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On the possible relationships between Entamoeba Moshkovskii, the Laredo strains and Brumpt's Entamoeba Dispar
285
CORRESPONDENCE LEISHMANIASIS
IN
SOUTHERN
IRAN
SIR,-With reference to the article “ Leishmanjasis in Southern Iran: The Occurrence of all Three Varieties in the same Area” (Transactions, 1968, 62, 668), I would like to point out the fact that the authors are presenting a case of cutaneous leishmaniasis which produced invasion of the mucous membranes by contiguity. This is not the essential meaning of muco-cutaneous leishmaniasis as observed in South America, where a good proportion of cases, after l-3 years of evolution, develop mucous membrane lesions originated by the spread of the parasites from a distant cutaneous lesion. The invasion of mucous membranes by contiguity in cutaneous leishmaniasis of the Old World has been reported in different areas for many years, but this does not make a significant point concerning the natural history of the disease. I am, etc., FERNANDO BELTRAN-H. Prqfessor of Parasitology.
Apartado 20372, Mexico 20, D.F.
18 January,
1969.
ON THE POSSIBLERELATIONSHIPS
BETWEEN AND
BRUMPT'S
ENTAMOEBA ENTAMOEBA
MOSHKOVSKII,
THE
LAREDO
STRAINS
DISPAR
%&-The exact taxonomic position and habitat of Entamoeba moshkovskii is still a vexed question. Is this the only free-living species of Entumoeba, or have the cysts, which are found in polluted water, been passed by some unidentified vertebrate or invertebrate host (DE CARNBRI, 1963) ? According to the view taken, E. moshkovskii is placed either close to the origin of the genus Entumoebq (DE CARNERI, 1960, 1966, 1968; MEEROVITCH, 1965) or on some more or less advanced branch of the phylogenetic tree. Recently, GOLDMAN (1968) suggested that this amoeba is a parasite resembling most closely the Laredo strains of E. histolytica isolated from man (GOLDMAN et al., 1962) and that these, in turn, may be aggregated with Brumpt’s non-pathogenic species Entumoeba &par. Both these procedures seem to me to be unjustified. Firstly, the attempted identification of the Laredo strains with E. &spar ignores some of the more important characteristics of this proposed species as originally described by BRUMPT (1949). Thus, growth of E. &par takes place only at temperatures close to 37”C., whereas the Laredo strains will grow even at lower temperatures (10°C.). Further, it is probable that about a third of all strains of E. histolytica sensu lato could be identified with E. ∥ this proportion is higher in temperate countries such as Northern Italy and in Britain (HOARE, 1952). In contrast, the Laredo strains represent only a tiny minority of those isolated. Even more doubtful is the aggregation of the Laredo strains with E. moshkovskii. E. moshkovskii is frequently found in areas where amoebiasis of man is not prevalent and where Laredo strains have never been isolated. For example, in September 1968, I isolated E. moshkovskii from 8 out of 10 polluted water courses and ponds in the Milan area; there was no direct water connexion between most of these sites. Yet, in Milan, the prevalence of E. histolytica infection does not exceed 1%. The number of amoebae found at these sites ranged from 10 to 800 per gramme of mud; no strain was isolated that showed a growth preference of 37°C. compared with 26°C. It is perhaps significant that the chemical pollution at some of these sites was such that frogs, leeches and other possible hosts were absent. Even allowing for the serological analogies reported by ALI KHAN and MEEROVITCH (1968), I believe that the evidence at the present time favours the view of the Russian workers that E. moshkovskii is a separate and free-living species. I am, etc., Ivo DE CARNERI. Istituto di Igiene e Microbiologia, Universita di Pavia (Italy). 28 January, 1969. F
286
CORRESPONDENCE REFERENCES
ALI KHAN, Z. & MEEROVITCH, E. (1968). Amer.J. trap. Med. Hyg., 17, 528. BRUMPT, E. (1949). Pr&is de Parasitologic, 6th ed., Masson, Paris. 2,138 p. DE CARNBRI, I. (1960). Rev. bras. Med., 17, 493. (1963). Trans. R. Sot. trop. Med. Hyg., 57, 148. (1966). Riv. Parassit., 27, 73. (1968). G. Mal. infett., 20, 320. GOLDMAN, M. (1968). Abstr. 8th Int. Congr. trop. Med. Malaria, Teheran, 248. -, GLEASON, N. N. & CARVER, R. K. (1962). Amer. J. trap. Med. Hyg., 11, 341, HOARE,C. A. (1952). Exp. Parasit., 1, 411. MEEROVITCH, E. (1965). Excerpta Med. Int. Congr., Series 91,227.
