Investigation of Peste des petits ruminants virus circulation in Uttarakhand, India: a step towards global eradication of PPR by 2030.

This study was conducted to estimate the seroprevalence of Peste des petits ruminants virus (PPRV) and to determine the virus distribution in unvaccinated goats in the Pantnagar region of Uttarakhand state, India. A total of 212 serum samples from goats were collected randomly from various villages in three districts (Udhamsingh Nagar, Nainital, and Almora) of Uttarakhand. Serum samples were tested for anti-PPRV antibodies by a commercially available kit. RNA was extracted from the clinical samples and it was subjected to one-step RT-PCR, followed by virus isolation from positive samples. A total of 41 animals from various villages were found to be seropositive with a prevalence rate of 19.33%. PPR outbreaks were also reported from the Tarai region of Uttarakhand, and detection by PCR confirmed PPRV in 8 goats. Two representative swab samples were subjected to virus isolation in Vero cells and both samples showed typical cytopathic effects. The present study shows that PPRV is circulating in the Tarai region of Uttarakhand and mass vaccination for PPR must be followed in this region to increase herd immunity to a protective level. To the best of our knowledge, this is the first investigation of PPRV seroprevalence in unvaccinated goats of Uttarakhand, India.

A novel approach for estimation of anti-FMDV protective immunity generated in multiple vaccinated field animals.

In this study, forty serum samples from field buffaloes vaccinated with inactivated foot-and-mouth disease (FMD) vaccine were collected. These animals were multiple vaccinated with the above vaccine during previous years. The study was conducted to determine the actual status of the protective antibodies generated after vaccination. Initially, the serum samples were tested by Liquid phase blocking ELISA (LPBE), and only samples with titer more than 1.4 in LPBE were chosen for further analysis. These samples were tested with an in-house Gold Nanoparticle-based test for detection of anti-FMDV structural protein antibodies, in which the antibodies were detected at 10-4 dilution; this was suggestive of strong antibody titer generated post-vaccination. To test the binding affinity of these antibodies with the antigen, an avidity ELISA was developed and outcomes were expressed in terms of avidity index (AI). It was found that the avidity was low in some of the animals even after multiple vaccinations. Therefore, multiple vaccinations and strong antibody titer generation may not be the actual indicator of the protective immune response generated. We conclude that avidity ELISA can be a better approach than LPBE to measure the level of protective antibodies generated post-vaccination. Keywords: avidity ELISA; foot-and-mouth disease; post-vaccination monitoring; herd immunity; PCP-FMD.

Development and Validation of Confirmatory Foot-and-Mouth Disease Virus Antibody ELISAs to Identify Infected Animals in Vaccinated Populations.

In foot-and-mouth disease (FMD)-endemic countries, vaccination is commonly used to control the disease, whilst in FMD-free countries, vaccination is considered as an option, in addition to culling the infected and in contact animals. FMD vaccines are mainly comprised of inactivated virions and stimulate protective antibodies to virus structural proteins. In contrast, infection with FMD virus leads to virus replication and additional antibody responses to viral nonstructural proteins (NSP). Therefore, antibodies against NSPs are used to differentiate infection in vaccinated animals (DIVA), in order to estimate the prevalence of infection or its absence. Another advantage of NSP antibody tests is that they detect FMD infection in the field, irrespective of the serotypes of virus in circulation. In cattle, the NSP tests that target the 3ABC polyprotein provides the highest sensitivity, detecting up to 90% of vaccinated animals that become carriers after exposure to infection, with a specificity of around 99%. Due to insufficient diagnostic sensitivity and specificity, detection of a low level of infection is difficult at the population level with a high degree of confidence. The low level of non-specific responses can be overcome by retesting samples scored positive using a second confirmatory test, which should have at least comparable sensitivity to the first test. In this study, six in-house tests were developed incorporating different NSP antigens, and validated using bovine sera from naïve animals, field cases and experimentally vaccinated and/or infected animals. In addition, two (short and long incubation) new commercial NSP tests based on 3ABC competitive blocking ELISAs (ID Screen® FMD NSP Competition, IDvet, France) were validated in this study. The two commercial ELISAs had very similar sensitivities and specificities that were not improved by lengthening the incubation period. Several of the new in-house tests had performance characteristics that were nearly as good as the commercial ELISAs. Finally, the in-house tests were evaluated for use as confirmatory tests following screening with the PrioCHECK® and ID Screen® FMDV NS commercial kits, to assess the diagnostic performance produced by a multiple testing strategy. The in-house tests could be used in series (to confirm) or in parallel (to augment) with the PrioCHECK® and IDvet® FMDV NS commercial kits, in order to improve either the specificity or sensitivity of the overall test system, although this comes at the cost of a reduction in the counterpart (sensitivity/specificity) parameter.

Multiplexed DIVA tests for rapid detection of FMDV infection/circulation in endemic countries.

Foot-and-mouth disease (FMD) is an important transboundary disease affecting domestic and wild ruminants. Due to FMD outbreaks, the annual economic losses in endemic countries range from USD 6.1 billion to 200 billion. It also restricts the export of animals/animal by-products to FMD-free countries. FMD-free countries can experience a more severe economic loss due to the culling of infected animals as experienced by the UK in 2001 outbreaks. In endemic countries outbreaks occur mainly due to unrestricted animal movements. This creates a difficult situation in an endemic setting for controlling FMD spread to nearby areas. During post-vaccination surveillance, testing of serum samples using single test may not be able to substantiate complete freedom from infection. Thus, there is a requirement of more sensitive, robust, and accurate diagnostic tests to detect the FMDV infection/virus circulation in the vaccinated population with more accuracy than the available diagnostic tests. This can be achieved by using multiple antigens and setting the criteria for the positivity/negativity of the samples. Thus, this review emphasizes the comparison and the practical utility of the available diagnostic tests which detect antibodies against single antigen with those which detect antibodies against multiple antigens in single testing. It also emphasizes the utility of these tests in PCP-FMD (Progressive Control Pathway for Foot-and-Mouth Disease) going on in endemic countries.

