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The lack of cheap, easy-to-use, rapid diagnostic tests has led to the development of several rapid diagnostic tests for cysticercosis. The new prototype two-strip, Taenia solium point of care test (TS POC) detects antibodies against taeniosis (TS POC T) and cysticercosis (TS POC CC). This study evaluated the diagnostic performance of the TS POC CC in the Sinda district in eastern Zambia. A sample of 1254 participants was recruited and tested with the TS POC. Out of the 1249 participants with a valid TS POC result, 177 (14%) tested positive while 1072 (86%) tested negative. All individuals with a positive TS POC and a subset of negative TS POC participants were selected for serum sampling, and were subjected to the recombinant glycoprotein T24H enzyme-linked immunoelectrotransfer blot (rT24H EITB) and the serum B60/158 (serum Ag) enzyme-linked immunosorbent assay (Ag ELISA). Performance characteristics were estimated using a Bayesian approach with probabilistic constraints. Based on 255 complete cases, the estimated sensitivity and specificity of the TS POC CC test were 35% (95% CI: 14–63%) and 87% (95% CI: 83–90%), respectively. The diagnostic performance needs to be improved, possibly by titrating antigen and other reagents’ concentration in the strip to produce a performance similar to existing cysticercosis tests such as the rT24H EITB.

Taenia solium taeniosis diagnosis is challenging because current tests perform sub-optimally and/or are expensive, require sophisticated equipment, infrastructure and trained manpower, and therefore are not community deployable. A recently-developed, multi-strip, T. solium point-of-care test (TS POC) for simultaneous detection of tapeworm (TS POC T) and cysticercus (TS POC CC) human antibodies was evaluated for diagnostic accuracy on consecutively recruited community participants in Sinda district, Zambia. All participants were tested using the TS POC test. All test-positives and 20% of the test-negative participants were invited to give a blood and stool sample for reference testing. Three different reference tests were used for taeniosis diagnosis: recombinant rES33 enzyme-linked immunoelectrotransfer blot (rES33 EITB), copro PCR and copro Ag ELISA. Bayesian analysis with probabilistic constraints was used to estimate sensitivity and specificity. In total, 1254 participants were tested with the TS POC test, of whom 13 tested positive using the TS POC T. Based on 161 participants with complete data, the estimated sensitivity and specificity for the TS POC T test were 38% (95% CI: 5–93%) and 99% (95% CI: 98–100%), respectively. The challenge of highly variable inter-assay performance is highlighted. We recommend either increasing the sensitivity or redesigning the test.

Taenia spp. are responsible for a substantial health and economic burden in affected populations. Knowledge of the fate of the eggs of Taenia spp. in the environment and of other factors facilitating the transmission of eggs to intermediate hosts is important for the control/elimination of infections caused by Taenia spp. The aim of this systematic review was to summarize current knowledge of the factors influencing the survival and dispersal of Taenia spp. eggs in the environment. Publications retrieved from international databases were systematically reviewed. Of the 1465 papers initially identified, data were ultimately extracted from 93 papers. The results of this systematic review indicate that survival is favoured at moderate temperatures (0–20 °C). Humidity seems to affect the survival of Taenia spp. eggs more than temperature. Under field circumstances, Taenia spp. eggs have been found to survive for up to 1 year. Taenia spp. eggs are commonly found on vegetables (0.9–30%) and in soil and water samples (0–43%), with their presence posing a risk to the consumer. Invertebrates may act as transport hosts, transferring the infection to an intermediate host, but the importance of this route of transmission is still open to question. Wastewater treatment systems are not capable of entirely eliminating Taenia spp. eggs. Access to surface water and the use of sewage sludge as fertilizer on pastures are important risk factors for bovine cysticercosis. Although information on the survival and spread of Taenia spp. eggs is available, in general the data retrieved and reviewed in this article were old, focused on very specific geographical regions and may not be relevant for other areas or not specific for different Taenia spp. Furthermore, it is unknown whether egg survival differs according to Taenia sp. Future studies are necessary to identify sustainable methods to identify and inactivate parasite eggs in the environment and reduce their spread. Graphical Abstract

