Many have dengue despite negative antigen test: Study
The joint study by the Society for Medical Virologists, Bangladesh and the US-Bangla Medical College conducted dengue NS-1, antibody and PCR tests on 197 potential dengue patients, who were suffering from the fever for up to a week.
Many patients with symptoms of dengue may test negative on the widely used NS-1 antigen test, but still have the mosquito-borne virus infection, a new study shows.
The joint study by the Society for Medical Virologists, Bangladesh and the US-Bangla Medical College conducted dengue NS-1, antibody and PCR tests on 197 potential dengue patients, who were suffering from the fever for up to a week.
Dengue virus was detected in 68 or 34.5% of the patients by PCR method, while 28 or 41% of the 68 patients tested negative for NS-1.
The study, titled "Performance of dengue NS-1 test and dengue virus serotype determination amid ongoing dengue outbreak," was led by Dr Ruksana Raihan, associate professor of the microbiology department at US-Bangla Medical College and also the science affairs secretary of the Society for Medical Virologists, Bangladesh (SMVB).
"Dengue PCR test is a universally accepted method to confirm dengue virus infection in the human body. In many cases, doctors suspect dengue and initially recommend only the dengue NS-1 test. In some cases, the patient tests for dengue NS-1 on his own initiative without consulting a doctor," reads a SMVB press release.
The negative results of the NS-1 test make many people think that they do not have dengue, but later suffer from various complications related to dengue. In such cases, many times it is not possible for the doctors to recover the patient, according to the release.
In the study, of the 68 dengue patients with PCR positive results, 63 had Den-2 variant, four had Den-3 and one had both Den-2 and Den-3 variants.
Researchers suggest that dengue NS-1 test results are more likely to be negative in cases of Den-2 variant infection.
The Den-3 serotype of dengue has been more common in Bangladesh in the last few years.
However, as per the few studies conducted so far this year, the prevalence of the Den-2 variant was higher, which researchers believe as one of the main reasons behind the overwhelming number of negative NS-1 results.