Article Information

Authors:
Louis J. La Grange1,2
Björn Reininghaus1
Samson Mukaratirwa2

Affiliations:
1Department of Agriculture, Rural Development, Land and Environmental Affairs, Mpumalanga, South Africa

2School of Life Sciences, University of KwaZulu-Natal, Westville Campus,

Correspondence to:
Louis la Grange

Postal address:
Private Bag X11309, Nelspruit 1200, South Africa

Dates:
Received: 25 June 2014
Accepted: 05 Sept. 2014
Published: 20 Nov. 2014

How to cite this article:
La Grange, L.J., Reininghaus, B. & Mukaratirwa, S., 2014, ‘First report of a mixed infection of Trichinella nelsoni and Trichinella T8 in a leopard (Panthera pardus) from the Greater Kruger National Park, South Africa’, Onderstepoort Journal of Veterinary Research 81(1), Art. #836, 3 pages. http://dx.doi.org/10.4102/
ojvr.v81i1.836

Copyright Notice:
© 2014. The Authors. Licensee: AOSIS OpenJournals.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
First report of a mixed infection of Trichinella nelsoni and Trichinella T8 in a leopard (Panthera pardus) from the Greater Kruger National Park, South Africa
In This Original Research...
Open Access
Abstract
Introduction
Materials and methods
Results
Discussion
Acknowledgements
   • Competing interests
   • Authors’ contributions
References
Abstract

At least three Trichinella species, namely Trichinella nelsoni, Trichinella britovi and Trichinella zimbabwensis, and one genotype (Trichinella T8), have been isolated from sylvatic carnivores on the African continent. With the exception of T. britovi, the other species are known to circulate in wildlife of the Kruger National Park (KNP), South Africa, and KNP neighbouring game reserves (collectively known as the greater KNP area). Lions (Panthera leo) and spotted hyenas (Crocuta crocuta) appear to be the most important reservoirs of T. nelsoni and Trichinella T8 in the KNP and surrounding areas. Interspecies predation between lions and hyenas has been implicated as a primary mode of maintaining the life cycles of these two Trichinella species. This is the first report of a mixed natural infection of T. nelsoni and Trichinella T8 in a leopard (Panthera pardus) from South Africa. Trichinella muscle larvae were identified to species level by multiplex polymerase chain reaction (PCR). Probable sources of infection, based on the known dietary preference and prey species’ range of leopards, are also discussed. The described occurrence of Trichinella species in a leopard from the greater KNP area raises the question of possible sources of infection for this predator species.

Introduction

The genus Trichinella is comprised of the species Trichinella spiralis, Trichinella nativa, Trichinella britovi, Trichinella pseudospiralis, Trichinella murrelli, Trichinella nelsoni, Trichinella papuae, Trichinella zimbabwensis and three genotypes (Trichinella T6, T8, T9) (Pozio & Zarlenga 2005; Pozio et al. 2009), and a newly described species, Trichinella patagoniensis from Patagonia, Argentina (Krivokapich et al. 2008, 2012). Of these, at least three species (T. nelsoni, T. britovi and T. zimbabwensis) and one genotype (Trichinella T8) have been isolated from sylvatic carnivores in Africa (Pozio et al. 1994, 2002, 2005, 2007). With the exception of T. britovi, these species have been reported in wild carnivores from the Kruger National Park (KNP) and neighbouring game reserves of South Africa (La Grange, Marucci & Pozio 2010; La Grange et al. 2013; Marucci, La Grange & Pozio 2009).

Lions (Panthera leo) and spotted hyenas (Crocuta crocuta) appear to be important reservoirs of T. nelsoni and Trichinella T8 in the greater KNP area of South Africa. Interspecies predation between lions and hyenas has been hypothesised to play a role in the maintenance of the life cycles of these two parasite species (Mukaratirwa et al. 2013). Trichinella spp. infections in humans have been reported due to the consumption of undercooked meat derived from bush pigs (Potamochoerus larvatus) in Kenya (Forrester 1964; Forrester, Nelson & Sander 1961; Hutcheon & Pamba 1972; Nelson 1970; Okelo & Bhatt 1987) and warthogs (Phacocoerus africanus) in Tanzania (Bura & Willett 1977). Results from previous studies suggest that these species of sylvatic Suidae may play an additional, yet less pronounced, role in the epidemiology of T. nelsoni and Trichinella T8, and have shown that warthogs and bush pigs represent only a small percentage of naturally infected animal reservoirs in Africa (Mukaratirwa et al. 2013). Limited passive surveillance based on convenient samples from 17 warthogs culled in the KNP and adjacent nature reserves have, to date, not yielded any positive samples (La Grange & Mukaratirwa unpublished data; Marucci et al. 2009). Trichinella nelsoni infection in leopards (Panthera pardus) has been reported from Tanzania (Pozio et al. 1997) and Kenya (Pozio 2007), whereas T. britovi has been described in a leopard from Iran (Mowlavi et al. 2009). In addition to one leopard tested in 1974 in KNP (Marucci et al. 2009), three more, originating from the nature reserves adjacent to the western KNP, have been tested since 2012, with negative results (La Grange & Mukaratirwa unpublished data).

