Detection of dengue virus serotype 3 in Cajamarca,Peru:Molecular diagnosis and clinical characteristics

Objective:To describe and molecularly characterize an outbreak of dengue virus(DENV)infection in Cajamarca,an Andean region in Peru.Methods:A total of 359 serum samples from patients with acute febrile illness were assessed for the presence of DENV via RT-PCR,ELISA NS1,Ig M and Ig G in Cajamarca,Peru from January 2017 to June 2017.The evaluation of the different diagnostic tests and their applicability was performed.Results:Dengue virus was detected in 24.7%of samples by RTPCR.Meanwhile,serological analysis detected 30.3%positive cases via ELISA NS1 antigen,16.7%via ELISA Ig G and 9.7%via ELISA Ig M.Most of the cases corresponded to DENV-3(77.5%).The use of RT-PCR performed better in primary infections(P<0.01),while detection of ELISA Ig M performed better in secondary infections(P<0.01).The combination of NS1 and Ig M performed better than the other assays in detecting primary(92.5%)and secondary infections(96.6%).The most frequent symptoms associated with fever were headaches,myalgias,and arthralgias across all groups.Conclusions:We report an important outbreak of dengue infection caused by DENV-3 in Cajamarca,Peru.Our findings encourage the use of NS1 antigen and Ig M co-detection.These findings demonstrate an increasing expansion of DENV-3 in Peru and highlight the importance of molecular diagnosis and serotype characterization among the clinically defined dengue cases to strengthen the Peruvian epidemiological surveillance.