During the period between January 1999 and December 2000, the distribution and seasonal patterns of amphistome infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe were determined through monthly coprological examination. Cattle faecal samples were collected from 12 and nine dipping sites in the highveld and lowveld communal grazing areas, respectively. Patterns of distribution and seasonal fluctuations of intermediate host-snail populations and the climatic factors influencing the distribution were also determined by sampling at monthly intervals for a period of 24 months (November 1998 to October 2000) in six dams and six streams in the highveld and in nine dams in the lowveld communal grazing areas. Each site was sampled for relative snail density and the vegetation cover and type, physical and chemical properties of water, and mean monthly rainfall and temperature were recorded. Aquatic vegetation and grass samples 0-1 m from the edges of the snail habitats were collected monthly to determine the presence or absence of amphistome metacercariae. Snails collected at the same time were individually checked for the emergence of larval stages of amphistomes. A total of 16 264 (calves 5 418, weaners 5 461 and adults 5 385) faecal samples were collected during the entire period of the study and 4 790 (29.5 %) of the samples were positive for amphistome eggs. For both regions the number of animals positive for amphistome eggs differed significantly between the 2 years, with the second year having a significantly higher prevalence (P < 0.01) than the first year. Significantly higher prevalences were found in the highveld compared to the lowveld (P < 0.001), for adult cattle than calves (P < 0.01), and in the wet over the dry season (P < 0.01). Faecal egg output peaked from October to March in both years of the study. Bulinus tropicus, Bulinus forskalii and Biomphalaria pfeifferi were recorded from the study sites. The main intermediate host for amphistomes was B. tropicus with a prevalence of infection of 8.5 %. However, amphistome cercariae were also recorded in Biom. Pfeifferi and B. forskalii. Amphistome cercariae were recorded from both the highveld and lowveld areas with peak prevalence during the post-rainy season (March to May). Metacercariae were found on herbage from the fringes of the snail habitats between February and August, with most of the metacercariae concentrated on herbage 0-1 m from the edges of the habitats. Based on the epidemiological findings a control programme was devised. From this study, large burdens of immature flukes could be expected in cattle during the dry months. Since adult cattle would be resistant to the pathogenic effects of the migrating immature amphistomes the target for control would be young animals being exposed to the infection for the first time. Therefore, the first anthelmintic treatment can be administered in calves in mid June when maximum migration of immature amphistomes starting 3-4 weeks after infection in the early dry season would be expected. A second treatment could be given in late July or early August to remove potentially dangerous burdens of immature flukes acquired later in the dry season. Where resources permit, another strategy would be to treat against the mature flukes in March or April in order to reduce the number of eggs deposited on pastures and the opportunity for infection of the intermediate host snails. To reduce cercarial shedding by the intermediate host snails molluscicides can also be applied during the peak transmission periods (April/May and August/September).

During December/January 1996/97 typical summer syndrome (hyperthermia and a 30 % drop in milk yield) occurred in succession in two Holstein dairy herds (n = 240 and n = 150 milking cows, respectively) on the South African Highveld. These farms are situated in the midst of the prime maize and dairy farming areas of South Africa where this condition had never been diagnosed before. The individual components of the concentrate on both farms were negative for ergot alkaloids. Endophytic fungi and/or ergot infestation of teff and other grasses fed to the cows were then suspected of being involved, but neither endophytes nor ergot alkaloids could be implicated from these sources. By measuring the serum prolactin levels of groups of sheep (n = 5) fed the first farm's total mixed ration (TMR) or its three individual fibre components for a period of 11 days, the source of the ergot alkaloids was identified. A statistically significant decrease in the level of this hormone occurred only in the group on maize silage (which constituted 28 % on dry matter base of the TMR). The involvement of the maize silage was further chemically confirmed by the high levels of total ergot alkaloids, predominantly ergocryptine, found by LC-MS in the silage as well as in the TMR (115-975 ppb and 65-300 ppb, respectively). The ergot alkaloid content (mainly ergocryptine) of the maize silage on the second affected farm was 875 ppb. Withdrawal of contaminated silage resulted in gradual recovery of stock on both farms. Nut sedge (Cyperus esculentus and Cyperus rotundus of the family Cyperaceae) has a world-wide distribution and is a common weed in annual crops, and can be parasitized by Claviceps cyperi. Careful examination of the maize silage from both farms revealed that it was heavily contaminated with nut sedge and that it contained minute sclerotia, identified as those of Claviceps cyperi, originating from the latter. Nut sedge was abundant on both farms and it is believed that late seasonal rain had resulted in mature, heavily ergotised nut sedge being cut with the silage. Claviceps cyperi sclerotia, collected on the affected fields in the following autumn contained 3 600-4 000 ppm ergocryptine. That the dominant alkaloid produced by this particular fungus was indeed ergocryptine, was confirmed by negative ion chemical ionization MS/MS. In one further outbreak in another Holstein herd, teff hay contaminated with ergotised nut sedge and containing 1 200 ppb alkaloids, was incriminated as the cause of the condition. This is the first report of bovine ergotism not associated with the Poaceae infected with Claviceps purpureum or endophytes but with the family Cyperaceae and this particular fungal phytopathogen.

