scholarly journals Brucellae through the food chain : the role of sheep, goats and springbok (Antidorcus marsupialis) as sources of human infections in Namibia

2011 ◽  
Vol 82 (4) ◽  
Author(s):  
K. Magwedere ◽  
A. Bishi ◽  
G. Tjipura-Zaire ◽  
G. Eberle ◽  
Y. Hemberger ◽  
...  
Keyword(s):  
Goat Milk ◽  
Raw Milk ◽  
Cross Reactivity ◽  
Control Programme ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Brucellosis ◽  
Serum Samples ◽  
Clinically Normal ◽  
Source Of Infection ◽  
Human Infections

A confirmed case of human brucellosis motivated an investigation into the potential source of infection in Namibia. Since domestic animals are principal sources of Brucella infection in humans, 1692 serum samples were screened from sheep, goats and cattle from 4 presumably at-risk farms and 900 springbok (Antidorcas marsupialis) serum samples from 29 mixed farming units for Brucella antibodies by the Rose-Bengal test (RBT) and positive cases confirmed by complement fixation test (CFT). To assess the prevalence of human brucellosis, 137 abattoir employees were tested for Brucella antibodies using the standard tube agglutination test (STAT) and by enzyme linked immunosorbent assay (ELISA). Cattle and sheep from all 4 farms were negative by RBT and CFT but 2 of the 4 farms (Ba and C) had 26/42 and 12/285 seropositive goats, respectively. Post mortem examination of seropositive goats revealed no gross pathological lesions typical of brucellosis except enlarged mesenteric and iliac lymph nodes seen in a single buck. Culture for brucellae from organs of seropositive animals was negative. None of the wildlife sera tested positive by either RBT or CFT. Interviews revealed that besides the case that prompted the investigation, a family and another person from other farms with confirmed brucellosis shared a common history of consumption of unpasteurised goat milk, home-made goat cheese and coffee with raw milk and prior contact with goats, suggesting goats as the likely source of infection. All 137 abattoir employees tested negative by STAT, but 3 were positive by ELISA. The 3 abattoir workers were clinically normal and lacked historical connections with clinical cases. Although goats are often associated with B. melitensis, these studies could not explicitly implicate this species owing to cross-reactivity with B. abortus, which can also infect goats. Nevertheless, these data reinforce the need for a better National Control Programme for brucellosis in Namibia.

scholarly journals Seroprevalence and Associated Risk Factors of Brucellosis in Livestock and Residents of New Valley Governorate, Egypt

2020 ◽  
pp. 531-539
Author(s):  
Mohamed Said Diab ◽  
Sherif Abd Allah Zidan ◽  
Nermin Abdalla A. Hassan ◽  
Haitham Elaadli ◽  
Ahmed Mohamed Bayoumi
Keyword(s):  
Risk Factors ◽  
Raw Milk ◽  
Cross Sectional Study ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Brucellosis ◽  
Human Occupation ◽  
Serum Samples ◽  
Cross Sectional ◽  
Significant Difference ◽  
Associated Risk Factors

Brucellosis is a worldwide zoonotic disease which is now considered endemic in most parts of Egypt. A cross-sectional study was carried out from December 2018 to February 2020 to investigate the seroprevalence of brucellosis in humans and livestock residing in two regions located in New Valley Governorate, Egypt. A total of 1254 animals (673 cattle, 348 sheep, and 233 goats) and 523 human serum samples were examined for brucellosis using Rose Bengal test (RBT) and then randomly selected sera (15 from cattle, 7 from sheep, 3 from goats, and 45 from humans) were further analyzed by complement fixation test, enzyme-linked immunosorbent assay to compare and detect the sensitivity and specificity of RBT. The prevalence of brucellosis was 0% in cattle, sheep, and goats while it was 23.9% in humans using RBT. Concerning humans, there was a higher percentage of infection in EL Kharga (33.6%). The prevalence of this infection was also at a higher level among individuals aged above 40 years (28.57%). Furthermore, men (26.11%) were more inclined to be inflicted, compared to women (22.5%) with no significant difference. Considering the human occupation, abattoir workers were the most predominant group of people at risk (33.3%), followed by farmers (31.25%) and animal keepers (20.6%) while the lowest prevalence was demonstrated in the housewives where the prevalence was 18.8 %. As a result, risk factors of the age range, locality, time of infection, contact with animals, and occupational groups could significantly affect the prevalence of human brucellosis in the New Valley Governorate. In conclusion, brucellosis is an alarming problem among residents of the New Valley Governorate. Thus, reducing the prevalence in humans and animals in the region of study may include restriction of the marketing the raw milk and enhancing public health awareness.

