A cross-sectional survey was undertaken to study the prevalence and intensity of infestation with Toxocara cati in 108 stray cats, including 44 males and 64 females, from December 1996 to May 1997 in Shiraz city, southern Iran. A total of 57 cats (52.8%) were infected with T. cati. There was no significant difference between the rate of infection between males and females, young and adult cats, or the prevalence of infection in different geographical areas. The number of recovered worms per cat or intensity of infection ranged from one to a maximum of 50 worms per animal, with an average of 6.53 T. cati in each cat.Istraživanje je provedeno na 108 mačaka lutalica i to 44 mužjaka i 64 ženke u razdoblju od prosinca 1996. do svibnja 1997. na području grada Shiraza u Iranu. Potvrđeno je da je čak 52,8% pretraženih životinja bilo invadirano oblićem Toxocara cati. Nije utvrđena značajna razlika u učestalosti invazije s obzirom na spol i dob te mjesto istraživanja. Broj oblića kretao se od 1 do 50, u prosjeku 6,53 oblića po mački

Abdol Reza Jalai

Ahmad Oryan

Davood Mehrabani

Seyed Mahmoud Sadjjadi

Hrčak - Portal of scientific journals of Croatia

149Prevalence and intensity of infestation with Toxocara cati instray cats in Shiraz, IranSeyed Mahmoud Sadjjadi1*, Ahmad Oryan2, Abdol Reza Jalai1, andDavood Mehrabani31 Department of Parasitology and Mycology, School of Medicine, Shiraz University of MedicalSciences2Department of Pathobiology, School of Veterinary Medicine, Shiraz University,3Razi Research Institute, Shiraz, IranSADJJADI, S. M.,  A. ORYAN, A. R.  JALAI, D. MEHRABANI: Prevalenceand intensity of infestation with Toxocara cati in stray cats in Shiraz, Iran.Vet. arhiv 71,  149-157, 2001.ABSTRACTA cross-sectional survey was undertaken to study the prevalence and intensity of infestation withToxocara cati in 108 stray cats, including 44 males and 64 females, from December 1996 to May1997 in Shiraz city, southern Iran. A total of 57 cats (52.8%) were infected with T. cati. There was nosignificant difference between the rate of infection between males and females, young and adult cats,or the prevalence of infection in different geographical areas. The number of recovered worms per cator intensity of infection ranged from one to a maximum of 50 worms per animal, with an average of6.53 T. cati in each cat.Key words: toxocariasis, Toxocara cati, visceral larva migrans, cat, IranIntroductionToxocara cati is a common parasite of cats and Felidae, and has acosmopolitan distribution (YAMAGUCHI et al., 1996; VANPARIJS et al., 1991;BAKER et al., 1989; REP, 1975; ENGBAEK et al., 1984; McCOLM and HUTCHISON,1980; SADIGHIAN, 1970; MIRZAYANS, 1971). It is one of the helminthiczoonoses which causes visceral larva migrans in human beings (BUIJS,1993). Paratenic hosts, such as man and small rodents, can infect themselves* Contact address:Dr. S. M. Sadjjadi, Department of Parasitology and Mycology, School of Medicine, Shiraz University of MedicalSciences, Shiraz, P. O. Box 71345-1735, Iran; Phone: +98 711 2305 410-18 Ext. 342;  Fax: +98 711 2359 847 ; E-mail:parasito@sums.ac.irISSN 0372-5480Printed in CroatiaVETERINARSKI ARHIV  71 (3), 149-157, 2001150unintentionally by swallowing infective eggs (BEAVER, 1969; BEAVER et al.,1984). Infected cats are of high potential risk to infect human beings,especially children. The larvae hatch in the intestine and then invade thehost’s viscera, given the name Visceral Larva Migrans (VLM). Infectionwith T. cati is known to be of wide geographical distribution.The rate of infection in the human population depends on the historyof pica, the abundance of pet animals, personal public health, prevalenceof Toxocara in animals, and the rate of infection in the environment(CHARLESTON, 1977; KAZURA, 1996). About 10% of world’s population areseropositive (LAPPIN, 1993). T. cati is mostly prevalent throughout tropical,subtropical and temperate regions (BUIJS, 1993). VLM is one of the mostimportant parasitic diseases of man transmitted by carnivores in Iran(KABIRI et al., 