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Changing patterns of cutaneous leishmaniasis in Israel and neighbouring territories
649
TRANSACTIONS OF THE ROYAL SOCIETY OF TROPICALMEDICINEAND HYGIENE(1994) 8% 649-650
Changing territories
patterns
of cutaneous
leishmaniasis
in Israel and neighbouring
Sidney Klaus, Ofra Axelrod, Flory Jonas and Shoshana Frankenbutg Organization, P.O.B.
Department of Dermatology, Hadassah Medical
12 OOO,Jerusalem, Israel
Abstract The most frequent form of cutaneous leishmaniasis (CL) in Israel and the neighbouring territories is due to Leishmania major, which is endemic mainly in the Jordan Valley and in the Rift Valley. CL due to L. tropica is much less common, and in the past only sporadic caseshave been reported. In this study we present data obtained during the years 1988-1992 regarding CL in the area. Our clinic has diagnosed a total of 371 leishmaniasis cases, most of whom acquired the infection in the Jordan Valley, mainly during June and July. About one-third of the patients had single lesions, and one-third more than 5 lesions. We also describe an outbreak of leishmaniasis in Kfar Adumim, a village 15 km east of Jerusalem, where leishmaniasis was previously unknown. Parasites were characterized by the polymerase chain reaction and by immunostaimng, and found to be both L. tropica and L. major. The localization of the homes of the affected people on a slope where hyraxes were abundant suggeststhat these animals might have been involved in the transmission of L. tropica in this area. Introduction The most common form of cutaneous leishmaniasis (CL) in Israel and the adjacent region is caused by Leishmania major. The disease is endemic in the Jordan Valley, the Rift Valley (Arava), and in some areas of the Negev Desert. The major reservoirs are Psammomys obesus in the Jordan Valley and Meriones crassus in the Rift Valley and in the Negev Desert (SCHLEIN et al., 1984). A less common form of CL is caused by L. tropica. Sporadic casesoccur in the mountains between Jenin and Nablus, and recently a case from Eilat was identified. The reservoir for L. tropica is unknown. In some parts of the world the diseasehas been described as anthroponotic (WHO, 1984); in Israel this possibility seemsunlikely, mainly due to the sporadic and relatively widespread nature of the disease.In Salfit, the site of one outbreak in 1978, infected Rattus rattus have been found, but the parasite strain was not identified (BLUM, 1978). Clinically, the disease caused by L. major lasts 2-6 months, whereas that caused by L. tropica lasts 6-12 months. In addition, lesions caused by L. tropica are usually larger, last longer and are more difficult to treat than those caused by L. major. L. tropica lesions are usually resistant to topical paromomycin, the treatment of choice for L. major infection in Israel (EL-ON et al., 1985; our unpublished observations). L. major promastigotes readily grow in culture medium, whereas it is more difficult to grow L. tropica in vitro (unpublished observations) . In this paper we present data obtained during the years 1988-1992 regarding cutaneous leishmaniasis and describe an outbreak of leishmaniasis caused by L. tropica and L. major in an area in which these parasites were previously unknown. Materials and Methods Study group. Patients were seen and diagnosed in the Dermatology Clinic of the Hadassah Medical Organization, Jerusalem, Israel. Diagnosis. Diagnosis was made by microscopical examination of Giemsa-stained smearsprepared with material from the lesions and by culture of lesion material in Schneider’s medium (Biological Industries, Beth Haemek, Israel) containing 10% foetal calf serum. Parasite identification. Three methods were used. (i) Serodiagnosis (SCHNUR et al., 1972) or isoenzyme analysis (LE BLANCQ et al., 1986, kindly performed by L. Schnur). (ii) Polymerase chain reaction (PCR), using primers recently developed that distinguished between L. major (650 kilobase (kb) product) and all other strains of Leishmania tested (L. tropica, L. donovani, L. infantum and L. aethiopica, which gave an 800 kb product) (ERESH et al., 1993). (iii) Immunostaining of Cytospin@preparations. For this method, 2 monoclonal antibodies were
used-WIC 79.3, specific for L. major (DE IBARRA et al., 1982), and Tll, specific for L. tropica (JAFFE & SARFSTEIN, 1987), kindly provided by C. Jaffe. The slides were developed using biotin conjugated to rabbit antimouse serum and streptavidin conjugated to peroxidase. Results Distribution of cutaneous leishmaniasis
During the years 1988-1992, 371 cases of leishmaniasis were diagnosed in our dermatoloev clinic. The total number of-casesper year, as well as”iheir distribution by location, by time of infection and by number of lesions, were very similar for each of the 4 years studied (data not shown). 25 -
20 s 8 f% IJ s P E E al 8 ,u
. 15-
lo. 5-
0-i
, 0
2
.
