Muhammad Mudasser Nazir and Prof Dr Azhar Maqbool

Worldwide an increased need for commodities especially in developing countries results of increase in population. This need stems from the desire of having an increased life quality to get the minimum goods to survive in an environment of self-esteem.
A remarkable pressure has been put on food of animal origin, especially meat and milk consumption has increased. This pressure has led to increased production rates and more intensive farming practices.
According to Pakistan Economic Survey 2009, Pakistan has a herd size of around 63 million animals, which is the third largest in the world. About 35 million people are involved in dairy, deriving more than 40% of their total income from livestock. With the evolution of the dairy sector, the incidence of infectious and metabolic diseases increased, leading to increased economic losses.
The global percentage of abortion during the period between 1988 and 2003 varied between 7.5 and 12% but at individual farms abortion rates close to 30% occurred. In Pakistan incidence rate of abortion varied from 6.8 to 23% between 1990 and 2009.
 Brucellosis was the most important infectious disease causing abortion.Abortion is one of the most important threats which affects the dairy industry causing production loss. In 1984, parasite Neospora caninum was discovered a major cause of bovine abortion.
The parasite is an intracellular and grouped in the Sarcocystidae family, phylum Apicomplexa and subclass Coccidiasina. Neosporosis has been extensively studied in in dairy cattle, may be due to economic and industrial importance of neosporosis.
The life cycle of N. caninum is now well understood but it is hard to set some particular suggestions about prevention because other species may act as a final host than canids. In spite of that farmer’s education is an important tool to protect the feed and water from canine feces contamination. Neosporosis can be controlled by culling of infected cattle and replacement of seropositive heifers by adopting this strategy, birth of congenitally infected calves can be controlled.
Keeping in view the importance of the disease the present proposed study was designed to record the seroprevalence of Neospora caninum infection in dogs, cattle and human beings by using milk and serum. The zoonotic potential of the disease was also studied. In vitro chemotherapeutic trials were also conducted to check efficacy of drugs: Diclazuril, toltrazuril, clindamycin and sulphadiazene.
For the achievement of this purpose, the core objectives were:
To have an overview on the overall seroprevalence of neosporosis throughout the country by means of cELISA.
Overall seroprevalence of N. caninum in dairy cattle was found to be 43.4% with a significant difference (P < 0.05)  of seropositivity among all 18 herds.
Furthermore, we have described the seroprevalence of N. caninum in clinically healthy dairy cows. A total of 760 animals were selected from 13 dairy herds to demonstrate the presence of infection in dairy cattle.  The status of seroreactivity of the cows towards N. caninum was detected by cELISA (VMRD, Pullman, WA). Out of 760 animals, (43.2%) were found seropositive to N. caninum. A significant difference of positivity was recorded among all 13 dairy herds.
In the second phase of this experiment, it has been observed that the seroprevalence of 240 animals from 5 herds with a high rate of abortion, the percentage of seropositivity observed in these herds was 43.8%, slightly higher than the clinically healthy and non-aborting cattle.  The assessment of lactating cow’s milk sample also determined for Neospora caninum  antibodies by means of Iscom ELISA and showed a good level of agreement between the two tests cELISA and Iscom ELISA. The cELISA expressed a higher seropositivity and sensitivity than Iscom ELISA.
Epidemiological study was also conducted to determine seroprevalence of N. caninum in dogs of different breeds and age groups. The dog’s serum sample indicated a seropositivity of 23.5%. Difference was, male 26.1% and female 18.8%.
Moreover, the study described the seroprevalence and transmission of N. caninum in humans. A selection of 52 humans serum samples were additionally analyzed for the presence of N. caninum antibodies. The status of the humans towards N. caninum antibodies was determined by using commercially available antigen coated IFAT slides and conjugate.
A low prevalence 1.9% of antibodies in human beings was reported is this study. Only one case was found as positive. These findings indicate that there is no strong evidence of N. caninum infection in humans has been noted but we cannot exclude the chances of transmission. The vitro drug trials were conducted to access the efficacy of three commercially available anticoccidial drugs including Clindamycin, Diclazuril and Sulfadiazine. It has been found that among these drugs, Diclazuril has shown the maximum inhibitory effect.
The writers are from Department of Parasitology, University of Veterinary and Animal Sciences, Lahore