scholarly journals Rapid Diagnosis of Japanese Encephalitis by Using an Immunoglobulin M Dot Enzyme Immunoassay

1998 ◽  
Vol 36 (7) ◽  
pp. 2030-2034 ◽  
Author(s):  
Tom Solomon ◽  
Le Thi Thu Thao ◽  
Nguyen Minh Dung ◽  
Rachel Kneen ◽  
Nguyen The Hung ◽  
...  

Japanese encephalitis (JE) occurs in rural settings in southern and eastern Asia, where diagnostic facilities are limited. For the diagnosis of JE virus (JEV) infection, we developed a nitrocellulose membrane-based immunoglobulin M (IgM) capture dot enzyme immunoassay (MAC DOT) that is rapid, simple to use, requires no specialized equipment, and can distinguish JEV from dengue infection. In a prospective field study in southern Vietnam, 155 cerebrospinal fluid (CSF) and 341 serum samples were collected from 111 children and 83 adults with suspected encephalitis. The JEV MAC DOT, performed on site, was scored visually from negative to strongly positive by two observers, and the results were compared subsequently with those of the standard IgM capture enzyme-linked immunosorbent assay. For the 179 patients with adequate specimens, the MAC DOT correctly identified 59 of 60 JEV-positive patients and 118 of 119 JEV-negative patients (sensitivity [95% confidence intervals], 98.3% [92.1 to 99.9%]; specificity, 99.2% [95.9 to 100.0%]; positive predictive value, 0.98; negative predictive value, 0.99). The MAC DOT also correctly identified three patients with dengue encephalopathy. Admission specimens were positive for 73% of JE patients. Interobserver agreement for MAC DOT diagnosis was excellent (kappa = 0.94). The JEV MAC DOT is a simple and reliable rapid diagnostic test for JE in rural hospitals.

2001 ◽  
Vol 8 (2) ◽  
pp. 349-351 ◽  
Author(s):  
Paul N. Levett ◽  
Songee L. Branch ◽  
Carol U. Whittington ◽  
Charles N. Edwards ◽  
Helene Paxton

ABSTRACT Leptospirosis is a common and underdiagnosed zoonosis. Two rapid assays for serological diagnosis of acute leptospirosis in diagnostic laboratories, the immunoglobulin M (IgM)-dipstick assay and the indirect hemagglutination assay (IHA), were evaluated and compared with standard assays. Sera were examined from 104 patients admitted to a hospital for investigation in a leptospirosis diagnostic protocol. Specimens for serology were taken on days 1 and 4 of the patients' hospital stay. Antibodies were detected using an IgM-enzyme-linked immunosorbent assay (ELISA), microscopic agglutination test (MAT), an IgM-dipstick assay, and an IHA. Fifty-one patients were found to have leptospirosis. The sensitivity of the IgM-dipstick assay was 98%, its specificity was 90.6%, its positive predictive value was 90.9%, and its negative predictive value was 98%. The sensitivity of the IHA was 92.2%, its specificity was 94.4%, its positive predictive value was 95.9%, and its negative predictive value was 92.7%. The standard IgM-ELISA and MAT, were positive in the first samples tested from 67 and 55% of the cases, respectively, and the rapid IgM-dipstick assay and IHA were positive in 71 and 49%, respectively, in the first sample tested. Both rapid assays are highly sensitive and specific. Neither requires specialized equipment, and both are suitable for use in diagnostic laboratories.


2006 ◽  
Vol 13 (11) ◽  
pp. 1185-1189 ◽  
Author(s):  
Philippe Dussart ◽  
Bhety Labeau ◽  
Gisèle Lagathu ◽  
Philippe Louis ◽  
Marcio R. T. Nunes ◽  
...  