BLOOD GORGED RESTING BLACKFLIES IN CAMEROON AND EVIDENCE OF ZOOPHILY IN SIMULICJM
DAMNOSUM
.%&-The WHO Expert Committee on Onchocerciasis (1966, Wld Hlth Org. techn. Rep. Ser., 335) reviewing research needs with regard to the feeding preferences of S. damnosum, noted that “the use of the precipitin test is limited at present by difficulty in obtaining engorged females away from an obvious host.” In view of this we consider the following observations worth reporting. In July 1968 one of us (R.H.L.D.) made a brief expedition to the Sudan savanna region south of Garoua in the Federal Cameroon Republic. By the Mayo (River) Boki (8” 43’ N, 13” 33’ E) an assistant, Mr. R. E. Oguama, observed some S. schoutedeni resting in small clusters under the leaves of a plant rooted in the water. The females of this species were only identifiable from their association with males. At the nearby Mayo Douka S. unicornutum was found resting alongside S. schoutedeni so that females could not be reliably named. Systematic searching then showed that resting blackflies of 4 species, including S. damnosum, were quite common on the riverside vegetation, and also on the underside of the guy ropes of our tents 100 m. from the river (where S. adersi, not found by the river, was also encountered). Significant numbers of the females were gravid or engorged with blood. In about 40 man-hours. 1.135 restine blackflies were collected (includine 37 S. damnosum) of which 92 (3 S. ~amhosum) conrained blood meals that were‘subsequ&tly identifiable. The blood meals were preserved by squashing on to filter paper and were then sent to Imperial College for precipitin testing (by P.F.L.B.) using the technique of Weitz (1956, Bull. W’ld Hlth Org., 15, 437). The rest of the fly was mounted in Puri’s medium for subsequent indentification. The flies collected by the Mayo Boki together with the results of precipitin tests are summarized in the Table. The primate blood meals at Mayo Boki may have been of human origin, for S. damnosum and S. griseicolle are known to bite man. However, baboons, vervets and patas monkeys were common in the area, and S. schoutedeni has never been caught biting man. The avian blood meals in S. damnosum, taken with Duke’s evidence (1967, Ann. trop. Med. Parasit., 61, 200) that infective filarial larvae of non-human origin were found in flies from this site, suggest that this species shows a considerable degree of zoophily in the Sudan savanna region, It is also noteworthy that the biting density of S. damnosum in relation to observed pupal densities was relatively low at Mayo B&i, compared with places in the guinea savanna and forest zones further south. In the guinea savanna zone at Vina River (7” 12’ N, 13” 35’ E) 56 females and 20 males (belonging to S. schoutedeni, S. cervicornutum and S. damnosum) were collected in about 15 man-hours of searching. 2 female S. damnosum (of 34 females and 4 males) contained blood meals which were identified as being of primate origin. They were probably obtained from man, as monkeys have rarely been seen near the Vina River. Very extensive searching of riverside vegetation in the forest zone near Kurnba has resulted in less than half-a-dozen unfed, resting female flies being collected. Recently a few unfed S. damnosum have been sucked out of crab burrows and other small excavations in river banks; but the lack of gorged or gravid females and of males indicates that the typical resting sites of blackflies in the forest zone still await discovery.
