Serodiagnosis of bovine cysticercosis by detecting live Taenia saginata cysts using a monoclonal antibody-based antigen-ELISA

An ante mortem antigen-ELISA-based diagnosis of Taenia saginata cysticercosis was studied in artificially (n = 24) and naturally (n = 25) infected cattle with the objective of further validating the assay as a field diagnostic test. Based on total dissection as the definitive method of validity, the assay minimally detected 14 live cysticerci in artificially infected calves and 2 in naturally infected steers. In natural infections, the minimum number of live cysticerci consistently detected by Ag-ELISA was 5 while in artificial infections it was above 14. However, other animals with 12 and 17 live cysticerci in artificially infected calves, and 1 and 2 live cysticerci in naturally infected steers, escaped detection for unknown reasons. Animals harbouring dead cysticerci gave negative reactions in the assay as was the case in non-infected experimental control calves. There was a statistically significant positive linear correlation between Ag-ELISA optical density values and burdens of live cysticerci as obtained by total dissection of both artificially infected calves (r = 0.798, n = 24 ; P < 0.05) and naturally infected steers (r = 0.631, n = 25 ; P < 0.05). These results clearly show the potential effectiveness of ante mortem monoclonal antibody-based antigen detection ELISA in the diagnosis of bovine cysticercosis in cattle. Its value lies in the diagnosis of infection in cattle as a screening test in a herd, rather than as a diagnostic test at the individual level, due to false positive and negative reactions. In a herd of heavily infected cattle, the assay may, however, provide for individual diagnosis. Nevertheless, more work is recommended to increase its sensitivity so as to be able to diagnose light infections consistently in the field

Experimental transmission of Besnoitia caprae in goats : research communication

Experimental transmission of Besnoitia caprae from naturally chronically-infected goats to susceptible ones was achieved by intra-nasal instillation and intra-conjunctival inoculation of cystozoite-containing suspensions, subcutaneous implantation of fascia containing cysts and alternate needle pricking between the infected and non-infected goats. Typical chronic symptoms developed in the fascia-infected does. Cystozoite inoculation into the eyes and mouth did not result in infection. Kids born of dams with acute and chronic besnoitiosis did not contract the infection in utero, suggesting that intra-uterine transmission may not occur. In contrast to does with acute besnoitiosis, which occasionally aborted, the does with chronic besnoitiosis gave birth to healthy kids. Kids below the age of 4 months (pre-weaned period) born of both infected and non-infected does were susceptible to besnoitiosis but appeared to be more resistant than adult goats

The impacts of aflatoxin standards on health and nutrition in sub-Saharan Africa: The case of Kenya

Human food and animal feed can contain many different hazards, which may be biological, chemical, or physical. In most countries, there are regulations that limit the levels of these hazards permitted in food and feed so as to protect consumers. Optimally, the levels specified in the standards should make the food safe enough for everyone to consume, and often this is done by carrying out a risk assessment, based on scientific evidence of the levels that can be considered safe and the amount of contaminated products consumed. However, for some substances, especially carcinogens, it is difficult to calculate how much is safe to consume and some groups of people, such as small children or pregnant women, may be more sensitive than the population at large. While imposition of standards is motivated by health benefits, standards also have costs. These include the costs of compliance and verification, which translate- into increased costs of purchase and reduction of the products available. In this paper we summarize current standards in sub-Saharan Africa related to aflatoxins, a priority hazard, and discuss their coherence and evidence-base. Next, using our recent research findings, we estimate the health risks of consuming foods contaminated with aflatoxins in Kenya. We also estimate the negative health and economic effects that would arise from strict application of different standards for aflatoxins. We discuss the results in light of health and nutrition goals