A total of 17 commercially reared ostriches (Struthio camelus) from Msengi farm, Chinhoyi, Zimbabwe, observed with swollen eyes, severe conjunctivitis and constant lacrimation accompanied by a purulent exudate, were restrained for further clinical examination. Some of the birds were semi-blind with severe loss of body condition. When examined, tiny organisms were observed attached to the nictitating membranes and the conjuctival sacs of both eyes. The organisms were identified as Philophthalmus gralli, the "oriental eye-fluke" and Melanoides tuberculata, a prosobranch snail, was confirmed as the intermediate host through natural and experimental infection. To the best of our knowledge this is the first record of the oriental eye-fluke infection in birds in Zimbabwe and Africa and extends its known geographical range.

Seroprevalence rates of Toxoplasma gondii anti-antibodies in adult goats and sheep from different parts of Zimbabwe were determined. A total of 225 (67.9 %) of the 335 serum samples tested were positive for anti-T. gondii IgG antibodies with the indirect fluorescent antibody test. There were differences in antibody seroprevalences among communal land goats from the different agro-ecological zones (Natural regions IIb and III: 80 and 96.7 %, respectively; Natural region IV: 65.9 %; Natural region V: 45 %; and Natural region III had a significantly higher seroprevalence than IV and V. The highest seroprevalences found in Natural regions II b and III are likely to be linked to the existence of more households and hence the possibility of a higher concentration of domestic cats that increases the chances of environmental contamination with their faeces harbouring T. gondii oocysts. The seroprevalence rate in sheep from a large commercial farm (10 %) was significantly lower than that of sheep reared under the communal grazing system (80 %). Overall, significantly higher proportions of seropositive animals had antibody titres of 1:50 (34.2 % of 225) and 1:100 (44 % of 225) as compared to the 9.8 % and 12 % with antibody titres of 1:200 and > 1:400, respectively.

A total of 100 fecal samples from goats were coprologically examined to investigate the main cause of diarrhea. Animals were divided according to the age into 3 groups (7-35 days, 35 days - 6month and over one year). The results revealed that Eimeria species was the most predominant parasite (70%), the parasitic gastroenteritis (28%) and Cryptosporidium species (21%). Ten species of Eimeria were identified from the infected animals, E. hirci, E. arloingi, E. intericata, E. ahsata , E. christenseni, E. marisca, E. crandalis, E. weybridegenesis, E. faurei and E. ovina. Three species of parasitic gastroenteritis (Haemonchus contortus, Ostertagia species and Trichostrongylus species). Cryptosporidium oocysts were found common in young goats

Studies were conducted to determine the utility of lysate antigens for rapid evaluation of the local entero-3 vaccine, antigens were prepared from cell cultures infected with bovine rota virus (BRV) and bovine corona virus (BCV) as well as from Enterotoxigenic E. coli strain K99. Prepared antigens were tested with field serum samples collected from both late pregnant entero-3 vaccinated cows and their offsprings using different serological assays including: microagglutination test, indirect ELISA and immunofluorescent antibody technique. Results of this endeavor were correlated to that of the standard virus neutralization test. The locally prepared antigens were proved useful for vaccine evaluation. Moreover, these antigens are recommended for both detection and assessment post vaccination or post infection of sero-conversion against BRV, BCV and E. coli.