In Europe, bovine cysticercosis (BCC) is detected by routine meat inspection (MI) at the slaughterhouse. The prevalence of BCC in Belgium based on MI is estimated at 0.23%. MI has a known low sensitivity for animals with localised infections and alternative detection techniques should be considered. A mathematical scenario-analysis model was built to determine the current prevalence of BCC in Belgium based on MI results combined with results of dissection of the predilection sites (PS) and the B158/B60 Ag-ELISA on serum of 614 carcasses found negative on MI. Additionally, the impact of the introduction of the B158/B60 Ag-ELISA at slaughter on the prevalence of BCC and taeniosis and on the economic impact related to Taenia saginata was estimated for Belgium. Data for estimating the economic impact were gathered from multiple sources within the meat and human health sectors and included value loss for infected carcasses, inspection costs, carcass destruction costs, cattle insurance costs and costs related to taeniosis (consultation physician, drugs and laboratory test). The model estimated the current prevalence of BCC to be 42.5% (95% CI: 32.4-60.7%) and the sensitivity of the MI for viable and degenerated cysticerci at only 0.54% (95% CI: 0.37-0.71%). A total of 213,344 viable cysticerci (95% CI: 122,962-386.249) were estimated to be present in the infected carcasses in one year and only 408 (95% CI: 356-464) of these were present in the carcasses detected at current MI. The annual number of human taeniosis cases is estimated at 11,000 by using the sale numbers of niclosamide in Belgium. Implementation of the Ag-ELJSA at slaughter (Se = 36.37%; Sp = 99.36%) would greatly reduce the prevalence of BCC to 0.6% and the number of taeniosis cases to 89 in year 10. Unfortunately, the accompanying resulting increase in costs for the animal owners, slaughterhouses and the insurance company, would be extremely high in the first years. Cattle owners would suffer losses of up to (sic)21 million in the first year after implementation of the Ag-ELISA (compared to an annual loss of (sic)3.5 million in the current situation), slaughterhouses of (sic)10 million (compared to (sic)200,000 currently) and the insurance company of almost (sic)6 million (compared to (sic)2.3 million profit currently). Therefore, implementation of the Ag-ELJSA might not be feasible and other options for controlling T. saginata should be investigated.

A Bayesian model was developed to estimate values for the prevalence and diagnostic test characteristics of bovine cysticercosis (Taenia saginata) by combining results of four imperfect tests. Samples of 612 bovine carcases that were found negative for cysticercosis during routine meat inspection collected at three Belgian slaughterhouses, underwent enhanced meat inspection (additional incisions in the heart), dissection of the predilection sites, B158/B60 Ag-ELISA and ES Ab-ELISA. This Bayesian approach allows for the combination of prior expert opinion with experimental data to estimate the true prevalence of bovine cysticercosis in the absence of a gold standard test. A first model (based on a multinomial distribution and including all possible interactions between the individual tests) required estimation of 31 parameters, while only allowing for 15 parameters to be estimated. Including prior expert information about specificity and sensitivity resulted in an optimal model with a reduction of the number of parameters to be estimated to 8. The estimated bovine cysticercosis prevalence was 33.9% (95% credibility interval: 27.7-44.4%), while apparent prevalence based on meat inspection is only 0.23%. The test performances were estimated as follows (sensitivity (Se) - specificity (Sp)): enhanced meat inspection (Se 2.87% - Sp 100%), dissection of predilection sites (Se 69.8% - Sp 100%), Ag-ELISA (Se 26.9% - Sp 99.4%), Ab-ELISA (Se 13.8% - Sp 92.9%).

A cross-sectional systematic sampling was carried out during three consecutive winters from 2012 to 2015, to update the knowledge on the fox tapeworm (Echinococcus multilocularis) distribution in the red fox (Vulpes vulpes) in Flanders. Earlier studies reported the low endemicity status of this tapeworm in the northern region of Belgium, in contrast to the south of the country and neighbouring countries. Using a modified Segmental Sedimentation and Counting Technique, followed by PCR-RFLP and sequencing, 923 foxes' intestines were examined for the presence of E. multilocularis. Based on microscopic examination, 38 out of 923 foxes were suspected to be infected with either E. multilocularis or Amoebotaenia spp., of which 19 were molecularly confirmed to be E. multilocularis, 18 were found positive for Amoebotaenia spp. and one was negative. The overall prevalence for E. multilocularis of 2.1% confirms the low endemicity of the fox tapeworm in Flanders. However, in one area in the most eastern part of Flanders (Voeren), neighbouring the Netherlands and Wallonia, a prevalence of 57% (12/21) was observed. Continuous monitoring of the fox tapeworm remains needed to assess spatio-temporal trends in distribution and to assess the risk of this zoonotic infection in Europe. The challenging differential diagnosis of E. multilocularis and Amoebotaenia spp. based on microscopic examination calls for attention.

