| 2020 | Validation of a Novel Commercial ELISA Test for the Detection of Antibodies against . | Pathogens | Q fever is a zoonosis caused by , a Gram-negative pathogen with a complex life cycle and a high impact on public and animal health all over the world. The symptoms are indistinguishable from those belonging to other diseases, and the disease could be symptomless. For these reasons, reliable laboratory tests are essential for an accurate diagnosis. The aim of this study was to validate a novel enzyme-linked immunosorbent assay (ELISA) test, named the Chorus Q Fever Phase II IgG and IgM Kit (DIESSE, Diagnostica Senese S.p.A), which is performed by an instrument named Chorus, a new device in medical diagnostics. This diagnostic test is employed for the detection of antibodies against Phase II antigens in acute disease. Our validation protocol was performed according to the Italian Accreditation Body (ACCREDIA) (Regulation UNI CEI EN ISO/IEC 17025:2018 and 17043:2010), OIE (World Organization for Animal Health), and Statement for Reporting Studies of Diagnostic Accuracy (STARD). Operator performance was evaluated along with the analytical specificity and sensitivity (ASp and ASe) and diagnostic accuracy of the kit, with parameters such as diagnostic specificity and sensitivity (DSp and DSe) and positive and negative predictive values (PPV and NPV), in addition to the repeatability. According to the evaluated parameters, the diagnostic ELISA test was shown to be suitable for validation and commercialization as a screening method in human sera and a valid support for clinical diagnostics. |
| 2020 | Evaluation of the diagnostic accuracy of an affordable rapid diagnostic test for African Swine Fever antigen detection in Lao People's Democratic Republic. | J Virol Methods | African Swine Fever (ASF) is a transboundary animal disease of pigs and wild suids that appeared in Lao People's Democratic Republic (Lao PDR) in mid-2019, having spread across China and Vietnam in the months prior. Despite the scale of the Asian ASF pandemic and the availability of pen-side rapid diagnostic tests (RDT) on the market, few locally produced and easily available ASF RDTs have been evaluated for diagnostic accuracy. In this study, an ASF antigen detection RDT from Shenzhen Lvshiyuan Biotechnology Co. Ltd was evaluated using clinical field samples submitted to the National Animal Health Laboratory (NAHL) from ASF suspect cases between June and December 2019 in Lao PDR. Positive (n = 57) and negative (n = 50) samples of whole blood, serum and haemolysed serum were assessed by RDT and PCR, with the latter used as the gold standard reference comparator. Overall the RDT had a diagnostic sensitivity (DSe) of 65 %, 95 % CI [51-77] and diagnostic specificity (DSp) of 76 %, 95 % CI [62-87]. The RDT demonstrated improved performance on samples with lower PCR cycle threshold (ct) values with each additional cycle reducing the odds of the RDT returning a positive by 17 % relative to the previous cycle, 95 % CI [8 %-28 %] (P < 0.01). While this test shows promise for field application, complete validation of diagnostic accuracy requires a larger sample size. |
| 2019 | Development and validation of a pen side test for Rift Valley fever. | PLoS Negl Trop Dis | Rift Valley fever (RVF) is one of the main vector borne zoonotic diseases that affects a wide range of ruminants and human beings in Africa and the Arabian Peninsula. A rapid and specific test for RVF diagnosis at the site of a suspected outbreak is crucial for the implementation of control measures.A first-line lateral flow immunochromatographic strip test (LFT) was developed for the detection of the nucleoprotein (N) of the RVF virus (RVFV). Its diagnostic performance characteristics were evaluated using reference stocks isolates recovered from different hosts and in geographic regions mimicking clinical specimens and from known RVF negative serum samples. A high level of diagnostic accuracy (DSe (35/35), DSp (167/169)) was observed, including the absence of cross-reactivity with viruses belonging to different genera.The fact no specialized reagents and laboratory equipment are needed, make this assay a valuable, first-line diagnostic tool in resource-poor diagnostic territories for on-site RVFV detection, however the staff require training. |
