Reprocessing of N95 masks: Experience from a resource-limited setting in India.

OBJECTIVES: Due to the surge in demand for N95 masks during the Covid-19 pandemic, and considering the situation in countries grappling with acute shortages of N95 masks, this study investigated the possibilities of decontamination and reuse of masks. METHODS: Three N95 masks of different makes (A, B and C) were subjected to six decontamination methods: ultraviolet (UV) irradiation, isopropyl alcohol (IPA) dip, plasma sterilization (Sterrad®), ethylene oxide (ETO, 3M®), dry heat sterilization, and moist heat sterilization (autoclaving). The integrity of the N95 masks was assessed by measuring their particle filtering efficiency at particle sizes ranging 0.3-0.5 microns. RESULTS: All the masks decontaminated with ETO and plasma sterilization retained over 95% particle filtering efficiency. Masks decontaminated using IPA dip and autoclaving showed a drop, and UV irradiation showed variations in particle size efficiency degradation after decontamination. CONCLUSIONS: Plasma sterilization is recommended for decontamination of N95 masks in low-resource settings. ETO is not recommended due to hazards associated with handling of ethylene oxide, although the filtering efficiency was retained. Since the UV irradiation method showed variations in results, evaluation of UV decontamination for N95 masks needs to be performed on a case-by-case basis.

The mutational analysis unveils the distribution of G614 genotype of SARS-CoV-2in different Indian states and its association with case fatality rate of COVID-19

Pan genomic analysis of the global SARS-CoV-2 isolates has resulted in the identification of several regions of increased genetic variation but there is absence of research on its association with the clinical outcome. The present study fills the vacuum and does mutational analysis of genomic sequence of Indian SARS-CoV-2 isolates. Results reveal the existence of non-synonymous G614 spike protein mutation in 61.45% of the total study genome along with three other mutations. Further, temporal variation in the frequencies of G614 genotype in the country is observed. The examination of the probable association of G614 genotype with COVID-19 severity shows that CFR G614 genotype in India is positively and strongly correlated. It appears that the clinical outcome of the COVID-19 cases in India are significantly and adversely affected by the increasing trend in the G614 genotype; which needs to be addressed combining both laboratory experiments and epidemiological investigations.

Improvement of PCR for detection of Opisthorchis viverrini DNA in human stool samples.

Opisthorchis viverrini is an important food-borne trematode in Southeast Asia. The infection causes significant morbidity in terms of hepatobiliary diseases and cholangiocarcinoma. The aim of this study was to improve the sensitivity of the PCR-based diagnosis of O. viverrini infection. A new fecal DNA extraction protocol for the detection of O. viverrini DNA using cetyltrimethyl-ammoniumbromide to remove PCR inhibitor was used and compared with the commercial stool kit method. The sensitivity of the new test was 79.3%, compared with the 44.8% of the previous method (P < 0.01). PCR-positive tests identified several cases judged parasite negative by the parasitological method (28.6%), indicating the new test's advantage in the diagnosis of individuals with light infections.