Dear Javed,

I am no expert in the area but would like to point you to some work that may help answer your question:

1. Evaluation of diagnostic tests: dengue

http://www.nature.com/nrmicro/journal/v8/n12_supp/full/nrmicro2459.html

2. Diagnosis of dengue virus infection with IgA anti Dengue rapid tests

http://www.xcdsystem.com/icid2012/55.011.html

3. Development of Dengue IgA Rapid Test for the Detection of Anti-dengue IgA from Dengue Infected Patients

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3162809/

4. Use of Saliva for Early Dengue Diagnosis

http://www.plosntds.org/article/info%3Adoi%2F10.1371%2Fjournal.pntd.0001046

I suspect IgA testing may be come very important in early diagnosis.

Amar

(Amar-Singh HSS, Malaysia)

by far the PCR based diagnosis gives the accurate result. IgA can be used but not solely for the dengue detection. however mostly used diagnosis test are either IgM ELISA or PCR. IgM titers appear near fifth day of infection.

There are a concept that specific IgA antidengue could be a good indicator for recent infection. Talarmin et al (J Clin Microbiol 1998, 36: 1189-1192) determined the presence of both IgM and IgA in the sera of 178 patients with classical dengue: the median time of detection was 3,8 days for IgM and 4,6 days for IgA. Since then most of commercial kits adopted the IgM for rapid diagnostic tests.

we have some experience of Ig A in dengue and it was quite useful in picking up the disease in first week ... better than IgM

There is a rapid KIT recently launched for IgA detection, ASSURE . I'm not sure about its sensitivity and specificity but you can read it ( attached I sent you 2 papers).

During the fisrt week of infection a combination of PCR and NS1 antigen detection are usually the best option. How IgA detection will improve dengue diagnostic in the early onset of diseases is still unknow.

IgA is known as a good indicator for Dengue virus infection,as stated by other workers as above.

Ig A can be detected in dengue, but unlike IgM for acute phase or IgG for convalescent phase there is no definite criteria for diagnosis using this. I hope levels are very low, which cannot correlated with diagnosis and its not in standard practice as well as not specific.

to be precise u cannot detect IgM within 0-3 days.... u just go for either RT-PCR or NS1 antigen detection......... and i would suggest go directly for NS1 antigen detection for 0-7 days rather than RT-PCR and MAC-ELISA beyond 7 days...... RT-PCR less sensitive than NS1 antigen detection... we observed in our routine diagnosis

There are some studies which demonstrated that Dengue IgA RT has a good performance and is applicable as one of the dengue early diagnostic tools

I have already given my views.I agree with the explanation given by Khaled Saad and others.which are conducive.