Ascaris lumbricoides is the "large roundworm" of humans, growing to a length of up to 35 cm. It is one of several species of Ascaris. An ascarid nematode of the phylum Nematoda, it is the most common parasitic worm in humans.

1. ASCARIS

2. INTRODUCTION
● Ascaris is a genus of parasitic nematode worms.
● It is a parasitic worm of the small intestine.
● It belongs to the class of Helminths.
● One species, Ascaris lumbricoides, affects humans and causes the disease
ascariasis. Another species, Ascaris suum, typically infects pigs.
● Parascaris equorum, the equine roundworm also called Ascarid. This is a
host-specific helminth intestinal parasite that can infect horses, donkeys, and
zebras.

3. INTRODUCTION
● A. lumbricoides is the largest intestinal roundworm and is the most common
helminth infection of humans worldwide.
● Infestation can cause morbidity by compromising nutritional status, affecting
cognitive processes, inducing tissue reactions such as granuloma to larval
stages, and by causing intestinal obstruction, which can be fatal.

4. MORPHOLOGY
● Adult: cylindrical shape, creamy white or pinkish in color.

5. MORPHOLOGY
● Male: average 15–30 cm (6-12 inches) and is more slender than female
● Female: average 20–35 cm (8-14 inches) in length

6. MORPHOLOGY
● The body is long, cylindrical, and fusiform (pointed at both the ends).
● The body wall is composed of cuticle, epidermis and musculature.
● There is a pseudocoelom (false body cavity).
● Respiration is by simple diffusion.
● The nervous system consists of a nerve ring and many longitudinal nerve
cords.
● Reproduction is exclusively sexual, and males are usually shorter than
females.

7. LIFE CYCLE OF ASCARIS
● Humans and swine are the major hosts for Ascaris; see Causal Agents for
discussion on species status of Ascaris from both hosts. Natural infections
with A. lumbricoides sometimes occur in monkeys and apes.
● Occasionally, Ascaris sp. eggs may be found in dog feces. This does not
indicate true infection but instead spurious passage of eggs following
coprophagy.

8. LIFE CYCLE OF ASCARIS LUMBRICOIDES
1. Adult worms live in the lumen of the small intestine. A female may
produce approximately 200,000 eggs per day, which are passed with the
feces .
2. Unfertilized eggs may be ingested but are not infective
3. Larvae develop to infectivity within fertile eggs after 18 days to several
weeks , depending on the environmental conditions (optimum: moist,
warm, shaded soil). After infective eggs are swallowed.
4. the larvae hatch.

9. LIFE CYCLE OF ASCARIS LUMBRICOIDES
5. invade the intestinal mucosa, and are carried via the portal, then
systemic circulation to the lungs.
6. 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.
7. 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.

11. ASCARIASIS
● High number of ascaris worms visible as black
tangled mass.
● (X-ray image with barium as contrast medium)

12. ASCARIASIS
● Ascariasis is a disease caused by the parasitic roundworm Ascaris
lumbricoides.
● An estimated 807 million–1.2 billion people in the world are infected with
Ascaris lumbricoides (sometimes called just Ascaris or ascariasis). Ascaris,
hookworm, and whipworm are parasitic worms known as soil-transmitted
helminths (STH). Together, they account for a major burden of parasitic
disease worldwide.

13. ● Infections have no symptoms in more than 85% of cases, especially if the
number of worms is small. Symptoms increase with the number of worms
present. Children are the most affected group.
● Heavy infections can block the intestines and slow growth in children. Other
symptoms such as cough are due to migration of the worms through the
body. Ascariasis is treatable with medication prescribed by your healthcare
provider.
● Humans can also be infected by pig roundworm (Ascaris suum). Ascaris
lumbricoides (human roundworm) and Ascaris suum (pig roundworm) are
hard to tell apart. It is unknown how many people worldwide are infected
with Ascaris suum.

