Comparison of loop-mediated isothermal amplification (LAMP) and PCR for the diagnosis of infection with Trypanosoma brucei ssp. in equids in The Gambia.

INTRODUCTION: Infection of equids with Trypanosoma brucei (T. brucei) ssp. is of socioeconomic importance across sub-Saharan Africa as the disease often progresses to cause fatal meningoencephalitis. Loop-mediated isothermal amplification (LAMP) has been developed as a cost-effective molecular diagnostic test and is potentially applicable for use in field-based laboratories. PART I: Threshold levels for T. brucei ssp. detection by LAMP were determined using whole equine blood specimens spiked with known concentrations of parasites. Results were compared to OIE antemortem gold standard of T. brucei-PCR (TBR-PCR). RESULTS I: Threshold for detection of T. brucei ssp. on extracted DNA from whole blood was 1 parasite/ml blood for LAMP and TBR-PCR, and there was excellent agreement (14/15) between tests at high (1 x 103/ml) concentrations of parasites. Detection threshold was 100 parasites/ml using LAMP on whole blood (LWB). Threshold for LWB improved to 10 parasites/ml with detergent included. Performance was excellent for LAMP at high (1 x 103/ml) concentrations of parasites (15/15, 100%) but was variable at lower concentrations. Agreement between tests was weak to moderate, with the highest for TBR-PCR and LAMP on DNA extracted from whole blood (Cohen's kappa 0.95, 95% CI 0.64-1.00). PART II: A prospective cross-sectional study of working equids meeting clinical criteria for trypanosomiasis was undertaken in The Gambia. LAMP was evaluated against subsequent TBR-PCR. RESULTS II: Whole blood samples from 321 equids in The Gambia were processed under field conditions. There was weak agreement between LWB and TBR-PCR (Cohen's kappa 0.34, 95% CI 0.19-0.49) but excellent agreement when testing CSF (100% agreement on 6 samples). CONCLUSIONS: Findings support that LAMP is comparable to PCR when used on CSF samples in the field, an important tool for clinical decision making. Results suggest repeatability is low in animals with low parasitaemia. Negative samples should be interpreted in the context of clinical presentation.

Parasitic infections and resource economy of Danish Iron Age settlement through ancient DNA sequencing.

In this study, we screen archaeological soil samples by microscopy and analyse the samples by next generation sequencing to obtain results with parasites at species level and untargeted findings of plant and animal DNA. Three separate sediment layers of an ancient man-made pond in Hoby, Denmark, ranging from 100 BC to 200 AD, were analysed by microscopy for presence of intestinal worm eggs and DNA analysis were performed to identify intestinal worms and dietary components. Ancient DNA of parasites, domestic animals and edible plants revealed a change in use of the pond over time reflecting the household practice in the adjacent Iron Age settlement. The most abundant parasite found belonged to the Ascaris genus, which was not possible to type at species level. For all sediment layers the presence of eggs of the human whipworm Trichuris trichiura and the beef tapeworm Taenia saginata suggests continuous disposal of human faeces in the pond. Moreover, the continuous findings of T. saginata further imply beef consumption and may suggest that cattle were living in the immediate surrounding of the site throughout the period. Findings of additional host-specific parasites suggest fluctuating presence of other domestic animals over time: Trichuris suis (pig), Parascaris univalens (horse), Taenia hydatigena (dog and sheep). Likewise, alternating occurrence of aDNA of edible plants may suggest changes in agricultural practices. Moreover, the composition of aDNA of parasites, plants and vertebrates suggests a significant change in the use of the ancient pond over a period of three centuries.

Management practices associated with strongylid parasite prevalence on horse farms in rural counties of Kentucky.

