Toxoplasma gondii is a ubiquitous protozoan parasite that can infect a wide range of animals including humans. This single known species in the genus Toxoplasma is considered as one of the most successful eukaryotic pathogens which is of major medical and veterinary importance. Effective vaccines may contribute toward preventing and controlling the spread of toxoplasmosis. The present communication addresses the current status of development of vaccines against T. gondii. Further discussion is made on the difficulties along with challenges, such as vaccine construct, mode of vaccine administration and standardization of immunization evaluation. Finally suggestions are made on possible directions for future research on the development of vaccines against T. gondii.

We monitored the prevalence of endoparasitic infections of rodents in Punjab State, India, between January 2004 and December 2005. Three species of wild rodents, namely the house rat, Rattus rattus (n= 42), the lesser bandicoot rat, Bandicota bengalensis (n= 34) and the Indian gerbil, Tatera indica (n= 15), were live‐captured from houses and crop fields. Examination of various organs revealed that the highest rates of endoparasitic infection occurred in R. rattus (40.5%), followed by B. bengalensis (35.3 %) and then T. indica (20.0%), with an overall infection rate of 35.2%. All three rodent species were found naturally infected with one or more species of helminths. Metacestodes (1–6) of Cysticercus fasciolaris (larvae of Taenia taeniaeformis) were found in all three rodent species (in the liver). In one male T. indica, numerous robust T. taeniaeformis metacestodes were found in oval sacs attached to the mesentery and the abdominal wall, an unusual site. The cauda epididymal fluid of the same gerbil was also found to be infected with a very rare species of strongylid nematode, which could not be identified to genus or species level. It is possible that this nematode is transmitted sexually and thus may affect the reproductive potential of gerbils. This appears to be the first report of this phenomenon. In one B. bengalensis individual, the intestine was found to be obstructed with an acanthocephalan, Moniliformis moniliformis, with concurrent infection with C. fasciolaris in the form of multiple cysts in the liver. Although no natural protozoan infection was found in these field rodents, experimental Trypanosoma evansi infection has been established in all three species with high pathogenicity, and the possibility of sexual transmission was supported by the presence of T. evansi in the cauda epididymal fluid of male rats.

The aim of this study was to explore the prevalence of gastrointestinal parasitism in small ruminants in relation to various risk factors in the western zone of Punjab. During the study, 603 fecal samples (391 of sheep and 212 of goats) were examined qualitatively by floatation and sedimentation techniques, and quantitatively by McMaster technique. Out of the 603 fecal (391 sheep and 212 goats) samples examined, 501 were found positive for endoparasitic infection with an overall prevalence of 83.08%, consisting of 85.16% and 79.24% in sheep and goats, respectively. Egg per gram in sheep was apparently more 1441.88±77.72 than goats 1168.57±78.31. The associated risk factors with the prevalence of gastrointestinal tract (GIT) parasites showed that females (85.97%) were significantly more susceptible than males (69.23%). Age wise the adults (>6 months) were significantly more prone to parasitic infection as compared to young ones (<6 months). Seasonal variation was recorded throughout the year and was significantly highest during monsoon (90.10%), followed by winter (83.84%) and summer (78.35%). The study revealed an overall prevalence of 83.08% of GIT parasitic infections in small ruminants constituting 85.16% in sheep and 79.24% in goats in the western zone of Punjab. The most relevant risk factors for the prevalence of gastrointestinal parasitism in ruminants were sex, age, and season.

Specific duplex polymerase chain reaction (PCR) was employed on 411 (386 cattle and 25 buffaloes) blood samples of dairy animals from 9 districts of Punjab, India, for simultaneous detection ofBabesia bigeminaandTrypanosoma evansi. The results were compared and correlated with conventional Giemsa stained thin blood smear (GSTBS) examination and haematological alterations to know the clinical status and pathogenicity of infections. The Bg3/Bg4 and TR3/TR4 primers were used in duplex PCR forB. bigeminaandT. evansiamplified products of 689 bp and 257 bp, respectively. The overall prevalence by duplex PCR was found to be 36.49, 2.43, and 3.41% forT. evansi,B. bigemina, and dual infection, respectively. A more significant difference was observed for dual infection status (P≤0.005) as compared toT. evansi(P≤0.05) andB. bigemina(P≤0.01) among various districts under study. A very low prevalence ofT. evansi(0.73%) andB. bigemina(0.48%) was seen by GSTBS. The highly sensitive, specific, and cost-effective duplex PCR was able to detect latentT. evansiandB. bigeminainfection in cattle and buffaloes. Haematological evaluation revealed marked pathology inB. bigeminainfected group and in dual infected group in contrast to that infected withT. evansialone.