ABSTRACT We evaluated a one-step sandwich-format microplate enzyme immunoassay for detecting dengue virus NS1 antigen (Ag) in human serum by use of Platelia Dengue NS1 Ag kits (Bio-Rad Laboratories, Marnes La Coquette, France). We collected 299 serum samples from patients with dengue disease and 50 serum samples from patients not infected with dengue virus. For the 239 serum samples from patients with acute infections testing positive by reverse transcription-PCR and/or virus isolation for one of the four dengue virus serotypes, the sensitivity of the Platelia Dengue NS1 Ag kit was 88.7% (95% confidence interval, 84.0% to 92.4%). None of the serum samples from patients not infected with dengue virus tested positive with the Platelia Dengue NS1 Ag kit. A diagnostic strategy combining the Platelia Dengue NS1 Ag test for acute-phase sera and immunoglobulin M capture enzyme-linked immunosorbent assay for early-convalescent-phase sera increased sensitivity only from 88.7% to 91.9%. Thus, NS1 antigen detection with the Platelia Dengue NS1 Ag kit could be used for first-line testing for acute dengue virus infection in clinical diagnostic laboratories.


1970 ◽  
Vol 11 ◽  
pp. 189-192 ◽  
Author(s):  
Basu Dev Pandey ◽  
Ramesh Pun ◽  
Krishna Prasad Pant

Japanese encephalitis (JE) and dengue are vector borne viral diseases that are endemic in the territory of Nepal. The purpose of the study was to assess the disease burden and to compare the results between particle agglutination and enzyme linked immunosorbent assay. A total of 185 serum samples of suspected Japanese encephalitis (JE) viral fever, dengue fever, malaria and typhoid were collected in the year 2005 (August-October) and 2006 (August- November) from hospitals of Bardiya, Banke, Dang, Kathmandu and Parsa. The samples were investigated by particle agglutination and enzyme immunoassay at Everest International Clinic and Research Centre, Kathmandu. Out of 141 samples from suspected diseased patients, 51% had a positive Japanese encephalitis virus (JEV) specific immunoglobulin M by particle agglutination assay while the anti-dengue immunoglobulin M positivity rate was 22.7% among 44 samples by the same assay. The specificity of particle agglutination kit against Japanese encephalitis and dengue was high as evident from absence of cross reactivity with other diseases like malaria, typhoid, kala-azar and leptospira. Thus, particle agglutination assay can be used as a tool for diagnosis of the diseases in developing countries like Nepal. Key words: dengue virus; endemic; Japanese encephalitis; particle agglutination DOI: 10.3126/njst.v11i0.4144Nepal Journal of Science and Technology 11 (2010) 189-192


1998 ◽  
Vol 5 (1) ◽  
pp. 7-10 ◽  
Author(s):  
Chew Theng Sang ◽  
Andrea J. Cuzzubbo ◽  
Peter L. Devine

ABSTRACT A commercially available capture enzyme-linked immunosorbent assay (ELISA) for the detection of specific immunoglobulin M (IgM) and IgG antibodies produced during dengue infection (PanBio Dengue Duo) was evaluated with paired serum specimens from 176 patients. Diagnosis was based on a hemagglutination inhibition (HAI) assay, with patients having either primary dengue (n = 90), secondary dengue (n = 58), or no dengue (n = 28) infection. The combined use of IgM and IgG (sensitivity, 99%; specificity, 96%) was superior to the use of IgM alone (sensitivity, 88%; specificity, 96%) or IgG alone (sensitivity, 85%; specificity, 96%). Furthermore, with the first serum sample of the pair of serum samples, the ELISA was able to diagnose significantly more cases of dengue than the HAI assay (55% versus 14%). The results of the IgG capture ELISA gave a significant correlation with those of the HAI assay (r = 0.91; P < 0.0001), and the IgG capture ELISA could be used to distinguish between primary and secondary infection. The best distinction was observed when an IgG cutoff ratio of 3.0 was used, with 88% of primary infections and 98% of secondary infections being correctly classified. This ELISA should prove to be useful in the clinical diagnosis of dengue infection.


