INTRODUCTION

The evolutionary variability of the monkeypox virus requires improvement of differential diagnostics. In the Russian Federation, the virus is classified as one of the most dangerous pathogens. A complex procedure for delivering samples to the laboratory for identification is required. On-site analysis or sample inactivation and preservation without loss of specific analytes can simplify the procedure. Formaldehyde treatment is considered reliable. The ELISA method can confirm the results of laboratory detection of viral DNA, provided that it is adapted to the analysis of treated samples.

MATERIAL AND METHODS

The antigen preparation was prepared by infecting a monolayer of Vero cells with the hMpxV/Russia/St.Petersburg-02/2022 strain, followed by inactivation of one aliquot with 8% formaldehyde solution. To detect the antigen in the native and inactivated preparation, an experimental test system containing a peroxidase conjugate of monoclonal antibodies to the A29L protein as the main reagent was used in non-instrumental and instrumental formats.

RESULTS

The virus was detected without use of instruments in the native preparation and using instruments in the inactivated preparation without any difference in sensitivity.

Formaldehyde inactivation reduced the sensitivity of detection of the treated preparation in the non-instrumental ELISA format by 100 times with an equal increase in the sensitivity of detection in the instrumental format of the native preparation.

CONCLUSION

For differential diagnostic purposes, cases of monkeypox can be confirmed by ELISA on-site of a native preparation or delivered to the laboratory a formaldehyde-treated antigen preparation.