A computer implemented method for providing a viral infection status of at least one cell in a cell sample comprising receiving holographic information of the cell sample obtained by digital holographic microscopy, and determining from the holographic information, the viral infection status of the at least one cell, wherein the infection status is determined from cellular parameter data comprising one or more measured cellular parameters of the cell derived from the holographic information wherein the one or more measured cellular parameters, MCPs, comprises a subset of the MCPs of Table 1, where the subset comprises one or more MCP from at least one of the groups (a) Phase Texture (F40 to F51), (b) Refraction Peak (F20, F33-F37), wherein: the subset comprises one or more (group (a)) MCPs selected from F45 (ID PhaseCorrelationFeature), F44 (ID PhaseContrastFeature), F48 (ID PhaseSkewnessFeature), F47 (ID PhaseHomogeneityFeature), F43 (ID PhaseAverageUniformityFeature), F51 (ID PhaseUniformityFeature), and/or the subset comprises one or more (group (b)) MCPs selected from F20 (ID EquivalentPeakDiameterFeature), F33 (ID PeakAreaFeature), F34 (ID PeakAreaNormalizedFeature), F36 (ID PeakHeightFeature), F37 (ID PeakHeightNormalizedFeature), and/or the subset further comprises one or more MCPs of group (d) Optical Height (F24-F32, F38-F39), optionally selected from F27 (ID OpticalHeightMeanFeature), F32 (ID OpticalVolumeFeature), F38 (ID OpticalHeightStandardDeviationFeature), F39 (ID OpticalHeightStandardDeviationInMicronFeature), and/or the subset comprises: F45 (ID PhaseCorrelationFeature) and F44 (ID PhaseContrastFeature), or F45 (ID PhaseCorrelationFeature), F44 (ID PhaseContrastFeature), and F48 (ID PhaseSkewnessFeature), or F45 (ID PhaseCorrelationFeature), F44 (ID PhaseContrastFeature), F48 (ID PhaseSkewnessFeature), and F20 (ID EquivalentPeakDiameterFeature), or F45 (ID PhaseCorrelationFeature F44 (ID PhaseContrastFeature, F48 (ID PhaseSkewnessFeature, F20 (ID EquivalentPeakDiameterFeature, and F33 ((ID PeakAreaFeature or F34 (ID PeakAreaNormalizedFeature). the subset comprises one or more (group (a)) MCPs selected from F45 (ID PhaseCorrelationFeature), F44 (ID PhaseContrastFeature), F48 (ID PhaseSkewnessFeature), F47 (ID PhaseHomogeneityFeature), F43 (ID PhaseAverageUniformityFeature), F51 (ID PhaseUniformityFeature), and/or the subset comprises one or more (group (b)) MCPs selected from F20 (ID EquivalentPeakDiameterFeature), F33 (ID PeakAreaFeature), F34 (ID PeakAreaNormalizedFeature), F36 (ID PeakHeightFeature), F37 (ID PeakHeightNormalizedFeature), and/or the subset further comprises one or more MCPs of group (d) Optical Height (F24-F32, F38-F39), optionally selected from F27 (ID OpticalHeightMeanFeature), F32 (ID OpticalVolumeFeature), F38 (ID OpticalHeightStandardDeviationFeature), F39 (ID OpticalHeightStandardDeviationInMicronFeature), and/or the subset comprises: F45 (ID PhaseCorrelationFeature) and F44 (ID PhaseContrastFeature), or F45 (ID PhaseCorrelationFeature), F44 (ID PhaseContrastFeature), and F48 (ID PhaseSkewnessFeature), or F45 (ID PhaseCorrelationFeature), F44 (ID PhaseContrastFeature), F48 (ID PhaseSkewnessFeature), and F20 (ID EquivalentPeakDiameterFeature), or F45 (ID PhaseCorrelationFeature F44 (ID PhaseContrastFeature, F48 (ID PhaseSkewnessFeature, F20 (ID EquivalentPeakDiameterFeature, and F33 ((ID PeakAreaFeature or F34 (ID PeakAreaNormalizedFeature). F45 (ID PhaseCorrelationFeature) and F44 (ID PhaseContrastFeature), or F45 (ID PhaseCorrelationFeature), F44 (ID PhaseContrastFeature), and F48 (ID PhaseSkewnessFeature), or F45 (ID PhaseCorrelationFeature), F44 (ID PhaseContrastFeature), F48 (ID PhaseSkewnessFeature), and F20 (ID EquivalentPeakDiameterFeature), or F45 (ID PhaseCorrelationFeature F44 (ID PhaseContrastFeature, F48 (ID PhaseSkewnessFeature, F20 (ID EquivalentPeakDiameterFeature, and F33 ((ID PeakAreaFeature or F34 (ID PeakAreaNormalizedFeature).