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compared to that of non-pathogenic E. histolyrica zymodemes (lanes C, G, H, K, and L). This fact emphasizes the necessity to use the 4 isoenzyme systems originally defined by SARGEAUNT et al. (1982~) to determine an amoebic zymodeme, and not to rely on hexokinase alone. References

Anonymous (1985). Is that amoeba harmful or not? Lancer, i, 732-733 [editorial]. Levine, N. D. (1961). Protozoan Parasites of Domestic Animals and of Man. Minneapolis, Minnesota: Burgess. Robinson, G. L. (1968). The laboratory diagnosis of human parasitic amoebae. Transactions of the Rqal Society of Tropical Medicine and Hygiene, 62,285-294.

Sargeaunt, P. G., Williams, J. E. & Jones, D. M. (1982a). Electrophoretic isoenzyme patterns of Entamoeba histolytica and

Entamoeba chattoni in a primary survey. Journal of Protozoology, 29, 136-139. Sameaunt, I’. G., Tackson. T. F. H. G. & Simiee. A. (1982b). Biochemical homogenhty of Entamoeba h&ol$ica ‘isolates, especially those from liver abscess.Lancer, i, 1386-1388.

Sargeaunt, P. G., Williams, J. E., Bhojnani, R., Campos, J. E. & Gomez, A. (1982~).The epidemiology of Entamoeba histolytica in a rural and an urban area of Mexico. A pilot survey II. Transactions of the Royal Society of Tropical Medicine and Hygiene, 76,208-210.

WHO (1981). Intestinal Protozoan and Helminthic Infections. Geneva: World Health Organization, Technical Report Series, no. 666. Received 20 November 1991; revised II March acceptedfor publication I I March 1992

1992;

TRANSACTIONS OF THE ROYAL SOCETY OF TROPICAL MEDICINE AND HYGIENE (1992) 86, 634

pziq Entamoeba pole&i: human infections in Venezuela Instituto de Investigaciones Clinicas, de1 Zulia, Apartado 11.51, Maracaibo,

L. Chacin-Bonilla

Universidad Venezuela

Entamoeba polecki is still considered to be a rare parasite of humans, with relatively few cases having been reported in the world. However, it may be a common infection in communities where humans are closely associated with pigs. Most reported cases have been from the New Guinea region; high prevalence rates have been reported in Papua (DESOWITZ & BARNISH, 1986). E. polecki has seldom been recorded in man in the western hemisphere. In Venezuela, it was reported for the first time in a subject from Zulia state by GARCIA LAVERDE (1977). Stool examinations, using iron haematoxylin staining and formalin-ether concentration, of 2069 individuals in 6 marginal communities and of an estimated 6000 hospital out-patients have revealed 7 infections with this amoeba, 2 of them already reported (CHAC~N-BONILLA, 1980, 1983). These cases apuear to be the only human infections reported from- Latin America. Diagnosis of E. nolecki was made on the basis of finding consistently u&nuclear cysts, usually with abundant spherical, ovoid or rod-shaped chromatoid bodies and a polymorphic karyosome which was usually large, compact or granular. Some of the cysts contained a dark-stained inclusion mass. Occasional binucleate cysts were observed. Our cases originated from different areas of Zulia state; one from the east, one from the west and 5 from 3 different communities in Maracaibo City in the north of the state. Only 3 of the patients reported contact with pigs, which naturally harbour the amoeba. Other modes of infection, that might explain the other cases, could include human to human transmission or acquisition from other domestic animals. Although E. polecki has occasionally been incriminated in the causation of gastrointestinal symptoms (LEVIN & ARMSTRONG, 1970), it is generally believed to be nonpathogenic. In our series, 3 persons were symptomatic;

however, other pathogenic parasites were present: 2 were infected with Giardia duodenalis and one with Trichuris trichiura. Only 3 of our patients could be treated. The first was successfully treated with metronidazole at a dosage of 750 mg orally thrice daily for 5 d (CHAC~N-BONILLA, 1980). Entamizole@ (dispensed as tablets containing diloxanide furoate 250 mg and metronidazole 200-mg) was administered at a dose of 2 tablets 3 times dailv for 5 and 10 d respectively to the other 2 patients. Parasitological cure was assessed by examination of direct preparations and formalin-ether concentrations of faecal specimens on 3 consecutive days after treatment. The first of these 2 patients stopped passing cysts after 5 d of treatment with Entamizole@ but relansed. as confirmed bv follow-up examination 4 weeks 1ater;‘another course of treatment was prescribed but the patient did not return. The other case was successfully treated, as determined by stool examination at the end of the 10 d of therapy and again at follow-up examinations after 4 and 8 weeks. Most of the known amoebicides are ineffective against E. polecki. Our findings suggest that human infections with E. polecki are uncommon in Zulia state, although widely distributed. They probably occur in other areas of Venezuela but as stained faecal smears are not used routinely in coprological examinations this amoeba is probably often erroneously diagnosed as E. histolytica. References

Chacin-Bonilla, L. (1980). Successfultreatment of human Entamoebapolecki infection with metronidazole. AmericanJournal of Tropical Medicine and Hygiene, 29,521-523.

Chacin-Bonilla. L. (1983). Entamoeba aolecki infection in Venezuela. Report of a new case. Transdctions of the Royal Society of TropicalMedicine

and Hygiene, 77, 137.

Desowitz, R. S. & Barnish, G. (1986). Entamoeba Dolecki and other intestinal protozoa in Papua New Guinea highland children. Annals of Tropical Medicine and Parasitology, 80, 399-402

Garcia Laverde, A. (1977). Infection humana por Entamoeba polecki: presentation de un case y revision. Investigation Clinica, 18, 126-135. Levin, R. L. & Armstrong, D. E. (1970). Human infection with Entamoeba polecki. American Journal of Clinical Pathology, 54,611-614.

Received 17 October 1991; revised 19 March 1992; accepted for publication 19 March 1992

Entamoeba polecki: human infections in Venezuela.

634 compared to that of non-pathogenic E. histolyrica zymodemes (lanes C, G, H, K, and L). This fact emphasizes the necessity to use the 4 isoenzyme...
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