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Toxocariasis is a soil-transmitted helminthozoonosis due to infection of humans by larvae of Toxocara canis. The disease could produce cognitive and behavioral disturbances especially in children. Meanwhile, in our modern era, the incidence of immunosuppression has been progressively increasing due to increased incidence of malignancy as well as increased use of immunosuppressive agents. The present study aimed at comparing some of the pathological and immunological alterations in the brain of normal and immunosuppressed mice experimentally infected with T. canis. Therefore, 180 Swiss albino mice were divided into 4 groups including normal (control) group, immunocompetent T. canis-infected group, immunosuppressed group (control), and immunosuppressed infected group. Infected mice were subjected to larval counts in the brain, and the brains from all mice were assessed for histopathological changes, astrogliosis, and IL-5 mRNA expression levels in brain tissues. The results showed that under immunosuppression, there were significant increase in brain larval counts, significant enhancement of reactive gliosis, and significant reduction in IL-5 mRNA expression. All these changes were maximal in the chronic stage of infection. In conclusion, the immunopathological alterations in the brains of infected animals were progressive over time, and were exaggerated under the effect of immunosuppression as did the intensity of cerebral infection.

Trichinellosis is a zoonosis acquired by the ingestion of undercooked meat containing the infective larvae of Trichinella spiralis. Trichinellosis continues to be a public health concern throughout the world. It has been estimated that 11 million people worldwide could be infected [1]. Murrell and Pozio [2] reported that there is an increase in the occurrence of infection among pigs and wildlife, with a consequent increase among humans in the past 10 years. Trichinellosis is of such varied symptomatology that includes abdominal pain, diarrhea, fever, myalgia and periorbital oedema and it resembles other conditions such as nephritis, encephalitis, myositis and tetanus. Particularly, the early phase of infection is difficult to diagnose due to the non-specificity of the signs and symptoms that may be misdiagnosed as alimentary intoxication or enterobacterial infection [3]. The diagnosis of intestinal infections by detection of parasitespecific antigens in faeces (coproantigens) is an approach applied to a broad range of infectious organisms [6]. This new approach has been implemented for intravital diagnostics of taeniasis and echinococcosis. The highest degree of coproantigen excretion is during the progressive growth and maturation of the adult worms with increased shedding of surface antigens that is associated with a higher metabolic rate just before patency [7,8]. Diagnosis of trichinellosis relies largely on the serodiagnostic procedures to detect antibodies which are of great value but unfortunately most of the diagnostic methodologies have not been able to detect the early phase of the infection when an anti-parasitic treatment would be most effective [4]. Moreover, the detection of Trichinella circulating antigens in the serum needs an extremely sensitive and stable system to detect minute quantities of circulating antigens as it fluctuates widely at various periods post infection. Therefore, it is mandatory to use; otherwise, false negative results may be easily obtained [5]. The main advantages of the coproantigen assay over other diagnostic methods are that coproantigens indicate the current infection only. Moreover, coproantigen excretion is closely correlated to the presence of intestinal immature and mature parasite stages and their numbers. In addition, they are detected earlier than antibodies and it does not depend on the ability of the host to develop antibody response [9]. Studies on coproantigens indicated that they are resistant to degradation by faecal enzymes, protease-insensitive and remain active after formalin treatment and even contamination by bacteria and fungi [10]. They also could be detected regardless of faecal condition; and thus coproantigen detection is useful even on faeces excreted more than 1 week previously [11]. Moreover, coproantigens are heat stable. This heat stability may be due to their highly glycosylated nature, which may also protect any protein core. Such stability is of practical importance in epide