Co-positivity of anti-dengue virus and anti-Japanese encephalitis virus IgM in endemic area: co-infection or cross reactivity?
OBJECTIVE
To report high co-positivity of anti-dengue virus (DV) and anti-Japanese encephalitis virus (JEV) IgM in an area endemic for both the viruses and to discuss the possibilities of co-infection.


METHODS
Serum samples from the patients who presented with fever, suspected central nervous system infection and thrombocytopenia, were tested for anti-DV IgM and anti-JEV IgM antibodies. Conventional reverse transcriptase polymerase chain reaction was done for detection of DV RNA and JEV RNA.


RESULTS
Of 1 410 patient sera tested for anti-DV and anti-JEV antibodies, 129 (9.14%) were co-positive for both. This co-positivity was observed only in those months when anti-JEV IgM positivity was high. Titers of both anti-DV IgM and anti-JEV IgM were high in most of the co-positive cases. Among these 129 co-positive cases, 76 were tested by conventional reverse transcriptase polymerase chain reaction for both flaviviruses, of which eight cases were co-positive for DV and JEV.


CONCLUSIONS
Co-infection with more than one flavivirus species can occur in hyperendemic areas.
Department of Microbiology, K.G. Medical University, Lucknow-226003, India.
Kaleshwar Prasad
KP
Singh
Department of Microbiology, K.G. Medical University, Lucknow-226003, India.
Gitika
G
Mishra
Department of Microbiology, K.G. Medical University, Lucknow-226003, India.
Parul
P
Jain
Department of Microbiology, K.G. Medical University, Lucknow-226003, India.
Nidhi
N
Pandey
Department of Microbiology, K.G. Medical University, Lucknow-226003, India.
Rachna
R
Nagar
Department of Microbiology, K.G. Medical University, Lucknow-226003, India.
Shikha
S
Gupta
Department of Microbiology, K.G. Medical University, Lucknow-226003, India.
Shantanu
S
Prakash
Department of Microbiology, K.G. Medical University, Lucknow-226003, India.
Om
O
Prakash
Department of Microbiology, K.G. Medical University, Lucknow-226003, India.
Danish Nasar
DN
Khan
Department of Microbiology, K.G. Medical University, Lucknow-226003, India.
Sakshi
S
Shrivastav
Department of Microbiology, K.G. Medical University, Lucknow-226003, India.
Desh Deepak
DD
Singh
Department of Microbiology, K.G. Medical University, Lucknow-226003, India. Electronic address: amita602002@yahoo.com.
Amita
A
Jain
D000293:Adolescent; D000914:Antibodies, Viral / Q000097:blood*; D002648:Child; D015331:Cohort Studies; D060085:Coinfection / Q000097:blood / Q000276:immunology*; D003429:Cross Reactions; D003715:Dengue / Q000097:blood / Q000276:immunology*; D003716:Dengue Virus / Q000276:immunology*; D004664:Encephalitis Virus, Japanese / Q000276:immunology*; D004672:Encephalitis, Japanese / Q000097:blood / Q000276:immunology*; D019353:Endemic Diseases; D005260:Female; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood*; D007194:India / Q000453:epidemiology; D008297:Male
D000914:Antibodies, Viral; D007075:Immunoglobulin M
Co-circulation; Co-infection; Dengue virus; IgM; Japanese encephalitis virus; Reverse transcriptase polymerase chain reaction