Leopards are solitary animals; they avoid contact with lions and hyenas and do not normally prey on them (Hayward et al. 2006). This suggests the existence of alternate sylvatic species serving as sources of infection, such as small and medium-sized game species, including warthogs, bush pigs and baboons (Papio spp.), all of which could potentially serve as sources of Trichinella spp. infection. Although natural infection with Trichinella spp. has not been documented in free-ranging baboons, monkeys and bush pigs in South Africa, they could possibly serve as hosts for Trichinella spp. in southern Africa because experimental infection of T. zimbabwensis in baboons, monkeys (Cercopithecus aethiopis) (Mukaratirwa et al. 2008) and domestic pigs (Matenga et al. 2006; Mukaratirwa & Foggin 1996) has previously been successful. Furthermore, they are known to hunt and feed on other vertebrates in the wild (Butynski 1982). Between 1966 and 1974, five baboons from the greater KNP area have been tested, with negative results (Marucci et al. 2009); an additional two have been tested since 2012 (La Grange & Mukaratirwa unpublished data). As in the case with bush pigs, the number of samples tested is limited and this precludes any assumptions that these species do not play a role in the epidemiology of the Trichinella spp. in southern Africa. Experimental infections by Mukaratirwa et al. (2008) have shown that baboons are highly susceptible to the parasite, with fatal cases, and this might be the case in the wild.

In the present study, a mixed natural infection of T. nelsoni and Trichinella T8 was confirmed in a leopard from a nature reserve in the west of the greater KNP area of South Africa.

Materials and methods

In July 2012, a fresh carcass of an adult male leopard (about 5 years old) was found in a riverine stretch in a nature reserve in the west of the greater KNP area (24º47’57.1’’S, 31º29’24.0’’E), and this was reported to the local state veterinary services. On post-mortem examination the animal showed signs of severe and generalised haemorrhages, including widespread distinct suggillations in the large muscle groups of the forelimbs and hindlimbs. Secondary rodenticide poisoning was identified as the most likely reason for the observed findings. As part of the post-mortem examination and sampling procedures, muscle specimens were collected for routine surveillance for Trichinella infection and submitted for testing to the Parasitology Laboratory, School of Life Sciences, University of KwaZulu-Natal, Westville Campus, Durban. Muscle specimens that were collected consisted of sections of about 40 g, and were collected bilaterally from the musculus masseter, musculus tricipitis brachii, flexor muscle group of the antebrachium, musculus intercostales, musculus diaphragmaticus, musculus quadriceps femoris and the flexor muscle group of the lower hindlimbs, which were pooled as one source sample. Muscle samples were artificially digested as previously described (Nöckler & Kapel 2007) and examined under a stereo microscope for the detection of Trichinella larvae. Larvae observed in the digest were washed and used to infect Sprague-Dawley rats and the remaining muscle tissues were preserved in 2% sodium azide solution and submitted to the International Trichinella Reference Centre (ITRC) in Rome, Italy, for harvesting of additional larvae for species identification. A sample of the larvae was deposited in the ITRC in Rome, Italy (Isolate code ISS 4413).

Results

Initial testing by artificial digestion showed an infection intensity of three larvae per gram (lpg) in pooled muscle samples. In subsequent experimental infection of three Sprague-Dawley rats, only one rat established infection with an establishment of 702 lpg of muscle tissues. Three larvae were recovered from the muscle tissue submitted to ITRC and identified by a multiplex polymerase chain reaction (PCR) (Pozio & La Rosa 2003). One larva was identified as T. nelsoni, whilst the two remaining larvae were identified as Trichinella T8.