CORRESPONDENCE LEISHMANIASIS
IN
SOUTHERN
IRAN
SIR,-With reference to the article “ Leishmanjasis in Southern Iran: The Occurrence of all Three Varieties in the same Area” (Transactions, 1968, 62, 668), I would like to point out the fact that the authors are presenting a case of cutaneous leishmaniasis which produced invasion of the mucous membranes by contiguity. This is not the essential meaning of muco-cutaneous leishmaniasis as observed in South America, where a good proportion of cases, after l-3 years of evolution, develop mucous membrane lesions originated by the spread of the parasites from a distant cutaneous lesion. The invasion of mucous membranes by contiguity in cutaneous leishmaniasis of the Old World has been reported in different areas for many years, but this does not make a significant point concerning the natural history of the disease. I am, etc., FERNANDO BELTRAN-H. Prqfessor of Parasitology.
Apartado 20372, Mexico 20, D.F.
18 January,
1969.
ON THE POSSIBLERELATIONSHIPS
BETWEEN AND
BRUMPT'S
ENTAMOEBA ENTAMOEBA
MOSHKOVSKII,
THE
LAREDO
STRAINS
DISPAR
%&-The exact taxonomic position and habitat of Entamoeba moshkovskii is still a vexed question. Is this the only free-living species of Entumoeba, or have the cysts, which are found in polluted water, been passed by some unidentified vertebrate or invertebrate host (DE CARNBRI, 1963) ? According to the view taken, E. moshkovskii is placed either close to the origin of the genus Entumoebq (DE CARNERI, 1960, 1966, 1968; MEEROVITCH, 1965) or on some more or less advanced branch of the phylogenetic tree. Recently, GOLDMAN (1968) suggested that this amoeba is a parasite resembling most closely the Laredo strains of E. histolytica isolated from man (GOLDMAN et al., 1962) and that these, in turn, may be aggregated with Brumpt’s non-pathogenic species Entumoeba &par. Both these procedures seem to me to be unjustified. Firstly, the attempted identification of the Laredo strains with E. &spar ignores some of the more important characteristics of this proposed species as originally described by BRUMPT (1949). Thus, growth of E. &par takes place only at temperatures close to 37”C., whereas the Laredo strains will grow even at lower temperatures (10°C.). Further, it is probable that about a third of all strains of E. histolytica sensu lato could be identified with E. ∥ this proportion is higher in temperate countries such as Northern Italy and in Britain (HOARE, 1952). In contrast, the Laredo strains represent only a tiny minority of those isolated. Even more doubtful is the aggregation of the Laredo strains with E. moshkovskii. E. moshkovskii is frequently found in areas where amoebiasis of man is not prevalent and where Laredo strains have never been isolated. For example, in September 1968, I isolated E. moshkovskii from 8 out of 10 polluted water courses and ponds in the Milan area; there was no direct water connexion between most of these sites. Yet, in Milan, the prevalence of E. histolytica infection does not exceed 1%. The number of amoebae found at these sites ranged from 10 to 800 per gramme of mud; no strain was isolated that showed a growth preference of 37°C. compared with 26°C. It is perhaps significant that the chemical pollution at some of these sites was such that frogs, leeches and other possible hosts were absent. Even allowing for the serological analogies reported by ALI KHAN and MEEROVITCH (1968), I believe that the evidence at the present time favours the view of the Russian workers that E. moshkovskii is a separate and free-living species. I am, etc., Ivo DE CARNERI. Istituto di Igiene e Microbiologia, Universita di Pavia (Italy). 28 January, 1969. F
286
CORRESPONDENCE REFERENCES
ALI KHAN, Z. & MEEROVITCH, E. (1968). Amer.J. trap. Med. Hyg., 17, 528. BRUMPT, E. (1949). Pr&is de Parasitologic, 6th ed., Masson, Paris. 2,138 p. DE CARNBRI, I. (1960). Rev. bras. Med., 17, 493. (1963). Trans. R. Sot. trop. Med. Hyg., 57, 148. (1966). Riv. Parassit., 27, 73. (1968). G. Mal. infett., 20, 320. GOLDMAN, M. (1968). Abstr. 8th Int. Congr. trop. Med. Malaria, Teheran, 248. -, GLEASON, N. N. & CARVER, R. K. (1962). Amer. J. trap. Med. Hyg., 11, 341, HOARE,C. A. (1952). Exp. Parasit., 1, 411. MEEROVITCH, E. (1965). Excerpta Med. Int. Congr., Series 91,227.