Rift Valley fever (RVF) is one of the major viral zoonoses in Africa, affecting humans and several domestic animal species. The epidemics in eastern Africa occur in a 5-15 year cycle coinciding with abnormally high rainfall generally associated to the warm phase of the El Nino event. However, recently, evidence has been gathered of inter-epidemic transmission. An open-source, easily applicable, accessible and modifiable model was built to simulate the transmission dynamics of RVF. The model was calibrated using data collected in the Kilombero Valley in Tanzania with people and cattle as host species and AEdes mcintoshi, AE. aegypti and two Culex species as vectors. Simulations were run over a period of 27 years using standard parameter values derived from two previous studies in this region. Our model predicts low-level transmission of RVF, which is in line with epidemiological studies in this area. Emphasis in our simulation was put on both the dynamics and composition of vector populations in three ecological zones, in order to elucidate the respective roles played by different vector species: the model output did indicate the necessity of Culex involvement and also indicated that vertical transmission in AEdes mcintoshi may be underestimated. This model, being built with open-source software and with an easy-to-use interface, can be adapted by researchers and control program managers to their specific needs by plugging in new parameters relevant to their situation and locality.

Bovine cysticercosis (BCC), caused by the helminth Taenia saginata, is currently diagnosed solely by official meat inspection (MI) based on macroscopic detection of viable cysticerci or typical lesions of degenerated larvae. MI has a known low sensitivity (16%), leading to a large proportion of infected cattle carcasses entering the human food chain and posing a risk to public health. Prevalence in Belgium based on MI results is estimated at around 0.22%. Due to the low sensitivity of MI, alternative techniques to detect BCC should be considered. This study evaluates MI, MI with additional incisions in the heart, specific antibody detection against excretory/secretory (E/S) in the Ab-ELISA and circulating antigens in the B158/B60 Ag-ELISA on 715 (101 MI-positive and 614 MI-negative) samples collected from carcasses at slaughterhouses in Belgium. Full dissection of the predilection sites was considered the reference test. During the study, mostly carcasses with (very) light infections were detected containing predominantly degenerated or calcified cysticerci and only few viable cysticerci. Dissection of the predilection sites detected 144 (23%) additional infections in the 614 MI-negative carcasses. When sequentially performing first the dissection of the predilection sites, followed by the Ag-ELISA and the Ab-ELISA, an additional 36% of MI-negative carcasses were found positive for BCC, resulting in a prevalence very much higher than the above mentioned 0.22%. The B158/B60 Ag-ELISA showed a sensitivity of 40% for the detection of carcasses containing viable cysticerci and a specificity of 100%, and detected 70 positive carcasses of which only 14 had been identified as positive during MI. If Ag-ELISA were implemented as a detection technique for BCC in the slaughterhouses, many infected carcasses would still not be detected due to the sensitivity of 40%. But as sensitivity increases with increasing number of cysticerci in the carcass, the infected carcasses passing inspection will be the ones containing only a few viable cysticerci and thus posing a smaller food safety problem. Ag-ELISA is preferred over the ES Ab-ELISA in this study, which had a sensitivity of 13.3% and a specificity of 91.7% in a population with overall low infection burdens.

The monoclonal antibody-based circulating antigen detecting ELISA (B158/B60 Ag-ELISA) has been used elaborately in several studies for the diagnosis of human, bovine and porcine cysticercosis. Interpretation of test results requires a good knowledge of the test characteristics, including the repeatability and the effect of the borders of the ELISA plates. Repeatability was tested for 4 antigen-negative and 5 antigen-positive reference bovine serum samples by calculating the Percentage Coefficient of Variation (%CV) within and between plates, within and between runs, overall, for two batches of monoclonal antibodies and by 2 laboratory technicians. All CV values obtained were below 20% (except one: 24.45%), which indicates a good repeatability and a negligible technician error. The value of 24.45% for indicating the variability between batches of monoclonal antibodies for one positive sample is still acceptable for repeatability measures. Border effects were determined by calculating the %CV values between the inner and outer wells of one plate for 2 positive serum samples. Variability is a little more present in the outer wells but this effect is very small and no significant border effect was found.

Theileria parva is an important veterinary protozoan causing the tick-borne disease East Coast fever. Transfection of Theileria parasites will facilitate the investigation of many aspects of this apicomplexan infection and its unique host-parasite interaction. The pathogen has the extraordinary capacity of transforming B and T cells into clonally dividing cancerous cell lines in a reversible way. Sequence data of the entire T. parva genome are available and in vitro infected cell lines can easily be generated, thereby eliminating the use of animals in the evaluation of the evolution of the transfected sporozoites. Here we report, for the first time, on experiments towards successful transient transfection of T. parva sporozoites, making use of a new generation transfection device. Plasmid DNA containing the strong EF-1α promoter and an Azami Green reporter gene were integrated by nucleofection into freshly purified T. parva sporozoites. Expression of Azami Green was detected with a fluorescence microscope and confirmed by counter staining with a monoclonal directed against a sporozoite protein. Despite the fact that transfection efficiencies are still low, this is the first step towards a stable infection method of T. parva parasites. In the long run, transfected parasites might become an alternative way to induce immunity without clinical signs.

