Ascariasis. by:Dr. Sajid Mumtaz Sodhar,

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Good health is a blessing of ALLAH. Then which of the blessings of your ALLAH will you ( human & jin ) deny. ( Surrat Rahman ):

Good health is a blessing of ALLAH. Then which of the blessings of your ALLAH will you ( human & jin ) deny. ( Surrat Rahman ) To make money, we loose our health and then to restore our health, we loose money. We live as if we are never going to die and we die as if we never lived…… Dr. Sajid Mumtaz Sodhar

Ascaris lumbricoides:

Dr. Sajid Mumtaz Ascaris lumbricoides

Case Study (06-03-2009):

Case Study (06-03-2009) Mr. Khan, 35 yrs old Afghani pt: referred from private clinic to the surgeon as a case of intestinal obstuction.

History :

History 35yrs old male Afghani, not to known any chronic disease,presented in ER with h/o off and on generalized abdominal pain,, not radiating, associated with nausea and sometime vomiting for wks. No h/o fever/loose motion/constipation. No h/o weight loss. Not smoker/Denying using illicit drugs. O/E: Vitals – N, G/Exam: unremarkable. S/Exam: unremarkable except tenderness in rt:hypochondrium,lumbar & iliac regions with mild rigidity but no rebound tenderness, no visceromegaly, no ascitis, sluggish bowel sounds and no bruit. Investigations: FBC, Hb:14gm, MCV: 75, WBC: N, differential-N, Plt: N…….Bioch: N. A.X.Ray: showed gaseous distention and few scattered fluid levels in central adbomen and cecum. U.S abdomen showed gaseous distention and fluid collection in POD.

Case Study:

Case Study

PowerPoint Presentation:

Ascariasis is a disease caused by a parasite , which is an organism that depends on another organism for its survival.  The specific parasite involved in Ascariasis is known as Ascaris lumbricoides.  A. lumbricoides is a type of nematode or roundworm.  It has also been referred to more commonly as the giant, intestinal roundworm .  A. lumbricoides is actually the largest intestinal round worm found in humans.  It is also one of the most common parasites found in humans.  It currently affects more than 1-1.5 billion people worldwide.  Ascaris lumbricoides

Ascaris lumbricoides:

Most people harboring A. lumbricoides show no signs of infection with the roundworm .  Some people may show early pulmonary symptoms and eosinophilia during the larval migration of the parasite.  Later on, some patients may also have abdominal symptoms.  Occasionally, A. lumbricoides can cause life-threatening disease from the worm bolus or ectopic migration of the worms .  The worm lives in the upper part of the small intestine, and there are no reservoirs for the parasite.  Ascaris lumbricoides

Ascaris is known as a large, intestinal roundworm. :

Ascaris is known as a large, intestinal roundworm. 

PowerPoint Presentation:

It looks like a garden worm. It has 3 finely toothed lips. Transmission is through feco-oral. It migrates through liver & lungs, settling in small intestine. Often asymptomatic. If in bile ducts, cholangitis or pancreatitis can occur. GI obstruction/perfaration is rare.

Ascaris lumbricoides:

Here is the specific classification of Ascaris lumbricoides : Domain  Eukarya Phylum   Nematoda Order     Asaridida Family    Ascaridoidea Genus     Ascaris Species   lumbricoides Ascaris lumbricoides

History of Discovery:

History of Discovery Anatomy of A. lumbricoides was first described by Edward Tyson in 1683.  However, at that time it was known as Lumbricus teres not A. lumbricoides.   It was actually Linnaeus, who renamed Ascaris and gave it its current name. Linnaeus named the roundworm Ascaris lumbricoides because it showed very morphology as that of the similar earthworm, Lumbricus terrestrias .

Clinical Presentation in Humans:

Clinical Presentation in Humans Clinical Case Study A 37-year-old man comes to your office after passing something in his stool that he thought was a rubberband.  He became worried when he saw the objectmoving in the toilet.  Apart from this occurrence, he is a healthy man and is not taking any medications.  He has had no recent change in bowel habits or stoolappearance.  He has not had fever, abdominal pain, cough or rash.  He does notsmoke, drink alcohol, or use recreational drugs.  He has been physically activeand recently completed a weeklong backcountry hiking expedition in the Southeastern U.S.  Other than this expedition, he has not been traveling recently.