1979; FARIVAR and RAFAT, 1991; DALIMI and MOBEDI, 1992). Theadult T. cati lives in the small intestine of cats and is morphologicallysimilar to Ascaris lumbricoides, although smaller by about a quarter tohalf of its size. The eggs, which require a period of maturation outside thehost, are infective for cats and human beings. The risk of man coming intocontact with contaminated soil is plausible as 15% (adults) and 90%(puppies) of dogs and 24% to 67% of cats carry adult parasites (VANPARIJSand THIENPONT, 1973). Catching an infection directly from cats or throughfresh droppings is unlikely due to the long period required for eggmaturation. The eggs are washed from the soil’s surface into the deeperlayers, and because of their resistance to climatic changes they may remainviable for several years (BUIJS, 1993). Due to the close association andproximity of man with his domestic animals (in particular, cats), thereexist possibilities of human infection with helminth parasites of theseanimals. Although the larvae of non-human ascarids, such as T. cati, arecapable of limited development in human hosts, this may, in somecircumstances, lead to serious public health problems, e.g., encephalitisand granulomatous lesions (WOODRUFF et al., 1981). Since cats constitute apotential source of T. cati infection in man (McCOLM and HUTCHISON, 1980;MARKELL  et al., 1992) and a systematic study on the prevalence of this parasitehas not taken place among stray cats in the Shiraz area, it was thereforedecided to undertake a study on the prevalence and intensity of this parasiteVet. arhiv 71  (3), 149-157, 2001S. A. Sadjjadi et al.: Toxocara cati in southern Iran151in cats in this area, where the sero-prevalence of Toxocara in children ismore than 20% (SADJJADI et al., 2000).Materials and methodsFrom December 1996 to May 1997, with permission of the authoritiespost-mortem examinations were carried out on 108 stray domestic catsthat were collected from different locations of Shiraz city, southern Iran.Cats were from shelters, without owners and were to be euthanatised. Aftersedation and euthanasia with tiopenthal, cats were examinedmacroscopically. All helminth parasites were collected and preserved forlater identification. Before performing autopsy the animals’ sex and weightwere recorded, and the age of cats was estimated on the basis of theirdental development.All cats were autopsied less than two hours after being euthanatisedso that all adult worms were still alive prior to fixation in 10% formalinsolution. T. cati worms were separated from other helminths and the malesand females were identified by microscopic examination. The worms werecleared, and stained using FAAL (formalin alcohol azocarmin lactophenol).The mature male and female worms were identified according to themorphological features described by (YAMAGUTI, 1961). Presence of ovawas the criterion for distinguishing the mature female worms (SOULSBY,1982). The ova were assessed by simple observation at X 400 magnificationby examining the general appearance of the shell and its cellular contents.Only those ova that were specifically located in the tapering portion of theuterus (near the vulva at the anterior end of the worm) were considered forthis purpose. Those eggs that were both regular in shape and whichpossessed the characteristic pitted shell design were regarded as T.catieggs of. The uniformity of the cellular content of the ova was alsoconsidered. The worm burdens in this study were recorded directly atautopsy by counting. The length of both male and female worms and thematurity status of ova as a proportion of the overall female worm maturitywere also recorded in this study.    