Risk factors associated with taeniosis-cysticercosis in rural farming communities in Gauteng Province, South Africa

The aim of this study was to determine which of the livestock management and human practices known to be risk factors associated with taeniosis-cysticercosis occur in Gauteng Province. A questionnaire survey was conducted in two regions of Gauteng Province, Germiston and Pretoria. Results revealed that almost 20% of the interviewed farmers do not have toilets, most of them let their animals roam freely during the day for grazing and scavenging, and 47% use streams as the water source for their animals. This may create an infection opportunity through ingestion of Taenia-contaminated herbage or water. Furthermore, 26% mentioned that their animals might have access to human excreta. More than 70% of farmers in the province slaughter cattle and pigs for their own consumption without inspecting meat for cysticercosis. Only a few of the interviewed farmers in both regions were aware of the taeniosis-cysticercosis complex. Backyard slaughtering, consumption of uninspected meat by the public, poor livestock management, and limited sanitation in rural communities of Gauteng Province are identified as risk factors associated with the occurrence of Taenia saginata and Taenia solium infections in the province. Taenia saginata and T. solium are considered to have a global distribution; therefore, these risk factors may be applicable globally, not just in Gauteng Province. Programs on public awareness with regard to transmission and prevention of Taenia infections as well as more detailed studies on risk factors of taeniosis-cysticercosis are recommended.

Sero-prevalence of Taenia spp. infections in cattle and pigs in rural farming communities in Free State and Gauteng provinces, South Africa

The aim of this study was to determine sero-prevalence of bovine and porcine cysticercosis in cattle and pigs in rural farming communities in Free State and Gauteng Provinces, Republic of South Africa. Blood samples were collected for a period of twelve months from live cattle (n=1315; 1159) and pigs (n=436; 240) and the serum extracted and stored before analysis by a monoclonal antibody based (HP10) antigen detection ELISA. Results revealed a generally high sero-prevalence and wide distribution throughout the two provinces with Free State having a higher sero-prevalence in both cattle and pigs (23% and 34%) than Gauteng province (15% and 14%). Consumption of infected meat that is either not inspected/missed at meat inspection; poor livestock management practices and limited sanitation in rural communities might have contributed to the occurrence of Taenia spp. infections in the two provinces. It is therefore, recommended that cysticercosis status of animals be established before slaughter. This would assist in ensuring that infected animals are not slaughtered for human consumption or zoonosis preventive measures are taken. Furthermore, public awareness programs on life cycles of T. saginata, T. solium and T. hydatigena and the use of more sensitive diagnostic tools are recommended as part of effective control strategies against taeniid infections.

Molecular Analysis of South African Ovine Herpesvirus 2 Strains Based on Selected Glycoprotein and Tegument Genes

Ovine herpesvirus 2 (OvHV-2), is the causative agent of sheep-associated malignant catarrhal fever (SA-MCF), a generally fatal disease of cattle and other captive wild ruminants. Information on the OvHV-2 strains circulating in South Africa (SA) and other African countries with regard to genetic structure and diversity, and pattern of distribution is not available. This study aimed to characterize the OvHV-2 strains circulating in SA using selected genes encoding glycoproteins and tegument proteins. To establish the genetic diversity of OvHV-2 strains, four genes, Ov 7, Ov 8 ex2, ORF 27 and ORF 73 were selected for analysis by PCR and DNA sequencing. Nucleotide and amino acid multiple sequence analyses revealed two genotypes for ORF 27 and ORF 73, and three genotypes for Ov 7 and Ov 8 ex2, randomly distributed throughout the regions. Ov 7 and ORF 27 nucleotide sequence analysis revealed variations that distinguished SA genotypes from those of reference OvHV-2 strains. Epitope mapping analysis showed that mutations identified from the investigated genes are not likely to affect the functions of the gene products, particularly those responsible for antibody binding activities associated with B-cell epitopes. Knowledge of the extent of genetic diversity existing among OvHV-2 strains has provided an understanding on the distribution patterns of OvHV-2 strains or genotypes across the regions of South Africa. This can facilitate the management of SA-MCF in SA, in terms of introduction of control measures or safe practices to monitor and control OvHV-2 infection. The products encoded by the Ov 7, Ov 8 ex2 and ORF 27 genes are recommended for evaluation of their coded proteins as possible antigens in the development of an OvHV-2 specific serodiagnostic assay.