, 4
.
, 6 month
, 6
.
, 10
.
( 12
Figure. Incidence of leishmamasiscasesin Israel by month of exposure, 1988-1992(l=January, etc), based on 188 patients for whom the date of exposure could be accurately determined.
The distribution by location of acquisition of infection showed that the Jordan Valley had the highest incidence (202 cases), but significant numbers of people also became infected in other areas: Arava (44), Judean desert and mountains (39), Negev (37), and the Dead Sea region (46). It was uncertain in which area 3 patients had been infected. The Figure shows the distribution of patients by month of exposure; only patients who could determine within a range of 2-3 weeks the date when they had been exposed to infection in an endemic area were included; residents from endemic areaswere excluded. Clearly, June and July were the months of highest infectivity, but a small number of people becameinfected throughout the year. The number of lesions per person ranged between one and 58. The numbers of people with one lesion (107),
650
with 2-5 lesions (155), and with more than 5 lesions (109) were almost identical. Most patients (289) were over 18 years of age, 58 were aged 6-18 years, and 25 were under 6 years old. This probably reflects occupational differences rather than a preference of the sandfly for adults, since most people entering the endemic area were adults. Kfar Adumim outbreak
-Nineteen casesof leishmaniasis have been diagnosed since 1989in Kfar Adumim. a village 15 km east of Terusalem (population 650, altitide 35O”m).Three addiGona1 caseswere diagnosed a short distance from the village. The parasite strains isolated from the lesions of 6 patients were characterized, since the ecology of Kfar Adumim was not considered typical of that for L. major, and in some casesthe lesions were larger and lasted longer than would be expected for L. rnajir. Parasites from the lesions of these 6 natients were identified bv PCR as L. tropica and in 2 Easeswere further confirmed by immunostaining. These 2 isolates grew very slowly in culture, but after approximately 2 months much fast&r growth o& curred. The fast erowmg cultures were retested bv PCR and found to be i. majo;. One of the isolates, at ihe beginning of fast growth, showed 2 bands, one of 650 kb (L. ma’or) and one of 800 kb (L. tropica). Two additional casesI rom Kfar Adumim were identified as L. major by serotyping. Discussion The number of patients seen in our clinic was almost identical to the total number of casesreported to the Israel Health Ministry, suggesting that leishmaniasis, although a notifiable disease, is in fact largely under-reported; some patients are seenin other clinics, and many persons do not seekmedical advice. L. major has been known to be endemic in Israel and the nei hbouring region for many years; we did not find major if uctuations from year to year in the 4 years of our study. The situation for L. tropica is different. Although sporadic caseshave been seen, only one outbreak, which may have been caused by L. tropica but has not been Droven to be so, has been reDorted (BLUM, 1978). The present report from Kfar Adimim and its &rroundinngs is the first time an outbreak of leishmaniasis known to be due to L. tropica has been reported from Israel. L. major and L. tropica are the only two Leishmania species causing cutaneous disease which have been reported from Israel and surrounding countries (GREENBLATT et al., 1985; SUKKAR, 1985). The fact that 2 isolates were first characterized as L. tropica and then, at a later stage, as L. major was probably not due to a technical mistake, since the isolates were obtained from different patients at different times. The areas endemic for L. major and L. tropica overlap to a certain extent, making it possible for an animal reservoir or a human patient to be infected with both species. It appears that, in the original 2 isolates, the predominant parasite was L. tropica, which caused the lesions, but that a small number of L. major parasites was also present. These L. major parasites gradually outgrew the L. tropica in culture. The vector and reservoir host of L. tropica in this region are not known. Neither infected sandflies nor infected reservoir mammals have been found (Y. Schlein, personal communication), but it is interesting to note that during the years of this study hyraxes were abundant on the southern slope of Kfar Adumim, where an open water pipe kept the soil moist. It was on this side of
