Indirect Hemagglutination Assay Research Articles

Comparison of a commercial ELISA and indirect hemagglutination assay with the modified agglutination test for detection of Toxoplasma gondii antibodies in giant panda (Ailuropoda melanoleuca).

Toxoplasma gondii is a worldwide-distributed zoonotic protozoan parasite which causes toxoplasmosis and has a significant effect on public health. In the giant panda (Ailuropoda melanoleuca), toxoplasmosis can cause asymptomatic infections, reproductive disorder and even death, which poses a serious threat to the conservation of this rare protected species. Therefore, serological investigation of T. gondii is essential to understanding its risk to giant pandas, however, there are no specific testing kits for giant pandas. Previous research has used MAT as the reference method for screening T. gondii, to investigate this further, this study focused on the agreement comparing of MAT with ELISA and IHA tests for detecting T. gondii antibodies in 100 blood samples from 55 captive giant pandas in Chengdu, China. The results showed 87.0%, 87.0%, 84.0%, samples were sero-positive for T. gondii using ELISA (kits a, b, c), respectively, while MAT and IHA tests were 84.0% and 9.0% sero-positive, respectively. There was no significant difference between MAT and the three ELISA kits and these two methods had substantial agreement (0.61 < қ ≤ 0.80). Meanwhile, there was a significant difference (P < 0.001) between MAT and IHA, and these two methods had only a slight agreement (қ ≤ 0.20). The relative sensitivity of the ELISA (kits a, b, c) were 89.0%, 91.5% and 95.1%, and the specificity were 86.7%, 80.0% and 80.0%, respectively, which showed these three ELISA kits all had great accuracy. It is suggested that MAT is the recommended test method for primary screening T. gondii in giant pandas and then verified by ELISA.

Diagnostic efficacy of indirect haemagglutination assay for detection of Schistosoma japonicum infections among boatmen and fishermen in the Dongting Lake region

To evaluate the diagnostic efficacy of indirect haemagglutination assay (IHA) for detection of Schistosoma japonicum infections among boatmen and fishermen in Dongting Lake region, so as to provide insights into improving the schistosomiasis surveillance program among boatmen and fishermen. The boatmen and fishermen were detected for S. japonicum infections using IHA and Kato-Katz technique or miracidium hatching test nylon gauze simultaneously at schistosomiasis testing sites in the anchor sites for boatmen and fishermen in the Dongting Lake region during the period from 2014 to 2016, and using IHA for serological screening followed by parasitological testing of seropositives during the period from 2017 to 2019. The sensitivity and specificity of IHA were evaluated for detection of S. japonicum infections among boatmen and fishermen, with the 2014-2016 parasitological testing results as a gold standard. In addition, the seroprevalence of S. japonicum infections was compared among boatmen and fishermen with different characteristics and among years. A total of 306 schistosomiasis testing sites were assigned for boatmen and fishermen, and a total of 143 360 person-time boatmen and fishermen were tested for S. japonicum infections in the Dongting Lake region from 2014 to 2019. The sensitivity and specificity of IHA were 69.9%, 97.3% and 96.1% (χ2 = 74.6, P < 0.05), and 70.9%, 74.5% and 71.9% for detection of S. japonicum infections from 2014 to 2016 (χ2 = 29.4, P < 0.05), respectively. The seroprevalence of S. japonicum infections reduced from 30.3% in 2014 to 1.8% in 2019 among boatmen and fishermen, appearing an overall tendency towards a decline (Z = 1 552.4, P < 0.05). In addition, male, individuals at ages of 45 to 60 years, full-time boatmen and fishermen were more likely to be seropositive for S. japonicum infections (all P values < 0.05). The seroprevalence of S. japonicum infections appeared a tendency towards a decline among boatmen and fishermen in the Dongting Lake region year by year from 2014 to 2019. IHA presented a high efficacy for screening of S. japonicum infections among boatmen and fishermen in the Dongting Lake region.

