© Hungarian Natural History Museum Hungarian Society of Parasitologists

Parasit. hung., 28: 43-56, 1995

Occurrence and epidemiology of Echinococcus granulosus and E. multilocularis in the Covasna County, East Carpathian

Mountains, Romania

Sándor S l K Ó B A R A B Á S I , 1 E lv i ra B O K O R , 1 Éva F E K E Á S , 1 *

Imre N E M E S , 1 Éva M U R A I 2 and A n d r á s G U B Á N Y I 2

1 Veterinary Directorate of Covasna County, 4000 Sf. Gheorghe Str. Ciucului, No. 149, Romania

2Zoological Department, Hungarian Natural History Museum,

1088 Budapest, Baross utca 13, Hungary

(Received 20 October, 1995)

Abstract: In the period between 1981 and 1990 the epidemiological data of Echi­nococcus granulosus and E multilocularis (Cestoda, Taeniidae) were studied in the subalpine region of the East Carpathian Mountains, Covasna County, Romania. The definitive hosts of £ granulosus are dogs: 15.4% of2,993 Canisfamiliáris examined were infected. The intermediate hosts are domesticated and wild ungulates: 23.3% of 209,670 cattle; 19.5% of 290,300 sheep; 6.9% of 375,720 pigs; 1.9% of 514 red deer, 6.8% of 88 roe-deer; 22.0% of 635 wild boars and 3 .1% of 32 bears were infected with hydatid cysts of E. granulosus. The red fox, which is the final host of Echinococcus multilocularis (535 specimens), as well as the farmed silver fox (1,418 specimens) were found to be uninfected. Metacestodes of E multilo­cularis were found in 0.0015% of the cattle and 0.45% of the 422 small rodents examined (2 Microtus nivalis). This is the first record of alveolar echinococcosis from the Carpathian Region in Romania.

Key words: Echinococcus granulosus, E. multilocularis, Cestoda, Taeniidae, hyda-tidosis, alveolar echinococcosis, epidemiology, East Carpathian Mountains, Romania

I N T R O D U C T I O N

In the past few decades, the epidemiology of echinococcosis has been studied by Arseni

(1981), Olteanu and Panaitescu (1984), Nesterov et al. (1973, 1991), and Stefànoiu (1991) in

Romania. According to the results, Echinococcus granulosus (Batsch, 1786) has reached a

nationwide spread and is responsible for a variety of severe health problems in both animals and

humans. Olteanu and Panaitescu (1984) expect the occurrence of E. multilocularis Leuckart, 1863

We should like to dedicate this paper to the memory of our colleague Dr. Éva Fekeas, who departed this life during the preparation of this work

(syn. Alveococcus multilocularis Leuckart, 1863), too. According to their findings, the prevalence of alveolar echinococcosis is 0.05% in cattle, 0.02% in sheep, 0.016% in swine.

Adult E. granulosus infestation was found in 72% of stray dogs living around slaughter­houses (with a worm count of 396-7831 per animal) and 37.3% of sheep-dogs, 7.3% of watch-dogs, 2.7% of dogs kept as pets were found to be infected (Olteanu and Panaitescu 1984). Nesterov et al. (1991) reported a 5.8% prevalence of E. granulosus infestation in wolves.

In the period between 1962 and 1981, the prevalence of infestation by the larval form of E. granulosus (hydatidosis, E H ) varied between 9.5% and 60.3% in cattle, and between 10.8%o and 65.9% in sheep inspected at several slaughterhouses in Romania. As regards the prevalence o f infestation in free-living intermediate hosts, Nesterov et al (1973, 1991) reported an infestation rate o f 4.8%) for fallow deer, 8.0% for chamois, 10.4% for w i l d boar, and 0.09% for hare.

Food animals infected by hydatid cysts act as a permanent source of infection. Although cysts can be excised from moderately infected organs, organs wi th submacros-copic lesions might be consumed. To avoid this, it is reasonable to completely exclude the infected organs from public consumption. During the above-mentioned period, the quantity of condemned organs was more than 18 mi l l ion kilograms per year. Cysts located in different organs can affect metabolism, markedly impairing the conception rate and production capacity o f the infected animals.

Larval E. multilocularis infestation (alveolar echinococcosis, A E ) represents a malignant diagnosis in humans and rodents.