scholarly journals Dogs as Sentinels for Flavivirus Exposure in Urban, Peri-Urban and Rural Hanoi, Vietnam

Viruses ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 507
Author(s):  
Long Pham-Thanh ◽  
Thang Nguyen-Tien ◽  
Ulf Magnusson ◽  
Vuong Bui-Nghia ◽  
Anh Bui-Ngoc ◽  
...  
Keyword(s):  
Mosquito Control ◽  
Risk Mitigation ◽  
Significant Risk ◽  
Cross Sectional Study ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Cross Sectional ◽  
Major Health ◽  
Household Level

Diseases caused by flaviviruses, including dengue fever and Japanese encephalitis, are major health problems in Vietnam. This cross-sectional study explored the feasibility of domestic dogs as sentinels to better understand risks of mosquito-borne diseases in Hanoi city. A total of 475 dogs serum samples from 221 households in six districts of Hanoi were analyzed by a competitive enzyme-linked immunosorbent assay (cELISA) for antibodies to the pr-E protein of West Nile virus and other flaviviruses due to cross-reactivity. The overall flavivirus seroprevalence in the dog population was 70.7% (95% CI = 66.4–74.8%). At the animal level, significant associations between seropositive dogs and district location, age, breed and keeping practice were determined. At the household level, the major risk factors were rural and peri-urban locations, presence of pigs, coil burning and households without mosquito-borne disease experience (p < 0.05). Mosquito control by using larvicides or electric traps could lower seropositivity, but other measures did not contribute to significant risk mitigation of flavivirus exposure in dogs. These results will support better control of mosquito-borne diseases in Hanoi, and they indicate that dogs can be used as sentinels for flavivirus exposure.

scholarly journals Development of a Smartphone-Based Nanozyme-Linked Immunosorbent Assay for Quantitative Detection of SARS-CoV-2 Nucleocapsid Phosphoprotein in Blood

2021 ◽  
Vol 12 ◽  
Author(s):  
Bochao Liu ◽  
Ze Wu ◽  
Chaolan Liang ◽  
Jinhui Lu ◽  
Jinfeng Li ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Cross Reactivity ◽  
Quantitative Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Primary Screening ◽  
Global Pandemic ◽  
Novel Coronavirus ◽  
Acid Test ◽  
Control Samples

Since December 2019, a novel coronavirus (SARS-CoV-2) has resulted in a global pandemic of coronavirus disease (COVID-19). Although viral nucleic acid test (NAT) has been applied predominantly to detect SARS-CoV-2 RNA for confirmation diagnosis of COVID-19, an urgent need for alternative, rapid, and sensitive immunoassays is required for primary screening of virus. In this study, we developed a smartphone-based nanozyme-linked immunosorbent assay (SP-NLISA) for detecting the specific nucleocapsid phosphoprotein (NP) of SARS-CoV-2 in 37 serum samples from 20 COVID-19 patients who were diagnosed by NAT previously. By using SP-NLISA, 28/37 (75.7%) serum samples were detected for NP antigens and no cross-reactivity with blood donors’ control samples collected from different areas of China. In a control assay using the conventional enzyme-linked immunosorbent assay (ELISA), only 7/37 (18.91%) serum samples were detected for NP antigens and no cross-reactivity with control samples. SP-NLISA could be used for rapid detection of SARS-CoV-2 NP antigen in primary screening of SARS-CoV-2 infected individuals.