Development of a rapid test for detection of foot-and-mouth disease virus specific antibodies using gold nanoparticles.

Foot and mouth disease is an economically important transboundary disease of wildlife and cloven hoofed animals including ruminants. In the absence of vaccination, detection of antibodies against structural proteins (SPs) of foot-and-mouth disease virus is an indicator of infection. In the present study, a rapid dot blot assay using gold nanoparticlees was developed for the detection of antibodies against SPs of FMDV. Commercially available FMD vaccine was used as a source of FMD antigen. After the synthesis of gold nanoparticles (GNPs), the GNP-dot blot assay was tested and was found very sensitive, as the detection of antibody was up to 10-4 of serum dilution. The GNP-dot assay was found specific as it didn't give dot with normal horse sera, fetal bovine sera and neonatal bovine calf serum samples when tested at 10-3 working dilution. When 30 serum samples from post-vaccinated buffaloes were tested at dilution of 10-3, all the samples were found positive with the variable intensity of dot. The synthesized GNPs and conjugated GNPS with antibody were characterized for their absorption limit, for their stability and for their approximate size. These characterized conjugated and non-conjugated GNPs were also analyzed by Transmission electron microscopy and Scanning electron microscopy. The GNP dot blot assay developed in this work gave promising results using vaccine antigen and can form an important tool for rapid diagnosis of FMD in FMD free countries, zones free of FMD and during last stage of FMD eradication when FMD vaccination will be withdrawn.

Incidental Findings on Bedside Ultrasonography: Detection Rate and Accuracy of Resident-Performed Examinations in the Acute Setting.

BACKGROUND: Bedside ultrasonography has become a valuable tool in the emergent care setting for triage and rapid evaluation of patients who are acutely ill. Given the cross-sectional nature of ultrasound technology, incidental findings are frequently encountered during imaging. These can impact clinical management and can pose a diagnostic dilemma for emergency medicine (EM) physicians and EM residents. PURPOSE: Our retrospective study was designed to evaluate the prevalence and detection rate of incidental findings on bedside ultrasound examinations performed by EM residents. We also sought to identify types of incidental findings encountered and the diagnostic accuracy of those findings. MATERIALS AND METHODS: Board-certified radiologists retrospectively reviewed bedside ultrasonography examinations performed and interpreted by EM residents at a large urban academic hospital. Our sample included patients who presented with traumatic and nontraumatic symptoms in the acute setting. Findings were defined as incidental only if they were previously unknown and not related to a patients presenting symptoms. The results were corroborated with electronic medical records and additional pertinent imaging when available. RESULTS: Of 196 examinations analysed, EM residents identified incidental findings on 26% of the studies, which mostly involved the renal and biliary system. Radiologist review detected incidental findings in 20.9% but was more accurate when supplemental imaging was available. EM residents detected incidental findings at rates similar to that published previously and had moderate interobserver agreement with radiologist review. Worrisome and indeterminate findings were confirmed by additional work-up and further imaging. CONCLUSION: Incidental findings are frequently encountered on bedside ultrasonography and have the potential to alter clinical management. Expertise in detection and knowledge of the presence and spectrum of these incidental findings is essential for appropriate triage, patient management, and follow-up.

Colorectal emergencies and related complications: a comprehensive imaging review--noninfectious and noninflammatory emergencies of colon.

OBJECTIVE: In this article, we illustrate imaging findings of colorectal emergencies encountered in the acute setting that are primarily noninfectious and noninflammatory in origin. Our review should enable the reader to identify and understand common colorectal emergencies and related complications in clinical practice. CONCLUSION: The diagnosis of colorectal emergencies is mostly straightforward, but it can be challenging because of the overlap of presenting symptoms and imaging findings. Therefore, it is essential to clarify the cause, narrow the differential diagnosis, and identify associated complications.

Colorectal emergencies and related complications: a comprehensive imaging review--imaging of colitis and complications.

OBJECTIVE: Colorectal emergencies are a common presentation in the emergency medicine setting and their timely diagnosis plays a crucial role in avoiding dreaded complications. The quintessential role of a radiologist lies in identifying the cause, narrowing the differential diagnosis according to imaging features, and, most importantly, identifying the associated complications. CONCLUSION: This review focuses on imaging features of the spectrum of colitides and the complications related to colitides.

Small-bowel obstruction associated with Crohn's enterolith.

One of the lesser known clinical manifestations of Crohn's disease is the formation of small-bowel enteroliths. These concretions precipitate in the setting of small-bowel stasis within the alimentary tract and are associated with a variety of disease states causing strictures or diverticula. In the acute setting, patients typically present with signs of intestinal obstruction due to stone impaction. The case we report involves a 67-year-old female with long-standing Crohn's disease who presented with a 6-day history of worsening abdominal pain. Plain abdominal radiographs demonstrated dilated bowel loops consistent with intestinal obstruction. Computed tomography revealed a 2.5-cm calcified density at the transition point in the distal ileum, and two additional stones were present in the proximal ileum. At surgery, multiple ileal strictures were found, and ileocolic resection with primary anastomoses was performed. The accurate diagnosis of enterolithiasis in the setting of Crohn's disease has significant clinical implications for management and is a harbinger of underlying bowel stenosis.