Flea index predicts plague epizootics among great gerbils (Rhombomys opimus) in the Junggar Basin China plague focus

BackgroundThe Junggar Basin plague focus was the most recently identified natural plague focus in China. Through extensive field investigations, great gerbils (Rhombomys opimus) have been confirmed as the main host in this focus, and the community structure of their parasitic fleas is associated with the intensity of plague epizootics. The aim of this study is to provide an indicator that can be surveyed to evaluate the risk of plague epizootics.MethodsBetween 2005 and 2016, rodents and fleas were collected in the Junggar Basin plague focus. The parasitic fleas on great gerbils were harvested, and anti-F1 antibody in the serum or heart infusion of great gerbils was detected through indirect hemagglutination assay. Yersinia pestis (Y. pestis) was isolated from the liver and spleen of great gerbils and their parasitic fleas using Luria-Bertani plates. Receiver-operating characteristic (ROC) curve was used to evaluate the predictive value of flea index.ResultsBetween 2005 and 2016, 98 investigations were performed, and 6778 great gerbils and 68,498 fleas were collected. Twenty-seven rodents were positive for Y. pestis isolation with a positivity rate of 0.4%; 674 rodents were positive for anti-F1 antibody with a positivity rate of 9.9%. Among these 98 investigations, plague epizootics were confirmed in 13 instances by Y. pestis-positive rodents and in 59 instances by anti-F1 antibody-positive rodents. We observed a higher flea index among rodents with confirmed plague epizootic compared to the negative ones (P = 0.001, 0.002), with an AUC value of 0.659 (95% CI: 0.524–0.835, P = 0.038) for Y. pestis-positive rodents and an AUC value of 0.718 (95% CI: 0.687–0.784, P < 0.001) for anti-F1 antibody-positive rodents.ConclusionsSignificantly higher flea index was associated with confirmed plague epizootic cases among great gerbils and could be used to predict plague epizootics in this focus.Graphical

Estimation of seroprevalence of melioidosis among adult high risk groups in Southeastern India by indirect Hemagglutination assay.

Burkholderia pseudomallei is an environmental saprophyte known to cause melioidosis, a disease endemic in northern Australia and Southeast Asia. With the increasing number of melioidosis cases, there is a lack of data on seroprevalence rates and extent of exposure in high risk population of melioidosis from different endemic regions in India. The present cross sectional study was undertaken to estimate the seroprevalence of melioidosis in high risk populations in and around Puducherry, a coastal town in Southeastern India. Blood samples were collected from 275 diabetic individuals attending a tertiary care centre in Southern India and 275 farmers residing under the rural field practice area of our hospital. The antibody levels were estimated using an Indirect Hemagglutination Assay. The overall seropositivity was found to be 19.8% with a titer ≥1:20. Farmers were 2.8 times more likely to be seropositive than non-farmers. Rates of seroprevalence among diabetic subjects were less compared to the non-diabetic individuals. The seropositivity rates in non-diabetic farmers were higher (56/203, 27.6%) compared to diabetic farmers (34/164, 20.7%). The lowest seropositivity was seen among diabetic non-farmers at 10.4%. Multivariable logistic regression analysis revealed domicile (adjusted odds ratio-aOR: 2.32, 95% Confidence interval-CI: 1.05, 5.13) and contact with animals (aOR: 1.89, 95% CI:1.04, 3.44) as significant predictors of seropositivity. None of the other socio-demographic factors including gender and age were significantly associated with seropositivity. This study demonstrates widespread exposure to B. pseudomallei among adults residing in and around Puducherry, including those engaged in non-farming occupations.

