Paratuberculosis, a chronic disease affecting ruminant livestock, is caused by Mycobacterium avium subsp. paratuberculosis (MAP). It has direct and indirect economic costs, impacts animal welfare and arouses public health concerns. In a survey of 48 countries we found paratuberculosis to be very common in livestock. In about half the countries more than 20% of herds and flocks were infected with MAP. Most countries had large ruminant populations (millions), several types of farmed ruminants, multiple husbandry systems and tens of thousands of individual farms, creating challenges for disease control. In addition, numerous species of free-living wildlife were infected. Paratuberculosis was notifiable in most countries, but formal control programs were present in only 22 countries. Generally, these were the more highly developed countries with advanced veterinary services. Of the countries without a formal control program for paratuberculosis, 76% were in South and Central America, Asia and Africa while 20% were in Europe. Control programs were justified most commonly on animal health grounds, but protecting market access and public health were other factors. Prevalence reduction was the major objective in most countries, but Norway and Sweden aimed to eradicate the disease, so surveillance and response were their major objectives. Government funding was involved in about two thirds of countries, but operations tended to be funded by farmers and their organizations and not by government alone. The majority of countries (60%) had voluntary control programs. Generally, programs were supported by incentives for joining, financial compensation and/or penalties for non-participation. Performance indicators, structure, leadership, practices and tools used in control programs are also presented. Securing funding for long-term control activities was a widespread problem. Control programs were reported to be successful in 16 (73%) of the 22 countries. Recommendations are made for future control programs, including a primary goal of establishing an international code for paratuberculosis, leading to universal acknowledgment of the principles and methods of control in relation to endemic and transboundary disease. An holistic approach across all ruminant livestock industries and long-term commitment is required for control of paratuberculosis. Electronic supplementary material The online version of this article (10.1186/s12917-019-1943-4) contains supplementary material, which is available to authorized users.
SummaryIn the last decades, many regional and country-wide control programmes for Johne's disease (JD) were developed due to associated economic losses, or because of a possible association with Crohn's disease. These control programmes were often not successful, partly because management protocols were not followed, including the introduction of infected replacement cattle, because tests to identify infected animals were unreliable, and uptake by farmers was not high enough because of a perceived low return on investment. In the absence of a cure or effective commercial vaccines, control of JD is currently primarily based on herd management strategies to avoid infection of cattle and restrict within-farm and farm-to-farm transmission. Although JD control programmes have been implemented in most developed countries, lessons learned from JD prevention and control programmes are underreported. Also, JD control programmes are typically evaluated in a limited number of herds and the duration of the study is less than 5 year, making it difficult to adequately assess the efficacy of control programmes. In this manuscript, we identify the most important gaps in knowledge hampering JD prevention and control programmes, including vaccination and diagnostics. Secondly, we discuss directions that research should take to address those knowledge gaps. K E Y W O R D Scontrol, Johne's disease, Mycobacterium avium subspecies paratuberculosis, prevention
Treatment for chronic hepatitis C virus (HCV) infection is evolving from interferon (IFN)-based therapy to direct-acting antiviral (DAA) agents, yet some safety concerns have arisen involving cardiac toxicity. In this study, we sought to better understand the potential off-target toxicities of new DAAs. We retrospectively evaluated the clinical and pathological findings of the sentinel case in a phase II study that led to clinical development discontinuation for BMS-986094, an HCV nucleotide polymerase (nonstructural 5B) inhibitor. We also report on outcomes from other patients in the same study, including electrocardiogram changes, cardiovascular biomarkers, and transthoracic echocardiograms. Thirty-four patients received IFN-free BMS-986094 regimens. Six patients had left ventricular ejection fractions (LVEFs) <30%, 8 had LVEFs 30%-50%, and 11 required hospitalization for suspected cardiotoxicity. Of the patients with LVEF <50%, 6 had normalization of systolic function after a median of 20 