Zika Virus IgM Antibody Found in West Nile Virus Patients
By LabMedica International staff writers Posted on 05 Oct 2021 |
Image: The Zika IgM antibody-capture, enzyme-linked immunosorbent assay (Zika MAC-ELISA) for antibody testing (Photo courtesy of the Centers for Diseases Control and Prevention).
West Nile virus (WNV) and Zika virus (ZIKV) are mosquito-borne viruses in the family Flaviviridae. Residents in, and travelers to, areas where the viruses are circulating are at risk for infection, and both viruses can cause an acute febrile illness.
In the contiguous USA, WNV disease is the most commonly reported arboviral disease, with about 2,000 to 6,000 reported cases each year. WNV disease presentations range from mild febrile illness to severe neuroinvasive disease. Almost all ZIKV disease cases in the continental USA are travel associated.
Vector Borne Disease experts at the Centers for Diseases Control and Prevention (CDC, Fort Collins, CO, USA) included serum samples from 153 persons with confirmed recent WNV infection in their analysis. The median age of patients was 59 years (range 10–92 years) and 53 (35%) were female. Samples were collected at a median of seven days (range 0–40 days) after symptom onset. Serum samples were tested for the presence of ZIKV IgM antibody with CDC's envelope protein antigen-based ZIKV IgM antibody capture-ELISA (Zika MAC-ELISA). A P/N value <2.0 was interpreted as negative, a P/N from 2.0 to <3.0 was equivocal, and a P/N ≥ 3.0 was positive.
The scientists reported that among 153 sera from patients with acute WNV infection, the ZIKV IgM antibody result was positive in 56 (37%; 95% confidence interval [CI] 29–44%) and equivocal in 28 (18%; 95% CI 13–25%). With 55% of samples having cross-reactive antibodies, it is important for health care providers to request appropriate testing based on the most likely cause of a patient's possible arboviral infection considering their clinical symptoms and signs, travel history, and place of residence. Patients were significantly more likely to have a ZIKV IgM antibody-positive or equivocal result if their sample had both WNV and St. Louis encephalitis virus (SLEV)-neutralizing antibodies, compared with patients with samples with only WNV-neutralizing antibodies (relative risk = 2.1), and this association was not modified by nor required adjustment for sex.
The authors concluded that for cases where the epidemiology does not support the preliminary IgM findings, confirmatory neutralizing antibody testing should be performed. These measures will avoid an incorrect diagnosis of ZIKV infection, based on cross-reactive antibodies, in a person truly infected with WNV. The study was published on July 22, 2021 in the journal Vector-Borne and Zoonotic Diseases.
Related Links:
Centers for Diseases Control and Prevention
In the contiguous USA, WNV disease is the most commonly reported arboviral disease, with about 2,000 to 6,000 reported cases each year. WNV disease presentations range from mild febrile illness to severe neuroinvasive disease. Almost all ZIKV disease cases in the continental USA are travel associated.
Vector Borne Disease experts at the Centers for Diseases Control and Prevention (CDC, Fort Collins, CO, USA) included serum samples from 153 persons with confirmed recent WNV infection in their analysis. The median age of patients was 59 years (range 10–92 years) and 53 (35%) were female. Samples were collected at a median of seven days (range 0–40 days) after symptom onset. Serum samples were tested for the presence of ZIKV IgM antibody with CDC's envelope protein antigen-based ZIKV IgM antibody capture-ELISA (Zika MAC-ELISA). A P/N value <2.0 was interpreted as negative, a P/N from 2.0 to <3.0 was equivocal, and a P/N ≥ 3.0 was positive.
The scientists reported that among 153 sera from patients with acute WNV infection, the ZIKV IgM antibody result was positive in 56 (37%; 95% confidence interval [CI] 29–44%) and equivocal in 28 (18%; 95% CI 13–25%). With 55% of samples having cross-reactive antibodies, it is important for health care providers to request appropriate testing based on the most likely cause of a patient's possible arboviral infection considering their clinical symptoms and signs, travel history, and place of residence. Patients were significantly more likely to have a ZIKV IgM antibody-positive or equivocal result if their sample had both WNV and St. Louis encephalitis virus (SLEV)-neutralizing antibodies, compared with patients with samples with only WNV-neutralizing antibodies (relative risk = 2.1), and this association was not modified by nor required adjustment for sex.
The authors concluded that for cases where the epidemiology does not support the preliminary IgM findings, confirmatory neutralizing antibody testing should be performed. These measures will avoid an incorrect diagnosis of ZIKV infection, based on cross-reactive antibodies, in a person truly infected with WNV. The study was published on July 22, 2021 in the journal Vector-Borne and Zoonotic Diseases.
Related Links:
Centers for Diseases Control and Prevention
Latest Immunology News
- Diagnostic Blood Test for Cellular Rejection after Organ Transplant Could Replace Surgical Biopsies
- AI Tool Precisely Matches Cancer Drugs to Patients Using Information from Each Tumor Cell
- Genetic Testing Combined With Personalized Drug Screening On Tumor Samples to Revolutionize Cancer Treatment
- Testing Method Could Help More Patients Receive Right Cancer Treatment
- Groundbreaking Test Monitors Radiation Therapy Toxicity in Cancer Patients
- State-Of-The Art Techniques to Investigate Immune Response in Deadly Strep A Infections
- Novel Immunoassays Enable Early Diagnosis of Antiphospholipid Syndrome
- New Test Could Predict Immunotherapy Success for Broader Range Of Cancers
- Simple Blood Protein Tests Predict CAR T Outcomes for Lymphoma Patients
- Cell Sorter Chip Technology to Pave Way for Immune Profiling at POC
- Chip Monitors Cancer Cells in Blood Samples to Assess Treatment Effectiveness
- Automated Immunohematology Approaches Can Resolve Transplant Incompatibility
- AI Leverages Tumor Genetics to Predict Patient Response to Chemotherapy
- World’s First Portable, Non-Invasive WBC Monitoring Device to Eliminate Need for Blood Draw
- Predictive T-Cell Test Detects Immune Response to Viruses Even Before Antibodies Form
- Single Blood Draw to Detect Immune Cells Present Months before Flu Infection Can Predict Symptoms