Anthelmintic resistance among cyathostomin parasites is a wide-spread problem. The parasite control guidelines written by the American Association of Equine Practitioners (AAEP) encourages the preservation of anthelmintic efficacy by reducing treatment frequency, using targeted deworming, and implementing environmental management practices. While there is knowledge regarding parasite management practices of affluent horse farms in the United States, surveys rarely explore the rural and underserved regions. The purpose of this study was to observe the management practices of horse farms in rural regions Kentucky, including working Amish farms, and determine factors associated with strongyle prevalence. A total of 160 horses among 38 owners from 28 different farms were enrolled in this study. A questionnaire survey regarding equine information, farm management, and deworming history was performed with each owner. Fecal samples were collected to determine fecal egg counts, perform coprocultures for subsequent strongyle larvae identification, and Strongylus vulgaris specific PCR. Serum samples were collected for the S. vulgaris antibody specific ELISA. The mean number of deworming treatments given in the last year was 2.1 with a 95% confidence interval of 1.9-2.3 with ivermectin being the most common active used. Statistical analysis showed horses treated within the last three months with a macrocylic lactone (ML) drug had significantly lower egg counts than horses treated with a ML 7-9 months ago (p = .0005). Despite the AAEP recommendations to reduce the overall number of treatments by using a surveillance-based approach and to no longer rotate treatments, only 17 horses reportedly had a fecal sample submitted for a fecal egg count and 65 horses were dewormed in a rotational manner. Horses whose owners utilized an informative deworming source (i.e., veterinarian, internet, magazine, local feed store) also had significantly lower counts (p = .0026). All coprocultures were negative for S. vulgaris while five horses were PCR positive. Interestingly, 95 horses tested ELISA positive for S. vulgaris. The strongyle egg counts of the working Amish horses were not significantly different from the other horses in this study and deworming practices including the use of efficacious drugs and low treatment frequencies were in accordance with the AAEP guidelines. This study was the first to summarize deworming management practices of rural regions in Kentucky, including a working Amish community. Overall, horse owners employed deworming practices recommended by the AAEP, however rotational deworming is still commonly implemented and fecal egg counts are rarely used.

Strongyle infections and parasitic control strategies in German horses - a risk assessment.

BACKGROUND: As a consequence of the increasing levels of anthelmintic resistance in cyathostomes, new strategies for equine parasite control are being implemented. To assess the potential risks of these, the occurrence of strongyles was evaluated in a group of 1887 horses. The distribution of fecal egg counts (FECs), the frequency of anthelmintic drug use, and the deworming intervals were also analyzed. Between June 2012 and May 2013, 1887 fecal samples from either selectively or strategically dewormed horses were collected at 195 horse farms all over Germany and analyzed quantitatively with a modified McMaster technique. All samples with FEC ≥20 eggs per gram (EPG) were subjected to coproculture to generate third-stage larvae (LIII) for species differentiation. RESULTS: Egg counts were below the limit of detection (20 EPG) in 1046 (55.4%) samples and above it in 841 (44.6%) samples. Strongylus vulgaris larvae were identified in two of the 841 positive samples. Infections with cyathostomes were found on every farm. The most frequently applied anthelmintic was ivermectin (788/50.8%), followed by pyrantel (336/21.6%). The mean time since last treatment was 6.3 months. High-egg-shedding (>500 EPG) strategically dewormed horses (183/1357) were treated, on average, three times/year. The planned treatment date was already exceeded by 72.5% of the high egg-shedders and by 58.1% of the moderate (200-500 EPG) and low egg-shedders (20-199 EPG). CONCLUSIONS: S. vulgaris seems to be rare in Germany and no difference in its frequency has yet been found between selectively treated horses and horses receiving treatment in strategic intervals. However, inconsistent parasite control has been observed. Therefore, to minimize the risks for disease, consistent and efficient parasite control should be implemented.

A questionnaire survey on helminth control on horse farms in Brandenburg, Germany and the assessment of risks caused by different kinds of management.