days. T-wave inversions were the most sensitive predictor of LVEF dysfunction. B-type natriuretic peptide levels increased over time and correlated with the degree of LVEF dysfunction. Pathological analysis of cardiac tissue revealed severe myocyte damage with elongated myofibrils without gross necrosis. These findings were consistent with some results of recent primate studies that were conducted to further investigate the potential mechanisms of BMS-986094 toxicity. Conclusion: A novel nucleotide analog polymerase inhibitor developed for HCV treatment may cause a toxic cardiomyopathy. Ongoing surveillance of DAAs for cardiotoxicities may be beneficial, especially among patients at higher risk for cardiovascular disease. (HEPATOLOGY 2015;62:409-416) C hronic hepatitis C virus (HCV) infection affects more than 3% (170 million) of the world's population and is a major cause of liver cirrhosis and hepatocellular carcinoma.1 Historically, HCV treatments have included pegylated (Peg) interferon (IFN)-a and ribavirin (RBV), but these agents are limited by restricted efficacy and frequent side effects.2 New regimens comprised of direct-acting antivirals (DAAs) that target different steps in the HCV life cycle are in development and some have received breakthrough therapy status by the U.S. Food and Drug Administration (FDA). [3][4][5] One DAA in development was BMS-986094 (formerly INX-08189), a nucleotide analog HCV nonstructural 5B polymerase inhibitor.6 BMS-986094, either alone or combined with RBV, was well tolerated and exhibited dose-dependent antiviral activity in treatment-na€ ıve HCV genotype 1-infected patients over 7 days of treatment. 7 In part A of a phase II study, the combination of BMS-986094 with Peg-IFN-a and RBV appeared to be well tolerated in patients with HCV genotype 2 or 3 infection.8 After review of safety data, BMS-986094 was evaluated in IFN-free combinations with daclatasvir (DCV) and
The longstanding assumption that calves of more than 6 months of age are more resistant to Mycobacterium avium subspecies paratuberculosis (MAP) infection has recently been challenged. In order to elucidate this, a challenge experiment was performed to evaluate age- and dose-dependent susceptibility to MAP infection in dairy calves. Fifty-six calves from MAP-negative dams were randomly allocated to 10 MAP challenge groups (5 animals per group) and a negative control group (6 calves). Calves were inoculated orally on 2 consecutive days at 5 ages: 2 weeks and 3, 6, 9 or 12 months. Within each age group 5 calves received either a high – or low – dose of 5 × 109 CFU or 5 × 107 CFU, respectively. All calves were euthanized at 17 months of age. Macroscopic and histological lesions were assessed and bacterial culture was done on numerous tissue samples. Within all 5 age groups, calves were successfully infected with either dose of MAP. Calves inoculated at < 6 months usually had more culture-positive tissue locations and higher histological lesion scores. Furthermore, those infected with a high dose had more severe scores for histologic and macroscopic lesions as well as more culture-positive tissue locations compared to calves infected with a low dose. In conclusion, calves to 1 year of age were susceptible to MAP infection and a high infection dose produced more severe lesions than a low dose.
The Alberta Johne's Disease Initiative (AJDI) is a voluntary, management-based prevention and control program for Johne's disease (JD), a wasting disease in ruminants that causes substantial economic losses to the cattle industry. Despite extensive communication about the program's benefits and low cost to participating producers, approximately 35% of Alberta dairy farmers have not enrolled in the AJDI. Therefore, the objective was to identify differences between AJDI nonparticipants and participants that may influence enrollment. Standardized questionnaires were conducted in person on 163 farms not participating and 61 farms participating in the AJDI. Data collected included demographic characteristics, internal factors (e.g., attitudes and beliefs of the farmer toward JD and the AJDI), external factors (e.g., farmers' JD knowledge and on-farm goals and constraints), as well as farmers' use and influence of various information sources. Nonparticipants and participants differed in at least some aspects of all studied categories. Based on logistic regression, participating farms had larger herds, higher self-assessed knowledge of JD, better understanding of AJDI details before participation, and used their veterinarian more often to get information about new management practices and technologies when compared with nonparticipants. In contrast, nonparticipants indicated that time was a major on-farm constraint and that participation in the AJDI would take too much time. They also indicated that they preferred to wait and see how the program worked on other farms before they participated.
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