Dynamics of the association between dung beetles (Coleoptera: Scarabaeidae) and the dog parasite Spirocerca lupi (Nematoda: Spiruromorpha: Spirocercidae)

Spirocercosis is a canine disease caused by the nematode parasite Spirocerca lupi (Rudolphi, 1809) (Spirurida: Spirocercidae) and is a potentially fatal condition in domestic dogs (Canis familiaris). The larval life cycle of this parasite involves intermediate and paratenic (transport) hosts. Various species of coprophagous dung beetles (Scarabaeidae: Scarabaeinae) serve as the principle intermediate hosts. Despite extraordinary advances in biomedical research, it is unlikely that these alone will alleviate the burden of this parasitic disease in dogs. Recently, there has been growing concern over the upsurge in incidence and reported cases of spirocercosis in domestic dogs in South Africa. There is a plethora of literature on the clinical, diagnostic and epidemiological aspects of this disease in dogs, yet no study has aimed at fully understanding the dynamic interactions between the various hosts and S. lupi, governed by the consequences of their behaviour under different and ever-changing environmental conditions. It is most likely that the impact of this disease is accentuated by constant changes in human demographics and behaviour. Studies on spirocercosis in dogs have considered the consumption of the various paratenic hosts or the deliberate ingestion of dung beetles to be the main cause of the transmission of S. lupi to dogs. However this study suggests that the coprohagous behaviour of dogs and the subsequent accidental ingestion of coprophagous dung beetles in or on faeces are mainly responsible for the transmission of this parasitic nematode to dogs. Changes in urban land use and subsequent changes along urban-rural gradients influence the nature of biological interactions partly due to changes in species assemblage structure and composition. Such alterations in assemblage structure of species pose a particular risk to altered rates of parasitism and disease transmission. It is concluded that these changes in landscape use coupled to altered dung beetle species assemblage structure have influenced the pattern of events observed in this host – parasite relationship. Furthermore, the social organization of domestic dogs (pets versus feral animals) and the availability of exposed excrement as a direct or indirect consequence of human behaviour played a pivotal role in the rate these parasites are transmitted to dogs.Thesis (PhD)--University of Pretoria, 2012.Zoology and Entomologyunrestricte

Improving policy coherence for food security and nutrition in South Africa: a qualitative policy analysis

Like most other low and middle-income countries, South Africa must address a rising burden of diet-related chronic disease in a situation of persistent food insecurity and undernutrition. Supply-side policy interventions are a critical component of action to address the double burden of malnutrition. However, the food supply is governed by a number of different policy sectors, and policy incoherence can occur between government action to promote a healthy food supply and objectives for economic liberalization. We analysed the coherence of food supply policy content with respect to nutrition and food security in South Africa, and conducted 14 in-depth interviews with 22 public and private sector actors to identify opportunities to improve policy coherence across sectors governing the food supply. Drawing on Sabatier’s conceptualization of actors as influential in shaping policy outcomes, we identified three coalitions of actors related to food security and nutrition in South Africa: the dominant Economic Growth coalition, the Food Security coalition, and the Health coalition. Understanding the frames, beliefs and resources held by these coalitions offers insights into the policy tensions faced by the Government of South Africa with respect to the food supply. The analysis indicates that the current reconsideration of economic policy agendas favouring liberalization in SouthAfrica, including the termination of most bilateral investment treaties, may present an opportunity for increased recognition of food security and nutrition priorities in food supply policy making. Opportunities to strengthen policy coherence across the food supply for food security and nutrition include: specific changes to economic policy relating to the food supply that achieve both food security/nutrition and economic objectives; creating links between producers and consumers, through markets and fiscal incentives that make healthy / fresh foods more accessible and affordable; increasing formal avenues for engagement by Civil Society in nutrition and food security policy making; and including consideration of the nutritional quality of the food supply in policy objectives across sectors, to create a framework for policy coherence across sectors relating to the food supply