An assessment of the safety of street foods in the Ga district, of Ghana; implications for the spread of zoonoses.

Street food refers to food and beverages prepared and sold by vendors in streets and other public places for immediate consumption. In Ghana street foods are sold at small eating places popularly known as 'chop bars'. Food safety studies were conducted on the premises of 160 'chop bars' in the Ga District of Ghana in July 1998. Only three (1.8%) of the proprietors met all the requirements (based on a five-point checklist) for basic hygiene. Twenty-four (15%) out of the 160 proprietors had access to potable water while the other 136 (85%) proprietors purchased water from vendors and six used pond water. These two latter sources of water were of poor microbiological quality (as shown by faecal coliform values which ranged from 1.0x10(2)-1.9x10(5) cfu/ml). One hundred and five proprietors (65.6%) did not obtain their meat supply from an approved source. Factors influencing the purchase of meat from an approved source included the proximity of a chop bar to a slaughter facility, the conduct of meat inspection personnel and affordable user fees.

The seroprevalence of toxoplasmosis in pigs in Ghana.

A serological survey of toxoplasmosis in pigs in Ghana was carried out between October 1997 and April 1998 in the three ecological zones of Ghana: the Coastal Savannah, the Forest Belt and the Guinea Savannah. Antibody against Toxoplasma gondii was measured in pig serum using a microplate-ELISA which had a sensitivity and specificity of 90.2 and 92.3%, respectively when compared with IFAT. A national seroprevalence of 39% was obtained in pigs, with the ecological distribution being 43.9, 30.5 and 42.5% for the Coastal Savannah, the Forest Belt and the Guinea Savannah, respectively. The age of the animal, the breed, the environmental conditions and the management practices appeared to be the major determinants of prevalence of antibodies against T. gondii. The prevalence of anti-T. gondii antibodies was found to increase with age (P<0.05). Pigs from the two Savannah zones had a significantly higher (P<0.05) antibody prevalence than those sampled from the Forest belt. Antibody prevalence (46.8%) in crossbreed pigs was significantly higher (P<0.05) than that of the exotic Large White breed (38.8%).

The prevalence of anti-Toxoplasma gondii antibodies in Ghanaian sheep and goats.

The enzyme-linked immunosorbent assay (ELISA) was used to detect anti-Toxoplasma gondii antibodies in 1258 small ruminants (732 sheep and 526 goats) sampled from 28 different locations in the three ecological zones of Ghana. The animals sampled had an overall seroprevalence of 30.5% (384 of the total). Sheep had a higher overall prevalence (33.2%) compared to the goats (26.8%). Animals sampled from the Coastal Savannah and the Forest zones had prevalences of 39.4% and 39.1%, respectively, which were significantly higher (P<0.01) than the prevalence recorded for the drier Guinea Savannah zone (20%). Prevalence of antibodies in female animals (35.8%) was significantly higher (P<0.01) than that for males (21.1%). Significant differences were also observed between breeds and age groups. The ELISA was found to be both highly sensitive (92%) and specific (91%) when compared to the IFAT, which was used as a reference test.

Supernumerary teats in Ghanaian livestock: II. Cattle.

In 988 heads of cattle of all age groups and both sexes of various breeds and crosses at location near Legon/Accra the occurrence of supernumerary teats was studied. They were found to be more frequent in Sokoto Gudale and mixed Zebus (21 and 27%) than in the West African Shorthorn and N'Dama (8 and 6%). Crosses of these breeds with Friesian also had a higher prevalence than those with Jersey. There were significantly more caudal supernumerary teats (16%) than intercalary (2%) and ramal (1.5%). Bulls had fewer supernumerary teats than female cattle.