Previous Article | Next Article 
Journal of Clinical Microbiology, August 2003, p. 3994-3995, Vol. 41, No. 8
0095-1137/03/$08.00+0 DOI: 10.1128/JCM.41.8.3994-3995.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.
Hymenolepis diminuta Infection in a Child Living in the Urban Area of Rome, Italy
Massimo Marangi, Barbara Zechini, Angelica Fileti, Giorgio Quaranta, and Antonio Aceti*
Department of Infectious Diseases, Sant'Andrea Hospital, II Faculty of Medicine, University of Rome "La Sapienza," 00189 Rome, Italy
Received 27 January 2003/
Returned for modification 23 March 2003/
Accepted 24 May 2003

ABSTRACT
We report a case of
Hymenolepis diminuta infection in an Italian
child affected by tuberous sclerosis. Praziquantel is the drug
of choice for the treatment of
H. diminuta infection. However,
considering the patient's neurological disease, we decided to
use not praziquantel but niclosamide, which proved equally effective.

CASE REPORT
A 2-year-old boy living in the urban area of Rome, Italy, was
referred to the Department of Tropical and Infectious Diseases
of the University of Rome "La Sapienza" owing to the emission
of tapeworm proglottids in his stool. In the previous 2 weeks,
the patient had episodes of itching and nocturnal restlessness.
His medical history was positive for tuberous sclerosis with
no overt neurological complications other than seizures that
were controlled with diazepam. The results of a physical examination
were normal. No abnormalities were revealed by blood and urine
analyses. Macroscopic and microscopic tapeworm examinations
were suggestive of
Hymenolepis diminuta proglottids. The parasitological
examination of concentrated stool samples revealed spherical
eggs, 70 µm in diameter, with a striated outer membrane
and a thin inner membrane and containing six central hooklets
but no polar filaments (Fig.
1); they were identified as
H. diminuta eggs and differentiated from
H.
nana eggs, which have
a similar appearance but are smaller and have two evident polar
thickenings, from each of which arise four to eight polar filaments.
Owing to the possible convulsant effect of praziquantel, oral
niclosamide (1 g for the first day, 500 mg/day for the following
6 days) was prescribed (
1,
3). Parasitological stool examinations
7, 9, 15, and 30 days after the end of treatment were negative
for
H. diminuta eggs.
H.
diminuta (rat tapeworm) is a rodent parasite for which arthropods
act as intermediate hosts. Eggs ingested by the arthropods develop
into cysticercoid larvae. Rodents become infected by ingesting
the arthropods; humans, usually children, can accidentally be
infected through the same mechanism. Rodents, particularly rats,
are the definitive hosts and natural reservoirs of
H.
diminuta.
Coprophilic arthropods (fleas, lepidoptera, and coleoptera)
act as intermediate hosts. When an infected arthropod is eaten
by the definitive host, the cysticercoids present in its body
cavity develop into an adult worm, whose eggs are passed in
the stool. It has recently been reported that beetle-to-beetle
transmission of
H. diminuta occurs in natural environments and
that eggs can be dispersed in the environment via beetle feces
(
13), thereby representing a source of additional infections
and a mechanism of egg dispersal.
H. diminuta infection in humans is uncommon (5, 8, 18); only a few hundred cases have been reported (2, 7, 9-12, 15-17). H. nana is more commonly reported as a cause of human infection since its transmission does not require any intermediate host and it can be spread directly from person to person. In developed countries, H. diminuta infection is very rare and is limited to rural or degraded areas. In Italy, a human H. diminuta infection was last reported as long as 10 years ago (4, 14). Our patient lived in the urban area of Rome. Evidence of a source of infection (rat infestation) has been found in other human cases observed in developed countries. In our case, the house and its surroundings, as well as the places habitually visited by the child, were inspected but no evidence of the presence of rodents or other possible sources of infection were found.
The human form of H. diminuta infection is often asymptomatic, but abdominal pain, irritability, itching, and eosinophilia have been reported. Praziquantel is the drug of choice for the treatment of H. diminuta infection. In our case, considering the patient's neurological disease, we used not praziquantel but niclosamide, which proved to be equally effective (6).
We recommend that, in order to improve our knowledge of the epidemiology and transmission routes of this rare infection, any cases of H. diminuta infection be reported.

FOOTNOTES
* Corresponding author. Mailing address: Department of Infectious Diseases, Sant'Andrea Hospital, II Faculty of Medicine, University of Rome "La Sapienza," Via di Grottarossa 1036, 00189 Rome, Italy. Phone: 39 06 80345272. Fax: 39 178 2228564. E-mail:
professoraceti{at}tiscali.it.