Efforts to eliminate schistosomiasis in Hubei province, China: 2005–2018

BackgroundThe Hubei province is one of the most schistosomiasis-epidemic-prone provinces in China. A series of strategies were adopted by the government to curb the rebound schistosomiasis endemic status that has prevailed since the early 2000s. This study aimed to elucidate the trends of schistosomiasis transmission and to appraise the effectiveness of the integrated control strategy in lake and marshland areas. MethodsSurveillance data of schistosomiasis in the Hubei province between 2005 and 2018 were analyzed, including conventional health control measures, integrated strategies, and measures that focused on the infection source. According to the local annual plan for schistosomiasis control in endemic counties, previous measures were human and snail control and surveillance. Residents aged 6–65 years were screened by an immunological detection method called indirect hemagglutination assay (IHA) after the transmission season each year. All residents who tested positive were then asked to provide a fecal sample for examination by the miracidium hatching technique (MHT) to detect the presence of schistosomes. Moreover, systematic snail surveys were conducted as a part of the combined environmental sampling method. The latter included integrated strategies and measures that focused on the infection source. Bovine stool samples were also collected and concurrently assessed using the MHT by the agriculture department, river-hardening slope protection was constructed by the water conservancy department, and forestation promotion was conducted by the forest department. The effectiveness of the integrated control strategy was assessed using two indicators of resident and livestock infection rates and three indicators of snail epidemics across all endemic areas. ResultsFrom 2005 to 2018, a total of 28. 46 million and 2. 05 million residents were assessed by immunological (IHA) and etiological (MHT) detection techniques, respectively. Snail surveys and molluscicide application were performed in 2. 26 hectares and 0. 37 hectares, respectively. Moreover, 2. 60 million bovines were assessed by etiological detection techniques (MHT). The river-hardening slope protection project was implemented in 503 places, and 46 thousand hectares in endemic areas underwent environmental modification. Forestation was implemented at an area of 0. 15 million hectares. Between 2005 and 2018, the epidemic indicators, including resident and livestock infection rates and the infested areas and infection rate of snails, all presented downward trends. The resident infection rate decreased from 3. 78% in 2005 to 0% in 2016, which persisted through 2018. The livestock infection rate decreased from 5. 63% in 2005 to 0% in 2013, which also persisted through 2018. From 2005 to 2018, the snail-inhabited area was slightly reduced, but the area of infected snails decreased to 0 in 2012; this persisted through 2018. All counties met the goal for schistosomiasis infection control, transmission control, and disruption of schistosomiasis activity in 2008, 2013, and 2018 separately. That means the goal has been achieved in each stage. ConclusionsThe decline of the schistosomiasis epidemic rate demonstrates that the Chinese government was successful in meeting its public health goal in Hubei province. In the next decade, precision interventions must be implemented in endemic counties with a relatively low epidemic status to achieve the goals of the Outline of the Healthy China 2030 Plan. A similar strategy can be applied in other countries to eliminate schistosomiasis globally.

Pulmonary Echinococcus in children: A descriptive study in a LMIC.

Echinococcus granulosus is a major public health problem in lower middle-income countries (LMIC). Children are commonly diagnosed with cysts in the lungs and/or the liver. The purpose of this study was to describe a pediatric cohort diagnosed with pulmonary Cystic Echinococcus (CE) and treated with a combination of medical and surgical therapy. This was a retrospective study performed between July 2017 and December 2020 at Tygerberg Hospital, South Africa. Clinical, laboratory, radiological, medical, and surgery-related outcomes were reviewed. The cohort consisted of 35 children, 17 (49%) were male, with a mean age of 9 ± 5.4 years. The most frequently encountered presenting symptom was cough (93%) followed by fever (70%). Isolated pulmonary CE accounted for the majority of cases (74%) with left lower lobe predominance. A significant proportion of the cohort exhibited chest computed tomography (CT) characteristics consistent with complicated pulmonary CE. Eighteen (58%) children had a positive indirect hemagglutination assay (IHA) test result. All children received medical treatment whilst 30 (86%) of children required surgery. Children with complicated pulmonary CE stayed a mean of 12.5 ± 6.6 days, while those with simple cysts stayed 6.8 ± 1.5 days. Isolated pulmonary CE is common in children, whereas extrapulmonary cysts are uncommon. Pulmonary CE is diagnosed using chest X-ray and, CT imaging. IHA serology has limited diagnostic utility for pulmonary CE. Combined surgery and chemotherapy remains the gold standard for treating pulmonary CE.

Development of Immunochromatographic Assay for the Rapid Detection of Mycoplasma capricolum subsp. capripneumoniae Antibodies.

Mycoplasma capricolum subsp. capripneumoniae (Mccp) is the cause of contagious caprine pleuropneumonia (CCPP), which is a highly significant respiratory disease in goats leading to significant economic losses in Africa and Asia. Currently available procedures for the diagnosis of CCPP have some limitations in sensitivity, specificity, operation time, requirement of sophisticated equipment or skilled personnel, and cost. In this study, we developed a rapid, sensitive, and specific colloidal gold-based immunochromatographic assay (GICA) strip for the efficient on-site detection of antibodies against Mccp in the serum within 10 min. For the preparation of this colloidal GICA strip, recombinant P20 protein, the membrane protein of Mccp, was expressed by Escherichia coli prokaryotic expression system after purification was used as the binding antigen in the test. The rabbit anti-goat immunoglobulin G labeled with the colloidal gold was used as the detection probe, whereas the goat anti-rabbit immunoglobulin G was coated on the nitrocellulose membrane as the control line. The concentration of the coating antibody was optimized, and the effectiveness of this colloidal GICA strip was evaluated. Our results proved that the detection limit of the test strip was up to 1:64 dilutions for the Mccp antibody-positive serum samples with no cross-reactivity with other pathogens commonly infecting small ruminants,including goat pox virus, peste des petits ruminants virus, foot-and-mouth disease virus type A, or other mycoplasmas. Moreover, the colloidal GICA strip was more sensitive and specific than the indirect hemagglutination assay for the detection of Mccp antibodies. The 106 clinical serum samples were detected by the colloidal GICA strip compared with the complement fixation test, demonstrating an 87.74% concordance with the complement fixation test. This novel colloidal GICA strip would be an effective tool for the cost-effective and rapid diagnosis of CCPP in the field.