The area of spread E. multilocularis includes the northern regions of America and Eurasia, Alaska, USA, Canada, the tundra-region of Europe and Asia, China and Japan (Hokkaido). Its hosts are arctic foxes (Alopex lagopus), red foxes (Vulpes vulpes), probably w i l d cats (Felis silvestris), domestic cats (F. catus) and perhaps some species of Mustelidae. Its intermediate hosts are rodents and humans. A large endemic area spreads from France to the Baltics, comprising Belgium, Luxembourg, Switzerland, Austria, Germany and Poland; exclusively its metacestode (echinococcus alveolaris) has been found in Turkey, Slovenia, Croatia, Bulgaria and Romania (Vogel 1960, Senk and Brglez 1966, Rausch 1967, 1968a, 1968b, 1986a, 1986b, Ohbayashi et al 1971, Petavy and Deblock 1980, Genov et al. 1980, 1981, Zeihle 1982, Frank 1987, Worbes et al 1988, Auer and Aspöck 1991, Eckert et al. 1991, Prosl and Schmid 1991, Stoye 1990, Worbes 1992, Ewald and Eckert 1993, Malczewski et al. 1995). The intermediate hosts are rodents and humans.

Studying the human consequences of the epidemiologic circulation of Echinococcus species, Arseni et al. (1981) reported a morbidity rate of 5.6%> in Romania, and stated that 1.9%) o f these cases were lethal. Examinations using IDR Casoni type reaction (Casoni skin test) proved that 22.6% of people working on cattle forms and 11.01% of shepherds were infected (Olteanu and Panaitescu 1984). During the 10-year period between 1979 and 1988, 8557 patients were hospitalized and operated upon with the diagnosis of EH in Romania: 516 (6%) of them died, and 210,000 days of hospital treatment were needed (Stefanoiu 1991).

Unt i l now, only sporadic surveys have been made on this subject in Covasna County, where - in our experiences - Echinococcus is responsible for more severe losses than in any other district of Romania. Thus, the publication of our systematic epidemiological observations made at slaughterhouses and in villages belonging to the Veterinary Directorate of Covasna County during a 10 year period seems to be timely.

M A T E R I A L S A N D M E T H O D S

Geographic location: Covasna (Kovászna) County is a high-altitude basin in the south-eastern part of Transylvania. It is surrounded by Eastern Carpathians, the Baraolt (Barót)-Mountains and the Hargita. The area of Covasna County is 375 km 2 , wi th the number of its inhabitants 210,000, its height above sea level varies from 468 m to 1777 m, the mean annual temperature is 5.8 °C, the annual rainfall is 761.9 mm, and 170,900 hectars (51%) of the area is covered by forest.

In order to systematize the studies and to make the results comparable, we divided Covasna County into 5 regions, which are separated geographically, climatologically, and in respect of livestock forming and game biology management: I . Sf. Gheorghe (Sepsi­szentgyörgy) zone; I I . Tg. Secuiesc (Kézdivásárhely) zone; I I I . Covasna zone; IV. Baraolt (Bárót) zone; V. Buzanul-Ardelean (Magyarbodza) zone (Fig. 1A).

Livestock farming: In the period of study, livestock farming was conducted in state farms and in farmers' cooperatives on a large scale. For the most part of the year, private farmers conduct mi lk and meat production in the traditional way, or mountain pastures, where domestic animals and game animals of the high-altitude woods encounter infectious agents in shared biotops. The characteristics of the area make it especially suitable for studiing the epidemiology of the two Echinococcus species.

Test material: From 1981 to 1990 EH infestation was studied on the basis o f only the pathological alterations, and 209,670 cattle, 290,300 sheep and 375,720 swine slaughtered at abattoirs [Sfintu Gheorge (Sepsiszentgyörgy), Tg. Secuiesc] and on private farms situated in the animal health districts were found to be infected (Sikó Barabási 199Id).

A n aimed study of 35,015 cattle, 20,011 sheep, and 42,403 swine was also carried out (Sikó Barabási and Bokor 1991). The prevalence and intensity of EH cases were evaluated in every single economic unit and at each farm.

Complex methods o f examination were used in the case of 7,646 cattle. In addition to gross pathological alterations, attention was paid to histopathological changes o f the infected organs and lymp nodes as well .

The preparations were stained by Ziehl-Neelsen and with haematoxylin-eozin + methylene blue (Sikó Barabási 1985, 1991b, 199Id, Sikó Barabási and Bokor 1991). In EH tests of 5,618 cattle, 8,641 sheep, 5,963 swine and 1,269 intermediate hosts (514 deer, 88 roe-deer, 635 w i l d boars and 32 bears) were used, the fertility of hydatid cysts was determined with the help of preparations made with Berlese solution. For caseified and calcified cysts modified Gram staining was used. The morphology of detected cysts, the number of cysts per organ and the prevalence rate (%) were also recorded (Sikó 1991c, 199Id).

