Systematic review and meta-analysis of bovine cysticercosis in Brazil: current knowledge and way forward

Prevalence of cysticercosis in cattle slaughterhouses in the western region of Minas Gerais, Brazil (2013-2020): Influence of sanitary regulations in reducing risks to human health

Bovine cysticercosis is a foodborne zoonosis that has a worldwide distribution, and its highest prevalence is found in developing countries with a large volume of cattle production, such as Brazil. The objective was to evaluate the prevalence of cysticercosis during seven years in three slaughterhouses located in the western region of Minas Gerais state, Brazil, and the impacts of the legislation on the identification and destination of infected carcasses. Three slaughterhouses (Sl) were selected for this study with averages of 200 (SlA), 721 (SlB) and 1138 (SlC) bovines slaughtered per day. The monthly number of slaughtered cattle, infected carcasses with cysticercosis and destination were used to calculate the condemnation occurrence index (COI) and the adjusted seasonal index (ASI). To assess the impact of the legislation, the prevalence rate and destination of infected carcasses were subdivided into the PRE (January 2013 to March 2017) and POST (April 2017 to December 2020) period of Decree 9013 of 2017 and the results were compared by chi-square (P < 0.05). SlA recorded the highest cysticercosis rate with 1.54 % and SlC the lowest rate with 0.33 %. In addition, it was observed that in the POST period there was an increase in the identification of infected carcasses in SlA and B (P < 0.05). The POST period also resulted in a change in the relative frequency of infected carcasses destination in the three slaughterhouses (P < 0.05). The ASI identified an increase in infected carcasses in February and a decrease in November for SlB, proving to be an important tool for planning the inspection team trainings. These results show that the disease is still present in the studied region and highlight the benefits of using the One Health concept in the evaluation of a time series prevalence of bovine cysticercosis by: identifying seasonality of the disease, trends during the time period and impacts brought by updates in the national sanitary legislation.

Bovine cysticercosis in the State of São Paulo, Brazil: Prevalence, risk factors and financial losses for farmers

Taenia saginata is the causative agent of bovine cysticercosis (BCC) and human taeniasis, two diseases that have economical and public health importance, respectively. This research focused on determining BCC prevalence in the state of São Paulo state, Brazil, in the period of 2017-2019, as well as associating risk factors related to disease occurrence and estimate the economic impact to beef producers. Data from 6,277,758 bovine carcasses originating from 571 municipalities and 15 different mesoregions in the state of São Paulo was gathered and analyzed. Cysticerci were detected in a total of 88,700 carcasses at meat inspection, resulting in an apparent prevalence of 1.41 % (C.I. 95 % 1.40-1.42 %). BCC was widespread in this state and its spatial distribution varied in municipalities and mesoregions. The variable number of milking cows in the municipality was significantly associated (OR = 1.48, p = 0.00) with BCC cases, conversely, the presence of peasant's settlements in the municipality was a protective factor (OR = 0.49, p = 0.02). Financial losses for cattle farmers were estimated at US$ 5,829,103.99. The results of this research show that there is still room for implementation of bovine cysticercosis control measures in endemic areas, aiming to reduce financial losses to farmers as well as reduction of human taeniasis cases in the population.

Zoonotic Taenia infections with focus on cysticercosis due to Taenia solium in swine and humans

Zoonotic taeniasis caused by the adult stage of Taenia solium, Taenia saginata or Taenia asiatica are considered neglected tropical diseases by the World Health Organization. The life cycle of these 3 metazoan species is very similar and includes an intermediate host: pigs in the case of T. solium and T. asiatica, and cattle in the case of T. saginata. By eating meat (pork/T. solium, T. asiatica; beef/T. saginata) containing live cysticerci, humans develop taeniasis, which is practically asymptomatic but is the main risk factor for intermediate hosts to become infected. T. saginata causes bovine cysticercosis, while T. solium and T. asiatica cause swine cysticercosis, of veterinary and economic importance. T. solium cysticerci cause neurological disease in humans: neurocysticercosis. Cysticerci develop after ingesting microscopic eggs released from a human tapeworm carrier. Here we describe the life stages of the parasites, diagnosis, pathogenesis, symptomatology of neurocysticercosis, and prevention and control measures. Highlighting the need to validate diagnostic tools, treatments and vaccination in endemic areas, with the challenge of addressing the most vulnerable populations that lack resources. If people understand the transmission route, avoid eating uncooked or insufficiently cooked meat and have adequate hygienic habits, the life cycle of the 3 zoonotic Taenia species may be interrupted. In addition, we describe the growing field of immune response and immunomodulation elicited by the parasites, which may provide essential tools for diagnosis, treatment, control of taeniasis/cysticercosis, as well as for identification of parasite-derived immunomodulators that could aid in the treatment of emerging inflammatory diseases worldwide.