Mapping occurrence of Taenia solium taeniosis/cysticercosis and areas at risk of porcine cysticercosis in Central America and the Caribbean basin

Background: This study aimed to map the occurrence of Taenia solium taeniosis/cysticercosis at national level within Central America and the Caribbean basin, and to map the distribution of porcine cysticercosis at first-level administrative subdivision level (department level) and the porcine population at risk. This zoonotic parasite is believed to be widely endemic across most of Latin America. However, there is little information readily available for Central America and the Caribbean basin. Taenia solium has been ranked the most important foodborne parasitic hazard globally and within endemic areas is a common cause of preventable epilepsy. Methods: We conducted a structured literature search in PubMed, supplemented and crossed-referenced with relevant academic databases, grey literature, and active searches in identified literature, to identify all records of T. solium presence in Central America and the Caribbean basin between 1986 and April 2017. To retrieve grey literature, government entities, researchers and relevant institutions across the region were contacted in an attempt to cover all countries and territories. Identified records containing data on porcine cysticercosis were geo-referenced to identify department level distribution and compared to modelled distributions of pigs reared under extensive production systems. Results: We identified 51 records of T. solium at the national level, covering 13 countries and an additional three countries were included based on World Organisation for Animal Health (OIE) reports, giving a total of 16 countries out of 41 with evidence of the parasite's presence. Screening records for porcine cysticercosis data at the departmental level confirmed porcine cysticercosis presence in 11 departments across six countries (Colombia, Guatemala, Honduras, Mexico, Nicaragua and Venezuela). Conclusions: When comparing these results to areas where pigs were kept in extensive production systems and areas where no information on porcine cysticercosis exists, it is apparent that porcine cysticercosis is likely to be underreported, and that a substantial part of the regional pig population could be at risk of contracting porcine cysticercosis. More detailed information on the distribution of T. solium and accurate burden estimations are urgently needed to grasp the true extent of this zoonotic parasite and the public health and agricultural problems it potentially poses

Epidemiological studies of parasitic gastrointestinal nematodes, cestodes and coccidia infections in cattle in the highveld and lowveld communal grazing areas of Zimbabwe

Between January 1999 and December 2000 faecal samples from 16 264 cattle at 12 dipping sites in the highveld and nine in the lowveld communal grazing areas of Zimbabwe were examined for gastrointestinal (GI) nematode and cestodes eggs, and coccidia oocysts. Strongyle larvae were identified following culture of pooled faecal samples collected at monthly intervals. The effects of region, age, sex and season on the prevalence of GI nematodes, cestodes and coccidia were determined. Faecal egg and oocyst counts showed an overall prevalence of GI nematodes of 43 %, coccidia 19.8 % and cestodes 4.8 %. A significantly higher prevalence of infection with GI nematodes, cestodes and coccidia was recorded in calves (P < 0.01) than in adults. Pregnant and lactating cows had significantly higher prevalences than bulls, oxen and non-lactating (dry cows) (P < 0.01). The general trend of eggs per gram (epg) of faeces and oocysts per gram (opg) of faeces was associated with the rainfall pattern in the two regions, with high epg and opg being recorded during the wet months. The most prevalent genera of GI nematodes were Cooperia, Haemonchus and Trichostrongylus in that order. Strongyloides papillosus was found exclusively in calves. Haemonchus was significantly more prevalent during the wet season than the dry season (P < 0.01). In contrast, Trichostrongylus was present in significantly (P < 0.01) higher numbers during the dry months than the wet months, while Cooperia and Oesophagostomum revealed no significant differences between the wet and dry season. These findings are discussed with reference to their relevance for strategic control of GI parasites in cattle in communal grazing areas of Zimbabwe

Molecular Detection of Leptospiral DNA in Environmental Water on St. Kitts

Leptospirosis is an important waterborne zoonotic disease caused by pathogenic Leptospira. The pathogen is maintained in a population due to chronic colonization and shedding from renal tubules of domestic and wild animals. Humans and other animals become infected when they come in contact with urine from infected animals, either directly or through urine-contaminated surface water. In this study, we screened environmental water on the island of St. Kitts by using a TaqMan based real time quantitative polymerase chain reaction (qPCR) targeting a pathogen specific leptospiral gene, lipl32. Our results indicate that around one-fifth of tested water sources have detectable leptospiral DNA

