Worm recovered from young girl
What’s your diagnosis?
A 6-year-old girl is urgently brought into the Weed Army Community Hospital’s pediatric clinic at Fort Irwin, California, after the mother removed a long worm from the toilet bowl right after the child had a bowel movement (Figure 1).
The child is otherwise a normal, although somewhat frightened, healthy and active 6-year-old girl. The family history is initially unremarkable. However, it was found on further questioning that the family recently moved to the United States from Kingston, Jamaica, after the father got into the U.S. Army about 4 months earlier. When pressed for a family history for worms, the mother did recall that the child had been treated for a similar problem twice before when she was several years younger in Jamaica. About 4 years earlier, the mother was treated for coughing up a very small worm. However, she was not ill and did not recall any other “worm history.”
Examination of the child revealed a normal-appearing 6-year-old girl with normal vital signs, normal growth and development, normal abdominal exam, normal rectal exam and clear breath sounds; essentially, no abnormalities were found. No lab tests or radiographs were obtained.
What’s your diagnosis?
A. Ancylostoma duodenale
B. Ascaris lumbricoides
C. Enterobius vermicularis
D. Trichuris trichiura
Answer and discussion:
The answer is B, Ascaris lumbricoides, the largest nematode (roundworm), and is found worldwide, especially in tropical or temperate climates, especially where sanitation is poor. As seen in Figure 1, the worm is tan color and can reach a length of over 35 cm. If the worm is seen, no testing need be done. It is a true visual diagnosis, as long as it can be tied to the patient (not literally, although it may be long enough). The history is also supported with the mother having been treated several years earlier for coughing up a small worm, which was highly likely to be Ascaris larvae in the pulmonary migratory phase. In the right setting, these problems tend to be recurrent.
Figure 2 shows Ascaris larvae being coughed up from its pulmonary phase of the life cycle. Essentially, the host consumes an embryonated Ascaris egg from contaminated food, which hatches under the influence of bile and stomach acid, releasing the larvae to attach and penetrate the gut and enter the circulation. It ends up in the lung, where it penetrates the alveoli and makes its way back up the airway, to be coughed up and swallowed, and the larvae then attaches to the intestinal wall and matures to an adult in the small intestine. During the pulmonary phase, the patient may be diagnosed with Loeffler pneumonia (pulmonary infiltrates with eosinophilia). This cycle may go on for a long time, which may increase the worm burden to a massive number, sufficient enough to result in an intestinal obstruction. The treatment of choice is a 3-day course of albendazole (see the 2021-2024 Red Book, pages 210-211 for details).
Enterobius vermicularis is the lowly pinworm, which may be diagnosed by the old, reliable tape test, which involves using clear adhesive tape and placing the adhesive side against the skin adjacent to the anal area of the child upon awakening in the morning. The tape can then be taken to the primary clinic and examined under a microscope for the characteristic eggs (Figure 3). The worms typically exit the rectal area to lay eggs at night, which can be picked up by the tape. Treatment can be effective with the cheaper over-the-counter drug, pyrantel pamoate, or a prescription for albendazole.
Trichuris trichiura, the “whipworm,” is another nematode with a simple life cycle: ingest the embryonated egg, the larvae hatch in the small intestine and migrate and attach in the colon. Its main pathology is causing rectal bleeding and intense tenesmus, which may result in rectal prolapse, with numerous whipworms attached to the rectal mucosa (Figure 4). A stool sample may reveal the characteristic “football-shaped” egg with a bipolar operculum, as shown in Figure 5. These worms can also be treated with a 3-day course of albendazole.
Ancylostoma duodenale is one of the two hookworms seen in the U.S. and is the second most common helminthic disease after Ascaris. This is another migrating worm that begins with penetration of the skin, usually of the bare foot, by the filariform larva, after which it gets into the circulation and ends up in the lung. From there, it is coughed up and swallowed and becomes an adult hookworm in the small intestine. They can be identified by the eggs (Figure 6) in the stool, but it is very difficult to tell the difference between Ancylostoma and Necator americanus by the appearance of the eggs.
However, the mouth parts of each worm are unique. Therefore, if a worm is found, it can easily be identified by its mouth parts examined under the microscope. Figure 7 shows the mouth of A. duodenale, or as I call it, Dracula hookworm.
Figure 8 shows the mouth parts of N. americanus, or as I call it, Bucky Beaver hookworm. These worms are much smaller than the Ascaris. Nowadays, PCR on a stool sample may replace looking for eggs and worms in the stool, which can be a tedious, albeit a much cheaper screening method. Treatment, as with the other worms, is usually with albendazole. Again, consult your 2021-2024 Red Book for details.
Columnist comments
This is an updated case that I originally published almost exactly 30 years ago (March 1993). The pediatricians at Fort Irwin, California, in 1993, were Captains Howard Oaks and Francis (Buzz) Malone. I want to thank them again for showing me this case when I was there on a consultant visit in 1992. I had been appointed to the position of pediatric consultant to the Army Surgeon General the previous summer. A big part of that job is to make all general pediatric and pediatric subspecialties assignments to the various Army medical facilities. Fort Irwin was a very unpopular assignment, as you might imagine, due to its remote, austere desert environment. Assignments such as this are typically given to the most junior officers, and afterward, they are given priority for their next assignment. Drs. Oaks and Malone distinguished themselves as outstanding pediatricians in that difficult place, never once complaining. Dr. Oaks, an outstanding graduate of the residency program at William Beaumont Army Medical Center in El Paso, Texas, went on to do an allergy and immunology fellowship in Washington, D.C., and at last check, was still practicing in Fayetteville, North Carolina. Dr. Malone, who also distinguished himself in residency at Brooke Army Medical Center in San Antonio, Texas, went on to an academic general pediatric position at Tripler Army Medical Center in Hawaii. Unfortunately, Buzz Malone’s career was cut short when he died around mid-career of complications of lupus erythematosus on Jan. 31, 2005. During his time at Tripler, Dr. Malone was a very popular teacher of students and residents, as well as a talented researcher, publishing several clinical research papers. I might add that Buzz Malone was also a personal friend of mine. I was on the teaching staff of the pediatric department at Brooke Army Medical Center during his time there. Before my deployment to the first Gulf War with Iraq in 1990-1991, Buzz provided me with an ample supply of Bullfrog sunscreen, which obviously came in very handy, and possibly prevented me from getting skin cancer all these years later.
I want to thank my friend, Margaret Takahashi, Buzz’s wife, for providing the updated information noted above.
For more information:
Brien is a member of the Healio Pediatrics Peer Perspective Board and an adjunct professor of pediatric infectious diseases at McLane Children's Hospital, Baylor Scott & White Health, in Temple, Texas. He can be reached at jhbrien@aol.com.
References:
American Academy of Pediatrics. Committee on Infectious Diseases. Red Book. Report of the Committee on Infectious Diseases. American Academy of Pediatrics; 2021. https://redbook.solutions.aap.org/redbook.aspx. Accessed Nov. 20, 2021.