PhD defence Salvator Minani

Supervisors

• Prof. dr. Katja Polman (ITM)

• Dr. Chiara Trevisan (ITM)

• Prof. dr. Sarah Gabriël (Ghent University)

• Prof. Anastasie Gasogo (University of Burundi) 

• Dr. Jean Bosco Ntirandekura (University of Burundi)

Abstract

Taenia solium and Toxoplasma gondii are important foodborne zoonotic parasites with public health and veterinary significance. In Burundi, pig farming and the demand for pork have been increasing in recent years. No studies were conducted on the pork value chain (PVC) or on the risks associated with pig farming, slaughtering, pork preparation, and consumption. Also, the burden associated with T. solium and T. gondii parasites has never been estimated. Four chapters were developed to achieve the specific objectives of the thesis.

In Chapter 1, stakeholders’ knowledge, practices, and attitudes along the PVC and the associated potential risks to T. solium and T. gondii infections were assessed. Most participants were unaware of the transmission and symptoms of T. solium and T. gondii in humans and pigs. Misconceptions about the causes and health consequences of T. solium and T. gondii infections led people to rely on traditional medicine. Most pigs were raised under extensive pig production farms, which exposed pigs to infections. Five PVC types were identified, which have important implications for human exposure to T. solium and T. gondii. By Hazard Analysis and Critical Control point (HACCP) assessment, cooking pork was found to be effective in eliminating T. solium and T. gondii in pork meals.

In Chapter 2, the occurrence of Taenia spp. and T. gondii in pigs slaughtered in Burundi was investigated. The prevalence of T. solium cysticercosis was estimated to be 2.4% based on meat inspection, 11.6% based on partial carcass dissection, and 11.5% based on molecular confirmation. The majority of T. solium cysticerci (88.3%) were viable. The seroprevalence of T. gondii infection in pigs was estimated at 17.7%.

In Chapter 3, the risk of human T. solium exposure from farm to fork was assessed using the quantitative microbial risk assessment model (QMRA). The overall probability that any pork meal would be potentially infective to humans was 9.7% before cooking and 1.8% after cooking. The probability of being exposed to infective meals was 99.7% for daily consumption, 60.3% for weekly consumption, 19.6% for monthly consumption and 1.8% for yearly consumption.

In Chapter 4, the burden of T. solium cysticercosis and congenital toxoplasmosis for the year 2020 was assessed. For T. solium neurocysticercosis (NCC), the health burden was estimated at 14,603 disabilities adjusted life years (DALYs) and 8,992 animal loss equivalents (ALEs). The economic impact was estimated at 4,261,063 USD. For congenital toxoplasmosis (CT), the incidence was 2.7 per 1000 children, and 1,180 children were born with CT. The health and economic burden were estimated at 7,283 DALYs and 550,000 USD, respectively.

This thesis highlights the need for integrated control interventions, including human (health) education, human treatment, pig treatment and vaccination, and control of animal slaughter to reduce the risk, prevalence, and burden of T. solium and T. gondii infections in Burundi. 

Invitation public defense_Salvator Minani.pdf