1998 ◽  
Vol 36 (5) ◽  
pp. 1189-1192 ◽  
Author(s):  
Antoine Talarmin ◽  
Bhety Labeau ◽  
Josiane Lelarge ◽  
Jean-Louis Sarthou

Dengue fever (DF) is usually diagnosed by testing for dengue virus immunoglobulin M (IgM) by a capture enzyme-linked immunosorbent assay (ELISA) (MAC-ELISA). However, IgM can last for months, and its presence might reflect a previous infection. We have tested the use of anti-dengue virus IgA capture ELISA (AAC-ELISA) for the diagnosis of DF by comparing the results of MAC-ELISAs and AAC-ELISAs for 178 serum samples taken from patients with confirmed cases of DF. IgM appears more rapidly (mean delay of positivity, 3.8 days after the onset of DF) than IgA (4.6 days) but lasts longer; the peak IgA titer is obtained on day 8. The specificity and the positive predictive value of AAC-ELISA are 100%; its sensitivity and negative predictive value (NPV) are also 100% between days 6 and 25 after the onset of DF, but they decrease drastically when data for tests conducted with specimens from the first days of infection are included, because the IgA titers, like the IgM titers, have not yet risen. AAC-ELISA is a simple method that can be performed together with MAC-ELISA and that can help in interprating DF serology.


Tick-borne encephalitis virus (TBEV) was isolated for the first time in Sweden in 1958 (from ticks and from 1 tick-borne encephalitis [TBE] patient).1 In 2003, Haglund and colleagues reported the isolation and antigenic and genetic characterization of 14 TBEV strains from Swedish patients (samples collected 1991–1994).2 The first serum sample, from which TBEV was isolated, was obtained 2–10 days after onset of disease and found to be negative for anti-TBEV immunoglobulin M (IgM) by enzyme-linked immunosorbent assay (ELISA), whereas TBEV-specific IgM (and TBEV-specific immunoglobulin G/cerebrospinal fluid [IgG/CSF] activity) was demonstrated in later serum samples taken during the second phase of the disease.


2003 ◽  
Vol 10 (2) ◽  
pp. 317-322 ◽  
Author(s):  
Angel Balmaseda ◽  
María G. Guzmán ◽  
Samantha Hammond ◽  
Guillermo Robleto ◽  
Carolina Flores ◽  
...  

ABSTRACT To evaluate alternative approaches to the serological diagnosis of dengue virus (DEN) infection, the detection of DEN-specific immunoglobulin M (IgM) and IgA antibodies in serum and saliva specimens was assessed in 147 patients with symptoms of DEN infection seen at the Ministry of Health in Nicaragua. Seventy-two serum samples were determined to be positive for anti-DEN antibodies by IgM capture enzyme-linked immunosorbent assay, the routine diagnostic procedure. Serum and saliva specimens were obtained from 50 healthy adults as additional controls. IgM was detected in the saliva of 65 of the 72 serum IgM-positive cases, 6 of the 75 serum IgM-negative cases, and none of the control group, resulting in a sensitivity of 90.3% and a specificity of 92.0% and demonstrating that salivary IgM is a useful diagnostic marker for DEN infection. Detection of IgA in serum may be another feasible alternative for the diagnosis of DEN infection, with serum IgA found in 68 (94.4%) of the IgM-positive cases. In contrast, detection of IgA in saliva was not found to be a useful tool for DEN diagnosis in the present study. Further studies of the kinetics of antibody detection in another set of 151 paired acute- and convalescent-phase serum samples showed that DEN-specific IgA antibodies were detected in more acute-phase samples than were IgM antibodies. Thus, we conclude that DEN-specific IgA in serum is a potential diagnostic target. Furthermore, given that saliva is a readily obtainable, noninvasive specimen, detection of DEN-specific salivary IgM should be considered a useful, cheaper diagnostic modality with similar sensitivity and specificity to IgM detection in serum.


