Human Enterovirus 71 (EV71), the newest member of Enterovirudae, is notable for its etiological role in epidemics of severe neurological diseases in children. It appears to be emerging as an important virulent neurotropic enterovirus in the upcoming era of poliomyelitis eradication. The illness usually peaks in June or July. EV71 infection may be asymptomatic or may cause diarrhea and rashes. EV71 one of the major causative agents for hand, foot and mouth disease (HFMD), is sometimes associated with severe central nervous system diseases. Direct detection of virus is the mainstay of diagnosis. EV 71 can be isolated from throat and stool specimens, as well as from skin vesicle fuid. PCR testing provides generally greater sensitivity than culture for throat and stool specimens, and viral RNA has also been detected in vesicular fuid, blood and urine. EV 71-specifc serological assays, including tests specific for IgM antibody, have also been developed to assist for early and easier diagnosis of the disease.
Pathogens identified in local institutional HFMD outbreaks
Seasonality of by onset date
► Wantai EV71-IgM ELISA is a solid-phase antibody capture assay in which microwell strips are pre-coated with antibodies directed to anti-human IgM antibodies. The patient’s sample is added, and any IgM antibodies will be captured in the wells. Purified EV71 antigen, and monoclonal anti-EV71 antibodie sconjugated to the enzyme horseradish peroxidase are simultaneously added into the wells. They willspecifically react only with the EV-71 IgM antibodies captured onto the wells. Chromogen solutions are then added into the wells. In presence of EV-71 IgM antibody in the sample, the colorless chromogens are hydrolyzed by the bound HRP-conjugate to a blue-colored product. The amount of color intensity can be measured and is proportional to the amount of antibody captured in the wells, and to the amount of antibody in the sample respectively.
► Wantai EV-71 IgM Rapid Test is a single use, rapid device intended for qualitative detection of IgM-class antibodies to human enterovirus-71 (EV71) in serum, plasma or whole blood samples. It is intended to be used in clinical laboratories for early diagnosis and management of patients related to infection with EV71.
► Wantai EV-71 IgM Rapid Test - performance characteristics study
Samples |
Wantai EV71 IgM Rapid Test Positive |
Wantai EV71 IgM Rapid Test Negative |
Sensitivity |
Specificity |
EV71 PCR positive samples |
23 |
3 |
88.5% (23/26) |
-- |
Non-EV71 hand, foot and mouth diseases samples |
9 |
177 |
-- |
95.2% (177/186) |
In total 212 clinical serum samples were tested including 26 EV71 PCR positive samples, 186 non-EV71 HFMD samples. The test demonstrated sensitivity of 88.5% (23/26) and specificity of 95.2% (177/186).
Wantai EV71 IgM Rapid Test demostrated very high sensitivity and specificity during this evaluation. The test is aplicable for clinical laboratories for early diagnosis and management of patients related to infection with EV71.
Download clinical evaluation report 
Catalog No.
|
Product
|
Certification
|
IFU
|
MSDS
|
WR-1696
|
EV-71 IgM ELISA
|
CE pending
|
|
|
WS-1206
|
EV-71 IgM DOT-ELISA
|
|
|
|
WJ-2010
|
EV-71 IgM Rapid Test
|
|
|
Wantai EV-71 IgM ELISA : performance characteristics
► Study I - Analysis performance
Samples |
Wantai EV-71 IgM ELISA positive |
Wantai EV-71 IgM ELISA negative |
Sensitivity |
Specificity |
Confirmed EV71 positive samples |
178 |
11 |
94.2%(178/189) |
-- |
Healthy individuals' samples |
24 |
3682 |
-- |
99.4%(3682/3706) |
► Study II - Analysis performance
Samples |
Wantai EV-71 IgM ELISA positive |
Wantai EV-71 IgM ELISA negative |
Sensitivity |
Specificity |
Confirmed EV71 positive samples |
25 |
2 |
92.6%(25/27) |
-- |
Non-EV71 hand, foot and mouth diseases samples |
1 |
17 |
-- |
94.4%(17/18) |
► Study III - The correlation between the days from the onset of of symptoms and detectable rate using Wantai EV-71 IgM ELISA
Days from onset |
Positive number detected |
Total sample number |
Positive rate |
1 day |
23 |
26 |
88.5% |
2 days |
40 |
53 |
75.5% |
3 days |
35 |
42 |
83.3% |
4 days |
18 |
21 |
85.7% |
5-6 days |
50 |
50 |
100.0% |
7-10 days |
51 |
54 |
94.4% |
11-30 days |
52 |
57 |
91.2% |
31-41 days |
24 |
25 |
96.0% |
Total |
293 |
328 |
89.3% |
The results indicate that Wantai EV-71 IgM ELISA had a high detectable rate at the early period of infection with EV71. The average detectable rate was up to 86.5% within the first 1-6 days after onset of symptoms.
► Study IV - The correlation between the days from the onset of of symptoms and IgM antibodies level detected in the patients' serum using Wantai EV-71 IgM ELISA
 |
The detectable level of IgM antibodies increase gradually from the first day of onset, and up to maximum after 13-14 days, then decline gradually. IgM antibodies can be detected until even 40th day after onset.
► Study V - The cross reaction with CA16 using Wantai EV-71 IgM ELISA
 |
Few cross reaction with CA16 for Wantai EV-71 IgM ELISA. 28 samples infected with CA16 were detected positive, but there were only 3 samples of which the A values were over 0.3. However, there were only 12 samples of which A values were blow 0.3 among 206 EV71 infected samples which were detected positive.