the village that the homes of most patients were located. The 19 casesdetected lived in only 9 households, further stressing the localization of the outbreak. We have shown that CL caused by both L. major and L. tropica has appeared in an area in which these infections were previously unknown. This might have been due to ecological changes and the intrusion of human hosts into the zoonotic mammal-sandfly transmission cvcle, as has hannened before in this Dart of the Middle Gast(GREENBL~+T et al., 1985; H. A&ah, 1987, unpublished report’; Y. 0. Oumeish, 1989, unpubhshed report*). Awareness of the presence of L. tropica and of its potential danger as a viscerotropic parasite (KREUTZER et al., 1993) is relevant to the control of infection and the managementof patients. Acknowledgements This work was supported by the Office of the Chief Scientist, Ministry of Health, Israel and the Leslie Nicholas Fund. We thank Dr L. Schnur for performing the serotyping and isoenzyme analysis of someof the samples. References Blum, M. (1978). Cutaneousleishmaniasisand leishnuzninreaction in residentsof Salfit (Samaria). MPH thesis, Department of Social Medicine, HadassahMedical School, Israel. De Ibarra, A. A. L., Howard, J. G. & Snary., D. (1982). Monoclonal antibodies to Leishmania tropica major: specificities and antigen location. Parasitology, 895,523-531. El-On, J., Weinrauch, L., Livshin, R., Even Paz, Z. & Jacobs, G. P. (1985). Topical treatment of recurrent cutaneous leishmaniasis with ointment contain@g paromomycin and methylF;m;;onium chloride. Bntlsh Medical Journal, 291, Eresh, S.,’ Axelrod! O., Greenblatt, C. L. & Barker, D. (in press). PCR in lelshmaniasis diagnosisdistinguishing Leishmania major from L. tropica. Journal of Eukatyotic Microbiology, supplement. Greenblatt, C. L., Schlein? Y. & Schnur, L. F. (1985). Leishmaniasis in Israel and vicinity. In: Lelshmoniasis, Chang, K. P. & Bray, R. S. (editors). Amsterdam: Elsevier, pp. 415426. Jaffe, C. L. & Sarfstein, R. (1987). Speciesspecific antibodies to Leishmania tropica minor recognize somatic antigens and exometabolites.Journal oflmmunology, 139,1310-1319. Kreutzer, R. D., Grog& M., Neva, F. A., Fryauff, D. J., Magill, A. J. & Aleman-Munoz? M. M. (1993). Identification and genetic comparison of lelshmanial parasites causing viscerotropic and cutaneous disease in soldiers returning from operation Desert Storm. American Journal of Tropical Medicine and Hygiene, 49,357-363. Le Blancq, S. M., Schnur, L. F. & Peters, W. (1986). Leishmania in the Old World: 1. The geographical and hostal distribution of L. major zymodemes. Transactions of the Royal Society of Tropical Medicine and Hygiene, 80,99-l 12. Schlein, Y., Warburg, A., Schnur, L. F., Le Blancq, S. & Gunders, A. R. (1984). Leishmaniasis in Israel: reservoir hosts, sandfly vectors and leishmanial strains in the Negev, Central Arava and along the Dead Sea. Transactions of the Royal Society of Tropical Medicine and Hygiene, 78,48U84. Schnur, L. F., Zuckerman, A. & Greenblatt, C. L. (1972). Leishmanial serotypes as distinguished by the gel diffusion of factors excreted in vitro and in vivo. Israel Journal of Medical Sciences.8.932-942. Sukkar,- F: (i985). ieishmaniasis in the Middle East. In: Leishmaniasis, Chang, K. P. & Bray, R. S. (editors). Amsterdam: Elsevier, pp. 393-414. WHO (1984). The Leishmaniases. Geneva: World Health Oraanization, Technical Report series, no. 701. Received 10 January February I994
1994; accepted for publication
2
*Reports to the 2nd and 3rd Pan Arab Seminars on Zoonotic and Parasitic Diseases,respectively.