REFERENCES
1 - Bada, J. L., B. Trevino, and J. Cabezos. 1988. Convulsive seizures after treatment with praziquantel. Br. Med. J. 296:646.
2 - Cohen, I. P. 1989. A case report of Hymenolepis diminuta in a child in St James Parish, Jamaica. J. La. State Med. Soc. 141:23-24.[Medline]
3 - Fong, G. C. Y., and R. T. F. Cheung. 1997. Caution with praziquantel in neurocysticercosis. Stroke 28:1648-1649.[Free Full Text]
4 - Foresi, C. 1967. Data on the epidemiology of hymenolepiasis in Italy. Arch. Ital. Sci. Med. Trop. Parasitol. 48:251-262.
5 - Hamrick, H. J., J. H. Bowdre, and S. M. Chrurch. 1990. Rat tapeworm: Hymenolepis diminuta infection in a child. Pediatr. Infect. Dis. J. 9:216-219.[Medline]
6 - Jones, W. E. 1979. Niclosamide as treatment for Hymenolepis diminuta and Dipylidium caninum infection in man. Am. J. Trop. Med. Hyg. 28:300-302.
7 - Kan, S. K., R. T. Kok, S. Marto, I. Thomas, and W. W. Teo. 1981. The first report in Hymenolepis diminuta infection in Sabah, Malaysia. Trans. R Soc. Trop. Med. Hyg. 75:609.
8 - Levi, M. H., B. G. Raucher, E. Teicher, D. J. Sheehan, and J. C. McKitrick. 1987. Hymenolepis diminuta: one of three pathogens isolated from a child. Diagn. Microbiol. Infect. Dis. 7:255-259.[Medline]
9 - Lo, C. T., Y. Ayele, and H. Birrie. 1989. Helminth and snail survey in Harerge region of Ethiopia with special reference to schistosomiasis. Ethiop. Med. J. 27:73-83.[Medline]
10 - McMillan, B., A. Kelly, and J. C. Walker. 1971. Prevalence of Hymenolepis diminuta infection in man in the New Guinea Highlands. Trop. Geogr. Med. 23:390-392.[Medline]
11 - Mercado, A., and B. Arias. 1995. Taenia sp. and other intestinal cestode infections in individuals from public outpatient clinics and hospitals from the northern section of Santiago, Chile (1985-1994). Bol. Clin. Parasitol. 50:80-83.
12 - Pampiglione, S., S. Visconti, and G. Pezzino. 1987. Human intestinal parasites in Subsaharan Africa. II. Sao Tome and Principe. Parasitologia 29:15-25.[Medline]
13 - Pappas, P. W., and A. J. Barley. 1999. Beetle-to-beetle transmission and dispersal of Hymenolepis diminuta (Cestoda) eggs via the feces of Tenebrio molitor. J. Parasitol. 85:384-385.[Medline]
14 - Scaglione, L., F. Troielli, E. Ansaldi, P. G. Orsi, and P. L. Garavelli. 1990. Hymenolepis diminuta: a rare helminthiasis in humans. Description of a clinical case. Minerva Med. 81:65-67.
15 - Stafford, E., E. M. Sudomo, S. Marsi, and R. J. Brown. 1980. Human parasitosis in Bali, Indonesia. Southeast Asian J. Trop. Med. Public Health 11:319-323.[Medline]
16 - Tena, D., M. Perez Simon, M. Gimeno, M. T. Perez Pomata, S. Illescas, I. Amondarain, A. Gonzalez, J. Dominguez, and J. Bisquert. 1998. Human infection with Hymenolepis diminuta: case report from Spain. J. Clin. Microbiol. 36:2375-2376.[Abstract/Free Full Text]
17 - Tesjaroen, S., K. Chareonlarp, A. Yoolek, W. Mai-iam, and P. Lertlaituan. 1987. Fifth and sixth discoveries of Hymenolepis diminuta in Thai people. J. Med. Assoc. Thail. 70:49-50.[Medline]
18 - Varghese, S. L., P. Sudha, P. Padmaja, P. K. Jaiswal, and T. Kuruvilla. 1998. Hymenolepis diminuta infestation in a child. J. Commun. Dis. 30:201-203.[Medline]
Journal of Clinical Microbiology, August 2003, p. 3994-3995, Vol. 41, No. 8
0095-1137/03/$08.00+0 DOI: 10.1128/JCM.41.8.3994-3995.2003
Copyright © 2003, American Society for Microbiology. All Rights Reserved.