Table 1

Haematologic values of wild boars (n = 10)

Normal value Actual value

Number of erythrocytes (mil/mm3) Number of leucocytes (/mm 3) Eosinophils (%) Haemoglobin (g/ml)

7.6-7.9 10,000-14,000

0.1-1.2 14.2-15.2

18,563-23,800 10.0-14.5 11.0-12.1

4.3-7.0

Fig. 1. Distribution of Echinococcus infestations in Covasna County. A — I . Sfintu Gheorge, I I . Tg. Secuiesc, I I I . Covasna, IV. Baraolt, V. Buzanul-Ardelean; B — Distribution pattern of EH infestation in cattle: 1 = Anghelus (Angyalos), 2 = Haghig (Hídvég), 3 = Aita Mare (Nagyajta), 4 = Baraolt, 5 = Batanii Mari (Nagybacon), 6 = Virghis (Vargyas), 7 = Turia (Torja), 8 = Bisericani (Szentlélek), 9 = Catalina (Szentkatolna), 10 = Borosneu Mare (Nagyborosnyó); C — Distribution pattern of EH infestation in sheep: 1 = Anghelus, 2 = Araci (Árapatak), 3 = Belin (Bölön), 4 = Batanii Mari , 5 = Turia, 6 = Bisericani, 7 = Poiana (Poján), 8. = Catalina, 9 = Zabala (Zabola); D — Dist r ibut ion pattern of EH infestation in swine: 1 = Anghelus, 2 = Ozon (Uzon), 3 = Baraolt, 4 = Turia, 5 = Cernat (Csernát), 6 = Tg. Secuiesc, 7 = Catalina, 8 = Brates (Barátos); E — Distribution pattern of EH infestation in wild animals (rising to left line = roe-deer, rising to right line = deer, dash line = wild boar, spot = bear); F — Distribution pattern of AE infestation (rising to left line = Covasna zone, Comandau (Kommandó).

In view of of the 50% E H prevalence, the 10 wi ld boars shot in the winter period of 1982-1983 were subjected to haematologic examination (Table 1; Sikó Barabási and László 1983, Sikó Barabási 1991d).

In a survay of alveolar echinococcosis (E. multilocularis) between 1989 and 1992 a total o f 422 rodents were examined by routine pathological and histopathological methods, in addition to the domestic and game animals listed above (Sikó Barabási 199Id, 1992b).

Examination of adult worms: Taenia infestation of 2,581 l iving dogs was established by the examinination o f faecal samples. We also tried to determine E. granulosus or E. multilocularis infestation in 432 dead dogs, 535 red foxes shot on huntings and 1,418 silver foxes skinned in order to be sold. The small intestines had previously been soaked in 4 % formalin which was prepared wi th physiological saline. The small intestines were opened and examined stereomicroscopically. From the mucous membrane suspected of being infected a smear was prepared by fixation in Berlese solution for microscopic examination, and then examined under a trichinoscope. For morphologic examination the preparations were stained wi th iron acetocarmine as described by Georgiev et al. (1986).

RESULTS

In the period between 1980 and 1990 a total of 875,690 food animals (cattle, swine, sheep), 2,581 dogs, 1,418 cultured silver foxes, 535 red foxes, 422 voles were examined parasitologically, w i t h especial regard to the different types o f echinococcosis [adult E, granulosus in dogs; the prevalence and incidence of larval cases of echinococcosis (EH) in cattle, sheep, swine, w i l d boar, deer (Cervus elaphus), roe-deer (Capreolus capreolus) and bear (Ursus arctos) populations; E. multilocularis larval infestation ( A E ) in cattle and voles].

EH infestation of cattle (Fig. 2A): 23.3% of20,967 cattle slaughtered annually in average were infected. Hydatidosis was the most prevalent in the regions of Baraolt and Batanii Mar i (Fig. IB, 41.0-68.3%)), followed by the regions of Virghis, AitaMare, Haghig(31.9, 26.6 and 36.2%); and the regions of Catalina, Turia, Bisericani (50.0, 20.5, 32.3%). EH prevalence in cattle herds of several owners showed an interesting variability: animals kept on state farms had the highest infection rate (33.3%»), followed by animals kept in farmers' cooperatives (26.0%o), on private farms (28.3%>), and in various feedlot units (19.1%»). Table 2 shows the distribution of E H infestation in cattle by organ. The quantity of liver condemned per year because of E H was 35,410.7 kg, which is worth more than 100,000 USD (Fig. 3).