Discussion

According to Hayward et al. (2006), wild pigs and baboons are not frequently preyed upon by leopards, whilst other carnivorous species such as jackals, cheetahs, civets and genets are preyed on more frequently. Prey species composition of leopards reported by Le Roux and Skinner (1989) in the western greater KNP area included the common warthog, making up 4%, the chacma baboon (Papio ursinus) 1%, vervet monkeys 6%, small mammalian carnivores (African civets and genets) 2% and reptiles (leopard tortoise, Mozambique spitting cobra and rock monitor) 4%. Other authors have found various carnivorous animals of mammalian and reptile origin to represent 12% of all kills by leopards in north-eastern Namibia (Stander 1997), and large carnivores to represent 4% in the KNP (Bailey 1993). The predation of other carnivorous species by leopards, like the jackals that scavenge on the carcasses of other wild carnivores, suggests a possibly important source of Trichinella spp. infection.

The confirmation of a mixed infection in a leopard from South Africa may suggest that wild pigs play a lesser role in the natural epidemiology of Trichinella spp. in southern Africa, when compared to lions and hyenas. Other mammals that are more frequently preyed upon by leopards may act as better reservoirs for these Trichinella taxa. The absence of human infections from consumption of undercooked meat from wild pigs or products derived from wild pigs in southern Africa may support this.

The report of a mixed infection of two species of Trichinella in a leopard confirms the importance of the greater KNP area as a habitat of reservoirs for Trichinella species circulating in sylvatic carnivores of this region (La Grange et al. 2010). The confirmation of a mixed infection of T. nelsoni and Trichinella T8 in a leopard further confirms the sympatric status of these parasites, and a mixed infection of the same species has been reported in a lion in the KNP area (Marucci et al. 2009). Despite the low number of wild pigs tested from the KNP and adjacent reserves, studies have revealed a 2.5% infection rate in bush pigs from Kenya (Nelson et al. 1963), 4.0% from warthogs in Senegal (Gretillat & Chevallier 1970) and 4.3% in warthogs from Kenya, South Africa, Senegal and Tanzania (Sachs 1970). These studies all preceded the elucidation of the Trichinella taxon (Pozio et al. 1997) but later studies have implicated T. britovi and T. nelsoni in 23.0% and 7.0% of all infections of swine, respectively (Pozio 2005). Infections of swine from Kenya and Tanzania have most probably involved T. nelsoni, whilst those reported from Senegal are considered to be T. britovi (Mukaratirwa et al. 2013; Pozio 2007). In South Africa, however, warthogs and bush pigs may very well act as reservoirs for both T. nelsoni and Trichinella T8, since both have been previously found in other mammals from this region (Marucci et al. 2009; Mukaratirwa et al. 2013), despite the fact that the latter has never been isolated from wild pigs. The preliminary prevalence amongst leopards in KNP and surrounding areas, as documented in the present report, is much higher at 25% and this possibly suggests alternative or additional sources of infection for these predators, although the number of animals tested is limited. The fact that leopards have a tendency to avoid preying on wild pigs (Hayward et al. 2006) may support the aforementioned theory, but should be interpreted with caution since the limited data on Trichinella spp. infection in leopards and wild pigs in southern Africa do not provide conclusive evidence. Furthermore, the fact that leopards prefer to avoid wild pigs does not imply that leopards never prey on these species at all. Future research should include screening of other smaller carnivorous animals frequently preyed upon by leopards, and surveillance efforts should be intensified amongst wild Suidae to elucidate the role of each in the natural epidemiology of the various Trichinella species circulating in the KNP area.

Acknowledgements

Competing interests
The authors declare that they have no financial or personal relationship(s) that may have inappropriately influenced them in writing this article.

Authors’ contributions
L.J.L.G. (Department of Agriculture, Rural Development, Land and Environmental Affairs) conducted the initial acquisition and testing of samples, and is the main author of the manuscript. B.R. (Department of Agriculture, Rural Development, Land and Environmental Affairs) performed the post-mortem examination, collected the muscle samples and is co-author of the manuscript. S.M. (University of KwaZulu-Natal) conducted the experimental infection, dissection and testing of muscle samples of rats, submitted the sample to the ITRC and is the secondary author of the manuscript.

References

Bailey, T.N., 1993, The African Leopard: Ecology and Behaviour of a Solitary Felid, Columbia University Press, New York.

Bura, M.W. & Willett, W.C., 1977, ‘An outbreak of trichinosis in Tanzania’, East African Medical Journal 54, 185–193.

Butynski, T.M., 1982, ‘Vertebrate predation by primates: A review of hunting patterns and prey’, Journal of Human Evolution 11, 421–430. http://dx.doi.org/10.1016/S0047-2484(82)80095-X

Forrester, A.T.T., 1964, ‘Human trichinellosis in Kenya’, in A. Corradetti (ed.), Proceedings of the 1st International Conference of Parasitology, vol. II, pp. 669–671, Pergamon, Oxford, Rome.

