Hookworm Larva Migrans Presentation
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Cutaneous Larva Migrans Cutaneous Larva Migrans (CLM) Causative agent: Hookworm species that
does not use humans as definitive hosts. Most common being A. braziliense and
A. caninum Cutaneous larva migrans (also known as
ground itch) is the most common manifestation of zoonotic infection with animal hookworm.
Symptoms Migrating larvae cause an intensely pruritic
serpiginous track in the upper dermis. Less commonly, larvae migrate to the bowel lumen and cause eosinophilic enteritis. Diagnosis can be made based on finding red,
raised tracks in the skin that are very itchy. Usually found on the feet or lower part of the legs
on persons who have recently traveled to tropical areas and spent time at the beach. Since the larvae will usually die after 5 – 6 weeks
in the human host, the course of CLM is considered self-limiting.
Epidemiology/Transmission The normal definitive hosts for these species are dogs
and cats. The eggs of these parasites are shed in the feces of
infected animals and can end up in the environment, contaminating the ground where the animal defecated. People become infected when the zoonotic hookworm
larvae penetrate unprotected skin, especially when walking barefoot or sitting on contaminated soil or sand. Found worldwide especially in warmer climates. Found
everywhere but most commonly on the East Coast. Often most reported by returning travelers to tropical
Epidemiology/Transmission Humans may become infected when filariform
larvae penetrate the skin . Most larvae cannot mature further in the human host, and migrate aimlessly in the epidermis, as much as several centimeters /day. Some larvae may persist in deeper tissue after
finishing their skin migration. Dogs and cats can become infected with several
hookworm species, including Ancylostoma brazilense, A. caninum, A. ceylanicum, and Uncinaria stenocephala.
Outbreak of Cutaneous Larva Migrans at a Children's Camp --- Miami, Florida, 2006
July 19, 2006: Director of a children's aquatic sports day camp notified the Miami--Dade County Health Department (MDCHD) of three campers who had received a diagnosis of cutaneous larva migrans (CLM).
1. The department conducted an investigation to determine the source and magnitude of the outbreak and prevent additional illness.
2. Although CLM rarely reported, it is a potential health hazard in Florida.
3. This disease cluster highlights the importance of appropriate environmental hygiene practices and education in preventing CLM.
Location and Attendees The camp property located in Miami included
swimming pools , main building, volleyball court, playground with sandbox, picnic area, and beach for boating and swimming. Camp consisted of Four 2-week sessions held
during July 5th through July 28th, 2006. Camp attendees were 2-6 year-olds for half-day
sessions, and 5-15 year-olds for full-day sessions. Approximately 300 campers and 80 staff
members attended each session.
Identification of the Outbreak On July 20th, camp administrators announced that
3 children had been diagnosed with CLM and asked parents to look for various symptoms of the infection, including snake-shaped (serpigninous) red rash, itching, pus-filled lesions. They also provided information on CLM to
households of campers and staff who attended sessions during the summer. They advised persons with signs or symptoms
seek medical care and to contact the health department to make a report.
The Health Department • The health department received a total of 22 reports of
persons with signs and symptoms of CLM. 4 staff and 18 campers, including the 3 initial patients.
• Phone interviews were conducted using a 60-item questionnaire that collected information regarding demographic variables, illness history, and activity history.
• Case was defined as illness consistent with CLM in a person who attended the camp at any time during June 5th to July 20th, 2006 and had symptoms June 5th to Aug. 20th.
• No lab samples were obtained, but all 22 patients received clinical diagnosis of CLM.
Outbreak Study • A descriptive, cross-sectional study of the 22 cases and
environmental health assessment of the camp property were conducted.
• Illness onset: Between June 20th to August 1st. • Median age of campers: 4 years (range 2-6 years) • Median age of staff: 17 years (range 16-19 years) • erythema (100%), pruritic rashes (100%), serpiginous
lesions (77.3%), changing location of rash or lesions (50.0%), blistering lesions (27.3%), and pus-containing lesions (18.2%). Lesions were noted on the buttocks (68.2%), feet (45.5%), legs (27.3%), hands (9.1%), groin (9.1%), and abdomen (4.5%).
Study continued • Nine (40.9%) patients had lesions in more than one
location either during a single episode or during the course of the infection.
• 20 patients used a nonprescription topical ointment at home before seeking treatment.
• All 22 sought medical attention. • Patients were treated with thiabendazole, mebendazole,
albendazole, or ivermectin. • The mean length of time patients were at the camp was
3.7 weeks. Approximately 40.9% attended for 2 weeks, and 27.3% attended for >6 weeks.
• All 22 patients participated in the half-day camp for 2-6 years.
The Playground • All 22 patients participated in the half-day camp for
children aged 2-6 years. • Although campers and staff members for both the half-day
and full-day camps were exposed to sand from the beach and the volleyball court, only those in the half-day camp were allowed in the playground area, which included a sandbox containing approximately 400 cubic feet of sand that had been placed in the box 2 years ago.
• Campers were in or around the sandbox for approximately 1 hour each day, and all campers wore bathing suits while in this area.
• Fourteen (63.7%) of the 22 who became ill did not wear shoes while sitting in the sandbox. Four (18.2%) of the persons reported seeing cats near the sandbox.
Site Investigation • MDCHD investigators investigated the camp grounds on
July 19th. • Camp admins already sectioned off the sandbox to
prevent children from using it due to the camp director’s online research on CLM. He identified contaminated sandboxes as possible source of infection.
• MDCHD observed cats around the playground sandbox and noticed animal feces in the sandbox.
• No fecal samples were collected. • Camp director revealed that general beach area was
frequented by dogs, to which campers in both age groups were exposed. This was considered possible source of exposure.
Things considered • Additional possible sources of exposure considered
included 1) having pets at home (10 patients [45%]; eight dogs, one cat, one unknown); 2) being exposed to another nearby beach in the week before symptom onset (nine [41%]); and 3) sharing personal items such as towels or clothes with other campers (four [18%]).
• After analyzing initial data collected during July 19--25, MDCHD suspected that the sandbox was the source of infection.
Outbreak Conclusion 1. Staff members inspected camp again July 26th, and found no
feces in the sandbox for laboratory testing. 2. Sandbox san was removed and replaced after the inspection. 3. 2 feral cats were removed from the premises by animal
control and euthanized. They were not tested for hookworm. 4. MDCHD staff recommended camp administrators that the
sandbox be covered when not in use to prevent fecal contamination.
5. Admin were also advised to report stray animals to animal control for removal and to inspect sandbox daily and remove feces to reduce infective larvae.
6. All new recommendations were implemented after July 26th, however, 3 additional cases were reported through Sept. 2nd. They may have been exposed before interventions.
Acknowledgments 1. Outbreak article:
2. Life cycle and photos: http://www.cdc.gov/dpdx/hookworm/index.html
3. General information and diagnostics: http://www.cdc.gov/parasites/zoonotichookworm/gen_info/index.html