Spatio-temporal variations and age effect on Toxoplasma gondii seroprevalence in seals from the Canadian Arctic

Parasitology ◽  
2011 ◽  
Vol 138 (11) ◽  
pp. 1362-1368 ◽  
Author(s):  
A. SIMON ◽  
M. CHAMBELLANT ◽  
B. J. WARD ◽  
M. SIMARD ◽  
J. F. PROULX ◽  
...  

SUMMARYToxoplasmosis is a significant public health threat for Inuit in the Canadian Arctic. This study aimed to investigate arctic seals as a possible food-borne source of infection. Blood samples collected from 828 seals in 7 Canadian Arctic communities from 1999 to 2006 were tested for Toxoplasma gondii antibodies using a direct agglutination test. Polymerase chain reaction (PCR) was used to detect T. gondii DNA in tissues of a subsample of seals. Associations between seal age, sex, species, diet, community and year of capture, and serological test results were investigated by logistic regression. Overall seroprevalence was 10·4% (86/828). All tissues tested were negative by PCR. In ringed seals, seroprevalence was significantly higher in juveniles than in adults (odds ratio=2·44). Overall, seroprevalence varied amongst communities (P=0·0119) and by capture year (P=0·0001). Our study supports the hypothesis that consumption of raw seal meat is a significant source of infection for Inuit. This work raises many questions about the mechanism of transfer of this terrestrial parasite to the marine environment, the preponderance of infection in younger animals and the natural course of infection in seals. Further studies to address these questions are essential to fully understand the health risks for Inuit communities.

1998 ◽  
Vol 121 (3) ◽  
pp. 615-621 ◽  
Author(s):  
U. D. PARASHAR ◽  
L. DOW ◽  
R. L. FANKHAUSER ◽  
C. D. HUMPHREY ◽  
J. MILLER ◽  
...  

Although food handlers are often implicated as the source of infection in outbreaks of food-borne viral gastroenteritis, little is known about the timing of infectivity in relation to illness. We investigated a gastroenteritis outbreak among employees of a manufacturing company and found an association (RR=14·1, 95% CI=2·0–97·3) between disease and eating sandwiches prepared by 6 food handlers, 1 of whom reported gastroenteritis which had subsided 4 days earlier. Norwalk-like viruses were detected by electron microscopy or reverse transcriptase-polymerase chain reaction (RT-PCR) in stool specimens from several company employees, the sick food handler whose specimen was obtained 10 days after resolution of illness, and an asymptomatic food handler. All RT-PCR product sequences were identical, suggesting a common source of infection. These data support observations from recent volunteer studies that current recommendations to exclude food handlers from work for 48–72 h after recovery from illness may not always prevent transmission of Norwalk-like viruses because virus can be shed up to 10 days after illness or while exhibiting no symptoms.


PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0239916
Author(s):  
Juscilânia Furtado Araújo ◽  
Alice Andrioli ◽  
Raymundo Rizaldo Pinheiro ◽  
Lucia Helena Sider ◽  
Ana Lídia Madeira de Sousa ◽  
...  

This study aimed to evaluate by means of Nested Polymerase Chain Reaction (nPCR), co-cultivation and sequencing, with genetic comparison between strains (mother/newborn), the occurrence of vertical transmission of Small Ruminant Lentiviruses (SRLV) from naturally occurring nannies infected for their offspring. For the detection of SRLV seropositive progenitors, blood was collected from 42 nannies in the final third of gestation in tubes with and without anticoagulant. The diagnostic tests used were Western Blot (WB) and nPCR. During the period of birth, the same blood collection procedure was performed on 73 newborns at zero hours of birth, with the same diagnostic tests. Seventeen blood samples from seven-day-old kids, proven positive for SRLV by nPCR, chosen at random, were subjected to coculture in goat synovial membrane (GSM) cells for 105 days. The pro-viral DNA extracted from the cell supernatant from the coculture was subjected to nPCR. For DNA sequencing from the nPCR products, nine positive samples were chosen at random, four nannies with their respective offspring, also positive. Each sample was performed in triplicate, thus generating 27 nPCR products of which only 19 were suitable for analysis. Among the 42 pregnant goats, in 50% (21/42) pro-viral DNA was detected by nPCR, while in the WB, only 7.14% (3/42) presented antibodies against SRLV. Regarding neonates, of the 73 kids, 34 (46.57%) were positive for the virus, using the nPCR technique, while in the serological test (WB), three positive animals (4.10%) were observed. The coculture of the 17 samples with a positive result in the nPCR was confirmed in viral isolation by amplification of the SRLV pro-viral DNA. When aligned, the pro-viral DNA sequences (nannies and their respective offspring) presented homology in relation to the standard strain CAEV Co. It was concluded that the transmission of SRLV through intrauterine route was potentially the source of infection in the newborn goats.