Sero - Prevalence and Risk Factors of Cattle and Human Brucellosis at Seka Chokorsa and Shebe Sonbo Jimma Zone Districts, South West Ethiopia

2019 ◽  
Author(s):  
Ftsum Assefa Tokon ◽  
Benti Deresa Gelalcha ◽  
Teferi Benti Moti ◽  
Redeat Belaneh Alemu ◽  
Hailu Degefu Awash
Keyword(s):  
Public Health ◽  
Risk Factors ◽  
Brucella Abortus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Brucellosis ◽  
Bacterial Disease ◽  
Serum Samples ◽  
Public Health Importance ◽  
Herd Level ◽  
Jimma Zone

Abstract Background: Brucellosis is contagious bacterial disease of major socio-economic and public health importance globally and it is also one of the priority zoonotic diseases in Ethiopia. Across-sectional epidemiological study was carried out from April 2017 to April 2018 to estimate the sero prevalence of bovine and human brucellosis and to assess the associated risk factors of brucellosis in Seka Chokorsa and Shebe Sonbo districts of Jimma zone. Results: The overall prevalence of cattle brucella infection at individual and herd level were 5.9% (95%CI: 4.1%-8.1%) and 26.6 (95%CI: 19.1%-35.3%) based on diagnosis using commercial kits of the competitive enzyme-linked Immunosorbent assay (CELISA) from Brucella abortus antibodies. Univariate logistic regression analysis at individual animal level showed that animals from large herd size and households which had a practice of introduction of new animals in their herds were 3.7 and 2.3 times more likely to be seropositive, respectively. The same scenario has been observed at herd level. Molecularly, five Brucella abortus was identified as the species affecting cattle in the study areas. From the total human serum samples tested only one serum was found to be positive for CFT and thus the prevalence is 0.42 %,( 95%CI: 0.01%-2.38%). From 238 respondents, 90% of them drink raw milk and milk products, and 70% of them also eat raw meat. Furthermore, slaughtering, assisting during delivery and poor management of aborted material is a common practice that favor transmission of the pathogen in the area. Conclusions: In conclusion, the results of this study showed that brucellosis is an important and widely distributed disease in cattle in the study areas. The finding of the infection in human indicates the public health importance of brucellosis in the area. The risk behaviors and practices observed suggests the need to design all-inclusive health programmes, such one-health approach aimed at controlling brucellosis spread in the study area.

scholarly journals Seroprevalence of human Brucellosis and associated risk factors among high-risk occupations in Mbeya Region of Tanzania

2020 ◽  
Vol 6 (1) ◽  
pp. 1 ◽  
Author(s):  
Frederick D. Sagamiko ◽  
Ruth L. Mfune ◽  
Bernard M. Hang’ombe ◽  
Esron D. Karimuribo ◽  
Alfred M. Mwanza ◽  
...  
Keyword(s):  
Public Health ◽  
Risk Factors ◽  
Statistical Significance ◽  
Raw Milk ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Brucellosis ◽  
P Value ◽  
Cross Sectional ◽  
Occupationally Exposed ◽  
Associated Risk Factors