Melioidosis: Laboratory Investigations and Association with Patient Outcomes.

Melioidosis is an infection caused by the bacterium Burkholderia pseudomallei. The most common presentation is bacteremia occurring in 38-73% of all patients, and the mortality rate ranges from 9% to 42%. Although there is abundant data representing risk factors for infection and patient outcomes, there is limited information regarding laboratory investigations associated with bacteremia and mortality. We assessed a range of baseline and diagnostic investigations and their association with patient outcomes in a retrospective cohort study in Townsville, Australia. 124 patients' medical and laboratory records were reviewed between January 1, 1997 and December 31, 2020. Twenty-seven patients died and 87 patients were bacteremic. The presence of lymphopenia (< 1.5 × 109 cells/L) was the highest risk for bacteremia (relative risk [RR] 2.2; 95% CI: 1.3-3.7, P < 0.001). Factors associated with mortality included lymphopenia, (RR: 1.4; 95% CI: 1.2-1.6, P = 0.004); uremia (RR: 1.7; 95% CI: 1.1-2.5, P = 0.03); and an elevated international normalized ratio (RR: 1.5; 95% CI: 1.2-2.0, P = 0.006). Median incubation to positive blood culture result was 28 hours with 15/82 (18%) positive in ≤ 24 hours. For serological testing during admission only 53/121 (44%) were indirect hemagglutination assay positive, 67/120 (56%) enzyme immunoassay IgG positive, and 23/89 (26%) IgM positive. Simple baseline investigations at time of presentation may be used to stratify patients at high risk for both bacteremia and mortality. This information can be used as a decision aid for early intensive management.

Investigation of Patients with Suspected Cystic Echinococcosis by ELISA and IHA Methods in Gaziantep, Turkey

Objective: Cystic echinococcosis (CE) caused by larval stage of Echinococcus granulosus is one of the neglected parasitic disease, of both medical and public health importance. It has a worldwide distribution including Turkey. The current study was designed to determine the seropositivity of E. granulosus infection in patients with suspected cystic echinococcosis attending to Dr.Ersin Arslan Training and Research Hospital in Gaziantep, Turkey. Materials and Methods: A total of 545 serum samples were taken from individuals were screened for the presence of E. granulosus IgG antibodies using in-house Enzyme-Linked Immunosorbent Assay (ELISA) and the commercial Indirect Hemagglutination Assay kit (IHA-Fumouze kit). Furthermore, socio-demographic characteristics as gender, age, residence were analyzed by SPSS. Results: Out of 545 samples, antibodies to E. granulosus were detected in 148 (27.2%) patients with ELISA and 83 patients (15. 2%) were found positive with IHA test. Statistical comparison of two dependent categorical values (ELISA and IHA) showed statistical significance p &lt;0.001. Lesion distribution of organ involvement in suspected patients was liver 498 (91.4%), lung 13 (2.4%), spleen 12 (2.2 %), multiple organ involvement 6 (1.1%) and other organ involvement 16 (2.9%). In the distribution according to age groups, the seropositivity of anti-E.granulosus IgG antibodies was increased in patients aged 40-49 years. According to ELISA and IHA results, 28 patients (18.9%) and 18 patients (21.7%) were in this age group, respectively. Conclusion: As a result, CE still represents a public health problem in Gaziantep, Turkey. Efforts should be continued, in both animals and humans side, by increasing public awareness.