In the present study, 3 pooled proventricular homogenates were collected from 3 broiler flocks, of chicken 15 to 30 days old, from Monofia Governorate. The 3 flocks were suffered from low growth rate, poor feed conversion rate, uneven growth and increased mortalities. Necropsy of dead chickens revealed proventriculitis with increased proventriculus size. IBD viral antigen was detected in the pooled proventricular homogenate of each flock by AGPT using reference antibodies against IBDV and RT-PCR technique. No other viruses were detected; such as Reo virus, CAV, NDV, IBV and ALV-J. Further characterization of the IBDV isolates were conducted by RFLP assay on PCR products using MboI and BstOI restriction enzymes. Results demonstrate that the 3 IBDV isolates are identical in their RFLP pattern and related to the Del/E variant strain of IBDV.

An unusual fowl pox outbreak has been diagnosed in 40 days-old-unvaccinated broilers farm in Dakahlia Governorate during summer, 2004. The most characteristic observation of this outbreak was that the pox signs and lesions were observed on the feathered parts of the body mainly in the posterior dorsal area of the chickens. Classical pox lesions were also seen in the mouth, comb, wattle, eyelids and shank of some chickens. Samples were collected from affected birds for virus isolation and histopathological studies. The isolated virus on the chorioallantoic membrane (CAM) was serologically confirmed. Histopathological examination revealed characteristic intracytoplasmic eosinophilic inclusion bodies in affected chicken tissues and CAM. This outbreak caused severe economic losses due to cutaneous lesions in the feathered area of the body that resulted in high condemnation rate at processing plant beside to high mortality which reached upto25%.

Thirty samples of freshly slaughtered broiler frame with skin were obtained from small scale poultry processing plant in Cairo and Giza markets. Samples of neck and breast skin were examined for Total colony count, Psychrotrophic count, Staphylococcus aureus count, Coliform Count, presumptive E. coli count and total yeast and mould count. In addition isolation of Salmonella spp. and thermotolerant Campylobater were performed. Lower bacterial counts were recorded in cooked samples, with mean value of 7.6 ± 0.18, 5.68 ± 0.16, 5.12 ± 0.14, 3.6 ± 0.3, 2.3 ± 0.39 and 6.85 ± 0.37 log10 cfu /g in raw samples and 0.91 ± 0.27, 0.74 ± 0.21, 0.56 ± 0.19, 1.1 ± 0.13, < 3 and 2.44 ± 0.12 log10 cfu/g in cooked samples respectively. The incidence of S. aureus, Salmonella and Campylobater jejuni in raw skin samples were 66.7%, 20%, and 56.6%, respectively. While S. aureus was unexpectedly isolated from cooked samples. Fat content was estimated by using Sohexelt method and fatty acids content of methylester were determined.

A total of 40 samples of beef and chicken luncheon (20 samples for each) were collected from different markets in Giza city. Samples were subjected to Mycological investigations. Beef luncheon were highly contaminated than chicken luncheon (3.1 x 103 /g ±0.3x 10³) and (4.0 x 102 /g ±0.2x 10² ) respectively . Seven mould genera were isolated from examined samples. The majority of which were Aspergillus (19.7% and 18.1%) and Penicillium (18.9% and 15.7 %), while, Mucor (7.1% and 4.7%), Cladosporium (4.7% and 3.9%) and other genera were also isolated from the same samples but in low percentages from beef and chicken luncheon respectively. The predominant identified Aspergillus species were; A. niger (18.7% and 14.5%), A. flavus (18.7% and 12.5%) and A. ochraceous (6.3% and 6.3%) in the two products respectively. The main identified Penicillium species were; P. citrinium (20.6% and 13.6%), P. expansum (11.4% and 13.6%) and P. verrucosum (6.8% and 6.8%) from the same products respectively. Examination for mycotoxin production revealed the detection of ochratoxin A at a higher level (mean 21.0 and 27.0 ng /kg) from 2 (10%) samples of beef luncheon and one (5%) sample of chicken luncheon, respectively. Aflatoxin B1 (mean 15.3 and 9.8 ng / kg) was detected in 4 (20%) samples of beef luncheon and 3 (15%) samples of chicken luncheon, respectively. Other mycotoxins (AFB2, AFG1, AFG2 and T-2) were detected but in minor levels. Public health significance of the identified mould species and the detected mycotoxins were discussed.