Background: Brucellosis is a bacterial zoonotic disease of public health and economic importance. A cross-sectional study was conducted in Mbeya region between November 2015 and January 2016 to investigate the seroprevalence of human brucellosis and identify associated risk factors among individuals in risky occupations. Methods: A total of 425 humans from six occupational categories were serially tested for Brucella antibodies using the Rose Bengal Plate Test (RBPT) and competitive Enzyme Linked Immunosorbent Assay (c-ELISA), for screening and confirmation, respectively. A questionnaire survey was also administered to participants to collect epidemiological data. Results: The overall seroprevalence among the occupationally exposed individuals was 1.41% (95% CI: 00.64-3.12). Seroprevalence was higher among butcher men 5.6% (95% CI: 1.68-5.26), herds men 1.35% (95% CI: 0.18-9.02); and abattoir workers 1.1% (95% CI: 0.26-4.22) although there was no statistical significance. (P value = .18). Seroprevalence was also higher among men (1.8%) compared to females (0%) (P value = .19). and also, among those aged < 11 years (2.5%). Individuals who consumed raw milk had a higher seroprevalence (1.56%) compared to those who drunk boiled milk while seropositivity was 0.88% among those who assisted animals during parturition (P value = .49). Butcher men were at higher risk of exposure compared to other occupational categories. Our findings show the presence of brucellosis in occupationally exposed individuals in Mbeya region.Conclusion: There is need to sensitize the concerned professions in order to reduce the risk of acquiring Brucella infections from animals and animal products This also calls for public health awareness about the disease, and implementation of measures to prevent further spread of brucellosis within and outside the study area.

scholarly journals Subtractive Phage Display Selection from Canine Visceral Leishmaniasis Identifies Novel Epitopes That Mimic Leishmania infantum Antigens with Potential Serodiagnosis Applications

2013 ◽  
Vol 21 (1) ◽  
pp. 96-106 ◽  
Author(s):  
Lourena E. Costa ◽  
Mayara I. S. Lima ◽  
Miguel A. Chávez-Fumagalli ◽  
Daniel Menezes-Souza ◽  
Vivian T. Martins ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Phage Display ◽  
Leishmania Infantum ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Phage Display Technology ◽  
Predictive Values ◽  
Content Type ◽  
Phage Elisa

ABSTRACTVisceral leishmaniasis (VL) is a zoonotic disease that is endemic to Brazil, where dogs are the main domestic parasite reservoirs, and the percentages of infected dogs living in regions where canine VL (CVL) is endemic have ranged from 10% to 62%. Despite technological advances, some problems have been reported with CVL serodiagnosis. The present study describes a sequential subtractive selection through phage display technology from polyclonal antibodies of negative and positive sera that resulted in the identification of potential bacteriophage-fused peptides that were highly sensitive and specific to antibodies of CVL. A negative selection was performed in which phage clones were adhered to purified IgGs from healthy andTrypanosoma cruzi-infected dogs to eliminate cross-reactive phages. The remaining supernatant nonadhered phages were submitted to positive selection against IgG from the blood serum of dogs that were infected withLeishmania infantum. Phage clones that adhered to purified IgGs from the CVL-infected serum samples were selected. Eighteen clones were identified and their reactivities tested by a phage enzyme-linked immunosorbent assay (phage-ELISA) against the serum samples from infected dogs (n= 31) compared to those from vaccinated dogs (n= 21), experimentally infected dogs with cross-reactive parasites (n= 23), and healthy controls (n= 17). Eight clones presented sensitivity, specificity, and positive and negative predictive values of 100%, and they showed no cross-reactivity withT. cruzi- orEhrlichia canis-infected dogs or with dogs vaccinated with two different commercial CVL vaccines in Brazil. Our study identified eight mimotopes ofL. infantumantigens with 100% accuracy for CVL serodiagnosis. The use of these mimotopes by phage-ELISA proved to be an excellent assay that was reproducible, simple, fast, and inexpensive, and it can be applied in CVL-monitoring programs.

scholarly journals Evaluation of the Serologic Cross-Reactivity between Transmissible Gastroenteritis Coronavirus and Porcine Respiratory Coronavirus Using Commercial Blocking Enzyme-Linked Immunosorbent Assay Kits

mSphere ◽  
2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Ronaldo Magtoto ◽  
Korakrit Poonsuk ◽  
David Baum ◽  
Jianqiang Zhang ◽  
Qi Chen ◽  
...  
Keyword(s):  
Culture Medium ◽  
Large Deletion ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Transmissible Gastroenteritis Virus ◽  
Serum Samples ◽  
Serological Tests ◽  
Transmissible Gastroenteritis ◽  
Respiratory Coronavirus ◽  
Porcine Respiratory