1981 19BZ 1983 1984 1985 1986 1987 1988 1989 1990 19811982198319841985 198619B7198819891990

Fig. 2. Prevalence of EH infestation in cattle (A) and sheep (B) by year (open bar = slaughterhouses, solid bar = other units, line = average).

Table 2

EH infestation of cattle by organ and type of cyst (n= 5,618)

Unil.-unicyst Unil.-polycyst Multil.-unic. MP Caseified cyst Calcified cyst P F

Organs 1-5 6-10 11 + 1-5 6-10 11 + 1-5 6-10 11 + 1-5 1-5 6-10 11 + 1-5 6-10 11 + % % Liver 408 340 581 108 98 55 209 45 68 8 175 105 86 148 223 16 48.4 21.0

Lungs 113 160 189 22 8 18 11 8 0 0 25 32 16 3 0 0 10.7 67.0

Kidney 14 0 0 2 1 0 1 0 0 0 0 0 0 0 0 0 0.04 8.8

Heart 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.003 0

Spleen 0 0 0 0 0 0 2 0 0 2 2 0 0 0 0 0 0.01 0

L i + L u 870 410 512 61 32 9 71 31 17 11 113 74 0 0 0 0 39.3 37.2

L i + L u + Ki 41 1 0 0 11 5 8 2 0 0 0 0 0 0 0 0 1.2 9.1

L i + L u + Sp 30 12 0 3 0 0 12 0 0 0 1 0 0 0 0 0 0 1 3.5

L u + Sp 3 0 0 9 2 0 0 0 0 0 0 0 0 0 0 0 0.02 0

Total 1,483 924 1,278 208 152 87 319 86 85 26 316 211 102 201 223 16 0.01 0

Prev. (%) 26.3 16.4 22.7 3.7 2.7 1.4 5.6 1.5 1.4 0 4 5.6 3.7 1 7 3 5 3 9 0 2

Total prev. (%) 65.4 7.8 8.5 0.4 11.0 7.6 100.0 12.2

MP = Multilobular polycyst, P = prevalence, F = fertility

EH infection of sheep: During the 10-year period of study 29,030 sheep were slaughtered annually. Their average EH infection rate reached 19.4%. EH prevalence was outstandingly high in 1982-1983, when one-third of the sheep flocks were infected in Covasna County (Fig 2B). O f the regions studied, the region of Batanii Mari (27.0-89.6%)) and the regions of Bisericani and Estelnic [(Esztelnek), 13.7-27.5%)] showed a high prevalence of infection. Sheep kept in farmers' cooperatives had the highest prevalence (27.1%>), followed by sheep kept in flocks of state farms (18.7%>), and by those of private farmers (9.7 %>). Table 3 summarizes E H infestation of sheep by organ and type of the cyst.

EH infection of swine: Dur ing the study it was found that EH infestation o f swine was also considerable: 6.9% o f 37,572 swine slaughtered annually were infected; in 1989 this rate reached 10.0% (Fig. 4). Considering each region separately, Ozun (33.3%) in 1990), Baraolt (10.7%) and Brates (10.6% in 1989) showed the highest prevalence of infec­tion. Swine of private farmers, especially tho­se of shepherds were most severely infected, their prevalence of infection reached 33.3% (Sikó Barabási and Bokor 1991, Sikó Barabási et al. 1991 ). As shown in Table 4, the prevalence of cysts was over 50%> in the liver.

O f the intermediate hosts, wi ld boars showed the highest prevalence of infestation (22.0 % of the 635 w i l d boars shot on hun­tings), especially in the zones of Baraolt

Fig. 3. Number of cattle slaughtered and the condemnation of livers because of

EH in a one-year period

19B1198219831984I9B519861987198819891090

Fig. 4. Prevalence of EH infestation in swine by year (open bar = slaughterhouses, solid

bar = other units, line = average).