PowerPoint Presentation:

With the clinical history and presentation in mind the following are some possible diagnoses: 1) Ascaris lumbricoides (round worm) infection 2) Toxocara (visceral larva migrans) infection 3) Trichuris (whipworm) infection 4) rubber band ingestion. It turned out that this patient had Ascaris lumbricoides. 

Clinical Correlation (Signs and Symptoms) :

Clinical Correlation (Signs and Symptoms) Ascariasis is the disease caused by the parasite Ascaris lumbricoides .  Typically, Ascaris infection does not cause visible disease.  Most cases of Ascaris infection tend to be asymptomatic.  Clinically inapparent disease occurs with low infection of Ascaris, meaning that not many eggs are ingested.  However, if hundreds of eggs are ingested, as seen in the early experiments by Shimesu Koino, the patient can develop pneumonitis.  Pneumonitis occurs when the larvae migrate to the lungs.  This pneumonitis also known as Loeffler’s syndrome, can appear four days to two weeks after infection occurs. 

PowerPoint Presentation:

Some patients may also develop asthma, and the asthma attacks can persist until worms are removed.  Often times the development of asthma in a non-asthmatic person can be a clue of ascariasis.  In addition, liver enlargement and general toxicity can also occur during this period and persist for up to two weeks.  Other health problems include fever, urticaria, malaise, nausea, vomiting, diarrhea, central nervous system disorders, and colic.  Nutritional problems that may develop can then lead to abnormal development in children. 

PowerPoint Presentation:

While the worms are in the intestine, they can sometimes cause a life-threatening disease.  If many worms are present, they can become entangled and form a bolus, which blocks the lumen.  Each year two cases out of one thousand have been reported noting this severe intestinal obstruction.  Another fatal condition has been reported where the worms have penetrated the small intestine leading toacute peritonitis.   

PowerPoint Presentation:

In addition, adult worms can migrate ectopically to the appendix, common bile duct, and pancreatic duct.  This is another life-threatening condition that is most often seen in small children with high parasite loads.  As a result of the worm in the biliary duct, cholecystitis, cholangitis, hepatic abscess, and pancreatitis can occur.  Suppuration can follow from deterioration of the trapped worm and secondary bacterial infection.

PowerPoint Presentation:

Early phase (The early phase coincides with larval tissue-migration.  Typically, 4-16 days after egg ingestion.)  The main symptoms include the following: -fever -cough -wheeze

PowerPoint Presentation:

Late Phase (The late phase coincides with the mechanical effects of the worms.These include GI symptoms from mechanical irritation.  Typically, 6-8 weeks after egg ingestion)  The main symptoms include the following:  -Vague abdominal complaints (cramping, nausea, vomiting) -Small bowel obstruction (mainly in children) -Pancreatitis (2ndary to worm migration) -Cholecystitis (2ndary to worm migration) -Appendicitis (less common, 2ndary to worm migration)

Transmission:

Transmission A.lumbricoides  is transmitted primarily through fecal-oral contamination .   The transmission can occur by ingesting contaminated soil, water, or food.  Usually, ascariasis is caused by directly or indirectly eating soil contaminated with feces carrying these eggs.  These eggs mature in the body , and adult female worms can then lay eggs that come out in the feces.   Note, however, that in order for the eggs to be infective or embryonated, the feces must have been infected 2-4 weeks before it is ingested.  Infection with Ascaris eggs is so common because the eggs are frequently found in the environment due to poor sanitation practices .

PowerPoint Presentation:

In addition to fecal-oral transmission of A. lumbricoides , it is also believed that ascariasis can occur by way of trans-placental transmission, since many neonatal cases have been documented.

Life Cycle:

Life Cycle Adult worms reside in the upper part of the small intestine, where they survive on predigested food.  The worms make themselves into an S-shape and press against the epithelium of the intestine while moving against the peristalsis to keep themselves in the small intestine.  The female worm lays eggs, and she can produce up to 200,000 eggs per day.   These eggs are fertilized but non embryonated, and the eggs are passed out with feces.

PowerPoint Presentation:

The fertilized eggs develop through embryonation in feces deposited in the soil.  The process of embryonation takes 2-4 weeks.  The eggs can survive many months before embryonation starts , but they need a moist aerobic environment to develop.  The eggs are only infective once they are embryonated and have larvae in them. 