ABSTRACTThis study compared the performances of three commercial transmissible gastroenteritis virus/porcine respiratory coronavirus (TGEV/PRCV) blocking enzyme-linked immunosorbent assays (ELISAs) using serum samples (n = 528) collected over a 49-day observation period from pigs inoculated with TGEV strain Purdue (n = 12), TGEV strain Miller (n = 12), PRCV (n= 12), or with virus-free culture medium (n = 12). ELISA results were evaluated both with “suspect” results interpreted as positive and then as negative. All commercial kits showed excellent diagnostic specificity (99 to 100%) when testing samples from pigs inoculated with virus-free culture medium. However, analyses revealed differences between the kits in diagnostic sensitivity (percent TGEV- or PRCV-seropositive pigs), and all kits showed significant (P < 0.05) cross-reactivity between TGEV and PRCV serum antibodies, particularly during early stages of the infections. Serologic cross-reactivity between TGEV and PRCV seemed to be TGEV strain dependent, with a higher percentage of PRCV-false-positive results for pigs inoculated with TGEV Purdue than for TGEV Miller. Moreover, the overall proportion of false positives was higher when suspect results were interpreted as positive, regardless of the ELISA kit evaluated.IMPORTANCECurrent measures to prevent TGEV from entering a naive herd include quarantine and testing for TGEV-seronegative animals. However, TGEV serology is complicated due to the cross-reactivity with PRCV, which circulates subclinically in most swine herds worldwide. Conventional serological tests cannot distinguish between TGEV and PRCV antibodies; however, blocking ELISAs using antigen containing a large deletion in the amino terminus of the PRCV S protein permit differentiation of PRCV and TGEV antibodies. Several commercial TGEV/PRCV blocking ELISAs are available, but performance comparisons have not been reported in recent research. This study demonstrates that the serologic cross-reactivity between TGEV and PRCV affects the accuracy of commercial blocking ELISAs. Individual test results must be interpreted with caution, particularly in the event of suspect results. Therefore, commercial TGEV/PRCV blocking ELISAs should only be applied on a herd basis.

scholarly journals Use of GRA6-Derived Synthetic Polymorphic Peptides in an Immunoenzymatic Assay To Serotype Toxoplasma gondii in Human Serum Samples Collected from Three Continents

2008 ◽  
Vol 15 (9) ◽  
pp. 1380-1386 ◽  
Author(s):  
Susana Sousa ◽  
Daniel Ajzenberg ◽  
Manuel Vilanova ◽  
José Costa ◽  
Marie-Laure Dardé
Keyword(s):  
Toxoplasma Gondii ◽  
Latin American ◽  
Enzyme Linked Immunosorbent Assay ◽  
Clear Correlation ◽  
Type I ◽  
Serum Samples ◽  
Typing Method ◽  
Microsatellite Genotype ◽  
Human Infections ◽  
Immunoenzymatic Assay

ABSTRACT Serotyping is a simple typing method that consists of an immunoenzymatic assay (enzyme-linked immunosorbent assay [ELISA]) using synthetic polymorphic peptides derived from Toxoplasma gondii antigens. We developed a new ELISA based on GRA6 C-terminal polymorphic peptides. Serum samples from 41 human infections due to 23 archetypal (type I, II, or III) and 18 nonarchetypal strains were selected in order to validate this approach. For 20 out of the 23 archetypal infections, there was a clear correlation between microsatellite genotype and GRA6 serotyping. All infections due to nonarchetypal strains were misclassified as archetypal strain infections. The GRA6 C-terminal peptides from these strains were analyzed to explain this misclassification. A second group of 455 patients with acute and chronic toxoplasmosis due to unknown genotypes from different European, African, and Latin American countries were included in this study, and the strain type predicted by this method. The results suggest that serotyping is a promising method for typing strains, although limitations exist for African and South American strains as a consequence of higher peptide polymorphism. Other peptides from different markers must be studied in order to discriminate archetypal from nonarchetypal strains.