In-vivo Immunomodulatory Activities of Isolated Compounds from the Leaves of Amaranthus spinosus and Achyranthes aspera

The purpose of this study was to look into the Immunomodulatory action of isolated compound of Achyranthes aspera and Amaranthus spinosus in experimental model of immunity. Cellular immunity was carried out by neutrophil adhesion test and carbon clearance assay, whereas, humoral immunity was analyzed by mice lethality test and indirect haemagglutination assay. The dose was selected after acute toxicity study of isolated compound of Achyranthes aspera and Amaranthus spinosus and administered at 5 mg/kg orally. The Levamisole (0.68mg/kg, p.o) was used as standard. Isolated compound of Achyranthes aspera (IAA) and Amaranthus spinosus (IAS) at 5 mg/kg produced significant increases in adhesion of neutrophils and an increase in phagocytic index in carbon clearance assay. Both doses of IAA and IAS significantly prevented the mortality induced by bovine Pasteurella multocida in mice. Treatment of animals with IAA, IAS and Levamisole significantly increased the circulating antibody titre in indirect haemagglunation test. Among the different Isolates, (IAS) was more effective in cellular immunity models than the (IAA). However, Both the Isolates IAA and IAS exhibited similar protection in humoral immunity procedures. It is concluded that isolated compound of Achyranthes aspera(IAA) and Amaranthus spinosus(IAS)possesses potential for augmenting immune activity by cellular and humoral mediated mechanisms more at doseof (5 mg/kg).

Schistosomiasis in the People's Republic of China - down but not out.

Schistosomiasis has been subjected to extensive control efforts in the People's Republic of China (China) which aims to eliminate the disease by 2030. We describe baseline results of a longitudinal cohort study undertaken in the Dongting and Poyang lakes areas of central China designed to determine the prevalence of Schistosoma japonicum in humans, animals (goats and bovines) and Oncomelania snails utilizing molecular diagnostics procedures. Data from the Chinese National Schistosomiasis Control Programme (CNSCP) were compared with the molecular results obtained.Sixteen villages from Hunan and Jiangxi provinces were surveyed; animals were only found in Hunan. The prevalence of schistosomiasis in humans was 1.8% in Jiangxi and 8.0% in Hunan determined by real-time polymerase chain reaction (PCR), while 18.3% of animals were positive by digital droplet PCR. The CNSCP data indicated that all villages harboured S. japonicum-infected individuals, detected serologically by indirect haemagglutination assay (IHA), but very few, if any, of these were subsequently positive by Kato-Katz (KK).Based on the outcome of the IHA and KK results, the CNSCP incorporates targeted human praziquantel chemotherapy but this approach can miss some infections as evidenced by the results reported here. Sensitive molecular diagnostics can play a key role in the elimination of schistosomiasis in China and inform control measures allowing for a more systematic approach to treatment.

Reindeer Anthrax in the Russian Arctic, 2016: Climatic Determinants of the Outbreak and Vaccination Effectiveness.

The Yamal Peninsula in the Russian Federation experienced a massive outbreak of anthrax in reindeer (Rangifer tarandus) in July–August 2016, with 2,650 (6.46% of the total susceptible population) animals infected, of which 2,350 died (case fatality rate of 88.67%). In our study, we analyzed climatic and epidemiological factors that could have triggered the outbreak. The cancelation of reindeer vaccination against anthrax in 2007 resulted in an increase in population susceptibility. In response to the outbreak, total vaccination of all susceptible animals was resumed. To assess the vaccination effectiveness, we tested 913 samples of blood serum taken from vaccinated reindeer using an antigenic erythrocyte diagnostic kit to detect specific anti-anthrax antibodies via an indirect hemagglutination assay (IHA) 9 months after vaccination. We found that 814 samples had sufficiently high levels of anti-anthrax antibodies to indicate a protection level of 89% (95% confidence interval: 87–91%) of the whole reindeer population. Abnormally high ambient temperature in the summer of 2016 contributed to the thawing of permafrost and viable Bacillus anthracis spores could have become exposed to the surface; the monthly average air temperatures in June, July, and August 2016 were 20–100% higher than those of the previous 30-year period, while the maximum air temperatures were 16–75% higher. Using the projected climate data for 2081–2100 according to the “worst case” RCP8.5 scenario, we demonstrated that the yearly air temperature may average above 0°C across the entire Yamal Peninsula, while the yearly number of days with a mean temperature above 0°C may rise by 49 ± 6 days, which would provide conditions for reactivation of soil anthrax reservoirs. Our results showed that the outbreak of anthrax occurred under conditions of a significant increase in air temperature in the study area, underlined the importance of vaccination for controlling the epidemic process, and demonstrated the effectiveness of monitoring studies using the IHA diagnostic kit for detecting erythrocyte anthrax antigens.