| 2019 | Validation of an indirect immunofluorescence assay (IFA) for the detection of IgG antibodies against Coxiella burnetii in bovine serum. | Prev Vet Med | There is limited knowledge of the true prevalence and distribution of coxiellosis in dairy and beef cattle populations in Australia. For this to occur, apparent prevalence estimates need to be reliably adjusted, accounting for diagnostic sensitivity (DSe) and diagnostic specificity (DSp) of the test used. However, there are few tests available with known diagnostic specifications suitable to inform screening and surveillance activities in the Australian context. We initially modified and optimised a human indirect immunofluorescence assay (IFA) test for the detection of IgG antibodies against phase I and/or phase II Coxiella burnetii in bovine sera and determined an optimal screening dilution cut-off to be 1:160. Direct comparison of the modified IFA with the commercial IDEXX enzyme-linked immunosorbent assay (ELISA) kit (Q Fever Ab Test IDEXX Laboratories, United States of America) was performed by testing 458 serum samples from four distinct cattle populations across the east coast of Australia and New Zealand. Cross classified test results were then analysed using Bayesian latent class modelling, to validate the tests in the absence of a gold standard reference test. Results from this analysis indicate that the IFA, at a 1:160 serum dilution, has an estimated DSe of 73.6% (95% Credible Interval (CrI) 61.1, 85.9) and DSp of 98.2% (95% CrI 95.1, 99.7). The commercial IDEXX ELISA kit was found to have a higher DSe of 87.9% (95% CrI 73.9, 96.4) and similar DSp of 97.7% (95% CrI 93.2, 99.7). Evaluation of the diagnostic performance of the IFA and ELISA methods, specifically for use in cattle will enable more accurate interpretation of prevalence estimates of C. burnetii exposure to be reported for cattle in Australia and other countries. |
| 2014 | Histoplasmosis outbreak associated with the renovation of an old house - Quebec, Canada, 2013. | MMWR Morb Mortal Wkly Rep | On May 19, 2013, a consulting physician contacted the Laurentian Regional Department of Public Health (Direction de santé publique des Laurentides [DSP]) in Quebec, Canada, to report that two masons employed by the same company to do demolition work were experiencing cough and dyspnea accompanied by fever. Other workers also were said to be ill. DSP initiated a joint infectious disease, environmental health, and occupational health investigation to determine the extent and cause of the outbreak. The investigation identified 14 persons with respiratory symptoms among 30 potentially exposed persons. A strong correlation was found between exposure to demolition dust containing bat or bird droppings and a diagnosis of histoplasmosis. Temporary suspension of construction work at the demolition site in Saint-Eustache, Quebec, northwest from Montreal, and transport of the old masonry elements to a secure site for burial were ordered, and information about the disease was provided to workers and residents. To prevent future outbreaks, recommendations included disinfection of any contaminated material, disposal of waste material with proper control of aerosolized dust, and mandatory use of personal protective equipment such as gloves, protective clothing, and adequate respirators. |
| 2013 | Food-borne disease outbreak of diarrhetic shellfish poisoning due to toxic mussel consumption: the first recorded outbreak in china. | PLoS One | This investigation was undertaken in response to an outbreak of suspected shellfish poisoning in Zhejiang Province, China. The objectives of this project were to confirm the outbreak and to identify the aetiology, source and mode of transmission.A probable case was defined as an individual with diarrhea (≥3 times/day) plus at least one of the following symptoms: fever (≥37.5°C), vomiting, or abdominal pain after consuming seafood between May 23(rd) and May 28(th), 2011. Using a case-control study design, we compared exposures to suspected seafood items and cooking methods between 61 probable cases and 61 controls.Over 220 suspected or probable cases of diarrhetic shellfish poisoning (DSP) were identified (incidence of 18 cases per 100,000). The case control study revealed that 100% of cases and 18% of controls had eaten mussels during the exposure period (OR = ∞, χ(2) = 84.72,P = 0.000). The number of mussels consumed was related to DSP risk (P = 0.004, χ2 test for trend). Consumption of other seafood items was not associated with disease. The frequency of diarrhea and vomiting were positively correlated with the number of mussels consumed (r = 0.424 and r = 0.562, respectively). The frequency of vomiting