PowerPoint Presentation:

Once embryonated, the infective egg must be swallowed to complete the life cycle of A. lumbricoides .  Bile salts and alkaline enteric juice of the small intestine stimulate the release of the larvae from the eggs.  These second-stage larvae then travel from the small intestine to the liver.   Then the larvae migrate to the heart via pulmonary circulation.  The larvae are now third-stage larvae in the alveolar capillaries, and they enter the alveolar spaces.  Afterwards they migrate to the bronchi into the tranchea and then to the epiglottis. 

PowerPoint Presentation:

The larvae are then swallowed, and they pass once again to the small intestine.  There they molt twice and mature into adult worms.  The adult worms can live up to one year, and the females can lay eggs in the small intestine.  However, A. lumbricoides cannot reproduce in the intestine, and it can only lay eggs that are not yet infective.

Ascaris lumbricoides:

Ascaris lumbricoides

PowerPoint Presentation:

Adult worms live in the lumen of the small intestine.   A female may produce up to 240,000 eggs per day, which are passed with the feces .   Fertile eggs embryonate and become infective after 18 days to several weeks , depending on the environmental conditions (optimum: moist, warm, shaded soil).  After infective eggs are swallowed , the larvae hatch , invade the intestinal mucosa, and are carried via the portal, then systemic circulation to the lungs .   The larvae mature further in the lungs (10 to 14 days), penetrate the alveolar walls, ascend the bronchial tree to the throat, and are swallowed .   Upon reaching the small intestine, they develop into adult worms   Between 2 and 3 months are required from ingestion of the infective eggs to oviposition by the adult female.  Adult worms can live 1 to 2 years.

Ascaris lumbricoides:

Ascaris lumbricoides

Ascaris lumbricoides:

Reservoir       No reservoir for this type of Ascaris exists outside of humans.  Pigs ave their own type of Ascaris, which was mentioned previously. Vector No vector exists for Ascaris. Ascaris lumbricoides

Ascaris lumbricoides:

Incubation Period The appearance of early symptoms of clinical disease can occur anywhere between 4-16 days after ingestion of the eggs.   Loeffler’s syndrome and other symptoms,  such as fever, coughing, and wheezing take this long to develop.  However, GI symptoms take 6-8 weeks after ingestion of the eggs to develop. Ascaris lumbricoides

Morphology:

Morphology  Ascaris is a large intestinal roundworm.  It superficially resembles the common earthworms found in the soil.  Female worms can be as long as 20-35 cms, and males tend to be smaller, no larger than 30 cms.  They can be anywhere from 2-6 mm wide.  Mature worms are cylindrical, creamy white or light brown. They tend to have tapered ends. An adult male (coiled posterior end) and a female A. lumbricoides .  Note that the anterior ends are more slender than the posterior ends.

Male and female worms.  The female shown is approximately 16 inches long.:

Male and female worms.  The female shown is approximately 16 inches long. A scanning electron micrograph picture taken of the anterior end of Ascaris. 

Diagnostic Test:

Diagnostic Test Diagnosis is usually not made clinically based on signs and symptoms .  Sometimes it can be diagnosed using ultrasonography and endoscopic retrograde cholangiopancreatography (ERCP).  Instead, diagnosis is made primarily by examining a stool specimen. Infection with A. lumbricoides is determined by microscopic identification of eggs in the stool.  Typically, the procedure used involves the following: 1) collecting stool specimen  2) fixing specimen in 10% formalin 3)concentrate using formalin-ethyl acetate sedimentation technique 4) examine wet mount of sediment Occasionally, emergence of a worm in the stool or coughed up can be used to diagnosis the patient.

Comparative egg morphology for different Nematodes and Cestodes using in diagnostics. :

Comparative egg morphology for different Nematodes and Cestodes using in diagnostics.

PowerPoint Presentation:

X-ray findings   Long, tubular filling defects, especially in distal small bowel The worm ingests barium and the barium may be seen as a thin line of contrast in the center of the worm Especially after the remainder of the barium exits the small bowel.  See below-linear streak of barium on left side of patient.

PowerPoint Presentation:

Ascariasis in an 11-year-old boy with a week of mild epigastric pain, nausea, and vomiting slightly blood-stained material. He is of Indian descent and came from Calcutta a year previously. Barium follow-through identifies several tubular filling defects seen in the jejunum, some including a thin central thread of barium, indicating the worm had ingested barium into its own alimentary tract. These are round worms (Ascads lumbricoides), a common infestation in tropical areas.