Perceptions and acceptability of piloted Taenia solium control and elimination interventions in two endemic communities in eastern Zambia

Infections with Taenia solium cause significant public health and economic losses worldwide. Despite effective control tools, long‐term sustained control/elimination of the parasite has not been demonstrated to date. Success of intervention programs is dependent on their acceptability to local communities. Focus group discussions (FGDs) and questionnaires (QS) were conducted in two study communities in eastern Zambia to assess local perceptions and acceptance of two piloted intervention strategies: one targeting pigs only (‘control’ study arm), and one integrated human‐ and pig‐based (‘elimination’) strategy. QS (n = 227) captured data regarding participation in project activities, knowledge and perceptions of T. solium and of the interventional drugs used in the study. FGDs (n = 18) discussed perceived advantages and disadvantages of the interventions and of the project's delivery and value. QS data revealed 67% of respondents participated in at least one educational activity, and 80% correctly identified at least one disease targeted by the education. All elimination study arm respondents (n = 113) had taken the human treatment, and 98% intended to do so next time. Most (70%) indicated willingness to pay for future treatments (median 0.20 USD per dose). Of pig‐owning respondents, 11/12 (92%) had allowed their pigs to be treated/vaccinated and all intended to do so again next time. Four pig owners indicated willingness to pay 0.10–0.50 USD per dose of treatment or vaccine. FGD feedback revealed positive perceptions of interventions; people reported improved health in themselves and their pigs, and fewer cysticerci in pork. Latrine use, hand washing, meat inspection and proper cooking of pork had reportedly increased since the program's inception. Preliminary assessment indicates that the piloted intervention methods are generally acceptable to the communities. The reported willingness of many respondents to pay for the medications would contribute to the feasibility of long‐term, government‐led T. solium intervention programs in future

Epidemiology of Taenia saginata taeniosis/cysticercosis: a systematic review of the distribution in the Americas

BACKGROUND: The distribution of Taenia saginata in the Americas is unclear. Establishing the distribution, economic burden, and potentials for control of bovine cysticercosis is increasingly important due to the growing demand for beef. This paper aims to take the first step and reviews the recent distribution of T. saginata taeniosis and bovine cysticercosis on a national level within the Americas. METHODS: We undertook a systematic review of published and grey literature for information on the occurrence, prevalence, and geographical distribution of bovine cysticercosis and human taeniosis in the 54 countries and territories of the Americas between January 1st, 1990 and December 31st, 2017. Data on bovine cysticercosis from OIE reports from 1994 to 2005 were also included. RESULTS: We identified 66 papers from the Americas with data on the occurrence of taeniosis or bovine cysticercosis and an additional 19 OIE country reports on bovine cysticercosis. Taeniosis was reported from 13 countries, with nine of these countries reporting specifically T. saginata taeniosis, and four countries reporting non-species specific taeniosis. The reported prevalence of taeniosis ranged between 0.04-8.8%. Bovine cysticercosis was reported from 19 countries, nine identified through the literature search, and an additional 10 identified through the OIE country reports for notifiable diseases. The reported prevalence of bovine cysticercosis ranged between 0.1-19%. Disease occurrence was restricted to 21 countries within the Americas, the majority from the mainland, with the only island nations reporting either bovine cysticercosis or taeniosis being Cuba, Haiti, and the US Virgin Islands. CONCLUSIONS: Taenia saginata is widely distributed across 21 of the 54 countries in the Americas, but insufficient epidemiological data are available to estimate the subnational spatial distribution, prevalence, incidence and intensity of infections. This needs to be addressed through active surveillance and disease detection programmes. Such programmes would improve the data quantity and quality, and may enable estimation of the economic burden due to bovine cysticercosis in the region in turn determining the requirement for and cost-effectiveness of control measures