2020 ◽  
Vol 10 (3) ◽  
pp. 178-185
Author(s):  
Anja Dörschug ◽  
Julian Schwanbeck ◽  
Andreas Hahn ◽  
Anke Hillebrecht ◽  
Sabine Blaschke ◽  
...  

AbstractIntroductionTo efficiently monitor the COVID-19 pandemic for surveillance purposes, reliable serological rapid diagnostic tests (RDTs) are desirable for settings where well-established high-throughput bench-top solutions are not available. Here, we have evaluated such an RDT.MethodsWe have assessed the Xiamen AmonMed Biotechnology COVID-19 IgM/IgG test kit (Colloidal gold) and the EUROIMMUN benchtop assay with serum samples from patients with polymerase chain reaction (PCR)-confirmed COVID-19 disease. Samples from patients with Epstein-Barr-virus (EBV) infection and blood donors were used for specificity testing.ResultsFor the colloid gold rapid test and the EUROIMMUN assay, the study indicated overall sensitivity of 15.2% and 67.4%, respectively, while specificity of 99.0% and 97.9% with the blood donor sera, as well as 100% and 96.8% with the EBV-patients, were observed, respectively. An association of the time period between positive PCR results and serum acquisition with serological test positivity could be observed for the immunologlobulin G subclass of the EUROIMMUN assay only.ConclusionsIn spite of acceptable specificity of the assessed RDT, the detected poor sensitivity leaves room for improvement. The test results remain difficult to interpret and therefore the RDT can currently not be recommended for routine diagnostic or surveillance use.


2015 ◽  
Vol 2 (2) ◽  
pp. 26-31 ◽  
Author(s):  
A. Paliy ◽  
A. Zavgorodniy ◽  
B. Stegniy ◽  
A. Gerilovych

Due to the absence of elaborated effi cient means for specifi c prevention of bovine tuberculosis, it is ex- tremely important to detect and eliminate the source of infection and to take veterinary and sanitary preven- tive measures. Here the critical role is attributed to disinfection, which breaks the epizootic chain due to the elimination of pathogenic microorganisms in the environment and involves the application of disinfectants of different chemical groups. Aim. To study the tuberculocidal properties of new disinfectants DZPT-2 and FAG against atypical mycobacteria Mycobacterium fortitum and a TB agent Mycobacterium bovis. Methods. The bacteriological and molecular-genetic methods were used. Results. It was determined that DZPT-2 prepara- tion has bactericidal effect on M. fortuitum when used in the concentration of 2.0 % of the active ingredient (AI) when exposed for 5–24 h, while disinfectant FAG has a bactericidal effect in the concentration of 2.0 % when exposed for 24 h. Disinfectant DZPT-2 in the concentration of 2.0 % of the AI, when exposed for 5–24 h, and FAG preparation in the concentration of 2.0 %, when exposed for 24 h, and with the norm of consump- tion rate of 1 cubic decimeter per 1 square meter disinfect the test-objects (batiste, wood, glazed tile, metal, glass), contaminated with the TB agent M. bovis. Conclusions. Disinfecting preparations of DZPT-2 in the concentration of 2.0 % of AI when exposed for 5 h and FAG in the concentration of 2.0 % when exposed for 24 h may be used in the complex of veterinary and sanitary measures to prevent and control TB of farm ani- mals. The possibility of using the polymerase chain reaction as an additional method of estimating tuberculo- cide activity of disinfectants was proven.


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