scholarly journals Specific Serodiagnosis of Canine Visceral Leishmaniasis Using Leishmania Species Ribosomal Protein Extracts

2009 ◽  
Vol 16 (12) ◽  
pp. 1774-1780 ◽  
Author(s):  
Eduardo A. F. Coelho ◽  
Laura Ramírez ◽  
Mariana A. F. Costa ◽  
Vinicio T. S. Coelho ◽  
Vivian T. Martins ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Ribosomal Proteins ◽  
High Sensitivity ◽  
Leishmania Species ◽  
Cross Reactivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Canine Visceral Leishmaniasis ◽  
Leishmania Chagasi ◽  
Serum Samples ◽  
Potential Tool

ABSTRACT In the present work, we have analyzed the antigenicity of Leishmania species ribosomal proteins (LRPs). To accomplish this, Leishmania infantum ribosomes were biochemically purified from promastigote cytosolic extracts, and their reactivities were analyzed by using the sera from dogs naturally infected with L. infantum. Since antibodies reacting against different ribosomal proteins were observed in all the serum samples obtained from dogs with symptomatic visceral leishmaniasis tested, we have analyzed the potential usefulness of the LRP extracts in the development of an enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of canine visceral leishmaniasis (CVL) in an area of Brazil where visceral leishmaniasis is endemic due to infection by Leishmania chagasi. A comparative ELISA with crude soluble Leishmania chagasi antigen (SLA) and L. infantum LRPs was performed. LRP- and SLA-based ELISAs gave similar sensitivities for the diagnosis of symptomatic CVL, but the LRP extract provided a very high sensitivity for the detection of oligosymptomatic and asymptomatic dogs. In addition, an LRP-based ELISA showed a higher specificity when the sera from dogs harboring other infections were included in the analysis. The LRP antigen displayed no cross-reactivity with sera from dogs that had any of the other diseases tested, notably, Chagas' disease. Our findings suggest that LRPs are a potential tool for the diagnosis of CVL and will be particularly useful for the diagnosis of asymptomatic CVL.

scholarly journals Seroprevalence Study of Human Brucellosis by Conventional Tests and Indigenous Indirect Enzyme-Linked Immunosorbent Assay

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Annapurna S. Agasthya ◽  
Srikrishna Isloor ◽  
Prabhudas Krishnamsetty
Keyword(s):  
Joint Pain ◽  
Indirect Elisa ◽  
Clinical Signs ◽  
Agglutination Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Brucellosis ◽  
Serum Samples ◽  
Heart Attacks ◽  
Highly Sensitive ◽  
Monitoring And Surveillance

Brucellosis is one of the most important reemerging zoonoses in many countries. Brucellosis is caused by Gram-negative coccobacillus belonging to genusBrucella. Human brucellosis often makes the diagnosis difficult. The symptoms and clinical signs most commonly reported are fever, fatigue, malaise, chills, sweats headaches, myalgia, arthralgia, and weight loss. Some cases have been presented with only joint pain, lower backache, and involuntary limb movement, burning feet, or ischemic heart attacks. The focus of this work was to develop a highly sensitive and specific indirect ELISA by using smooth lipopolysaccharide antigen ofBrucella abortus 99to detect anti-Brucellaantibodies at Project Directorate on Animal Disease Monitoring and Surveillance. Serum samples collected from 652 individuals in whom fever was not the major symptom but the complaint was of joint pain, headache, lower backache, and so forth, were screened by Rose Bengal plate agglutination test (RBPT) and standard tube agglutination test (STAT). Subsequent testing of sera by indigenous indirect ELISA detected 20 samples positive (3.6% seroprevalence), and indirect ELISA was found to be more sensitive than RBPT and STAT. The seroprevalence in South Karnataka was 2.14%, and in North Karnataka it was 0.92%.

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