The three most common Ixodes spp. ticks found on songbirds in Western Europe are Ixodes frontalis, I. arboricola and I. ricinus. As the latter species is a generalist, it shares several avian hosts with the two strictly ornithophilic species. Infestations of the three species can overlap in time and space, implying that tick-borne pathogens maintained by the ornithophilic ticks and their hosts could be bridged by I. ricinus to non-avian hosts. Whereas the endophilic Ixodes arboricola only occurs in cavities, I. frontalis has been collected frequently by flagging methods from understory vegetation, which is also the habitat of the field-dwelling I. ricinus. As the latter two species have rather similar morphological characteristics, they can easily be confused with each other. In this study, we present scanning electron photomicrographs of all developmental stages of I. arboricola and I. frontalis, and provide a differential diagnosis key to distinguish the ornithophilic ticks from I. ricinus. In addition, we interpreted their phylogenetic associations based on mitochondrial 16S rDNA with other Ixodes spp. ticks (I. lividus, I. turdus, I. brunneus, I. vespertilionis, I. trianguliceps, I. hexagonus, I. scapularis).

A cross-sectional serological study on cattle less than 2 years old, using an antigen ELISA for the detection of bovine cysticercosis was carried out between November 2009 and February 2010 in 10 slaughterhouses from the Catalonia region (North-Eastern Spain). Circulating antigen was detected in 23 of 2073 animals, i.e. a sero-prevalence of 1.11% (CI95%: 0.76–1.75%). The determined sero-prevalence was about 50 times higher than the prevalence obtained by visual inspection within the same period: 19 positive animals of 90,891 slaughtered animals (0.02%) in the same slaughterhouses. None of the animals with positive result in the Ag-ELISA was detected by meat inspection.

Background: In Catalonia (north-eastern Spain), Taenia saginata has been described in cattle but its occurrence in humans is unclear. Moreover, whether cattle acquired the infection in Catalonia or outside Catalonia and its economic impact have not been investigated. This study aimed to estimate the prevalence and spatial distribution of bovine cysticercosis in Catalonia (2008–2015), and the burden from T. saginata upon the animal and human sectors in Catalonia (2013–2015). Methods: Data on cattle diagnosed with cysticercosis at meat inspection were collected and analysed. Cattle movement history was used to identify the most likely place of bovine cysticercosis infection and to investigate its spatial distribution. Data on taeniosis treatment (niclosamide and praziquantel) costs and their supply in Catalonia as well as data on patients attending primary care with diagnosis of taeniosis were collected. The financial impact associated with T. saginata due to carcasses condemned and frozen, meat inspection and human taeniosis was estimated. Results: During 2008–2015, between 18 and 107 cattle were found positive for cysticercosis each year (prevalence at slaughter of 0.010%). Movement history was available for 44% of the infected cattle and in 53% of them Catalonia was identified as the place where the infection was acquired with highest probability. Two significant bovine cysticercosis clusters were detected. The number of patients diagnosed with taeniosis in primary care during the period 2013–2016 was 41–63/year. The overall economic impact of T. saginata (2013–2015) amounted to 154,903 €/year (95% CI: 113,075–196,762). Meat inspection accounted for 81.9% (95% CI: 75.8–86.2%) of the costs, followed by costs due to carcass condemnation and freezing (9.4%; 95% CI: 6.9–12.8%), and taeniosis-associated costs (8.7%; 95% CI: 6.7–11.6%). Costs due to freezing and condemnation of carcasses reached 19,442 €/year (95% CI: 17,528–21,391) (509 €/lightly infected carcass and 1,140 €/heavily infected carcass). Taeniosis-associated costs were estimated at 12,848.5 €/year (237 €/patient). Conclusions: The public health risk of T. saginata in the area seems to be low. The economic impact due to T. saginata was mainly attributed to meat inspection. The cost due to carcass condemnation and freezing was limited compared to the revenue of the beef sector. Developing and implementing risk-based surveillance is needed to lower the costs of meat inspection. Considering cattle movements might be useful in the development of such a strategy. Keywords: Taenia saginata, Bovine cysticercosis, Taeniosis, Economic impact info:eu-repo/semantics/publishedVersion