2009 ◽  
Vol 11 (10) ◽  
pp. 881-884 ◽  
Author(s):  
Annamaria Pratelli ◽  
Kadir Yesilbag ◽  
Marcello Siniscalchi ◽  
Ebru Yalçm ◽  
Zeki Yilmaz

Feline sera from Bursa province (Turkey) were assayed for coronavirus antibody using an enzyme-linked immunosorbent assay (ELISA). The study was performed on 100 sera collected from cats belonging to catteries or community shelters and to households. The serum samples were initially tested with the virus neutralisation (VN) test and the results were then compared with the ELISA. The VN yielded 79 negative and 21 positive sera but the ELISA confirmed only 74 as negative. The ELISA-negative sera were also found to be free of feline coronoviruses-specific antibodies by Western blotting. Using the VN as the gold standard test, ELISA had a sensitivity of 100% and a specificity of 93.6%, with an overall agreement of 95%. The Kappa (κ) test indicated high association between the two tests (κ=0.86, 95% confidence interval (CI) 0.743–0.980). The positive predictive value (PPV) was 0.8, and the negative predictive value (NPV) was 0.93. The prevalence of FCoV II antibodies in the sampled population based on the gold standard was 62% (95% CI 0.44–0.77) among multi-cat environments, and 4% (95% CI 0.01–0.11) among single cat households.


2003 ◽  
Vol 10 (3) ◽  
pp. 439-442 ◽  
Author(s):  
F. Roodbari ◽  
M. H. Roustai ◽  
A. Mostafaie ◽  
H. Soleimanjdahi ◽  
R. Sarrami Foroshani ◽  
...  

ABSTRACT Measles is a highly contagious respiratory virus infection, with typical clinical symptoms including maculopapular rash, fever, cough, coryza, and conjunctivitis. Despite implementation of widespread vaccination programs throughout the world, the rates of global morbidity and mortality are still considerable. This study was performed to design a reliable indirect enzyme-linked immunosorbent assay (ELISA) to measure measles-specific immunoglobulin M (IgM). First, human IgM was purified, and then an anti-IgM antibody was produced in rabbits and purified in a multistep process. The rabbit IgG against human IgM was conjugated with peroxidase. Measles virus-infected Vero cells produced viral antigen. One hundred serum samples from infants of 9 to 18 months of age, mostly vaccinated, were evaluated for determining the presence of specific IgM antibodies against measles virus. The samples were also evaluated for neutralizing antibodies against measles virus by a microneutralization test (MNT). By comparing the results of the ELISA with those of MNT, it was demonstrated that ELISA had a sensitivity and specificity of 100 and 92%, respectively. On the other hand, when the results obtained by our ELISA system were compared with those of an imported measles virus IgM ELISA kit (EIAgen; Adaltis Italia SPa, Bologna, Italy), a high level of agreement was shown (k = 0.926).


2020 ◽  
Vol 114 (7) ◽  
pp. 513-520
Author(s):  
Ruta Kulkarni ◽  
Shubham Shrivastava ◽  
Harshad P Patil ◽  
Divya Tiraki ◽  
Akhilesh Chandra Mishra ◽  
...  

Abstract Background Dengue is a public health problem worldwide. Therapeutic monoclonal antibodies (MAbs) against dengue virus (DENV) are likely to be available soon. In view of the feasibility issues pertaining to pretreatment viraemia quantitation for therapy decisions, we conducted this study for investigation of a correlation between patient serostatus (NS1/immunoglobulin M [IgM]/IgG) and viraemia levels among Indian dengue patients at the time of first diagnosis. Methods The study included 297 serum samples from dengue patients in Pune, India. The samples were tested for NS1, IgM and IgG (capture enzyme-linked immunosorbent assay [ELISA] for identifying secondary dengue) using Panbio ELISAs. Quantitation of viraemia was conducted using an NS1 ELISA-based 50% tissue culture infectious dose (TCID50) test in Vero cells. Results Viraemia was detectable only among NS1-positive patients (n = 229, range 0.5–8.3 logTCID50/ml) with a mean titre of 1.9 logTCID50/ml. Among the NS1-positive patients, DENV titres were higher in IgM-negative than IgM-positive patients (p &lt; 0.0001) and in primary (IgG &lt; 18 Panbio units) versus secondary (IgG &gt; 22 Panbio units) dengue patients (p = 0.002). Virus titres were higher during the first 3 days of illness and decreased later (p = 0.005). Conclusions The study provides a range of infectious DENV titres in relation to serologic status among dengue patients in India. The data suggest the possibility of using serological markers (NS1/IgM) as a basis for treatment decisions.


Sign in / Sign up

Export Citation Format

Share Document