Table 3

EH infestation of sheep by organ and type of cyst (n= 8,641)

UniLunicyst Unil. polycyst Multil.unicyst M P Caseified Calcified P F

Organs 1-5 6-10 11 + 1-5 6-10 11 + 1-5 6-10 11 + 1-5 6+ 1-5 6-10 11 + 1-5 6-10 11 + % % Liver 316 241 157 123 16 2 41 52 16 9 3 551 416 102 310 59 81 28.8 96.2

Lungs 621 560 881 229 16 19 12 0 0 3 0 243 312 171 111 43 7 37.3 98.6

Kidney 36 2 0 2 0 0 0 0 0 0 0 3 0 0 0 0 0 0.04 88 2 Spleen 5 0 0 1 0 0 0 0 0 0 0 2 0 0 0 0 0 0.009 92.0 L i + L u 531 818 459 176 14 11 17 19 0 0 0 411 258 129 111 2 0 34.2 97.2 L i + Lu+ K i 23 3 0 0 0 0 4 0 0 0 0 3 0 0 0 0 0 0.03 91.3 L i + L u + Sp 7 2 0 0 0 0 0 0 0 0 0 3 0 0 0 0 0 0.00270.1 L u + K i 19 3 0 5 0 0 4 2 0 0 0 0 0 0 0 0 0 0.03 90.2 L u + Sp 6 2 1 0 0 0 7 0 1 0 0 4 1 0 0 0 0 0.02 50.0 Total 1566 1631 1508 541 46 32 85 73 17 12 3 1220 987 402 332 104 88 Prevalence % 18.2 18.9 17.4 6.3 0.5 0 4 0.9 0.8 0.16 0.1 0.03 14.1 11.5 4.6 3 8 1.3 1.0 100.068.6 Total prev % 54.5 7.2 2.0 0.2 30.2 6.0

MP = multilobular polycyst, P = prevalence, F = fertility

Table 4

EH infestation of swine by organ and type of cyst (n= 5,963)

Unil.unicyst. Unil.polycyst. Multil.unic. M polyc. Caseified Calcified P F

Organs 1-5 6-10 11 + 1-5 6-10 11+ 1-5 6-10 1-5 5-10 1-5 6-10 11 + 1-5 6-10 11 + % % Liver 512 818 364 152 56 31 26 2 3 2 480 222 167 248 56 27 53.0 92.0 Lungs 232 246 19 14 2 0 4 0 0 0 241 162 34 128 15 22 18.7 83.1 Kidney 15 0 0 3 0 0 3 0 0 0 2 0 0 0 0 0 0.03 53.2 Spleen 3 0 0 0 0 0 0 0 0 0 4 0 0 0 0 0 0.01 33.3 L i + L u 318 323 217 18 12 6 17 5 0 0 371 128 123 192 19 29 28.9 91.5 L i + L u + Ki 3 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0.01 0.0 L i + L u + Sp 6 0 0 0 0 0 0 0 0 0 5 0 0 0 0 0 0.01 50.0 L u + Sp 18 6 2 7 0 0 1 0 0 0 7 0 0 2 0 0 0.06 50.0 Total 1,1071,393 582 195 70 37 51 7 3 2 1,112 512 324 460 90 78 Prevalence % 18.6 23.4 9 7 3.3 1.2 0 7 0.8 0.1 0.05 0.04 18.6 8.5 5.4 7.7 1.5 1 3 100.0 37.7 Total prev. % 51.7 5.2 0.9 0.09 32.5 10.5

P = prevalence, F = fertility

Table 5

EH infestation of wild animals by organ and type of the cyst (n= 115)

Unilobular unicyst U. polycyst M. unicyst Caseified Calcified Fertility

Animal / Organ 1-5 5-10 1-5 1-5 1-5 6+ 1-5 % Red deer (n= 514/10) Liver 7 2 0 0 0 0 0 30.0 Lungs 1 0 0 0 0 0 0 100.0 Roe-deer Liver 1 1 0 0 0 0 0 (I 0 Lungs 3 1 0 0 0 0 0 0 0 Wild boar (n= 635/98) Liver 42 5 6 0 6 0 1 36.6 Lungs 28 17 0 0 32 3 0 16.2 Bear(n= 32/1) Liver 0 0 0 1 0 0 0

(48.1%), Tg. Secuiesc (21.8 % ) and Covasna (16.4 % ) . A strikingly high rate of infestation

(50.0 % ) was found in the 10 w i l d boars shot in the winter of 1982-1983 around Turia.

The haematological values of these w i l d boars were also indicative o f parasitosis (Table 1).

The E H infestation of the other intermediate hosts was much lower: 1.9 % of 514 red deers, 6.8

% of 88 roe-deer, 3 . 1 % of 32 bears had EH, and 0.45 % of 422 voles had A E infestation.

A E infestation o f 0.0015%» prevalence was observed also in the liver of cattle. Table 5

summarizes the E H infestation o f game animals by organ and by type o f cyst. Mult i lobular

polycystic E H infestation has not been found.