TRANSACTIONS OF THE ROYAL SOCIETY OF TROPICALMEDICINEAND HYGIENE(1994) 8% 649-650
Changing territories
patterns
of cutaneous
leishmaniasis
in Israel and neighbouring
Sidney Klaus, Ofra Axelrod, Flory Jonas and Shoshana Frankenbutg Organization, P.O.B.
Department of Dermatology, Hadassah Medical
12 OOO,Jerusalem, Israel
Abstract The most frequent form of cutaneous leishmaniasis (CL) in Israel and the neighbouring territories is due to Leishmania major, which is endemic mainly in the Jordan Valley and in the Rift Valley. CL due to L. tropica is much less common, and in the past only sporadic caseshave been reported. In this study we present data obtained during the years 1988-1992 regarding CL in the area. Our clinic has diagnosed a total of 371 leishmaniasis cases, most of whom acquired the infection in the Jordan Valley, mainly during June and July. About one-third of the patients had single lesions, and one-third more than 5 lesions. We also describe an outbreak of leishmaniasis in Kfar Adumim, a village 15 km east of Jerusalem, where leishmaniasis was previously unknown. Parasites were characterized by the polymerase chain reaction and by immunostaimng, and found to be both L. tropica and L. major. The localization of the homes of the affected people on a slope where hyraxes were abundant suggeststhat these animals might have been involved in the transmission of L. tropica in this area. Introduction The most common form of cutaneous leishmaniasis (CL) in Israel and the adjacent region is caused by Leishmania major. The disease is endemic in the Jordan Valley, the Rift Valley (Arava), and in some areas of the Negev Desert. The major reservoirs are Psammomys obesus in the Jordan Valley and Meriones crassus in the Rift Valley and in the Negev Desert (SCHLEIN et al., 1984). A less common form of CL is caused by L. tropica. Sporadic casesoccur in the mountains between Jenin and Nablus, and recently a case from Eilat was identified. The reservoir for L. tropica is unknown. In some parts of the world the diseasehas been described as anthroponotic (WHO, 1984); in Israel this possibility seemsunlikely, mainly due to the sporadic and relatively widespread nature of the disease.In Salfit, the site of one outbreak in 1978, infected Rattus rattus have been found, but the parasite strain was not identified (BLUM, 1978). Clinically, the disease caused by L. major lasts 2-6 months, whereas that caused by L. tropica lasts 6-12 months. In addition, lesions caused by L. tropica are usually larger, last longer and are more difficult to treat than those caused by L. major. L. tropica lesions are usually resistant to topical paromomycin, the treatment of choice for L. major infection in Israel (EL-ON et al., 1985; our unpublished observations). L. major promastigotes readily grow in culture medium, whereas it is more difficult to grow L. tropica in vitro (unpublished observations) . In this paper we present data obtained during the years 1988-1992 regarding cutaneous leishmaniasis and describe an outbreak of leishmaniasis caused by L. tropica and L. major in an area in which these parasites were previously unknown. Materials and Methods Study group. Patients were seen and diagnosed in the Dermatology Clinic of the Hadassah Medical Organization, Jerusalem, Israel. Diagnosis. Diagnosis was made by microscopical examination of Giemsa-stained smearsprepared with material from the lesions and by culture of lesion material in Schneider’s medium (Biological Industries, Beth Haemek, Israel) containing 10% foetal calf serum. Parasite identification. Three methods were used. (i) Serodiagnosis (SCHNUR et al., 1972) or isoenzyme analysis (LE BLANCQ et al., 1986, kindly performed by L. Schnur). (ii) Polymerase chain reaction (PCR), using primers recently developed that distinguished between L. major (650 kilobase (kb) product) and all other strains of Leishmania tested (L. tropica, L. donovani, L. infantum and L. aethiopica, which gave an 800 kb product) (ERESH et al., 1993). (iii) Immunostaining of Cytospin@preparations. For this method, 2 monoclonal antibodies were
used-WIC 79.3, specific for L. major (DE IBARRA et al., 1982), and Tll, specific for L. tropica (JAFFE & SARFSTEIN, 1987), kindly provided by C. Jaffe. The slides were developed using biotin conjugated to rabbit antimouse serum and streptavidin conjugated to peroxidase. Results Distribution of cutaneous leishmaniasis
During the years 1988-1992, 371 cases of leishmaniasis were diagnosed in our dermatoloev clinic. The total number of-casesper year, as well as”iheir distribution by location, by time of infection and by number of lesions, were very similar for each of the 4 years studied (data not shown). 25 -
20 s 8 f% IJ s P E E al 8 ,u
. 15-
lo. 5-
0-i
, 0
2
.
