Evaluation of an Immunoglobulin E Capture Enzyme-Linked Immunosorbent Assay for the Early Diagnosis of Dengue.

Dengue virus (DENV) is the etiological agent of dengue, the most important mosquito-transmitted viral disease of humans worldwide. Enzyme-linked immunosorbent assays (ELISAs) designed to detect DENV IgM are commonly used for dengue diagnosis. However, DENV IgM is not reliably detected until ≥4 days after illness onset. Reverse transcription-polymerase chain reaction (RT-PCR) can diagnose early dengue but requires specialized equipment, reagents, and trained personnel. Additional diagnostic tools are needed. Limited work has been performed to determine whether IgE-based assays can be used for the early detection of vector-borne viral diseases, including dengue. In this study, we determined the efficacy of a DENV IgE capture ELISA for the detection of early dengue. Sera were collected within the first 4 days of illness onset from 117 patients with laboratory-confirmed dengue, as determined by DENV-specific RT-PCR. The serotypes responsible for the infections were DENV-1 and DENV-2 (57 and 60 patients, respectively). Sera were also collected from 113 dengue-negative individuals with febrile illness of undetermined etiology and 30 healthy controls. The capture ELISA detected DENV IgE in 97 (82.9%) confirmed dengue patients and none of the healthy controls. There was a high false positivity rate (22.1%) among the febrile non-dengue patients. In conclusion, we provide evidence that IgE capture assays have the potential to be explored for early diagnosis of dengue, but further research is necessary to address the possible false positivity rate among patients with other febrile illnesses.

Detection of hand, foot and mouth disease in the yucatan peninsula of Mexico.

We report a case of hand, foot and mouth disease (HFMD) in a 5-year-old male from Merida City in the Yucatan Peninsula of Mexico. A clinical and physical examination revealed that the patient had symptoms typical of HFMD, including fever, fatigue, odynophagia, throat edema, hyperemia, lesions on the hands and feet, and blisters in the oral cavity. The patient fully recovered after a convalescence period of almost three weeks. Reverse transcription-polymerase chain reaction and nucleotide sequencing revealed that the etiological agent was enterovirus 71 (EV71). The sequence has greatest (90.4%) nucleotide identity to the corresponding regions of EV71 isolates from the Netherlands and Singapore. Although HFMD is presumably common in Mexico, surprisingly there are no data in the PubMed database to support this. This case report provides the first peer-reviewed evidence of HFMD in Mexico.