The first record of ostrich feather louse (Struthiolipeurus struthionis) collected from farmed ostriches (Struthio camelus) in the United Arab Emirates

Background and Aim: Ostrich (Struthio camelus) farming in the United Arab Emirates (UAE) is a relatively new field of farming. Farmed ostriches are susceptible to ectoparasite infestation, which affects their production. This study was conducted to estimate the prevalence of ectoparasites on ostriches raised on a farm in Abu Dhabi Emirate. Materials and Methods: The feathers of 42 ostriches (26 females and 16 males) were collected and morphologically examined for ectoparasites. In total, 283 lice (89 males and 194 females) were collected from birds. However, there were no ticks or other ectoparasites. Lice were preserved in 1.5 mL tubes containing 70% ethanol and were later identified using taxonomic keys. The prevalence, mean intensity of infection, and mean abundance were estimated. Results: One louse species, Struthiolipeurus struthionis was identified. To the best of our knowledge, this is the first report of S. struthionis in ostriches raised in the UAE with an overall prevalence of 88%. The prevalence of lice was significantly higher in July (100%) than that in May (66.7%). Likewise, the mean intensity and abundance of lice were significantly higher in June (10.6 and 9.94, respectively) than in May (3.25 and 2.2, respectively). Conclusion: The high prevalence of lice poses a serious risk to ostrich farming by negatively affecting the health and productivity of ostriches

Effects of ‘The Vicious Worm’ educational tool on Taenia solium knowledge retention in Zambian primary school students after one year

Background: Taenia solium is a neglected zoonotic parasite endemic throughout many low-income countries worldwide, including Zambia, where it causes human and pig diseases with high health and socioeconomic burdens. Lack of knowledge is a recognized risk factor, and consequently targeted health educational programs can decrease parasite transmission and disease occurrence in endemic areas. Preliminary assessment of the computer-based education program The Vicious Worm' in rural areas of eastern Zambia indicated that it was effective at increasing knowledge of T. solium in primary school students. The aim of this study was to evaluate the impact of The Vicious Worm' on knowledge retention by re-assessing the same primary school students one year after the initial education workshops. Methodology/Principal findings: Follow-up questionnaires were administered in the original three primary schools in eastern Zambia in 2017, 12 months after the original workshops. In total, 86 pupils participated in the follow-up sessions, representing 87% of the initial workshop respondents. Knowledge of T. solium at follow-up' was significantly higher than at the initial pre' questionnaire administered during the Vicious Worm workshop that took place one year earlier. While some specifics of the parasite's life cycle were not completely understood, the key messages for disease prevention, such as the importance of hand washing and properly cooking pork, remained well understood by the students, even one year later. Conclusions/Significance: Results of this study indicate that The Vicious Worm' may be an effective tool for both short- and long-term T. solium education of rural primary school students in Zambia. Inclusion of educational workshops using The Vicious Worm' could be recommended for integrated cysticercosis control/elimination programs in sub-Saharan Africa, particularly if the content is simplified to focus on the key messages for prevention of disease transmission. Author summary The zoonotic parasite Taenia solium, commonly known as the pork tapeworm, causes substantial public health and economic losses worldwide. It is commonly found in low-income countries where pigs are raised in areas of poor sanitation, including Zambia. The links between the parasite and its different disease forms in humans and pigs are not very well known, and ignorance of the parasite is a known risk factor for infection. Health education can significantly increase knowledge and awareness of the parasite and can inspire behavioral change that reduces disease transmission. The Vicious Worm' is a computer-based program designed to provide T. solium education in a fun and interactive way. We conducted educational workshops in three primary schools in rural areas of eastern Zambia, and preliminary assessment indicated that the Vicious Worm' educational content significantly improved students' knowledge of T. solium. We also conducted follow-up studies in the same students one year later, and discovered that the students' knowledge was still significantly higher than at baseline. We conclude that The Vicious Worm' may be a useful educational component to enable targeting of school students, and would recommend its inclusion in integrated T. solium control programs in future