All statistical tests were expressed as significant at 95% confidencelevel. These analyses were performed using the “SPSS” (Statistical PackageVet. arhiv 71  (3), 149-157, 2001S. A. Sadjjadi et al.: Toxocara cati in southern Iran152for Social Science). For simplicity, only “P” values have been quoted. TheChi- square test was used to study the relationship between the prevalenceof these parasites and the age and sex of the cats. The relationship betweenhost sex and age to the overall worm burdens in cats was examined usingthe analysis of variance test.Results A total of 76 cats, more than 6 months and 32 less than 6 months ofage, were examined during this experiment (Table 1). The prevalence of   A ge    In fected*  N on in fected*  To tal    N o . ( % ) N o .  (% ) N o . (% ) >  6  m on ths   38 (50 .00) 38 (50 .00) 76 ( 70 .37) <  6  m on ths        19  (59 .37) 13 (40 .63) 32 ( 29 .63) To tal 57 (52 .78) 51(47.22) 108  (100 .00)  Table 1. Prevalence of Toxocara cati in stray cats according to age  * Chi-square = 0.46;   P = 0.9   S ex  In fected*  N on in fected*  To tal    N o . ( % ) N o .  (% ) N o . (% ) M ale 24 (54 .55) 20 (44 .45) 44 (40 .74) F em ale        33  (51 .56) 31 (48 .44) 64 (59 .26) To tal 57 (52 .78) 51 (47 .22) 108  (100 .00)    * Chi-square = 0.1;   P = 0.9Table 2. Prevalence of Toxocara cati according to sex of stray catsT. cati in these 108 stray cats, was 52.78%. T. cati was always confined tothe upper half of the small intestine (i.e., the anterior 60 cm). The studyalso showed no significant difference in the prevalence of infection to T.cati according to the areas where the cats were captured. Out of 44 maleand 64 female cats, 24 (54.55%) and 33 (51.56%) were infected with T.cati, respectively (Table 2). There were no significant differences in theVet. arhiv 71  (3), 149-157, 2001S. A. Sadjjadi et al.: Toxocara cati in southern Iran153prevalence of infection between male and female cats. The mean intensityof infection with T. cati was 6.52, with a range of from 1 to 50 worms percat. There was no significant difference in the intensity of infection betweenmale and female cats (Table 3). The intensity of infection was also studied   Sex   N o infected  M ean N o of nematodes sd M in. M ax. M ale 24 6.37 10.10 1 42 Female        33 6.63 8.76 1 50 Total 57 6.52 9.26 1 50    * P = 0.9Table 3. Intensity of infestation with Toxocara cati in stray cats according to sex   Age    Infected  Mean No of nematodes sd Min. Max. > 6 months   19 7.21 9.58 1 42 < 6 months      38 6.18 9.21 1 50 Total 57 6.52 1 1 50   * P = 0.7  Table 4. Intensity of infestation with Toxocara cati accorting to age of catsVet. arhiv 71  (3), 149-157, 2001S. A. Sadjjadi et al.: Toxocara cati in southern Iranaccording to different geographical areas of   Shiraz city. Older cats showeda higher intensity of infection than younger ones; however, the differencewas not significant (Table 4). Discussion Our study confirms that compared to most other localities worldwidethe prevalence of  T. cati infection in cats in Shiraz is high. The highprevalence of T. cati in stray cats in Shiraz (52.8%) indicates that themeteorological condition are suitable for the spread of and survival of thenematode eggs. Infection of cats with T. cati can occur either throughingestion of infective eggs or from eating rodents containing larvae intheir tissues. Since the cats habitually bury their faeces, the spread ofinfection through the medium of infective eggs is less likely to occur than154from the predatory habits of cats. The eggs of Toxocara are resistant tolow temperature and high humidity (UGA et al., 1996) but desiccation anddirect sunlight will decrease the infectivity (WOODRUFF et al., 1981).It is probable that infection can occur at any age, either by eggs ortissue containing the larvae, although the highest incidence of infectionoccurs in kittens and young cats (CHARLESTON, 1977). NICOL et al. (1981) inLondon and SHAW et al. (1983) in Perth, Western Australia, reported a higherprevalence of T. cati in kittens than in cats. However, the prevalence ofinfection in the present study was higher in younger cats compared toolder animals, but the difference was not significant. SWERCZEK et al. (1971)reported the cause of high incidence of Toxocara in kittens as beingtransmammary passage. Studies on T. cati have shown that intra-uterineinfection seldom occurs and that infection