Ascariasis- symptoms, cause, treatment and how to prevent it!

Ascariasis

Ascariasis is an infection of the small intestine caused by Ascaris lumbricoides (A. lumbricoides), which is a species of roundworm. Roundworms are a type of parasitic worm. Infections caused by roundworms are fairly common. Ascariasis is the most common roundworm infection. About 10 percent of the developing world is infected with intestinal worms, according to the World Health Organization (WHO). However, infections with parasitic worms are not as common in the United States, according to the Centers for Disease Control and Prevention (CDC).

Symptoms

The incubation period is variable because the parasite's life cycle may take four to eight weeks to be completed. The signs and symptoms of the nematode infection by Ascaris lumbricoides may include the following:

·         Abdominal discomfort

·         Abdominal cramping

·         Abdominal swelling (especially in children)

·         Fever

·         Coughing and/or wheezing

·         Nausea

·         Vomiting

·         Passing roundworms and their eggs in the stool

Cause

You can become infected with ascariasis after accidentally ingesting the eggs of the A. lumbricoides roundworm. The eggs can be found in soil contaminated by human feces or uncooked food contaminated by soil that contains roundworm eggs. Children often become infected when they put their hands in their mouths after playing in contaminated soil, according to WHO. Ascariasis can also be passed directly from person-to-person. After ingestion, the A. lumbricoides roundworm reproduces inside your intestine. The worm goes through several stages:

·         Swallowed eggs first hatch in the intestine.

·         The larvae then move through your bloodstream to your lungs.

·         After maturing, the roundworms leave your lungs and travel to your throat.

·         You’ll either cough up or swallow the roundworms in your throat. The worms that are swallowed will travel back to your intestine.

·         Once they’re back in your intestine, the worms will mate and lay more eggs.

·         The cycle continues. Some eggs are excreted through your feces. Other eggs hatch and return to the lungs.

Risk factors

Although the nematodes are distributed worldwide, the most common areas they inhabit are areas where the climate is warm and moist such as tropical and subtropical regions of the world. The highest risk factors for contracting this infection are poor sanitation and poor hygiene. Ascariasis is transmitted indirectly in most cases by an uninfected individual ingesting contaminated food or water that contain the Ascaris eggs deposited by infected humans in their feces into the environment. Children are commonly infected in these areas; children are more frequently infected than adults.

Complications

There are a number of complications that may occur with untreated ascariasis. Following is a list of these complications:

·         Bowel obstruction

·         Pancreatitis (inflammation of the pancreas)

·         Cholecystitis (inflammation of the gallbladder)

·         Peritonitis (inflammation of the abdominal cavity lining)

·         Intussusception (an intestinal condition in which part of the intestine is pulled into itself, creating an obstruction)

·         Volvulus (abnormal twisting of the intestine)

·         Peritoneal granulomas (scar tissue lining the abdomen)

·         Hepatic (liver) abscesses

·         Pneumonitis (inflammation of the lungs)

Organs other than the intestinal tract and lungs may be occasionally involved; some patients may have allergic reactions that may become severe. About 11,000 deaths occur each year worldwide due to bowel obstructions caused by ascariasis, with the majority of patients being children.

Diagnosis

Most diagnoses are made by identifying the appearance of the worm or eggs in feces. Due to the large quantity of eggs laid, physicians can diagnose using only one or two fecal smears. The diagnosis is usually incidental when the host passes a worm in the stool or vomit. The eggs can be seen in a smear of fresh feces examined on a glass slide under a microscope and there are various techniques to concentrate them first or increase their visibility, such as the ether sedimentation method or the Kato technique. The eggs have a characteristic shape: they are oval with a thick, mamillated shell (covered with rounded mounds or lumps), measuring 35-50 micrometer in diameter and 40-70 in length. During pulmonary disease, larvae may be found in fluids aspirated from the lungs. White blood cells counts may demonstrate peripheral eosinophilia; this is common in many parasitic infections and is not specific to ascariasis. On X-ray, 15–35 cm long filling defects, sometimes with whirled appearance (bolus of worms).

Treatment

Doctors usually treat roundworm with antiparasitic drugs. Medications most commonly used include:

·         albendazole (Albenza)

·         ivermectin (Stromectol)

·         mebendazole (Vermox)

If you have an advanced case, you may need other treatment. Your doctor may recommend surgery to control a larger infestation. You’ll need surgery if the roundworms are completely blocking your intestines.

Prevention

Prevention is by improved access to sanitation which includes the use of properly functioning and clean toilets by all community members as one important aspect. Handwashing with soap may be protective; however, there is no evidence it affects the severity of disease. Eliminating the use of untreated human faeces as fertilizer is also important. In areas where more than 20% of the population is affected treating everyone is recommended. This has a cost of about 2 to 3 cents per person per treatment. This is known as mass drug administration and is often carried out among school-age children. For this purpose, broad-spectrum benzimidazoles such as mebendazole and albendazole are the drugs of choice recommended by WHO.