Monkeypox Test

Monkeypox testing is primarily conducted through molecular diagnostics, specifically PCR (Polymerase Chain Reaction) testing, which detects the DNA of the monkeypox virus. The preferred sample types for the test are swabs of skin lesions, including vesicular, pustular, or crust material, where viral loads tend to be highest. In some cases, blood, respiratory, or other body fluid samples can also be used, but the yield from these samples might be lower compared to lesion-based swabs.

PCR Testing Methodology

PCR testing for monkeypox virus relies on targeting specific regions of the viral genome, such as the hemagglutinin gene or specific open reading frames (ORFs) unique to the Orthopoxvirus genus. The test amplifies these genetic sequences, allowing for detection even in small quantities. Real-time PCR is commonly used due to its ability to quantify viral load and offer faster results.

Sample Collection and Handling

The accuracy of monkeypox testing is contingent on proper sample collection and handling. Swabs from lesions should be collected using synthetic fiber swabs and transported in viral transport medium (VTM) or dry if processed quickly. Samples must be stored at appropriate temperatures (2–8°C for short-term storage and -80°C for longer periods) to preserve viral integrity.

Diagnostic Interpretation

Positive results from the PCR test confirm the presence of monkeypox virus DNA in the sample, indicating an active infection. Negative results do not exclude infection, especially if clinical suspicion remains high, due to potential issues with sampling or viral load being below detectable limits. False negatives can occur if the test is conducted too early in the infection cycle, when viral shedding may be minimal.