, 4
.
, 6 month
, 6
.
, 10
.
( 12
Figure. Incidence of leishmamasiscasesin Israel by month of exposure, 1988-1992(l=January, etc), based on 188 patients for whom the date of exposure could be accurately determined.
The distribution by location of acquisition of infection showed that the Jordan Valley had the highest incidence (202 cases), but significant numbers of people also became infected in other areas: Arava (44), Judean desert and mountains (39), Negev (37), and the Dead Sea region (46). It was uncertain in which area 3 patients had been infected. The Figure shows the distribution of patients by month of exposure; only patients who could determine within a range of 2-3 weeks the date when they had been exposed to infection in an endemic area were included; residents from endemic areaswere excluded. Clearly, June and July were the months of highest infectivity, but a small number of people becameinfected throughout the year. The number of lesions per person ranged between one and 58. The numbers of people with one lesion (107),
650
with 2-5 lesions (155), and with more than 5 lesions (109) were almost identical. Most patients (289) were over 18 years of age, 58 were aged 6-18 years, and 25 were under 6 years old. This probably reflects occupational differences rather than a preference of the sandfly for adults, since most people entering the endemic area were adults. Kfar Adumim outbreak
-Nineteen casesof leishmaniasis have been diagnosed since 1989in Kfar Adumim. a village 15 km east of Terusalem (population 650, altitide 35O”m).Three addiGona1 caseswere diagnosed a short distance from the village. The parasite strains isolated from the lesions of 6 patients were characterized, since the ecology of Kfar Adumim was not considered typical of that for L. major, and in some casesthe lesions were larger and lasted longer than would be expected for L. rnajir. Parasites from the lesions of these 6 natients were identified bv PCR as L. tropica and in 2 Easeswere further confirmed by immunostaining. These 2 isolates grew very slowly in culture, but after approximately 2 months much fast&r growth o& curred. The fast erowmg cultures were retested bv PCR and found to be i. majo;. One of the isolates, at ihe beginning of fast growth, showed 2 bands, one of 650 kb (L. ma’or) and one of 800 kb (L. tropica). Two additional casesI rom Kfar Adumim were identified as L. major by serotyping. Discussion The number of patients seen in our clinic was almost identical to the total number of casesreported to the Israel Health Ministry, suggesting that leishmaniasis, although a notifiable disease, is in fact largely under-reported; some patients are seenin other clinics, and many persons do not seekmedical advice. L. major has been known to be endemic in Israel and the nei hbouring region for many years; we did not find major if uctuations from year to year in the 4 years of our study. The situation for L. tropica is different. Although sporadic caseshave been seen, only one outbreak, which may have been caused by L. tropica but has not been Droven to be so, has been reDorted (BLUM, 1978). The present report from Kfar Adimim and its &rroundinngs is the first time an outbreak of leishmaniasis known to be due to L. tropica has been reported from Israel. L. major and L. tropica are the only two Leishmania species causing cutaneous disease which have been reported from Israel and surrounding countries (GREENBLATT et al., 1985; SUKKAR, 1985). The fact that 2 isolates were first characterized as L. tropica and then, at a later stage, as L. major was probably not due to a technical mistake, since the isolates were obtained from different patients at different times. The areas endemic for L. major and L. tropica overlap to a certain extent, making it possible for an animal reservoir or a human patient to be infected with both species. It appears that, in the original 2 isolates, the predominant parasite was L. tropica, which caused the lesions, but that a small number of L. major parasites was also present. These L. major parasites gradually outgrew the L. tropica in culture. The vector and reservoir host of L. tropica in this region are not known. Neither infected sandflies nor infected reservoir mammals have been found (Y. Schlein, personal communication), but it is interesting to note that during the years of this study hyraxes were abundant on the southern slope of Kfar Adumim, where an open water pipe kept the soil moist. It was on this side of
