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Letter
Bertiella studeri Infection,
China
Xin Sun,*†
Qiang Fang,*† Xing-Zhi Chen,*† Shou-Feng Hu,*† Hui Xia,*† and Xue-Mei
Wang*†
*Bengbu Medical College, Bengbu, China; and †Anhui Provincial Key Laboratory
of Infection and Immunity, Bengbu, China
Suggested
citation for this article
To the Editor: Bertiella is a genus of tapeworm in the
family Anoplocephalidae, many species of which exist as parasites
of nonhuman primates. Two species of the genus, Bertiella studeri
and B. mucronata, can infect humans (1).
More than 50 cases of human infection have been recorded, and the geographic
distribution of cases shows that the tapeworm exists in countries in Asia,
Africa, and the Americas. We report a B. studeri infection in a
person; to our knowledge, this case of bertiellosis is the first in China.
The patient was a 3.5-year-old Chinese boy from Suzhou City, Anhui Province.
The boy had a 6-month history of frequent abdominal pain. His parents
had noticed living "parasites" in his feces for 3 months; a
segment of the worm was expelled every 2 or 3 days. According to the symptoms,
doctors at the local hospital diagnosed his condition as Taenia solium
infection and prescribed praziquantel, but no drug was available in the
hospital or local drugstores. Consequently, the parents brought the child
to Bengbu Medical College for further diagnosis and treatment.
The patient appeared healthy; routine medical examination showed normal
heart, lung, liver, and spleen, and he had no fever. Though the patient
had intermittent epigastric pain, the abdomen was soft and tender. A total
of 133 proglottids were collected from the feces. Their average length
was 0.1 cm, and the total length of all proglottids was 13 cm; each segment
was 0.68–1.10 cm in width. Eggs (N = 53) were examined microscopically;
they were roundish or oval, an average of 45.31 μm diameter (range
37.93–50.00 μm), and clearly showed typical pyriform apparatus, with
visible hooklets (Figure). Other laboratory examinations
showed hemoglobin level of 110 g/L, erythrocytes 3.9 × 1012
cells/L, and leukocytes 8.0 × 109 cells/L. Although 2
species can parasitize humans, the geographic distribution and egg size
of these species differ (2). B. mucronata
has smaller eggs and is found only in the New World. On the basis of the
size of the proglottids (3), larger eggs with
pyriform apparatus and hooklets, and geographic distribution, the infecting
cestode was identified as B. studeri.
The origin of infection was not confirmed; the only clue was that the
boy's parents had once raised tame monkeys in a zoo. When the boy was
2 years old, he often played in the wildland, which is part of the zoo
near the forest, and frequently fed and played with the captured monkeys.
Further questioning showed that the boy had also been in frequent contact
with wild monkeys. We could not confirm whether he had been infected by
eating monkey food contaminated with mites.
The lifecycle of the cestode requires 2 hosts; nonhuman primates are
generally the final host, while oribatid mites are the intermediate host,
in which the infective cysticercoid of the cestode develops. Orbatid mites
may exist in soil to maintain natural infection, and the definitive host
is infected by eating or otherwise coming into contact with contaminated
soil or food. Animal infection has been recorded in some provinces in
China, and human bertiellosis has been recorded in Sri Lanka (4),
Saudi Arabia (5), Vietnam (6),
Japan (7), India (8),
Thailand, Malaysia, and other Asian countries. However, according to the
most recent Chinese authoritative text, Human Parasitology (9),
no human bertiellosis has been recorded in China. Humans are infected
by unconsciously swallowing infected mites, and in Mauritius, children
were infected by eating guavas that had fallen on the soil (10).
Other human infections may have occurred, but infected persons may have
had mild symptoms and not noticed expelling the segments, so local doctors
may have considered the cases to have been caused by a common cestode.
To prevent human bertiellosis, the relationship between human cases and
the natural host must be investigated.
Acknowledgments
We thank Guan-Ling
Wu, Yong Wang, You-Fang Gu, Bai-Qing Li, Ze Min, and Bei Yao for assisting
with our literature collection and manuscript writing.
References
- Beaver PC, Jung RC, Cupp EW. Cyclophyllidean tapeworms.
In: Beaver PC, Jung RC, Cupp EW, editors. Clinical parasitology. 9th
ed. Philadelphia: Lea and Febiger; 1984. p 505–6.
- Galan-Puchades MT, Fuentes MV, Mas-Coma S. Morphology
of Bertiella studeri (Blanchard, 1891) sensu Stunkard (1940)
(Cestoda: Anoplocephalidae) of human origin and a proposal of criteria
for the specific diagnosis of bertiellosis. Folia Parasitol (Praha).
2000;47:23–8.
- Frean J, Dini L. Unusual anoplocephalid tapeworm infections in South
Africa. Annals of the Australasian College of Tropical Medicine. 2004;5:8–11.
- Gallella SD, Gunawardena GS, Karunaweera ND. Bertiella
studeri infection: resistance to niclosamide. Ceylon Med J.
2004;49:65.
- El-Dib NA, Al-Rufaii A, El-Badry AA, Al-Zoheiry AA, Abd El-Aal AA.
Human infection with Bertiella species in Saudi Arabia. Saudi
Pharmaceutical Journal. 2004;12:168–9.
- Xuan le T, Anantaphruti MT, Tuan PA, Tu le X, Hien TV. The
first human infection with Bertiella studeri in Vietnam.
Southeast Asian J Trop Med Public Health. 2003;34:298–300.
- Ando K, Ito T, Miura K, Matsuoka H, Chinzei Y.
Infection of an adult in Mie Prefecture, Japan, by Bertiella studeri.
Southeast Asian J Trop Med Public Health. 1996;27:200–1.
- Panda DN, Panda MR. Record
of Bertiella studeri (Blanchard, 1891), an anoplocephalid tapeworm,
from a child. Ann Trop Med Parasitol. 1994;88:451–2.
- Bao H-E. In: Bertiella studeri. Guanling WU, editor. Human
parasitology. 3rd ed. Beijing: People's Health Publishing House; 2005.
p. 569–70.
- Bhagwant S. Human
Bertiella studeri (family Anoplocephalidae) infection
of probable Southeast Asian origin in Mauritian children and an adult.
Am J Trop Med Hyg. 2004;70:225–8.
Suggested citation
for this article:
Sun X, Fang Q, Chen
X-Z, Hu S-F, Xia H, Wang X-M. Bertiella studeri infection, China
[letter]. Emerg Infect Dis [serial on the Internet]. 2006 Jan [date
cited]. Available from http://www.cdc.gov/ncidod/EID/vol12no01/05-0579.htm
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