Prevalence of Chlamydia in Pigs in China from 1985 to 2020: A Systematic Review and Meta-Analysis.

Chlamydia is a small gram-negative (G-) microorganism that can be dangerous to human and animals. In this study, we conducted a systematic review and meta-analysis of Chlamydia infection in swine in China. From PubMed, ScienceDirect, Chinese Web of knowledge (CNKI), VIP Chinese journal database, and Wanfang database, we collected a total of 72 publications reported in 1985-2020. The prevalence of Chlamydia was 22.48% in China. In the sampling year subgroup, the prevalence after 2011 was the highest (26.14%). In southern China, the prevalence was 30.97%. By contrast, the prevalence in northern China was only 10.79%. Also the difference was significant (p < 0.05). In the provincial level, Hubei had the highest rate of 36.23%. Boars had a higher prevalence (29.47%). The prevalence of Chlamydia detection in pigs with reproductive disorders (21.86%) was higher than that without reproductive disorders. Among the three age groups, finishing pigs (21.43%) had the highest prevalence. The prevalence in large-scale farmed pigs (28.58%) was the highest in the subgroup of feeding methods. The prevalence in farms was 24.29%, which was the highest in the survey areas. The prevalence in spring was the highest with 40.51%. Other methods had the highest prevalence (39.61%) than enzyme-linked immunosorbent assay (ELISA) and indirect hemagglutination assay. The prevalence of Chlamydia psittaci 18.41% was lower than the prevalence of Chlamydia abortus (41.35%). We also analyzed the impact of different climate factor subgroups (rainfall, temperature, and humidity) on the probability of pigs suffering from the disease. The results showed that Chlamydia was widespread in pigs in China. We suggest that we should strengthen the detection of Chlamydia in the semen of breeding pigs and pigs with reproductive disorders, and reasonably control the environment of large-scale pig farms, so as to reduce further infection of Chlamydia in pigs.

Imported schistosomiasis in Paris region of France: A multicenter study of prevalence and diagnostic methods

BackgroundThere are few data on imported schistosomiasis – especially in children. The objectives of the present study were to estimate the prevalence of imported schistosomiasis in at-risk children in the greater Paris region of France and to compare diagnostic methods. MethodChildren at risk of schistosomiasis who consulted or were hospitalized in four hospitals in the greater Paris region were prospectively included. Clinical and laboratory data were collected. Urine and feces samples were screened for Schistosoma spp. using microscopy, a point-of-care circulating cathodic antigen and a real-time polymerase chain reaction assay. Serum samples were screened using Western blot, ELISA, indirect hemagglutination, and immunochromatographic assays. The diagnosis was characterized as confirmed (positive microscopy analysis) and as suspected (positive ELISA and Western blot assays). The prevalence of schistosomiasis and the tests’ performances were estimated using the latent class method. ResultsA total of 114 children were included. Most of the children were newly arrived migrants from sub-Saharan Africa. The mean age was 13.2 years-old. There were 12 (10.5%) confirmed cases and 13 (11.4%) suspected cases. Half of the confirmed and suspected cases were asymptomatic. The prevalence was 24.3%. The ELISA and the Western blot assays presented the same sensitivity (83%) and specificity (99%). The serum immunochromatographic assay also showed good performance. ConclusionsThe high prevalence of imported schistosomiasis among at-risk children in the greater Paris region confirms the need for systematic screening. A serum immunochromatographic assay appears to be one of the most effective screening methods for a low cost.

Comparison of Dot ELISA Using GroEL Recombinant Protein as an Antigen and an Indirect Hemagglutination Assay for Serodiagnosis of Melioidosis

Background: Melioidosis is a disease caused by the Burkholderia pseudomallei bacterium. The mortality rate of infected patients is quite high because the symptoms are similar to those of various diseases, making it difficult to diagnose clinically and preventing the immediate treatment with effective antibiotics that is required for the management of acute infections. To provide appropriate treatment, accurate and rapid diagnosis is required. Objective: The aims of this study were to develop Dot ELISA using purified GroEL B. pseudomallei recombinant protein as an antigen and to compare the newly developed assay with an indirect hemagglutination assay (IHA) for the diagnosis of melioidosis. Methods: The GroEL recombinant protein was purified by immobilized metal affinity chromatography before being used as an antigen. The optimal conditions of the Dot ELISA were determined and used for subsequent experiments. A total of 291 serum samples were evaluated by the established Dot ELISA and IHA, using the bacterial culture method as the gold standard of melioidosis diagnosis. Results: The results from Dot ELISA and IHA revealed sensitivity, specificity, and accuracy of 85.7% (Dot ELISA)/64.3% (IHA), 94.4%/85.5%, and 93.1%/82.5%, respectively. Conclusion: These results indicate that the Dot ELISA developed is an efficient, simple, rapid and cost-effective technique for the early diagnosis of melioidosis and can be used in a local laboratory without specialized equipment.