During our research (1981-1990) 638 human hydatidosis cases were recorded in three

districts o f Transylvania by the Institute of Public Health and Medical Research, Cluj , and

200 of these cases were found in Covasna County; 50% represented liver, 32%> lung

hydatidosis, while in 15%> of the cases, the diagnosis of echinococcus metastasis was

established. The affected people were mostly shepherds and villagers (Coroiu et al. 1992).

The prevalence of taeniid infestation in 2,581 living dogs was 32.0% on the average, as

revealed by egg counts in faecal samples. The shape and size of Echinococcus eggs do not differ

from those of the eggs of other species of Taeniidae; thus, specific prevalence could not be calculated

on the basis of faecal examination. To detect E. granulosus infestation 432 dead dogs were subjected

to pathological examination between 1981 and 1990: their average E. granulosus infestation rate

reached 15.4%. Adult worms mainly colonized the duodenum; they were found in lower numbers

in the ileum and jejunum (Figs 5B-C). Dogs living around slaughterhouses revealed the highest

prevalence rate (37.5%>), because these animals regularly had access to infected viscera intended

for destruction and stored in containers in the yard of the slaughterhouses. Sheep dogs (22.8%),

stray dogs (19.2%) and dogs living around livestock units (17.3%) also showed a considerably

high prevalence of infection. As regards the regional distribution of infection, dogs in the zones

of Tg. secuiesc and Sfintu Gheorge showed the highest prevalence (22.2% and 13.9%), which is

not surprising as the two slaughterhouses of the district can be found in those areas.

In 535 red foxes (V vulpes) necropsied in a 10-year period, neither E. granulosus nor E.

multilocularis specimens were found. The 1,418 silver foxes (V. vulpes fulvus) examined also

proved to be negative for Echinococcus spp., although they had been fed mainly on organs

condemned at slaughterhouses. These data support the fact that foxes are not definitive hosts

o f £ . granulosus (Sikó Barabási 199Id).

Table 6

Prevalence of taeniid infestation in dogs as determined by the examination of faecal samples

Dogs I II III I V V Total

Stray dogs 416 96% 348 61 % 161 2 9 % 32 87 % 29 14 % 986 14-96 %

Slaugtherhouse dogs 18 4 0 % 23 71 % 0 0 0 41 18-23 %

Sheep dogs 16 16% 346 51 % 129 48 % 131 6 9 % 21 3 6 % 643 16-69%

Hunting dogs 74 14% 86 2 6 % 86 30 % 36 41 % 0 282 14-41 %

Farm dogs 152 8 % 120 4 0 % 73 28 % 46 21 % 0 391 8-40 %

Watch dogs 23 12 % 40 14 % 14 18% 19 21 % 16 17 % 112 12-21 %

Dogs kept as pets 66 5 % 39 2%j 6 3 % 15 2 % 0 126 2-55 %

Total 765 1 002 469 279 66 2,581

I = Sf. Gheorghe zone; II = Tg. Secuiesc zone ; III = < Covasna zone; IV = Etaraoit zone;

V = Intorsura-Buzaului zone

Fig. 5. A Hydatid cysts with brood capsules, B — E. granulosus in the wall of the ileum (C. familiáris), C - Hook crown of E. granulosus, D - Unilobular unicyst in the liver

(S. scrofa), E — EH cysts in the lung (cattle), F — AF cysts in the l iver {Microtus nivalis), G — Protoscoleces in the EH cyst, H — AE cysts in the liver (cattle)

Larval Echinococcus multilocularis infestation (alveolar hydatiosis) was found in three cattle (0 .001% of the cases examined) and in 2 rodents (2 M. nivalis 0.45%> of cases examined). It is worth mentioning that cattle and rodents both lived in region of Comandau, which is located 900 and 1300 m above sea level (Fig . I F ) .

E H cysts present in intermediate hosts were grouped by infected organ, cyst morphology, and fert i l i ty rate. In morphology and structure the cysts do not differ from the forms described in the literature. Although Vanek and Slais (1988) described seven different forms of cysts, for the sake o f s implici ty the cysts were divided into 4 groups only: unilobular unicystic, unilobular polycystic, mult i lobular unicystic and mul t i lobu­lar polycystic. According to the content o f cysts, caseified and calcified forms were recorded (Tables 2-5). The unilobular unicystic form was the dominant type in our material wi th incidences of 65.4%> in cattle, 54.5% in sheep, 51.7%) in swine, 100%) in reddeer, 100% of roe-deer, 65.7%> in w i ld boars. Other forms occurred with a lower incidence. The liver was 48.4% in cattle, 28.8% in sheep, 53.0%> in swine, 44.4% in w i l d boars, 90.0% in reddeer, and 33.3% in roe-deer) followed by the liver + lungs (39.3%o in cattle, 34.2% in sheep, 28.9% in swine etc.) and lungs alone (10.7% in cattle, 37.3%) in sheep, 18.7% in swine). EH cysts were rarely found in other organs (kidney, spleen, heart).

