A 2-year-old boy from Central America presented with abdominal pain, diarrhea, vomiting and fever. During a routine diaper check, medical residents discovered a 10-inch roundworm. Stool analysis identified the parasite as Ascaris lumbricoides. The patient was given albendazole and diagnosed with ascariasis, a common infection in tropical areas with inadequate sanitation. Ascariasis is caused by ingesting soil contaminated with human or pig feces and can be prevented through proper hygiene and sanitation practices.
2. Patient History
• A previously healthy 2 year old boy from Central America
presents to the Emergency Department with abdominal pain,
diarrhea, non-bloody emesis (vomiting), fever, and seizure.
• Prior to admission the toddler was noted to have a 3-month
history of fatigue and chronic cough. Infectious Disease was
consulted within 24 hours of admission.
3. Differential Diagnosis
Pediatric Infectious Disease team at VUMC suspected
community acquired pneumonia was the primary cause of
infiltrates due to the chronic cough the toddler was
experiencing.
4. Laboratory Results
• Blood cultures: Negative
• Respiratory Pathogen Panel: Negative
• Hepatitis B surface Ag & Ab: Negative
• Hepatitis B core Ab: Negative
• Hepatitis C : Negative
• HIV Ag/Ab : Negative
• Trypanosoma cruzi IgG and IgM: Negative
• Rocky Mountain Spotted Fever IgG and IgM: Negative
• Ehrlichia PCR CSF & Serum: Negative
• Quantiferon: Negative
• Histoplasma Ag & Ab: Negative
• Meningitis panel: Negative
5. During a routine diaper inspection at
afternoon rounds, a resident came
across an interesting finding that was
immediately sent over to the VUMC
laboratory.
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6. An ova and parasite was
ordered on the stool specimen
and a macroscopic
identification was performed
on the submitted roundworm.
Photo Credit: Thessicar E. Antoine-Reid, Ph.D.
7. Stool Examination
• Ova and Parasites (O&P) are the most common procedure
performed in the Parasitology Laboratory.
• During this procedure stool is examined for the egg stages and
other morphologic forms of parasites.
• Macroscopic and microscopic examination are the two general
components associated with an O&P.
• As in all laboratory testing, the quality of the result is dependent
on the collection of the specimen.
• The general turn-around-time is 24hr.
8. Macroscopic Stool Examination
Consistency
Hard, soft, mushy, loose, watery,
formed and semiformed
Color
Dark brown, black, pale brown,
clay, yellow, red-brown, green
Gross Abnormalities Adult worms, proglottids, pus,
and mucus
Photo Credit: iStock.com/fotostorm
9. Common Nematodes
Found in the Intestines
Intestinal Species
Enterobius vermicularis
Trichuris trichiura
Ascaris lumbricoides
Necator americanus
Ancylostoma duodenale
Strongyloides stercoralis
Intestinal-Tissue Species
Trichinella spiralis
Dracunculus medinensis
10. Egg Stages of Common Nematodes Intestines
Photo Credit: Centers for Disease Control and Prevention
11. Macroscopic Examination Summary
Specimen Stool
Consistency Non-formed
Identification Ascaris lumbricoides
Common Name Roundworm of Man
Measurement 10 inches
Patient Travel History Recent relocation to TN from
Honduras
Photo Credit: Thessicar E. Antoine-Reid, Ph.D.
14. Ascariasis is the most
common human helminthic
infection globally. The
burden is highest in tropical
and subtropical regions in
climates are moist and
warm, and in areas with
inadequate sanitation.
Geographic Distribution
Approximately 1 billion
people are affected
worldwide. It ranks second
in frequency in the United
States, with the highest
incidences in the
Appalachian Mountains.
Humans and swine are the
major host of Ascaris.
Children who place their
contaminated hands into
their mouths are at the
highest risk. Ingestion of
vegetables from infected
soil can place individuals at
risk.
Epidemiology Risk Factors
15. Albendazole and
mebendazole are the
drugs of choice. Ascaris is
generally, treated for 1-3
days and has very few side
effects.
Poor personal hygiene, poor
sanitation, the usage of human
feces as fertilizer,
Transmission can be prevented by
the implementation of effective
sewage disposal systems.
Additionally, the prevention of
defecating outdoors is very
effective in preventing
transmission.
Clinical Symptoms Transmission Treatment
Symptom's include
abdominal pain, vomiting,
fever distention, cough,
intestinal blockage
intestinal perforation
and growth impairment in
children.
16. Transmission Prevention
The best way to prevent the contraction of Ascaris from humans or pigs is
to:
• Avoid the ingestion of soil that is contaminated with human or pig feces.
• Practice proper hand hygiene by washing hands with soap and water before
handling food.
• Wash your hands with soap and water after handling pigs, cleaning pig pens, or
handling pig manure.
• Teach children the importance of hand hygiene to prevent infection.
• Supervise children around pigs, ensuring that they do not place their unwashed
hands in their mouths.
• Wash peel and cook all raw vegetable and fruits before eating, particularly those
that have been grown in soil that has been fertilized by manure.
17. Patient Outcome
• After Ascaris lumbricoides was found in stool patient was
given Albendazole (400mg x1).
• The patient was suspected to have contracted the parasite
before moving to Tennessee.
18. References
1. Jourdan PM, Lamberton PH, Fenwick A, Addiss D. Soil-
transmitted Helminth Infections. Lancet 2018;391 (10117):252-
265.
2. Massara CL, Enk MJ. Treatment Options in the Management of
Ascaris lumbricoides. Expert Opinion Pharmacother. 2004
5(3):529-539.
19. Thessicar E. Antoine-Reid, Ph.D.
Dr. Antoine-Reid is a second year CPEP
fellow at the Vanderbilt University
Medical Center. She completed her Ph.D
training at the University of Illinois at
Chicago where she studied the usage of
nanoparticles to inhibit the entry,
replication, and spread of Herpes simplex
viruses. Dr. Reid’s research interest
include the tracking of multi-resistance
organism in hospital acquired infections.