An african male with lower abdominal discomfort. The bowel mucosal pattern and lumen calibre is normal throughout. There is a linear gap in the barium column which lies along the lumen of the ileum and has a line of barium at its centre. :

An african male with lower abdominal discomfort. The bowel mucosal pattern and lumen calibre is normal throughout. There is a linear gap in the barium column which lies along the lumen of the ileum and has a line of barium at its centre.

Linear structures within the bowel :

Linear structures within the bowel

Linear structures within the bowel :

Linear structures within the bowel

Ascariasis. USG image of the right lobe of liver shows a linear non-shadowing stripe without an inner tube (arrows), in the central intrahepatic biliary radicles - “stripe” sign :

Ascariasis. USG image of the right lobe of liver shows a linear non-shadowing stripe without an inner tube (arrows), in the central intrahepatic biliary radicles - “stripe” sign

Ascariasis. USG of the left lobe of the liver shows a thick echogenic stripe (arrows), with a central anechoic tube (black arrowhead) in the central intrahepatic biliary radicles - “inner-tube” sign :

Ascariasis. USG of the left lobe of the liver shows a thick echogenic stripe (arrows), with a central anechoic tube (black arrowhead) in the central intrahepatic biliary radicles - “inner-tube” sign

Ascariasis. USG image of the porta hepatis shows a thick echogenic stripe (arrows), with a central anechoic tube (black arrowhead) within the slightly dilated common hepatic duct - “inner-tube” sign :

Ascariasis. USG image of the porta hepatis shows a thick echogenic stripe (arrows), with a central anechoic tube (black arrowhead) within the slightly dilated common hepatic duct - “inner-tube” sign

Case Report:

Case Report A 30 years female presented with pain in the right upper abdomen and epigastric region with jaundice for 6 days. History of nausea and vomiting was also present. Prior history of passage of worms in the stool was present. On general examination jaundice was present. Abdominal examination revealed mild tenderness in the right hypochondrium. Liver function test shows raised serum bilirubin (4mg %) and alkaline phosphatase (400IU/L). USG abdomen revealed dilated gallbladder without any evidence of cholecystitis with tubular echogenic non-shadowing image in the gallbladder lumen and CBD. Diagnosis of gall bladder and CBD ascariasis was made. Patient was treated conservatively and albendazole (400mg) given once a week for three consecutive doses. Patient responded well to the treatment and liver function test and ultrasound abdomen performed after three week revealed no worm in the gall bladder without any evidence of cholecystitis.

Ultrasound showing round worm in gallbladder :

Ultrasound showing round worm in gallbladder

Ultrasound showing round worm in gallbladder:

Ultrasound showing round worm in gallbladder

Dilated bowel loop and the ball of worms :

Dilated bowel loop and the ball of worms

Photograph obtained during endoscopic extraction of the worm (arrow) shows that this is whitish and extends through the papilla of Vater. :

Photograph obtained during endoscopic extraction of the worm (arrow) shows that this is whitish and extends through the papilla of Vater.

Complications:

Complications Appendicitis Jaundice (if bile ducts are involved) Pneumonia Bowel perforation Mechanical obstruction

Management and Therapy   :

Management and Therapy   

Management and Therapy   :

Management and Therapy    People with Ascaris should be treated regardless of the presence of high worm load, for ectopic migration of worms can cause life-threatening health problems.  The choice drugs for the treatment of Ascaris infection are albendazole, mebendazole, and pyrantel pamoate.  These drugs are effective with few side-effects.

PowerPoint Presentation:

Mebendazole (Vermox) and Albedazole are one class of drugs used to treat Ascaris infection.  Mebendazole has often times been considered the choice drug to treat intestinal roundworm infections.  The adult dose is 100 mg PO BID on 3 consecutive days or 500 mg once.  A second course is administered if the patient is not cured in 3-4 weeks.  Side-effects are mild, but migratory activity has been reported in response to the drug.  The dosage for Albendazole is 400 mg once.  

PowerPoint Presentation:

Pyrantel pamoate is also effective in treating Ascaris.  It can treat other nematodes, and it works by paralyzing the worms.   The dosage is 11mg/kg once (max. 1 gram). 