Larval E. granulosus infestation of the liver (or other organs) of intermediate hosts manifests itself as a round cyst, filled with semi-transparent liquid and measuring 20 and 220 mm in diameter (Fig. 5D).

Studies on the fertility rate of cysts revealed that in swine and wi ld boars the EH cysts located in the liver were the most fertile (93.0%) and 36.6%>, respectively), while in cattle (67.0%), sheep (98.6%), red deer (100%), roe-deers (50.0%) the cysts formed in the lungs were the most fertile.

The alveolar hydatid cysts of cattle are located in the liver (Fig. 5H) and constitute a group of numerous vesicular cauliflower-like formations, which is 0.8-2.5 cm in diame­ter, and show continous proliferation. They are morphologically similar to cysts reported from the liver of cattle by Senk and Brglez (1966) and Stoye (1990).

E. multilocularis cysts found in the liver of snow voles ( M nivalis) are yellowish-white conglomerates of vesicles (Fig. 5F). Each of them is 0.5-1.3 cm in diameter, has a complex structure and consists of several alveoli. Structurally they are similar to the cysts described by Ohbayashi et al. (1971) and Genov et al. (1980).

The germinative pellicle lining the newly formed alveoli consists of well visible all groups showing vigarous proliferation, very similar to those seen in the case of fibrosarcoma.

DISCUSSION

Two out of the four Echinococcus species live in Europe: E. granulosus and E. multilocularis (Rausch 1967, 1986a, 1986b, Frank 1987, Worbes et al. 1988, Eckert et al. 1991, Brglez and Wikerhauser 1992, Ewald and Eckert 1993, Malczewski et al. 1995).

The metacestoda of ubiquitous E. granulosus are wide-spread in all ungulate species of the continent and also in humans as intermediate hosts. The adult form occurs in C. lupus and in several other species of Canidae. Hydatid disease causes huge economic losses and severe health problems in both humans and animals.

The life cycle and epidemiology of the Echinococcus species occuring in Europe were investigated over a 10-year peroid in Covasna County, which is situated in a subalpine area of the Eastern Carpathians.

In the area studied, the dog - domesticated ungulate life cycle of E. granulosus manifests itself as a severe epidemic. Domesticated ungulates and/or shepherds are continuously exposed to contamination originating from dogs, and may ingest eggs present in the faeces left behind by them. Wrong local practices of handling viscera containing hydatid cysts and temporarily stored in the yard of slaughterhouses while awaiting destruction allow dogs to have access to infested organs. Another problem is that at home slaughters and huntings no case is taken to prevent dogs from having access to organs containing fertile hydatid cysts.

Major endemic foci were found by the postmortem examination of dogs. In zone I (Sfintu Gheorge) 13.9% of 107 dogs were infested. The prevalence of infection was 31 .1% in stray dogs, 28.8%) in dogs living animal farms, 17.0% in dogs living around slaughterhouses. The highest number of worms found was 11,200 in a dog. In zone I I (Tg. Secuiesc), 22.2%> of 153 dogs were infested. The prevalence of infestation was 58.0% in dogs living around slaughter­houses, 28.9% in those kept around animal farms, 28.0%) in stray dogs and 27.0%> of sheep dogs. The maximum number of worms recorded was 19,000 E. granulosus specimens found in a dog living around a slaughterhouse. In zone I I I (Covasna) 8.4% of 77 dogs were infested. The prevalence of infection was 19.3%) in sheep dogs and 18.2% in stray dogs. In a hunting dog 9,200 mature stages were found. In zone I V (Baraolt) 12.0% of 62 dogs were infested: 39%o of sheep dogs, 11.0% of stray dogs, 11.8% of watch-dogs were infested by E. granulosus worms. The highest count was 11,200. In zone V (Buzaul-Ardelean) 33 dogs were examined: the prevalence of infection was 4.6%» with a maximum worm count of 10,200.