and the incubation period were significantly correlated with the total time the mussels were boiled (r = 0.594 and r = -0.336, respectively). Mussels from 3 food markets and one family contained Okadaic acid (OA) and Dinophysistoxin-1 (DTX-1).This outbreak was attributed to the consumption of mussels contaminated by DSP-toxins (OA and DTX-1) which are produced by different species of dinoflagellates (toxic microalgae) from the genus Dinophysis or Prorocentrum. Suspension of mussel sales and early public announcements were highly effective in controlling the outbreak, although oversight of seafood quality should be a priority to prevent future contamination and outbreaks. |
| 1996 | [Epidemiology of toxic and infectious risk related to shellfish consumption]. | Rev Epidemiol Sante Publique | For feeding purposes shellfish filter large amounts of water but also concentrate infectious agents and toxins that are present in the marine environment either naturally or because of pollution. Thus, the consumption of raw or undercooked shellfish is a substantial source of foodborne poisoning, mostly epidemic and sometimes sporadic. Most of shellfish-borne infectious diseases are linked to fecal contamination of the marine environment; they include: thyphoid fever, salmonellosis, shigellosis, campylobacteriosis, cholera, Norwalk or Norwalk-like gastroenteritis and hepatitis A. In warm climates, shellfish contains naturally occurring halopilic Vibrios and may cause severe sporadic infections (septicemias) among very susceptible consumers (immunocompromised). Shellfish also causes outbreaks of paralytic shellfish poisoning (PSP) and diarrheic shellfish poisoning (DSP) when they are contaminated by toxins produced when Dinophisis, a marine plancton, proliferates. Chemical compounds (heavy metals and organic toxins) that are dumped in the environment (soil, air, and water) also reach shellfish harvesting waters where they are cocentrated. Although acute or chronic effects of the chemical contamination of shellfish have not been clearly documented, the cadmium pollution of some shellfish harvesting waters raises a serious problem. Since it is impossible to prevent completely the contamination of coastal waters by any of the agents cited above, the prevention of shellfish-borne diseases requires monitoring of the marine environment and shellfish flesh (coliform count, Dinophysis toxins, heavy metals...). This surveillance allows the classification of growing areas as suitable or not for harvesting and distribution of shellfish. However, this surveillance is not always sensitive enough. Indicators of fecal pollution are particularly not reliable for shellfish viral contamination. A better knowledge of marine biology, the limitation of coastal waters pollution, improved surveillance, the development of more sensitive indicators, the responsabilisation of the industry and the information of the public on the health hazards associated with shellfish consumption are the key issues for the improvement of shellfish-borne disease prevention. |
| 1995 | [Analysis on the health status of residents from Diseases Surveillance Points in Gansu Province]. | Zhonghua Liu Xing Bing Xue Za Zhi | We have surveyed a population size of 6633315 from Diseases Surveillance Points (DSP) system in Gansu province for the last eleven years. The annual birth rate was 18.20% with an annual standard mortality rate 545.80/10(5). The annual standard mortality for male and female were 607.53/10(5) and 483.29/10(5) respectively. The major causes of death were Respiratory system diseases, Cardiovascular diseases, Neoplasms, Injuries, Digestive system diseases, Pediatric diseases, Infectious diseases in sequence. In eleven years, there seemed to be a rising trend in the mortalities of following diseases as: Cerebrovascular diseases, Ischemic heart diseases, Rheumatic fever and heart disease, Lung Cancer, Liver Cancer, Cancer of the Esophagus, Intestinal cancer, Cervical cancer, Injury, Congenital abnomalities, to different degrees. However, an obvious descending trend on the morbidity and mortality of infectious diseases was moticed. The average life expectancy was 71.05 years in DSP, with male 69.57 years, and female 72.72 years. Diseases with higher PYLL were Injuries, Neoplasms, Respiratory system diseases and the like. Data suggested not only the prevention andcontrol of infectious diseases, but also the surveillance of injuries and the prevention and control of chronic diseases should be strengthened. |