Control strategies for horse helminths are controversially discussed, and no ideal strategy exists. Presently, the spreading of anthelmintic resistance against all three classes of anthelmintics is of special concern. Advice on how to slow the development of anthelmintic resistance does not seem to have reached the majority of horse owners yet. In our study, we wanted to capture the current standard of helminth control and to analyse the effectiveness of these control strategies. Seven hundred horse farms in Brandenburg, Germany were sent a questionnaire in June/July 2006 asking various questions on farm structure and practices of helminth control. Two hundred thirty-five farms (33.6%) with 6,007 horses in total returned the questionnaire. The number of horses held on each farm varied from 1 to 320. From those returned questionnaires, a random sample of 126 horse farms and 1,407 horses was selected for faecal examination from August to December 2006. The questionnaire results from these farms were correlated with results from the faecal examination to perform risk analysis via multivariate regression. For each farm, results from faecal examination were summarized in index values. Risk was defined as an over-average level of strongyle egg shedding. Risk factors as established by multivariate regression analyses were integrated into three models. Rare deworming and infrequent cleaning of stables were identified as significant risk factors throughout all three models. Additional risk factors could be identified with respect to individual models: elevated percentage of young horses on a farm, not using macrocyclic lactones in the deworming process and dosing anthelmintics on the basis of weight and height. Pasture hygiene did not lead to significant risk reduction, indicating that such measures are inadequately performed on many farms. The questionnaire on its own gave us an insight into control strategies throughout a representative scope of farms in Brandenburg, Germany: faeces were collected from pasture on 22% of horse farms, 79% cleaned out the stables daily. A number of other measures were employed. With respect to anthelmintic use, 21% of the farms stated to use results from faecal examination as a criterion for deworming. We could also identify the most common deworming frequencies, with adult horses being dewormed two times a year (46% of farms) and foals being dewormed four times a year (35% of farms). The frequency ranged from 1 to 7 and 2 to 12 times, respectively.

Cystic echinococcosis and the Mediterranean Region: a long-lasting association.

Cystic echinococcosis (CE) is an important zoonosis in Italy and in the whole Mediterranean Region, as confirmed by the work by Ettore Biocca, whose contributions to the subject are reported in a summarised annex to the bibliography. The contribution to the understanding and control of CE are presented, with special emphasis on the socio-economic impact, on factors affecting the maintenance of CE in the Mediterranean Region, on the epidemiological situation and control measures, on the present status of epidemiological surveillance, on the control problems in normal and emergency situations, on health education and training. Also, the justifications of combined control programmes are discussed, which may be applied only in situations of peace and well-being.

Trypanosoma evansi control and horse mortality in the Brazilian Pantanal

The impact of three treatment strategies for Trypanosoma evansi control on horse mortality in the Brazilian Pantanal based on four size categories of cattle ranches is explored. The region's 49,000 horses are indispensable to traditional extensive cattle ranching and T. evansi kills horses. About 13 percent of these horses would be lost, annually, due to T. evansi if no control were undertaken. One preventive and two curative treatment strategies are financially justifiable in the Pantanal. The best available technology for the treatment of T. evansi from a horse mortality perspective is the preventive strategy, which spares 6,462 horses, annually. The year-round cure spares 5,783 horses, and the seasonal cure saves 5,204 horses on a regional basis relative to no control strategy. Regardless of the strategy adopted, 39 percent of the costs or benefits fall to the largest ranches, while 18 percent fall to the smallest ranches

[Evaluation of the medical and social cost of 2 trichinosis outbreaks in France in 1985]. / Evaluation du coût médical et social de deux épidémies de trichinose survenues en France en 1985.

Two outbreaks of trichinosis occurred in France in 1985 and 1,073 cases were identified. These outbreaks were related to the consumption of parasitized horse meat. The medical and social cost of these outbreaks have been estimated with a sample of 92 patients. The average medical cost was 1,200 FF by outpatient and 17,300 FF by hospitalized patient. For the 1,073 cases, the total cost of these 2 outbreaks is estimated to have been between 7 and 11 millions FF. Of this sum, the hospitalization fees exceeded 51% and the social cost was 36% (loss of productivity). Since October 1985, a decree of the French Ministry of Agriculture has imposed a parasitologic test on all horse carcasses slaughtered in France or imported. This examination costs under 5 FF (under $1) per carcass. This study shows that the systematic examination for trichinosis of horse meat carcasses should be continued and that more sensitive screening methods should be developed.