Diagnostic test accuracy for detecting Schistosoma japonicum and S. mekongi in humans: A systematic review and meta-analysis

BackgroundMost of national schistosomiasis elimination programmes in Asia are relying on stool examination, particularly Kato Katz stool examination technique for regular transmission monitoring. However, the Kato-Katz technique has shown low sensitivity for the detection of light-intensity infections, and therefore highly sensitive diagnostic tools are urgently required to monitor prevalence of infection in low transmission settings. The objective of this systematic review was to evaluate and synthesize the performance of diagnostic tests for detecting Schistosoma japonicum and S. mekongi infection in people living in endemic areas.Methodology/Principal findingsWe comprehensively searched these nine electronic databases and other resources until July 2019, with no language or publication limits: PubMed, EMBASE, MEDLINE, Web of Science, BIOSIS Citation Index, HTA, CINAHL PLUS, The Cochrane Library, and PsycINFO. We included original studies that assessed diagnostic performance using antibody, antigen, and molecular tests with stool examination test as a reference standard. Two reviewers independently extracted a standard set of data and assessed study quality. We estimated the pooled estimates of sensitivity and specificity for each index test. We used diagnostic odds ratio to determine the overall accuracy and hierarchical summary receiver operating characteristics (HSROC) curve to assess the index tests performance.Fifteen studies (S. japonicum [n = 13] and S. mekongi [n = 2]) testing 15,303 participants were included in the review. Five studies reported performance of enzyme-linked immunosorbent assay (ELISA), seven studies reported indirect hemagglutination assay (IHA), and four studies reported polymerase chain reaction (PCR) for detecting S. japonicum. The pooled sensitivity and specificity were 0.93 (95% CI: 0.84–0.98) and 0.40 (95% CI: 0.29–0.53) for ELISA, 0.97 (95% CI: 0.90–0.99) and 0.66 (95% CI: 0.58–0.73) for IHA, and 0.89 (95% CI: 0.71–0.96) and 0.49 (95% CI: 0.29–0.69) for PCR respectively. A global summary indicated the best performance for IHA, closely followed by ELISA. We were unable to perform meta-analysis for S. mekongi due to insufficient number of studies.Conclusions/SignificanceIHA showed the highest detection accuracy for S. japonicum. Further studies are needed to determine the suitable diagnostic methods to verify the absence of transmission of S. mekongi and also to compare detection accuracy against more sensitive reference standards such as PCR.

An Update on the Epidemiological Features of Imported Schistosomiasis and Cystic Echinococcosis in Kuwait, 2010–2018

Objective: Kuwait is considered a non-endemic country for most parasitic infections. However, ∼70% of 4.7 million residents in Kuwait are expatriates from Asian and African countries, which are endemic for parasitic infections. Results of microbiological investigations for schistosomiasis and cystic echinococcosis (CE) performed in a reference national laboratory were retrospectively collected and analyzed to provide an insight on the epidemiology of these 2 neglected tropical diseases in Kuwait. Subjects and Methods: Schistosoma infection in fecal and urine specimens from suspected patients was detected by microscopy. Schistosoma and CE infections were also detected by indirect hemagglutination assays (IHAs) using blood specimens. Patients’ epidemiological data were extracted from the laboratory records. Results: The overall prevalence rates of schistosomiasis and CE were 19.0 and 5.8%, respectively. Almost all schistosomiasis cases were seen among Egyptians, especially among males, and a significantly higher prevalence (p < 0.05) was seen for CE cases among the Syrian residents. A decreasing annual trend was observed for both the parasitic infections over time in Kuwait. Conclusions: This study confirmed that schistosomiasis is not autochthonous in Kuwait, as all cases were detected among expatriates from Schistosoma-endemic countries. Our data also showed that CE remains endemic among humans and livestock in Kuwait as is also seen in other Middle Eastern countries.

Molecular characterization of Toxoplasma gondii isolates from free-range chickens reveals new genotypes in Goiânia, Goiás, Brazil.