mostly results from the ingestionof infective eggs or of earth worms, cockroaches and rodents containinglarvae in their tissues (O’LORCAIN, 1994). Although absolute comparisonscannot be made among available data, many factors, including geographicaland climatic differences together, and methodological alterations, can affectresults. Our study confirms the findings of  O’LORCAIN  (1994) who reportedno difference between the rate of infection in male and female cats. Manystray cats are found in different residential areas of this city and in otherresidential areas of this country, and their population is rapidly increasing.This can significantly contribute to the dissemination of the viable Toxocaraova into the environment. A mild, temperate climate such as that found inShiraz would also seem to enhance further embryonation of Toxocara ovain the soil and their transmission to humans. Mean worm burden in centralScotland was 3, with a range of 1-9 per cat. T. cati, was most frequentlyencountered (33.3% of the cats harboring at least one worm) and wasalways confined to the upper half, i.e., the anterior 60 cm of the smallintestine (McCOLM and HUTCHISON, 1980). Mean worm burden was 2.77 ±6.24 with a range of 0-46 and a prevalence of 41.99% in 181 cats(O’LORCAIN, 1994) in Dublin, Ireland. Worm burdens greater than 50 wormswere not found for T. cati (O’LORCAIN, 1994). The maximum worm burdenin South Africa, Dublin, Tokyo and Belgium has been reported as 13, 500,128 respectively, (BAKER et al., 1989; O’LORCAIN, 1994; OISHI and KUME, 1973;VANPARIJS et al., 1991). In our study the maximum worm burden was 50 inVet. arhiv 71  (3), 149-157, 2001S. A. Sadjjadi et al.: Toxocara cati in southern Iran155one cat. Each female worm lays a total of 200,000 eggs per day. Therefore,with a high prevalence of infection each cat is capable of infecting a highproportion of the population. Results showed that the T. cati habitat wasin first half of the small intestine, with correlation to the McCOLM andHUTCHISON (1980) studies in Scotland. The high prevalence of T. cati incats in Shiraz could indicate that school children and younger children areseriously at risk and, if all the preventive and treatment regimes are nottaken to account, the prevalence rate may drastically increase still further.The high rate of sero-positive children to Toxocara infection in this region,where the population of infected stray cats is high, is important (SADJJADIet al., 2000). It is obvious that the worldwide distribution of stray cats wouldhave an impact on sanitation and it is necessary that public healthauthorities, pet owners and veterinarians in crowded urban centers paymore attention to this phenomenon, and that the general public is educatedin the hazards and zoonotic aspects of this parasite.AcknowledgementsThis research was financed in part by a grant made by the Razi Institute, Iran.ReferencesBAKER, M. K., L. LANGE,  A. VERSTER,  S. VAN DER PLAAT (1989): A survey ofhelminths in domestic cats in the Pretoria area of Transvaal, Republic of South Africa.Part 1: The prevalence and comparison of burdens of helminths in adult and juvenilecats. J. South Afr.Vet. Assoc. 60, 139-142.BEAVER, P. C. (1969): The nature of visceral larva migrans. J. Parasitol. 55,  3-12.BEAVER, P. C., J. R. CLIFTON,  E. W. CUPP  (1984): Clinical Parasitology. 9th ed.  Lea &Febiger, Philadelphia, USA. pp. 320-322.BUIJS, J. (1993): Toxocara infection and airway function: an experimental andepidemiological study. University of Utrecht, the Netherlands.CHARLESTON, W. A. G. (1977): Toxocara and public health. New Zealand Vet. J. 25,171-172.DALIMI, A., I.  MOBEDI (1992): Helminth parasites of carnivores in northern Iran. AnnalsTrop. Med. Parasitol. 