• No symptoms or very few
  
• Symptoms may occur immediately or take more than 20 years.
  
• At times, worms can be passed whole or in segments in the stool.
  
• Digestive tract (stomach, intestine, liver, colon, and rectum) with intestinal worms:
  Abdominal pain or bloating, weakness, diarrhea, loss of appetite, weight loss, vomiting, anemia, malnutrition with deficiencies of vitamins (B 12) minerals (iron), fats, and protein.  Itching around anus and vagina, inability to sleep, urinating in bed, and abdominal pain seen in pinworm infections.
  
• Skin:

- Eruptions, fluid-filled sacs called vesicles or bullae, intense facial swelling, especially around the eyes.

• Allergic reactions:

- Skin rash, skin itchiness and itchiness around the anus (pinworm).

• Lungs (threadworm and fluke):

- Coughing, coughing blood, difficulty breathing.

• Liver flukes:

- Enlarged tender liver, fever, abdominal pain, Diarrhea, yellowish skin.

• Brain (Cysticercosis):

- Headache, seizures, vomiting, visual changes, dizziness.

• Bones (Echinococcosis):

- Fractures

• Heart:

- Irregular heart rate

• Bladder:

- Blood in urine, pain below the belly button, and pain upon urination.

• Lymphatic involvement:

- Swollen elephant-like legs or testicles

1. Trichinella Spiralis -- the cysts of this worm can live in pork and other meats (dog, horse, bear, walrus) that when eaten, can cause serious disease in the host.  The disease is called Trichinosis (Tr.).
   
2. Toxocara Canis -- causes a syndrome called visceral and ocular larva migrans or Toxocariasis (To.).  The eggs are found in dog feces.  Often presented in kids' eating dirt.  Cat and raccoon feces may carry similar worms.
   
3. Ancyclostoma brazilien -- eggs of this worm pass from cat or dog feces and drop in the soil, where it can then enter humans through a cut in the skin, causing a condition known as cutaneous larva migrans (Creeping Eruptions or CE).
   
4. Angiostrongylus cantonenis (AC) or rat lungworm -- rat droppings contain the eggs picked up by snails and slugs.  Humans eat vegetables contaminated by snail slime, raw clams, snail, freshwater shrimp, crab, and fish that may have eaten or been exposed to this parasite.  The disease is known as Angiostrongyliasis.
   
5. Gnathostomiasis (Gn) is acquired by eating undercooked or raw fish (sashimi) or poultry.  The eggs of the Gnathestoma spinigerum are found in dog or cat feces eaten by chicken, fish, or other animals.

• Intestinal Nematodes:

1. Ascariasis (round worm Rw) -- the eggs are found in the feces of the worm ascaris and humans accidentally ingest them from contaminated soil, such as from fertilizer on vegetables.  The worms can grow in the intestine and migrate through the blood to other sites, such as the lungs.  They can grow up to 40cm.
   
2. Necator americanus and Ancylostoma duodenale (hookworm or Hw) -- worms deposit eggs through their feces in soil and the larvae enter a skin cut and invade the lungs of the host -- in this case man.
   
3. Strongyloidiasis (threadworm or Tw) -- worm feces containing the eggs hatch into larvae (in the soil) and enter a cut in the skin of its human host, to travel to the lungs where the worms grow and cause problems.
   
4. Trichuriasis (whipworm or Ww) -- transmitted via larvae in the soil and accidentally ingested to grow in the small and large intestine.
   
5. Entrobiasis (pinworm, Pw or seatworm) -- about 40 million Americans are infected.  The adult worm lives in the intestines and comes down to the rectum and anus, lays eggs so that when the human host scratches its anus area, eggs get under the nails and infect others.

• Trematodes or flukes:

1. Shistosomiasis (Sh) -- after the adult worm lays eggs, they hatch into Cercariae, infecting brain and muscle.  They come from eating raw or undercooked fish or meat from tiny fluke that live off snails, fish, Crabs, and vegetation in fresh water rivers and ponds.  The Cercariae penetrate through a cut in human skin and migrate to different parts of the body (intestine, liver, lungs, bladder, etc.) and cause various illnesses.  Eating undercooked crab, crayfish, or smoked and pickled fish are also ways of infection.
   
2. Paragonimiasis (oriental lung fluke), Clonorchiasis (oriental liver fluke) -- are examples of many different types of fluke, with variety of conditions associated with them.

• Cestodes or tapeworms:

1. These worms have many segments.  They often invade the digestive tract, where they get their nutrition from their host.
2. Diphyllobothriasis or fish tapeworm infection (intestine), Taeniasis Saginata or beef tapeworm infection (intestine), Cysticercosis (Cy) or pork tapeworm all come from animals that have eaten the eggs of these worms.
3. Echinococcosis (Ec) or hydatid diseases are caused by variety of worms infecting animals that ingest the eggs, such as rodents, dogs, sheep, cattle, and humans.  They can invade and grow in many organs, such as liver, bone, heart, and brain.
4. Hymenolepiasis Nana and Diminuta larval stage occurs inside insects and fleas (rats and mice) and if these insects are eaten, as in uncooked cereals, they can grow in the intestine and cause problems.

• Filariasis: