Evaluation of a genus-specific rGroEL1-524 IgM-ELISA and commercial ELISA kits during the course of leptospirosis in Thailand

AbstractIn the present study, we developed a genus-specific rGroEL1-524 IgM-ELISA assay for use in screening diagnosis of suspected leptospirosis among acute undifferentiated febrile illness patients during acute fever. The diagnostic accuracies of the rGroEL1–524 IgM-ELISA, commercial Panbio IgM-ELISA, and Virion-Serion Classic IgG-ELISA were evaluated using 133 Thai leptospirosis sera and 210 controls. Sensitivities were 91.7%, 59.6%, and 17.7% for acute infection, and the specificities were 92.6%, 90.2%, and 88.3% for the non-leptospirosis control, respectively. The rGroEL1-524 IgM-ELISA had high sensitivity, at 92.3% and 91.7%, among culture-positive and MAT-negative cases at 1–3 days post-onset of symptoms (DPO1–3), respectively. Impaired specificity on scrub typhus was found, possibly from antibody cross-reaction to ortholog GroEL. Commercial Panbio IgM-ELISA had sensitivities at DPO1–3 of 30.8% and 41.7% for culture-positive and MAT-negative cases whereas Virion-Serion IgG-ELISA showed sensitivities of 5.9% and 13.3%, respectively. The rGroEL1-524 IgM-ELISA could be useful as a screening test for early diagnosis. The performance of the commercial ELISA suggests the applicability of IgM-ELISA for diagnosis, while IgG-ELISA is useful for seroprevalence surveys. However, confirmation by reference tests is recommended.

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Evaluation of a Genus Specific rGroEL 1-524 IgM-ELISA and Commercially ELISA Kits During Course of Leptospirosis in Thailand

10.21203/rs.3.rs-352195/v1 ◽

2021 ◽

Author(s):

Santi Maneewatchararangsri ◽

Galayanee Doungchawee ◽

Thareerat Kalambaheti ◽

Viravarn Luvira ◽

Ngamphol Soonthornworasiri ◽

...

Keyword(s):

Early Detection ◽

Early Diagnosis ◽

Screening Test ◽

Scrub Typhus ◽

Acute Infection ◽

Febrile Illness ◽

High Sensitivity ◽

Elisa Assay ◽

Igm Elisa ◽

Post Onset

Abstract This work, we developed a genus-specific rGroEL1-524 IgM-ELISA assay for using as screening diagnosis of suspected leptospirosis among acute undifferentiated febrile illness patients during acute fever. Ddiagnostic accuracies of rGroEL1–524 IgM-ELISA, and commercial Panbio IgM-ELISA, and Virion-Serion Classic IgG-ELISA were evaluated with Thai 107 leptospirosis sera, and 189 controls, compared to reference culture and/or MAT methods. Sensitivities were 91.7%, 59.6%, and 17.7% for acute- infection, and were 97.1%, 54.8%, and 9.7% for early detection at 1-3 days post-onset of symptoms (DPO1-3), and the specificities were 87.5%, 86.6%, and 74.8% among controls, respectively. The rGroEL1-524 IgM-ELISA had high sensitivity, at 95.9% and 91.2% among culture and MAT negative cases. Impaired specificity on scrub typhus, possibly from antibody-cross reaction to ortholog GroEL. Commercial Panbio IgM-ELISA had sensitivities of 50%, 63.2%, and 89.9% compared with culture, MAT-negative and single MAT-positive cases whereas Virion-Serion IgG-ELISA provided sensitivities of 13.3%, 10.5% and 71.4%, respectively. A rGroEL1-524 IgM-ELISA could be useful as a screening test for early diagnosis. The performance of the commercial ELISA suggests the applicability of IgM-ELISA for diagnosis, while IgG-ELISA is useful for seroprevalence surveys. However, confirmation by reference tests is recommended.

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Diagnostic Accuracy of the InBios Scrub Typhus Detect™ ELISA for the Detection of IgM Antibodies in Chittagong, Bangladesh

Tropical Medicine and Infectious Disease ◽

10.3390/tropicalmed3030095 ◽

2018 ◽

Vol 3 (3) ◽

pp. 95 ◽

Cited By ~ 7

Author(s):

Stuart Blacksell ◽

Hugh Kingston ◽

Ampai Tanganuchitcharnchai ◽

Meghna Phanichkrivalkosil ◽

Mosharraf Hossain ◽

...

Keyword(s):

General Population ◽

Diagnostic Accuracy ◽

Diagnostic Tests ◽

Scrub Typhus ◽

Febrile Illness ◽

High Sensitivity ◽

Immunofluorescence Assay ◽

Immunoglobulin M ◽

Regional Assessment ◽

Igm Elisa

Here we estimated the accuracy of the InBios Scrub Typhus Detect™ immunoglobulin M (IgM) ELISA to determine the optimal optical density (OD) cut-off values for the diagnosis of scrub typhus. Patients with undifferentiated febrile illness from Chittagong, Bangladesh, provided samples for reference testing using (i) qPCR using the Orientia spp. 47-kDa htra gene, (ii) IFA ≥1:3200 on admission, (iii) immunofluorescence assay (IFA) ≥1:3200 on admission or 4-fold rise to ≥3200, and (iv) combination of PCR and IFA positivity. For sero-epidemiological purposes (ELISA vs. IFA ≥1:3200 on admission or 4-fold rise to ≥3200), the OD cut-off for admission samples was ≥1.25, resulting in a sensitivity (Sn) of 91.5 (95% confidence interval (95% CI: 96.8–82.5) and a specificity (Sp) of 92.4 (95% CI: 95.0–89.0), while for convalescent samples the OD cut-off was ≥1.50 with Sn of 66.0 (95% CI: 78.5–51.7) and Sp of 96.0 (95% CI: 98.3–92.3). Comparisons against comparator reference tests (ELISA vs. all tests including PCR) indicated the most appropriate cut-off OD to be within the range of 0.75–1.25. For admission samples, the best Sn/Sp compromise was at 1.25 OD (Sn 91.5%, Sp 92.4%) and for convalescent samples at 0.75 OD (Sn 69.8%, Sp 89.5%). A relatively high (stringent) diagnostic cut-off value provides increased diagnostic accuracy with high sensitivity and specificity in the majority of cases, while lowering the cut-off runs the risk of false positivity. This study underlines the need for regional assessment of new diagnostic tests according to the level of endemicity of the disease given the high levels of residual or cross-reacting antibodies in the general population.

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EVALUATION OF IGM ELISA, WEIL FELIX TEST AND INDIRECT IMMUNOFLUORESCENCE ASSAY IN THE DIAGNOSIS OF SCRUB TYPHUS.

10.36106/ijar/5405204 ◽

2020 ◽

pp. 1-4

Author(s):

Pooja Raghunath

Keyword(s):

Diagnostic Test ◽

Scrub Typhus ◽

Febrile Illness ◽

High Sensitivity ◽

Immunofluorescence Assay ◽

Research Centre ◽

Medical Sciences ◽

Serological Tests ◽

Igm Elisa ◽

Highly Sensitive

Scrub typhus is an acute febrile illness caused by Orientia tsutsugamushi. There are reports of resurgence of scrub typhus in different parts of India including Kerala. Many cases go undiagnosed due to the lack of knowledge regarding the diagnostic test to be used. This study was undertaken at Pushpagiri Institute of Medical Sciences and Research Centre, Tiruvalla in the Department of Microbiology from January 2014 to September 2015, to assess the validity of various tests in diagnosing scrub typhus. A total of 94 samples were subjected to IgM ELISA, Weil Felix (WF) test and Indirect Immunouorescence assay(IFA). The agreement between ELISA, IFA and Weil Felix test was assessed by κ (kappa) coefcient of Cohen using SPSS version 17. The sensitivity and specicity of ELISA with respect to IFA was 100% and 94.67% respectively, and that of IFA with respect to ELISA was 82.61% and 100% respectively. The sensitivity and specicity of WF test with respect to ELISA was 43.48 and 100% respectively and that of WF test with respect to IFA was 52.63% and 100% respectively. Although IgM ELISA is highly sensitive, it cannot be relied upon as the sole diagnostic test due to high false positivity. WF test is not a sensitive test, but when positive it is rather specic. IFA has high sensitivity and specicity, but is unsuitable for moderately equipped laboratories. Hence, we suggest that scrub typhus could be diagnosed using a combination of IgM ELISA and WF test and these tests should be included in the panel of serological tests ordered for patients presenting with undifferentiated febrile illnesses.

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Scrub typhus (Orientia tsutsugamushi), A rapidly spreading epidemic in Chennai - A standalone lab experience

International Journal of Bioassays ◽

10.21746/ijbio.2016.09.0021 ◽

2016 ◽

Vol 5 (09) ◽

pp. 4896

Author(s):

Sripriya C.S.* ◽

Shanthi B. ◽

Arockia Doss S. ◽

Antonie Raj I. ◽

Mohana Priya

Keyword(s):

Scrub Typhus ◽

Clinical Symptoms ◽

Clinical Manifestations ◽

Febrile Illness ◽

Orientia Tsutsugamushi ◽

The Past ◽

Igm Elisa ◽

The Mean ◽

Specific Symptoms ◽

Symptoms And Signs

Scrub typhus (Orientia tsutsugamushi), is a strict intracellular bacterium which is reported to be a recent threat to parts of southern India. There is re-emergence of scrub typhus during the past few years in Chennai. Scrub typhus is an acute febrile illness which generally causes non-specific symptoms and signs. The clinical manifestations of this disease range from sub-clinical disease to organ failure to fatal disease. This study documents our laboratory experience in diagnosis of scrub typhus in patients with fever and suspected clinical symptoms of scrub typhus infection for a period of two years from April 2014 to April 2016 using immunochromatography and IgM ELISA methods. The study was conducted on 648 patients out of whom 188 patients were found to be positive for scrub typhus. Results also showed that pediatric (0 -12 years) and young adults (20 – 39 years) were more exposed to scrub typhus infection and female patients were more infected compared to male. The study also showed that the rate of infection was higher between September to February which also suggested that the infection rate is proportional to the climatic condition. Statistical analysis showed that the mean age of the patients in this study was 37.6, standard deviation was 18.97, CV % was 50.45.

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Diagnostic evaluation of IgM ELISA and IgM Immunofluorescence assay for the diagnosis of Acute Scrub Typhus in central Nepal

10.21203/rs.2.10024/v5 ◽

2020 ◽

Author(s):

Rajendra Gautam ◽

Keshab Parajuli ◽

Tshokey Tshokey ◽

John Stenos ◽

Jeevan Bahadur Sherchand

Keyword(s):

Likelihood Ratio ◽

Predictive Value ◽

Gold Standard ◽

Scrub Typhus ◽

Febrile Illness ◽

Immunofluorescence Assay ◽

Acute Febrile Illness ◽

Central Nepal ◽

Igm Elisa ◽

Typhus Fever

Abstract Introduction Scrub typhus is an acute febrile illness caused by the obligate intracellular bacterium,Orientia tsutsugamushi. Given their affordability and ease of use, antibody based diagnostic assays can be important diagnostic tools for early detection of scrub typhus fever in resource poor countries like Nepal. Immunochromatography (ICT) and IgM ELISA are two of the routinely employed antibody based assays for diagnosis of Scrub typhus fever in Nepal, although the recommended gold standard diagnostic test is IgM Immunofluorescence assay (IFA). This study evaluated the InBios Scrub Typhus Detect™ Immunoglobulin M (IgM) ELISA and IgM Immunofluorescence assays in single serum sample at the time of admission. Methodology Study participants (1585 suspected cases), were enrolled based on acute febrile illness with suspected scrub typhus cases in central Nepal from April 2017 to March 2018. Blood sample was collected from the suspected patients of scrub typhus, presenting with acute febrile illness. IgM antibody to Orientia tsusugamushi was detected by using Scrub Typhus Detect™ Kit (In Bios International, USA) and an in-house IgM IFA (Australian Rickettsial Reference Laboratory, Geelong, Australia. The IFA assay was performed with the Gilliam, Karp, Kato strains and O. chuto antigens following the ARRL protocol. Result Statistical analysis of ELISA IgM results when compared to reference test, IgM IFA results demonstrated the following characteristics, sensitivity 84.0% (95%CI: 79.73%-87.68%), specificity 94.82% (95% CI: 93.43%-95.99%), positive likelihood ratio 16.21% (95% CI: 12.71%-20.67%), negative likelihood ratio 0.17% (95% CI: 0.13-0.21%), disease prevalence 22.08% (95% CI: 20.06%-24.21%), positive predictive value 82.12% (95% CI: 78.28-85.42%) and negative predictive value 95.44% (95% CI: 94.27%-96.38%) respectively. Conclusion The study indicated that the IgM ELISA has the sensitivity 84.0% (95% CI: 79.73%-87.68%) and specificity 94.82% (95% CI: 93.43%-95.99%). Although IgM IFA is considered the gold standard test for the diagnosis of scrub typhus cases, it is relatively expensive, requires trained personal and a microscope with fluorescence filters. Scrub typhus IgM ELISA with appropriate OD cut–off values may be the best alternative test and possible viable option for resource limited endemic countries like Nepal.

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Lateral Flow Rapid Test for Accurate and Early Diagnosis of Scrub Typhus: A Febrile Illness of Historically Military Importance in the Pacific Rim

Military Medicine ◽

10.7205/milmed-d-16-00091 ◽

2017 ◽

Vol 182 (S1) ◽

pp. 369-375 ◽

Cited By ~ 5

Author(s):

Chien-Chung Chao ◽

Zhiwen Zhangm ◽

Giulia Weissenberger ◽

Hua-Wei Chen ◽

Wei-Mei Ching

Keyword(s):

Early Diagnosis ◽

Scrub Typhus ◽

Rapid Test ◽

Febrile Illness ◽

Lateral Flow ◽

Pacific Rim ◽

The Pacific

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Development of an E2 ELISA Methodology to Assess Chikungunya Seroprevalence in Patients from an Endemic Region of Mexico

Viruses ◽

10.3390/v11050407 ◽

2019 ◽

Vol 11 (5) ◽

pp. 407 ◽

Cited By ~ 3

Author(s):

Young Chan Kim ◽

César López-Camacho ◽

Nallely Garcia-Larragoiti ◽

Alan Cano-Mendez ◽

Karina Guadalupe Hernandez-Flores ◽

...

Keyword(s):

Acute Infection ◽

Febrile Illness ◽

Population Based ◽

Cross Sectional Study ◽

Elisa Assay ◽

Serum Samples ◽

Endemic Region ◽

Cross Sectional ◽

Healthy Donors ◽

Epidemiological Information

Chikungunya fever is a debilitating disease caused by Chikungunya virus (CHIKV) that can result in long-lasting arthralgias. The early diagnosis of CHIKV relies on PCR during the acute infection phase to allow differential diagnosis with other co-circulating arboviruses such as dengue and Zika. Alternatively, serology can support diagnosis and provide epidemiological information on current and past outbreaks. Many commercial serological ELISA assays are based on the inactivated whole CHIKV, but their sensitivity and specificity show great variability. We produced recombinant CHIKV E2 that is suitable for ELISA assays, which was used for the serodiagnosis of CHIKV infections occurring in an arbovirus endemic Mexican region within Michoacán state. A cross-sectional study was conducted in 2016–2017; sera was obtained from 15 healthy donors and 68 patients presenting undifferentiated febrile illness. Serum samples were screened by RT-PCR and by our in-house ELISA assay. Our results indicate that IgM and IgG anti-CHIKV E2 antibodies were detected with our ELISA assay with higher sensitivity than a commercially available CHIKV ELISA kit. Our simple and sensitive ELISA assay for the serodiagnosis of CHIKV infections can be applied to population-based seroprevalence surveys and has potential for monitoring vaccine immunogenicity in CHIKV vaccine clinical trials.

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Use of Multiplex Real-Time PCR To Diagnose Scrub Typhus

Journal of Clinical Microbiology ◽

10.1128/jcm.02181-16 ◽

2017 ◽

Vol 55 (5) ◽

pp. 1377-1387 ◽

Cited By ~ 12

Author(s):

Wiwit Tantibhedhyangkul ◽

Ekkarat Wongsawat ◽

Saowaluk Silpasakorn ◽

Duangdao Waywa ◽

Nuttawut Saenyasiri ◽

...

Keyword(s):

Early Diagnosis ◽

Real Time ◽

Real Time Pcr ◽

Scrub Typhus ◽

Febrile Illness ◽

Asia Pacific ◽

Diagnostic Tools ◽

Pcr Assay ◽

Content Type ◽

Serologic Tests

ABSTRACTScrub typhus, caused byOrientia tsutsugamushi, is a common cause of acute undifferentiated febrile illness in the Asia-Pacific region. However, its nonspecific clinical manifestation often prevents early diagnosis. We propose the use of PCR and serologic tests as diagnostic tools. Here, we developed a multiplex real-time PCR assay using hydrolysis (TaqMan) probes targetingO. tsutsugamushi47-kDa,groEL, and human interferon beta (IFN-β gene) genes to improve early diagnosis of scrub typhus. The amplification efficiency was higher than 94%, and the lower detection limit was 10 copies per reaction. We used a human gene as an internal DNA quality and quantity control. To determine the sensitivity of this PCR assay, we selected patients with confirmed scrub typhus who exhibited a clear 4-fold increase in the level of IgG and/or IgM. The PCR assay result was positive in 45 of 52 patients, indicating a sensitivity of 86.5% (95% confidence interval [CI]: 74.2 to 94.4). The PCR assessment was negative for all 136 non-scrub typhus patients, indicating a specificity of 100% (95% CI: 97.3 to 100). In addition, this test helped diagnose patients with inconclusive immunofluorescence assay (IFA) results and using single blood samples. In conclusion, the real-time PCR assay proposed here is sensitive and specific in diagnosing scrub typhus. Combining PCR and serologic tests will improve the diagnosis of scrub typhus among patients presenting with acute febrile illness.

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Analytical Performance of the RIDASCREEN® Hantavirus Puumala IgG/IgM ELISA Assay

Viruses ◽

10.3390/v12020226 ◽

2020 ◽

Vol 12 (2) ◽

pp. 226

Author(s):

Melissa Depypere ◽

Katrien Lagrou ◽

Marjan Van Esbroeck ◽

Els Houben ◽

Marc Van Ranst

Keyword(s):

Western Europe ◽

Acute Infection ◽

Kappa Coefficient ◽

Puumala Virus ◽

Elisa Assay ◽

Substantial Agreement ◽

Past Infection ◽

National Reference ◽

Igm Elisa ◽

National Reference Center

The National Reference Center for Hantavirus in Belgium is currently using the Hantavirus IgM/IgG ELISA Progen kit (Heidelberg, Germany) for the detection of the most prevalent Hantavirus in Western Europe, Puumala virus (PUUV). Two commercially available PUUV kits were compared: Progen and RIDASCREEN® Hantavirus Puumala IgM/IgG ELISA assay (Darmstadt, Germany). Methods: The sensitivity was evaluated with a panel of 68 samples from patients with an acute infection (n = 44) or a past infection (n = 24). Specificity was evaluated with a panel of 62 samples from patients with potentially false borderline results (n = 7) (no seroconversion), seronegative samples (n = 25) and potentially cross reacting samples (n = 30). Discordances were resolved by immunoblot. Substantial agreement was calculated using Cohen kappa coefficient. Results: The RIDASCREEN® kit showed a higher specificity (IgM: 94.3%; IgG: 94.4%) than the Progen kit (IgM: 77.0% IgG: 93.0%). The sensitivity for IgM ELISA was 100% for both assays. IgG sensitivity was, respectively, 98.3% and 100% for Progen and RIDASCREEN®. A Cohen kappa coefficient of 0.76 and 0.90 was found between Puumala IgM and IgG, respectively. Conclusions: This study showed a higher specificity for the RIDASCREEN® kit than the Progen kit, while the sensitivity was as good as for the Progen kit.

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Seroprevalence and clinical profile of scrub typhus in patients presenting with undifferentiated acute febrile illness in a tertiary care centre

Asian Journal of Medical Sciences ◽

10.3126/ajms.v12i4.33353 ◽

2021 ◽

Vol 12 (4) ◽

pp. 54-60

Author(s):

Reena Anie Jose ◽

Hyma Jose ◽

Anjali Anne Jacob ◽

Pramod Thomas ◽

Renu Mathew ◽

...

Keyword(s):

Scrub Typhus ◽

Laboratory Finding ◽

Tertiary Care ◽

Elevated Serum ◽

Febrile Illness ◽

Clinical Profile ◽

Bivariate Analysis ◽

Enzyme Linked Immunosorbent Assay ◽

Rickettsial Infections ◽

Igm Elisa

Background: Scrub typhus (ST) is a common Rickettsial infection which has been increasingly reported from the various states of southern part of India. Aims and Objective: With very few reports from Central Kerala, we aimed to study the seroprevalence of scrub typhus and its clinical profile. Materials and Methods: Patients presenting with acute undifferentiated febrile illness and other symptoms and signs of Rickettsial infections during a period of two years were included in this prospective study. Serodiagnosis of ST was based on a positive Scrub typhus IgM Enzyme Linked Immunosorbent Assay (ELISA) and/or agglutination for OXK in Weil Felix test. The cut-off for ELISA was calculated. The clinical and laboratory details of the positive patients were obtained and bivariate analysis was performed. Results: The cut-off for ST IgM ELISA was calculated and found to be 0.38. Of the 636 samples screened, 34 (5.3%) were positive for ST IgM ELISA. Out of the 34 positive samples, only 5 (0.8%) were positive by Weil Felix test. Most of the ST patients presented during the months of May to January. Rashes were observed in 8.8% of the ST patients and none had signs of eschar. The commonest clinical features included fever, myalgia (52.9%), nausea & vomiting (32.4%), headache (29.4%) and hepatosplenomegaly (29.4%). The commonest abnormal laboratory finding and complication observed were elevated serum transaminases (52.9%) and acute respiratory distress syndrome (17.6%) respectively. Conclusion: The seroprevalence of ST in Central Kerala was 5.3% using Weil Felix test and ST IgM ELISA.

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