The aim of this study was to evaluate the genotypic characteristics of Toxoplasma gondii isolated from free-range chickens in the metropolitan area of Goiânia, Goiás, in Brazil's central-west region. The seroprevalence rate was found to be 96%, according to an indirect hemagglutination assay. Brain and heart samples were processed by peptic digestion for a mice bioassay. The tissues were homogenized and the resulting samples were subjected to polymerase chain reaction (PCR), which revealed that 64% of them contained the parasite's DNA. The mice bioassay revealed 15 isolates, 8 of them tachyzoites isolates from the peritoneal lavage and 7 from brain cysts. T. gondii genotypes were determined through PCR-RFLP, using the following markers: SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, alt. SAG2, Apico and CS3. Three genotypes were identified, inclued ToxoDB #65, and the other two are not yet described in the literature. Hence, we conclude that the isolates obtained from the metropolitan area of Goiânia showed relatively low genetic diversity.

Effect of Phage Targeting Therapy of Brucellosis on Host Antibody Response in Cattle.

Brucellosis caused by Brucella organisms is a major zoonosis globally. It causes heavy losses through abortions, delayed conception, and infertility in animals. Brucella is an intracellular bacterium. Antibiotic therapy for bovine Brucellosis is expensive and may sometimes be ineffective as Brucella can become resistant. Once infected, the animal may remain carrier and shed bacteria in milk, semen, and uterine discharges spreading infection to others for a long period. The live attenuated Brucella abortus strain S19 organisms that are commonly used as a vaccine were employed to deliver a broad acting lytic brucellaphage inside the phagocytes in vivo to reach the virulent Brucella hiding intracellularly. The phage pulsed vaccine induced sustained and significantly high titers of anti-Brucella antibodies compared with the untreated animals and animals vaccinated with S19 vaccine alone as estimated by standard tube agglutination test, microagglutination test, indirect hemagglutination assay test, and enzyme-linked immunosorbent assay. The current investigation is perhaps the first systematic attempt whereby efficacy of brucellaphage pulsed vaccine preparation in induction of specific antibody response was evaluated in cattle.

Unusual case of multiple hepatosplenic abscesses caused by Staphylococcus aureus

Background: Combined liver and splenic abscesses are very rare in people without underlying diseases or immune-deficiencies, and can be fatal. Clinical presentation may not be straight-forward. Case description: A 19 year old male was admitted to the Emergency Unit with 2 days fever, left-sided loin pain and vomiting. After examination, the patient was admitted to a medical ward with a presumptive diagnosis of urinary tract infection. Physical examination revealed signs of an acute abdomen and the patient was referred to a surgeon. On further history, a fall from a tree with blunt trauma to the abdomen was elicited. Splenic rupture was suspected and confirmed by ultrasound scan abdomen. Laparotomy was performed. The spleen was lacerated in several places with peri-splenic haematoma formation. Splenectomy was performed. Multiple small abscess-like lesions were observed on the liver and biopsies were taken and sent for microbiology and histopathology. Meropenem was started post-operatively on a presumptive diagnosis of melioidosis and clindamycin. Primary culture of liver tissue showed no growth after 24 hour incubation. A pure growth of Staphylococcus aureus sensitive to cloxacillin was obtained on enrichment of the tissues in Blood Heart Infusion broth. Treatment was changed to intravenous cloxacillin and ciprofloxacin and the patient kept under strict observation. The histopathology report revealed colonies of Gram positive cocci in the biopsies taken from the liver and spleen. Size of the lesions in the liver initially increased up to 1 cm and then gradually reduced. Inflammatory markers (CRP, FBC), too, initially increased, then gradually normalized. Serology by the indirect hemagglutination assay for Burkholderia pseudomallei antibody was negative. Patient was fever free by the 5th day. Computed tomography chest, abdomen and head were done to exclude abscesses in other organs and 2D-echocardiogram to exclude endocarditis. The patient was treated with IV cloxacillin for 6weeks and discharged on oral cloxacillin for 3 weeks after giving vaccines as indicated in asplenism. Discussion: Atypical presentation of hepatosplenic abscesses may lead to misdiagnosis. Vigilance and open-mindedness for unusual manifestation of hepatosplenic abscesses on the differential diagnosis, even in patients without any risk factors, may improve the prognosis. Conclusion: Awareness and vigillance for atypical infections is life saving.