Forrester, A.T., Nelson, G.S. & Sander, G., 1961, ‘The first record of an outbreak of trichinosis in Africa south of the Sahara’, Transactions of the Royal Society of Tropical Medicine and Hygiene 55, 503–513. http://dx.doi.org/10.1016/0035-9203(61)90072-4

Gretillat, S. & Chevallier, J.L., 1970, ‘Preliminary note on the epidemiology of trichinosis in wild animals in Western Africa’, Bulletin of the World Health Organization 43, 749–757 (in French).

Hayward, M.W., Henschel, P., O’Brien, J., Hofmeyr, M., Balme, G. & Kerley, G.I.H., 2006, ‘Prey preferences of the leopard (Panthera pardus)’, Journal of Zoology 270, 298–313.

Hutcheon, R.A. & Pamba, H.O., 1972, ‘Report of a family outbreak of trichinosis in Kajiado district – Kenya’, East African Medical Journal 49, 663–666.

Krivokapich, S.J., Cinthia, L., Gonzàlez, P., Graciana, G.M. & Viviana, C., 2008, ‘Molecular evidence for a novel encapsulated genotype of Trichinella from Patagonia, Argentina’, Veterinary Parasitology 156, 234–240. http://dx.doi.org/10.1016/j.vetpar.2008.06.003

Krivokapich, S.J., Pozio, E., Gatti, G.M., Prous, C.L., Ribicich, M., Marucci, G. et al., 2012, ‘Trichinella patagoniensis n. sp. (Nematode), a new encapsulated species infecting carnivorous mammals in South America’, International Journal for Parasitology 42, 903–910. http://dx.doi.org/10.1016/j.ijpara.2012.07.009

La Grange, L.J., Marucci, G. & Pozio, E., 2010, ‘Trichinella zimbabwensis in a naturally infected mammal’, Journal of Helminthology 84, 35–38. http://dx.doi.org/10.1017/S0022149X09990241

La Grange, L.J., Govender, D. & Mukaratirwa, S., 2013, ‘The occurrence of Trichinella zimbabwensis in naturally infected wild crocodiles (Crocodylus niloticus) from the Kruger National Park, South Africa’, Journal of Helminthology 87, 91–96. http://dx.doi.org/10.1017/S0022149X12000089

Le Roux, P.G. & Skinner, J.D., 1989, ‘A note on the ecology of the leopard (Panthera pardus Linnaeus) in the Londolozi Game Reserve, South Africa’, African Journal of Ecology 27, 167–171. http://dx.doi.org/10.1111/j.1365-2028.1989.tb00940.x

Marucci, G., La Grange, L.J. & Pozio, E., 2009, ‘Trichinella nelsoni and Trichinella T8 mixed infection in a lion (Panthera leo) of the Kruger National Park, South Africa’, Veterinary Parasitology 159, 225–228. http://dx.doi.org/10.1016/j.vetpar.2008.10.041

Matenga, E., Mukaratirwa, S., Bhebhe, E. & Willingham, A.L., 2006, ‘Comparison of the infectivity of Trichinella zimbabwensis in indigenous pigs (Mukota) and exotic Large White pigs’, International Journal of Applied Research in Veterinary Medicine 4, 301–305.

Mukaratirwa, S. & Foggin, C.M., 1996, ‘Infectivity of Trichinella sp. isolated from Crocodylus niloticus to the indigenous Zimbabwean pig (Mukota)’, International Journal for Parasitology 29, 1129–1131. http://dx.doi.org/10.1016/S0020-7519(99)00066-1

Mukaratirwa, S., Dzoma, B.M., Matenga, E., Ruziwa, S.D., Sacchi, L. & Pozio, E., 2008, ‘Experimental infections of baboons (Papio spp.) and vervet monkeys (Cercopethicus aethiops) with Trichinella zimbabwensis and successful treatment with ivermectin’, Onderstepoort Journal of Veterinary Research 75, 173–180. http://dx.doi.org/10.4102/ojvr.v75i2.16

Mukaratirwa, S., La Grange L.J. & Pfukenyi, D.M., 2013, ‘Trichinella infections in animals and humans in sub-Saharan Africa: A review’, Acta Tropica 125, 82–89. http://dx.doi.org/10.1016/j.actatropica.2012.09.005

Mowlavi, G., Marucci, G., Mobedi, I., Zahabiioon, F., Mirjalali, H. & Pozio, E., 2009, ‘Trichinella britovi in a leopard (Panthera pardus saxicolor) in Iran’, Veterinary Parasitology 164, 350–352. http://dx.doi.org/10.1016/j.vetpar.2009.05.001

Nelson, G.S., 1970, ‘Trichinosis in Africa’, in S.E. Gould (ed.), Trichinosis in Man and Animals, pp. 473–492, Charles C. Thomas Publisher, Springfield, Illinois.

