Development and Evaluation of a Molecular Test for Monkeypox Virus in the Federal District, Brazil

Monkeypox virus, the etiological agent of Mpox, is a double-stranded DNA virus belonging to the Orthopoxvirus genus that has attracted increasing attention due to sporadic outbreaks in humans. In 2022, it was responsible for the largest Mpox outbreak outside the African continent, infecting over 117,000 individuals worldwide. In Brazil, since the first confirmed case in June 2022, more than 13,000 people have been diagnosed with the virus.

In July 2022, we developed the first molecular test for the detection of monkeypox virus in the Midwest region of the country, allowing the diagnosis of the disease in various patients, mainly residents of the Federal District. Thus, in this work, we present the validation of a laboratory-developed qPCR test (LDT) for monkeypox virus detection, as well as a retrospective epidemiological analysis based on laboratory results.

The developed qPCR test demonstrated 100% accuracy, with a detection limit of 21.25 copies per reaction, and was validated for samples from swabbed pustule exudates and lesion crusts. To date, 295 tests have been conducted, with 88 (30%) returning positive. The positivity rate was 41.15% in male patients and 2.41% in female patients. A peak in positivity was observed in August 2022. From 2023 to 2024, there was a marked decline in test demand with occasional positive results.

The rapid implementation of the test by our laboratory allowed for an immediate response to patients and provided important data for understanding the dynamics of monkeypox virus spread in Brazil, particularly in the Midwest region.