the village that the homes of most patients were located. The 19 casesdetected lived in only 9 households, further stressing the localization of the outbreak. We have shown that CL caused by both L. major and L. tropica has appeared in an area in which these infections were previously unknown. This might have been due to ecological changes and the intrusion of human hosts into the zoonotic mammal-sandfly transmission cvcle, as has hannened before in this Dart of the Middle Gast(GREENBL~+T et al., 1985; H. A&ah, 1987, unpublished report’; Y. 0. Oumeish, 1989, unpubhshed report*). Awareness of the presence of L. tropica and of its potential danger as a viscerotropic parasite (KREUTZER et al., 1993) is relevant to the control of infection and the managementof patients. Acknowledgements This work was supported by the Office of the Chief Scientist, Ministry of Health, Israel and the Leslie Nicholas Fund. We thank Dr L. Schnur for performing the serotyping and isoenzyme analysis of someof the samples. References Blum, M. (1978). Cutaneousleishmaniasisand leishnuzninreaction in residentsof Salfit (Samaria). MPH thesis, Department of Social Medicine, HadassahMedical School, Israel. De Ibarra, A. A. L., Howard, J. G. & Snary., D. (1982). Monoclonal antibodies to Leishmania tropica major: specificities and antigen location. Parasitology, 895,523-531. El-On, J., Weinrauch, L., Livshin, R., Even Paz, Z. & Jacobs, G. P. (1985). Topical treatment of recurrent cutaneous leishmaniasis with ointment contain@g paromomycin and methylF;m;;onium chloride. Bntlsh Medical Journal, 291, Eresh, S.,’ Axelrod! O., Greenblatt, C. L. & Barker, D. (in press). PCR in lelshmaniasis diagnosisdistinguishing Leishmania major from L. tropica. Journal of Eukatyotic Microbiology, supplement. Greenblatt, C. L., Schlein? Y. & Schnur, L. F. (1985). Leishmaniasis in Israel and vicinity. In: Lelshmoniasis, Chang, K. P. & Bray, R. S. (editors). Amsterdam: Elsevier, pp. 415426. Jaffe, C. L. & Sarfstein, R. (1987). Speciesspecific antibodies to Leishmania tropica minor recognize somatic antigens and exometabolites.Journal oflmmunology, 139,1310-1319. Kreutzer, R. D., Grog& M., Neva, F. A., Fryauff, D. J., Magill, A. J. & Aleman-Munoz? M. M. (1993). Identification and genetic comparison of lelshmanial parasites causing viscerotropic and cutaneous disease in soldiers returning from operation Desert Storm. American Journal of Tropical Medicine and Hygiene, 49,357-363. Le Blancq, S. M., Schnur, L. F. & Peters, W. (1986). Leishmania in the Old World: 1. The geographical and hostal distribution of L. major zymodemes. Transactions of the Royal Society of Tropical Medicine and Hygiene, 80,99-l 12. Schlein, Y., Warburg, A., Schnur, L. F., Le Blancq, S. & Gunders, A. R. (1984). Leishmaniasis in Israel: reservoir hosts, sandfly vectors and leishmanial strains in the Negev, Central Arava and along the Dead Sea. Transactions of the Royal Society of Tropical Medicine and Hygiene, 78,48U84. Schnur, L. F., Zuckerman, A. & Greenblatt, C. L. (1972). Leishmanial serotypes as distinguished by the gel diffusion of factors excreted in vitro and in vivo. Israel Journal of Medical Sciences.8.932-942. Sukkar,- F: (i985). ieishmaniasis in the Middle East. In: Leishmaniasis, Chang, K. P. & Bray, R. S. (editors). Amsterdam: Elsevier, pp. 393-414. WHO (1984). The Leishmaniases. Geneva: World Health Oraanization, Technical Report series, no. 701. Received 10 January February I994
1994; accepted for publication
2
*Reports to the 2nd and 3rd Pan Arab Seminars on Zoonotic and Parasitic Diseases,respectively.