Nelson, G.S., Guggisberg, C.W.A. & Mukundi, J., 1963, ‘Animal hosts of Trichinella spiralis in East Africa’, Annals of Tropical Medicine and Parasitology 57, 332–346.

Nöckler, K. & Kapel, C.M.O., 2007, ‘Detection and surveillance for Trichinella: Meat inspection and hygiene, and legislation’, in J. Dupouy-Camet & K.D. Murrell (eds.), FAO/WHO/OIE Guidelines for the Surveillance, Management, Prevention and Control of Trichinellosis, pp. 69–97, World Organisation for Animal Health, Paris.

Okelo, G.B. & Bhatt, K.M., 1987, ‘A case of trichinosis seen at the Kenyatta National Hospital (KNH)’, East African Medical Journal 64, 155.

Pozio, E., 2005, ‘The broad spectrum of Trichinella hosts: From cold- to warm-blooded animals’, Veterinary Parasitology 132, 3–11. http://dx.doi.org/10.1016/j.vetpar.2005.05.024

Pozio, E., 2007, ‘World distribution of Trichinella spp. infections in animals and humans’, Veterinary Parasitology 149, 3–21. http://dx.doi.org/10.1016/j.vetpar.2007.07.002

Pozio, E., De Meneghi, D., Roelke-Parker, M.E. & La Rosa, G., 1997, ‘Trichinella nelsoni in carnivores from the Serengeti ecosystem, Tanzania’, Journal of Parasitology 83, 1195–1198. http://dx.doi.org/10.2307/3284388

Pozio, E., Foggin, C., Gelanew, T., Marucci, G., Hailu, A., Rossi, P. et al., 2007, ‘Trichinella zimbabwensis in wild reptiles of Zimbabwe and Mozambique and farmed reptiles of Ethiopia’, Veterinary Parasitology 143, 305–310. http://dx.doi.org/10.1016/j.vetpar.2006.08.029

Pozio, E., Foggin, C.M., Marucci, G., La Rosa, G., Sacchi, L., Corona, S. et al., S., 2002, ‘Trichinella zimbabwensis n.sp. (Nematoda), a new, non-encapsulated species from crocodiles (Crocodylus niloticus) in Zimbabwe also infecting mammals’, International Journal for Parasitology 32, 1787–1799. http://dx.doi.org/10.1016/S0020-7519(02)00139-X

Pozio, E., Hoberg, E., La Rosa, G. & Zarlenga, D.S., 2009, ‘Molecular taxonomy, phylogeny and biogeography of nematodes belonging to the Trichinella genus’, Infection, Genetics and Evolution 9, 606–616. http://dx.doi.org/10.1016/j.meegid.2009.03.003

Pozio, E. & La Rosa, G., 2003, ‘PCR-derived methods for the identification of Trichinella parasites from animal and human samples’, Methods in Molecular Biology 216, 299–309.

Pozio, E., Pagani, P., Marucci, G., Zarlenga, D.S., Hoberg, E.P., De Meneghi, D. et al., 2005, ‘Trichinella britovi etiological agent of sylvatic trichinellosis in the Republic of Guinea (West Africa) and a re-evaluation of geographical distribution for encapsulated species in Africa’, International Journal for Parasitology 35, 955–960. http://dx.doi.org/10.1016/j.ijpara.2005.03.013

Pozio, E., Verster, A., Braack, L., De Meneghi, D. & La Rosa, G., 1994, ‘Trichinellosis south of the Sahara’, in C.W. Campbell, E. Pozio & F. Bruschi (eds.), Trichinellosis, pp. 527–532, Istituto Superiore di Sanità Press, Rome.

Pozio, E. & Zarlenga, D.S., 2005, ‘Recent advances on the taxonomy, systematics and epidemiology of Trichinella’, International Journal for Parasitology 35, 1191–1204. http://dx.doi.org/10.1016/j.ijpara.2005.07.012

Sachs, R., 1970, ‘Zur Epidemiologie der Trichinellose in Afrika [The epidemiology of Trichinellosis in Africa]’, Zeitschrift für Tropenmedizin und Parasitologie 20, 117–126.

Stander, P.E., 1997, ‘The ecology of lions and conflict with people in north-eastern Namibia’, in J. van Heerden (ed.), Proceedings of a Symposium on Lions and Leopards as Game Ranch Animals, Onderstepoort, Oct 1997, pp. 10–17.



Crossref Citations

No related citations found.