BLOOD GORGED RESTING BLACKFLIES IN CAMEROON AND EVIDENCE OF ZOOPHILY IN SIMULICJM
DAMNOSUM
.%&-The WHO Expert Committee on Onchocerciasis (1966, Wld Hlth Org. techn. Rep. Ser., 335) reviewing research needs with regard to the feeding preferences of S. damnosum, noted that “the use of the precipitin test is limited at present by difficulty in obtaining engorged females away from an obvious host.” In view of this we consider the following observations worth reporting. In July 1968 one of us (R.H.L.D.) made a brief expedition to the Sudan savanna region south of Garoua in the Federal Cameroon Republic. By the Mayo (River) Boki (8” 43’ N, 13” 33’ E) an assistant, Mr. R. E. Oguama, observed some S. schoutedeni resting in small clusters under the leaves of a plant rooted in the water. The females of this species were only identifiable from their association with males. At the nearby Mayo Douka S. unicornutum was found resting alongside S. schoutedeni so that females could not be reliably named. Systematic searching then showed that resting blackflies of 4 species, including S. damnosum, were quite common on the riverside vegetation, and also on the underside of the guy ropes of our tents 100 m. from the river (where S. adersi, not found by the river, was also encountered). Significant numbers of the females were gravid or engorged with blood. In about 40 man-hours. 1.135 restine blackflies were collected (includine 37 S. damnosum) of which 92 (3 S. ~amhosum) conrained blood meals that were‘subsequ&tly identifiable. The blood meals were preserved by squashing on to filter paper and were then sent to Imperial College for precipitin testing (by P.F.L.B.) using the technique of Weitz (1956, Bull. W’ld Hlth Org., 15, 437). The rest of the fly was mounted in Puri’s medium for subsequent indentification. The flies collected by the Mayo Boki together with the results of precipitin tests are summarized in the Table. The primate blood meals at Mayo Boki may have been of human origin, for S. damnosum and S. griseicolle are known to bite man. However, baboons, vervets and patas monkeys were common in the area, and S. schoutedeni has never been caught biting man. The avian blood meals in S. damnosum, taken with Duke’s evidence (1967, Ann. trop. Med. Parasit., 61, 200) that infective filarial larvae of non-human origin were found in flies from this site, suggest that this species shows a considerable degree of zoophily in the Sudan savanna region, It is also noteworthy that the biting density of S. damnosum in relation to observed pupal densities was relatively low at Mayo B&i, compared with places in the guinea savanna and forest zones further south. In the guinea savanna zone at Vina River (7” 12’ N, 13” 35’ E) 56 females and 20 males (belonging to S. schoutedeni, S. cervicornutum and S. damnosum) were collected in about 15 man-hours of searching. 2 female S. damnosum (of 34 females and 4 males) contained blood meals which were identified as being of primate origin. They were probably obtained from man, as monkeys have rarely been seen near the Vina River. Very extensive searching of riverside vegetation in the forest zone near Kurnba has resulted in less than half-a-dozen unfed, resting female flies being collected. Recently a few unfed S. damnosum have been sucked out of crab burrows and other small excavations in river banks; but the lack of gorged or gravid females and of males indicates that the typical resting sites of blackflies in the forest zone still await discovery.