14. EPIDEMIOLOGY AND RISK FACTORS
● Ascariasis caused by Ascaris lumbricoides is one of the most common
intestinal worm infections. It is found where access to personal hygiene and
proper sanitation practices are not available, and in places where human
feces is used as fertilizer.
● Ascariasis caused by Ascaris suum is found where there are pigs. People who
raise pigs or use raw pig manure as fertilizer may be at risk. Contact with pigs
should be considered when someone is diagnosed with ascariasis.
● Children are most commonly affected, and in this age group the infection may
also cause poor weight gain, malnutrition, and learning problems.

15. Geographic Distribution
● Ascaris lumbricoides infections happen all over the world. The eggs from the
parasite are passed in human feces and can contaminate the soil.
● The eggs survive best in warm, humid areas and must grow in the soil before
they can infect others.
● Most cases occur in tropical and subtropical areas of Asia, sub-Saharan
Africa, and America.
● Ascaris suum is found wherever pigs are found.

16. SYMPTOMS
● Although heavy infections in children may cause stunted growth via
malnutrition, adult worms usually cause no acute symptoms.
● High worm burdens may cause abdominal pain and intestinal obstruction
and potentially perforation in very high intensity infections.
● Migrating adult worms may cause symptomatic occlusion of the biliary tract,
appendicitis, or nasopharyngeal expulsion, particularly in infections involving
a single female worm.

17. SYMPTOMS
● People infected with Ascaris often show no symptoms, regardless of the
species of worm. If symptoms do occur they can be light and include
abdominal discomfort.
● Heavy infections can cause intestinal blockage.
● Other symptoms such as cough are due to migration of the worms through
the body.
● Ascariasis is treatable with medication prescribed by your healthcare
provider.

18. DIAGNOSIS
● The standard method for
diagnosing ascariasis is by
identifying Ascaris eggs in a stool
sample using a microscope.
● Because eggs may be difficult to
find in light infections, a
concentration procedure is
recommended for preparing the
fecal smears.The diagnosis is
usually incidental when the host
passes a worm in the stool or
vomit.
Microscopic view of A. Lumbricoides
eggs in stool sample.

19. ● 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 (involves a standardized amount of sieved feces being examined under
light microscopy, and subsequently get a standardized count of the amount of
eggs therein, in terms of number of eggs per gram.).
● 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).

20. TREATMENT
● Anthelmintic medications
(drugs that remove parasitic
worms from the body), such as
albendazole and mebendazole,
are the drugs of choice for
treatment of Ascaris infections,
regardless of the species of
worm.
● Infections are generally treated
for 1–3 days.
● The drugs are effective and
appear to have few side
effects.

22. PREVENTION AND CONTROL
The best way to prevent people from getting ascariasis from humans or pigs is to always do the
following:
● Avoid ingesting soil that may be contaminated with human or pig feces, including where
human fecal matter (“night soil”), wastewater, or pig manure is used to fertilize crops.
● Wash your hands with soap and water before handling food.
● Wash your hands with soap and water after touching or handling pigs, cleaning pig pens, or
handling pig manure.
● Teach children the importance of washing hands to prevent infection.
● Supervise children around pigs, ensuring that they do not put unwashed hands in their
mouths.
● Wash, peel, or cook all raw vegetables and fruits before eating, particularly those that have
been grown in soil that has been fertilized with manure.

24. PREVENTION AND CONTROL
Transmission of Ascaris lumbricoides
infection to others in a community setting
can be prevented by:
● Not defecating outdoors.
● Effective sewage disposal systems.

25. PREVENTION AND CONTROL
● Ascaris suum eggs left in the soil from pigs can survive for up to 10 years.
● The eggs are very hardy and can survive extreme environmental conditions
like freezing and extreme heat.
● It is virtually impossible to completely remove Ascaris suum eggs from the
environment where an infected pig has been present. Consult a veterinarian
for recommendations on preventing and controlling Ascaris suum in your
pigs.

26. SOURCE- CDC, Wikipedia,
NCBI, HealthHub.

27. THANKYOU