68, 395-397.ENGBAEK, K., H. MADSEN,  S. O. LARSEN  (1984): A survey of helminths in stray catsfrom Copenhagen with ecological aspects. Zeitschrift für Parasittenkunde 70, 87-94.FARIVAR, K., S. RAFAT (1991): Visceral larva migrans,  Report of 2 cases. J. Med. Assoc.Iran 11, 94-97. (In Persian)Vet. arhiv 71  (3), 149-157, 2001S. A. Sadjjadi et al.: Toxocara cati in southern Iran156KABIRI, M., S. SHARIAT, P. MIRBOD, N. BEHRAVAN (1979): A case of visceral larvamigrans. Med. J. National Univ. Iran. 7, 136-140.KAZURA, J. (1996): Toxocariasis. In: Nelson’s  Text book of  Pediatrics. (W. Nelson et al.,Eds.) 15th ed. W.B. Saunders Co. Philadelphia, USA, p. 1004.LAPPIN, M. (1993): Feline zoonotic diseases. Veterinary Clinics of  North America. SmallAnimal Practice 23, 57-78.MARKELL, E. D., M. VOGE, D. T.  JOHN (1992): Medical Parasitology, 7th ed.W.B.Saunders, Philadelphia, USA.McCOLM,  A. A., M. HUTCHISON  (1980): The prevalence of intestinal helminths instray cats in central Scotland. J. Helm. 54, 255-257.MIRZAYANS,  A. (1971): Incidence of gastrointestinal helminths of domestic cats in Tehranarea of  Iran. J. Parasitol. 57, 296.NICOL, S., S. J. BALL, K. R. SNOW (1981): Prevalence of intestinal parasites in domesticcats from the London area. Vet. Rec. 19, 252-253.OISHI, I., S.  D. KUME (1973): Helminth parasites of cats in Tokyo area. Japanese J.Parasitol. 27, 281-287.O’ LORCAIN, P. (1994): Epidemiology of Toxocara spp. in stray dogs and cats in Dublin,Ireland. J. Helminthol. 88, 331-333.REP, B. H. (1975): Intestinal helminths in dogs and cats on the Antillian Islands  Aruba,Curacao and Bonaire. Trop. Geog. Med. 7,  317-323.SADIGHIAN, A. (1970): Helminths of wild cats in the Shahsavar area, Caspian region,Iran. J. Parasitol. 56, 270.SADJJADI, S. M., M. KHOSRAVI, A. ORYAN, D. MEHRABANI (2000): Sero-prevalenceof toxocariasis in school children of Shiraz, Iran. J. Trop. Ped. 46, 327-330.SHAW, J., J. DUNSMORE, H. R. JAKOB (1983): Prevalence of some gastrointestinalparasites in cats in the Perth area. Australian Vet. J. 60, 15-152.SOULSBY, E. J. L. (1982): Helminths, arthropods and protozoa of domesticated animals.8th ed. Bailliere Tindall, London, UK.SWERCZEK, T. W., S. W. NELSON, C. F. HELMBOLDT  (1971): Transmammary passageof Toxocara cati in the cat. Am. J. Vet. Res. 32,  89-92.UGA, S., T. MINAMI, K. NEGATA  (1996): Defecation habits of cats and dogs andcontamination by Toxocara eggs in public parks and pits. Am. J. Trop. Med. Hyg. 54,122-126.VANPARIJS, O. F. J., D. C. THIENPONT (1973): Canine and feline helminth and protozoaninfectious in Belgium. J. Parasitol. 59,  321-330.VANPARIJS, O., L. HERMANS, L. VAN DER FLAES (1991): Helminth and protozoanparasites in dogs and cats in Belgium. Vet.  Parasitol. 38, 67-73.Vet. arhiv 71  (3), 149-157, 2001S. A. Sadjjadi et al.: Toxocara cati in southern Iran157WOODRUFF, A. W.,  S. Y. SALIH, D. SAVIGNY, E. I.  BAYA, A. I. SHAH (1981):Toxocariasis in the Sudan. Annals  Trop. Med. Parasitol. 75,  559-561.YAMAGUCHI, N., D. W.  MACDONALD, W. C. PASSANISI, D. A. HARBOUR,  C. D.HOPPER (1996): Parasite prevalence in free-ranging farm cats, Felis silvestris catus.Epidemiol. Infect. 116, 217-223.YAMAGUTI, S. (1961): Systema Helminthum, Vol. III, Nematodes of  Vertebrates, Part I& II. Inter Science Publisher Inc., New York, USA.Received: 21 December 1999Accepted: 21 June 2001Vet. arhiv 71  (3), 149-157, 2001S. A. Sadjjadi et al.: Toxocara cati in southern IranSADJJADI, S. M.,  A. ORYAN, A. R.  JALAI, D. MEHRABANI: Učestalost ijačina invazije oblićem Toxocara cati u mačaka lutalica u Shirazu, Iran. Vet.arhiv 71,  149-157, 2001.SAŽETAKIstraživanje je provedeno na 108 mačaka lutalica i to 44 mužjaka i 64 ženke u razdoblju odprosinca 1996. do svibnja 1997. na području grada Shiraza u Iranu. Potvrđeno je da je čak 52,8%pretraženih životinja bilo invadirano oblićem Toxocara cati. Nije utvrđena značajna razlika u učestalostiinvazije s obzirom na  spol i dob te  mjesto istraživanja. Broj oblića kretao se od 1 do 50,  u prosjeku6,53 oblića po mački.Ključne riječi: toksokaroza, Toxocara cati, visceralna larva migrans, mačka, Iran

Učestalost i jačina invazije oblićem Toxocara cati u mačaka lutalica u Shirazu, Iran.

Abstract

Similar works

Full text

Available Versions

Hrčak - Portal of scientific journals of Croatia

HRČAK - Portal of Croatian Scientific and Professional Journals