The patterns of infection found in dogs are reflected on the maps showing the infestation of cattle, sheep and swine (those areas are indicated where the prevalence exceeded the annual average, i.e. 26.6-68 % in cattle, 27.0-89.6 % in sheep, 10.6-48.1 % in swine, Figs I B -E) . Although wolves are likely to play a role in spreading E. granulosus, unfortunately it was not possible to examine wolves during this survey. Nevertheless, the presence of a wolf -wi ld ungulate and a dog-wild ungulate strain of E. granulosus should be assumed in Covasna County, with special regard to the EH infestation observed in wi ld ungulates.

This study was the first to demonstrate the presence of the larval form of E. multilocularis inside the range of the Carpathians (Fig. IF ) . Morphological and pathological data of the alveolar echinococcosis found in the region of Comandau are consistent wi th the literature data (cf. Ohbayashi et a. 1971, Genov et al . 1981, Stoye 1990, Brglez and Wiker -hauser 1992).

Human cases of metastatic echinococcosis, reported by Coroiu et al (1992), suggest the incidence of Echinococcus multilocularis among mountain shepherds.

A C K N O W L E D G E M E N T S

Grateful thanks are due to Dr. Árpád Bálint and Dr. Atti la Kondor veterinarians, Klára Kovács laboratory assistant, Árpád Fejér, Dóra Gábor, Margit Kisantal, Etelka Kiss, Ildikó Kovács and Jolán Kovács slaughterhouse assistants for their participation in the 10-year research conducted in Covasna County.

Sikó Barabási, S., Bokoç E . , Fekeás, É, Nemes, L , Murai, É. és Gubányi, A . : A z Echinococcus fertőzöttség vizsgálata a H á r o m s z é k i - m e d e n c é b e n

(Keleti Kárpátok, Románia)

A szerzők a Keleti Kárpátokban, szubalpin környezetben elterülő Háromszéki-medence (Covasna County) területén 10 év alatt az Európában elterjedt két Echinococcus faj életciklusát és járványügyi paramétereit vizsgálták. Post mortem vizsgált kutyáknál e r ő s endémiás gócokat figyeltek meg. Az I . körzetben (Sepsiszentgyörgy): 107 kutyából 13.9% f e r t ő z ö t t ; kóbor ebeknél 31.1%-os, állattartó telepeken 28.8%-os, vágóhidak környékén 17.0%-os volt a prevalencia; maximálisan 11,200 féreg/kutya. A I I . körzetben (Kézdivásárhely): 153 kutya 22.2%-a f e r t őzö t t , a vágóhíd körül 58.0%-os, állattartó telepek körül 28.9%-os, kóbor ebek 28.0%-os, pásztorkutyák 27.0%-os prevalenciával. Egy vágóhíd körül élő kutyában maximum 19,800 E. granulosus egyedet észleltek. A I I I . körzetben (Kovászna): 77 kutya 8.4%-a volt fertőzött, pásztorkutyák 19.3%-os, kóbor kutyák 18.2%-os prevalenciával bírtak. A IV. körzetben (Bárót): a pásztorkutyák 39%a, a kóbor ebek 11.0%-a, a h á z ő r z ő k 11.8%a volt fer tőzött E. granulosus férgekkel; a maximális féregszám 11,200 volt. Az V. körzetben (Magyarbodza) összesen 33 kutya vizsgálata alapján a prevalencia 4.6%, a maximális féregszám pedig 10,200 féreg/egyed volt. A vadászterületeken vizsgált 535 vörösróka és 1,418 tenyésztett ezüstróka (utóbbiakat Echinococcus cisztákkal fertőzött vágóhídi hulladékkal táplálták) negatív volt. Ez újabb bizonyíték arra, hogy a rókák nem definitív gazdái az E granulosus fajnak. Több mint 800,000 vágóállat (209,670 szarvasmarha, 290,300 juh, 375,720 sertés) hólyagféreg fertőzöttsége 10,7-89,6 % között mozgott., összefüggésben az I-V. körzetekben kutyáknál leírt járványügyi helyzettel. A z E . granulosus vadon élő köztigazdái közül őzben 6.8%, gímszarvasban 1.9 %, vaddisznóban 22.0 %, medvében 3 . 1 % EH fertőzöttséget észleltek. A szerzők a komandói járás területén magashegyi legelőkön tartott szarvasmarhák májában 3 esetben találtak alveolaris echinococcosist (5. ábra F) és két havasi pocok máján pedig E. multilocularis ciszták jelenlétét észlelték (5. ábra H). Az E. multilocularis lárvaformájának jelenlétét e l s ő ízben bizonyították a Kárpátok vonulatán belül.

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