Toxoplasma gondii prevalence in Israeli crows and Griffon vultures

doi:10.1016/j.vetpar.2012.07.029

Veterinary Parasitology

Volume 191, Issues 1–2, 16 January 2013, Pages 23-28

https://doi.org/10.1016/j.vetpar.2012.07.029 Get rights and content

Abstract

A cross-sectional Toxoplasma gondii seroprevalence study was performed on free ranging crows (Corvus cornis, Corvus monedula, Corvus splendens) and Griffon vultures (Gyps fulvus) from Israel in order to assess exposure to this pathogen in scavenger birds that feed on animal carcasses and their possible role in the epidemiology of toxoplasmosis. Using the modified agglutination test (MAT) with a cutoff titer of 1:25, 52 of 122 crows (42.6%) and 40 of 101 Griffon vultures (39.6%) were found to be T. gondii seropositive. Crow T. gondii seroprevalence was significantly higher in northern areas of Israel (p = 0.007) where annual precipitation is higher and annual summer maximum temperatures are lower than in the drier and warmer south. Seroprevalence in crows was positively associated with higher human population densities possibly related to the increased cat population in these areas. PCR analysis of brain extracts from crows resulted in the detection of T. gondii DNA in 1 seropositive crow from northern Israel. Genetic analysis of DNA from the positive crow brain confirmed infection with T. gondii type 2 using a multiplex multilocus nested PCR-RFLP (Mn-PCR-RFLP) of the SAG1, 5–3′ SAG2, alt.SAG2, SAG3, BTUB, GRA6, C22-8, c29-2, L358, PK1 and Apico loci. The high T. gondii seroprevalence in these bird species suggests that infected carrion may be responsible for widespread infection of carcass scavenger birds which may further transmit infection to other carnivorous intermediate hosts or feline definitive hosts when consumed post-mortally.

Section snippets

Background

Toxoplasmosis is one of the most common zoonoses worldwide (Tenter et al., 2000). The causative protozoal agent, Toxoplasma gondii, can infect all warm-blooded animals, including birds which become infected by ingesting tissue cysts from infective meat or by consuming food or drink contaminated with oocysts excreted by cats, the definitive host for the parasite (Dubey and Beattie, 1988). The disease is of veterinary and medical importance, because it may cause severe clinical disease, abortion

Birds

One hundred and twenty two crows of the species, Corvus cornix (Hooded crow), Corvus monedula (Jackdaw) and Corvus splendens (House crow, Table 1) were included in the survey. Crows were captured using Australian traps and sacrificed humanely as permitted by the Israeli Nature and Parks Authority during January–November 2011. Sera and brain material were collected from each individual crow and immediately frozen until further examination.

One hundred and one sera from wild Griffon vultures (Gyps

Results

Fifty-two of 122 (42.6%) crow sera and 40 of 101(39.6%) Griffon vulture sera were positive (Table 2). Crows sampled were mostly juvenile birds that had hatched approximately 2–4 months previously but were able to fly and feed independently.

There was a significant difference in T. gondii seroprevalence among crows in the north, center and south of Israel (p = 0.007), with crows from the north showing the highest seroprevalence of 60.7% versus 12.5% in the south. The difference stemmed from the low

Discussion

T. gondii seropositive rates were high both in vultures and crows. This may suggest an abundance of T. gondii infected carrion (the diet specifically eaten by Griffon vultures) as well as oocyst environmental contamination (ingested in the crow diet, in addition to infected carrion). Carnivorous birds could be expected to have higher infection rates compared to ground feeding birds due to their wide accessibility to potentially infected animal carrion, and perhaps also due to a limited ability

Acknowledgements

The authors thank Prof. Chunlei Su (Department of Microbiology, University of Tennessee, Knoxville, TN, USA) for typing of the T. gondii strain from the crow brain, Mrs. Yifat Guthmann (School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot) for providing technical assistance for preparation of the figure of sampled bird distribution, and Dr. Tali Bdolah-Abram for assistance in the statistical analysis. We thank Ohad Hazofe (Ornithologist of the Israel Nature and Parks

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Toxoplasma gondii prevalence in Israeli crows and Griffon vultures

Abstract

Section snippets

Background

Birds

Results

Discussion

Acknowledgements

Int. J. Parasitol.

Vet. Parasitol.

Vet. Parasitol.

Vet. Parasitol.

Vet. Parasitol.

Exp. Parasitol.

Int. J. Parasitol.

Res. Vet. Sci.

Vet. Parasitol.

Vet. Parasitol.

Int. J. Parasitol.

Int. J. Parasitol.

Seroprevalence of Toxoplasma gondii in vultures (Pseudogyps africanus) from eastern Nigeria

Acta Parasitol.

Local meteorological conditions, dynamics of seroconversion to Toxoplasma gondii in cats (Felis catus) and oocyst burden in a rural environment

Epidemiol. Infect.