the woods for a week-long fishing trip with your dog!

Question: Can I get roundworms and tapeworms from my pets? Good question and I get that question a lot. If you worm your pets regularly, you shouldn’t have this problem. Dog and cat worms are mostly different than most human worms. Most worms are species and host specific which means they can’t live in a human or animal that is not a part of their reproductive life cycle. For most people the benefits of having pets far outweigh the risks. The exception is zoonotic parasites which include those worms which include both animals and humans in their life cycles. Reference: http://www.pethealthcouncil.co.uk/people.shtml

There are only a few species of worms that are zoonotic (passed from your dogs and cats to you) but there are LOTS of worms and bacteria passed through contaminated water sources. (For information on how to test and filter your water, see our Water section.)

Question: Will store-bought wormer work the same as a wormer I’d get from my doctor or veterinarian? No. Many stores still carry Piperazine wormer which has been so overused that it is no longer an effective wormer. Piperazine is often marketed as a “monthly” wormer in the pet sections. And if the product contains a tapeworm medicine (like Clorpyriphos which is an organophosphate wormer), that may cause some serious side affects. Never use these store bought wormers on pregnant animals. They can strain to pass the worms so much that they can rupture their uterus and die. Always get tapeworm medicine from your doctor or veterinarian as we carry much safer brands than the grocery or feed stores do AND the professional guidance for their use. (See section on Common Wormers)

Well, that’s worms in a nutshell (or in this case, an intestine!) Appetizing, eh? What alarms me (and it should alarm you as well) is that clean, uncontaminated water is extremely important to us. You’ve just read almost a book on JUST those parasites that are passed to us through animals, fish, soil and water. This is just the tip of the iceberg here. I haven’t even talked about viruses or bacteria or chemicals that are passed through our water sources. I think the best we can do is keep educating and protecting ourselves as best as we can. So, get your water tested and get the appropriate filtration system!