Utility of MGG and Papanicolaou stained smears in the detection of Mucormycosis in nasal swab/scraping/biopsy samples of COVID 19 patients

Severe mold fungal infections in critically ill patients with COVID-19

The SARS-CoV-2 pandemic put an unprecedented strain on modern societies and healthcare systems. A significantly higher incidence of invasive fungal co-infections was noted compared with the pre-COVID-19 era, adding new diagnostic and therapeutic challenges in the critical care setting. In the current narrative review, we focus on invasive mold infections caused by Aspergillus and Mucor species in critically ill COVID-19 patients. We discuss up-to-date information on the incidence, pathogenesis, diagnosis and treatment of these mold-COVID-19 co-infections, as well as recommendations on preventive and prophylactic interventions. Traditional risk factors were often not recognized in COVID-19-associated aspergillosis and mucormycosis, highlighting the role of other determinant risk factors. The associated patient outcomes were worse compared with COVID-19 patients without mold co-infection.

Sensitivity of liquid-based cytology in the diagnosis of mucormycosis in COVID-19 treated patients

BACKGROUND

The coronavirus disease 2019 (COVID-19) infection caused by the novel severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) is associated with a wide range of disease patterns, ranging from mild to life-threatening pneumonia. COVID-19 can be associated with a suppressed immune response and/or hyperinflammatory state due to cytokine storm. Reduced immunity, combined with steroid usage to prevent cytokine storm along with various pre-existing co morbidities can prove to be a fertile ground for various secondary bacterial and fungal infection, including mucormycosis. Diagnosis of mucor is a challenging task given high negativity rate of various detection methods. While histopathology is considered the gold standard, the acquisition of necessary tissue biopsy specimens requires invasive procedures and is time consuming.

METHOD

In this study various methods of mucor detection, like conventional cytopathology (CCP), liquid-based cytology (LBC, BD SurepathTM ), potassium hydroxide mount (KOH) preparation, culture and histopathology were analysed. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for various methods.

RESULTS

This study showed that LBC has sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 72.4%,100%,100% and 38.4% respectively.

CONCLUSION

This study showed that, liquid-based cytology (LBC) can be a rapid and effective alternative to histopathology in mucor diagnosis.