PowerPoint Presentation:

Apart from the 3 drugs listed above , a few other treatment exist.  Yet, these are choice drug treatments listed by the CDC.  Levamisole hydrochloride is another type of drug used to treat Ascaris.   This drug has more side-effects than Mebendazole and Pyrantel, and it works by paralyzing the worm.   In addition, piperazine salts can also be used to treat Ascaris.  Not many side-effects have been noted, but they tend to be more common than other drugs available.  They are often times used because they are cheap and effective.

Piperazine salts:

Piperazine salts

Epidemiology:

Epidemiology Ascariasis plagues more people in the world than any other parasitic infection.  Some estimate that as many as 1-1.5 billion people or approximately 1 out of 4 people are infected with Ascaris.  In some tropical areas, 100% of the population have Ascaris.  Ascariasis tends to occur more commonly in places where sanitation is minimal and human feces is used to fertilize crops.  As a result, the majority of Ascaris infections are concentrated in the developing world. 

PowerPoint Presentation:

Approximately, 59 million people are at risk of morbidity or clinical illness from Ascaris.  Children are more likely to be infected and have higher levels of worms.  1.5 million children with Ascaris infections will suffer from irreversible growth retardation.  While death from Ascaris is rare, approximately 10,000 people die from Ascaris each year.  Males tend to be more infected then females , due to behavioral habits that make it more likely for them to ingest soil.  Some evidence of genetic predispositionhas also been noted in a study of families in Nepal. 

Country Information:

Country Information

PowerPoint Presentation:

Ascaris is found all over the world.  However, it is most prevalent in warm, tropical climates, where eggs can survive the longest in the soil.  It is less common in places that are arid and seasonal.  Concentration of Ascaris seems to fall mostheavily in South-EastAsia with less cases in Africa and Latin America.  In South-East Asia approximately 73% of the people are infected.  India, Bangladesh, Burma, Indonesia, Malaysia, Philippines, Vietnam, China, Kenya, Tanzania, West Africa, Turkey, Iran, Afghanistan, Brazil, Columbia, Mexico, and Peru have all reported areas where Ascaris occurs in more than 50% of the local population living in these places.

PowerPoint Presentation:

Even in the U.S ., many cases of Ascaris occur.  Approximately 4 million people in the U.S. are infected with Ascaris, and the majority of these cases are concentrated in the rural southeast part of the country.  

Public Health and Prevention Strategies (Vaccines) :

Public Health and Prevention Strategies (Vaccines) Prevention and control of Ascaris can occur on two fronts: drug treatment and sanitation improvement.   Mass chemotherapy programs given every 6 month scan help break the cycle of constant Ascaris infection.  It is also important to educate people about adopting healthier living habits.  For instance, people can avoid eating noncooked vegetables and fruits in places lacking proper sanitation and areas that use human fertilizer.  No vaccines are currently in use to prevent the spread of this parasite.

PowerPoint Presentation:

Some of the World Health Organization’s listed combined strategies to control soil-transmitted helminthes such as A. lumbricoides :

PowerPoint Presentation:

1) Ensuring the wide availability of  single dose antihelminthic drugs in all health services in endemic areas 2) Ensuring good passive and active case management 3) Regularly treating at least 75% of all school-age children at risk of morbidity by 2010 4) Regularly treating children at risk of morbidity through the IMCI strategy 5) Improving access to safe water and sanitation through intersectoral collaboration 6) Improving hygiene behavior by scaling up sanitation education, targeted at  high-risk groups such as school-age children, women, and special occupation groups

Post-operative snap showing resected bowel with ball of round worms :

Post-operative snap showing resected bowel with ball of round worms

Post-operative snap showing resected bowel with ball of round worms :

Post-operative snap showing resected bowel with ball of round worms

Post-operative snap showing resected bowel with ball of round worms :

Post-operative snap showing resected bowel with ball of round worms

Bolus of A. lumbricoides passed from intestinal tract.  Ascaris in the small intestine.:

Bolus of A. lumbricoides passed from intestinal tract.  Ascaris in the small intestine.

Child passing A. lumbricoides.   :

Child passing A. lumbricoides.  

A. lumbricoides penetrating the small intestine causing an acute condition known as peritonitis. :

A. lumbricoides penetrating the small intestine causing an acute condition known as peritonitis.  

Collection of passed Ascaris from treatment project in school children.  :

Collection of passed Ascaris from treatment project in school children.