Immunodiagnosis of bovine trypanosomiasis in Anambra and Imo states, Nigeria, using enzyme-linked immunosorbent assay: zoonotic implications to human health.

BACKGROUND & OBJECTIVES: The prevalence of trypanosomiasis was studied in cattle, being a major source of animal protein in Nigeria, thus, a very likely means of spread of Human African Trypanosomosis (HAT). METHODS: Enzyme-linked immunosorbent assay (ELISA) was used to diagnose bovine trypanosomiasis in 264 samples collected from adult cattle of mixed breeds, age and sex, in Anambra and Imo states, Nigeria. RESULTS: Out of 264 samples analysed, 21 (7.96%) were seropositive for Trypanosoma congolense while 20 (7.58%) were seropositive for T. vivax and 8 (3.03%) were seropositive for T. brucei infections in both the states. INTERPRETATION & CONCLUSION: The predominant species was found to be T. congolense. Mixed infection of three species, T. vivax, T. congolense and T. brucei was found to dominate other mixed infections in both the states. ELISA detected the infection of the three species of trypanosomes in the same group of animals. The usefulness of antigen capture ELISA in the diagnosis of human or animal trypanosomiasis was established, and the possibility of the spread of HAT caused by T. brucei gambiense and T.b. rhodesiense through cattle was expressed.

Detection of Trypanosoma congolense antibodies with indirect ELISAs using antigen-precoated microtitre plates.

The study reports the performance of four indirect enzyme-linked immunosorbent assays (ELISAs) for antibody (AB) detection using microtitre plates which were precoated with native or heat/detergent denatured antigens (AGs) from Trypanosoma congolense (T.c.) and T. vivax (T.v.), and stored for between 1 to 206 days at +37 degrees C. Bovine serum samples were obtained by sequential bleeding of 3-months old T.c.-infected bulls and their uninfected cohorts, as well as by a single bleeding of uninfected adult cattle. The first day of AB detection, and observations on samples after this (defined as estimated ELISA sensitivity), depended on the cut-off value in the specific ELISAs. Cut-off values from pre- and early post-infection samples of individual animals demonstrated a seroconversion in all ELISAs on average after 10-15 days post-infection (dpi). The AB detection was delayed in the T.c. native and denatured AG-based ELISAs using cut-off points from uninfected cohort cattle (16.5 dpi, 19.3 dpi) and the adult cattle population (22.1 dpi, 25.0 dpi). The T.v. AG-based ELISAs however lacked crossreactiviy to T.c. ABs. The estimated sensitivity of each T.c. AG-based ELISA was above 96% throughout, but significantly lower for the T.c. native AG-based ELISA (91.1%) when the adult cattle derived cut-off point was used (p<0.01). The sensitivity of the phase contrast buffy coat technique was similar to the T.c. AG-based ELISAs, but significantly lower when the T.c. denatured AG-based ELISA was used at the adult cattle derived cut-off point (p<0.05). The implications of the results and future research aspects on ELISAs to detect trypanosomal ABs and AGs are discussed.

Efficacy of a 2 per cent moxidectin gel against gastrointestinal parasites of ponies.

The efficacy of moxidectin was evaluated in young ponies naturally infected with gastrointestinal parasites. Eight animals were treated orally with moxidectin at 0.4 mg/kg bodyweight and eight received only the vehicle. They were all necropsied two weeks later. Faecal samples were examined daily for egg counts and larval cultures. Parasites were recovered from total faecal samples collected daily and from the gastrointestinal tracts at necropsy. Moxidectin reduced the strongyle egg counts by > 99 per cent from three days after treatment but some individuals remained positive for 10 days. The drug had little or no ovicidal activity. As evaluated in the critical-controlled test, moxidectin was 99 to 100 per cent effective (P < 0.05) against luminal stages of parascaris equorum, Strongylus vulgaris, Triodontophorus species, Craterostomum acuticaudatum, 19 cyathostome species and Oxyuris equi. Adult S edentatus were also completely removed. Its efficacy against third stage larvae of Gasterophilus intestinalis was 95 per cent (P < 0.05). Luminal nematode stages were removed within a few days, and bots continued to be eliminated for at least two weeks after treatment. No activity was observed against Anoplocephala perforliata. As evaluated in the controlled test, moxidectin was 100 per cent effective against Habronema muscae (P < 0.05) and had a 76 per cent but not significant efficacy against encysted small strongyle larvae.

Macrocystic serous cystadenoma of the pancreas. Diagnostic, therapeutic and pathological considerations of three cases.

BACKGROUND: Macrocystic serous cystadenoma (MSC) of the pancreas is a new entity that has recently been well recognised. This tumour is quite similar in aspect to the mucinous cystic tumours (MCT) but its prognosis is much better, so that a correct diagnosis before surgery is important. PATIENTS: Three patients undergoing surgery in the 1st Surgical Clinic of the University of Bologna for suspected cystic lesions were found to have macrocystic serous cystadenoma (MSC) of the pancreas. In two cases a biopsy was performed during surgery, but in only one was a correct diagnosis of MSC made; in the other the diagnosis was lymphangioma. In the remaining case a biopsy was not performed because the high 19/9 CA level in the blood suggested a diagnosis of MCT of the pancreas. In all 3 cases the tumour was successfully removed by surgery. CONCLUSIONS: Macrocystic serous cystadenoma (MSC) of the pancreas represents a variant of the serous cystic tumors, which encompass microcystic adenoma and serous cystadenocarcinoma. MSC must be distinguished from MCT because it exhibits a different biological pattern and requires a different surgical approach. Therefore, we would underline the importance of a biopsy in making the differential diagnosis.

Isolation and characterisation of Newcastle disease virus strain in a feral dove (Stigmatopelia senegalensis) in Nigeria.

An isolate of Newcastle disease virus (NDV) was obtained from a feral dove, (Stigmatopelia senegalensis). The isolate was shown to have a mean-death-time of 96 h and an intracerebral pathogenicity index of 0.10. It was immunogenic but not pathogenic for 6-week old chicks on experimental infection. Based on these observations the isolate was classified as a lentogenic strain. The role of such isolates of NDV from wild birds on the Nigerian poultry industry is discussed.