Neglected SARS-CoV-2 variants and potential concerns for molecular diagnostics: a framework for nucleic acid amplification test target site quality assurance

IMPORTANCE

Molecular tests like polymerase chain reaction were widely used during the COVID-19 pandemic but as the pandemic evolved, so did SARS-CoV-2. This virus acquired mutations, prompting concerns that mutations could compromise molecular test results and be falsely negative. While some manufacturers may have in-house programs for monitoring mutations that could impact their assay performance, it is important to promptly report mutations in circulating viral strains that could adversely impact a diagnostic test result. However, commercial test target sites are proprietary, making independent monitoring difficult. In this study, SARS-CoV-2 test target sites were sequenced to monitor and assess mutations impact, and 29 novel mutations impacting SARS-CoV-2 detection were identified. This framework for molecular test target site quality assurance could be adapted to any molecular test, ensuring accurate diagnostic test results and disease diagnoses.

Cerebral perfusion scanning in treating AIDS dementia: a pilot study

Acquired immunodeficiency syndrome (AIDS) dementia complex (ADC) is a common effect of the AIDS virus. We studied the regional cerebral blood flow of patients with early ADC and its response to atevirdine mesylate.

METHODS

Ten men with early ADC, who had failed or were intolerant to zidovudine or didanosine therapy, were treated with atevirdine mesylate for 12 wk. Cerebral perfusion SPECT using 99mTc-HMPAO was performed at Week 0 and Week 12. SPECT images were analyzed qualitatively and semiquantitatively.

RESULTS

The cerebral perfusion abnormalities in early ADC were usually mild and characteristically involved the cortices and periventricular regions bilaterally and symmetrically. Four patients were able to complete the protocol. Three of these patients responded to atevirdine clinically, two of whom showed improvement in their Week 12 SPECT images. The other responder had an essentially unchanged image. The patient who did not respond to atevirdine showed a definite deterioration in cerebral perfusion.

CONCLUSION

Cerebral perfusion SPECT is useful in detecting and assessing therapeutic responses in ADC. The preliminary results of atevirdine in treating ADC are promising and need further investigation.

Phage-typing and drug-resistance patterns as tools in mycobacterial epidemiology

Phage-typing by itself was not sufficient to delineate the boundaries of a mini-epidemic of tuberculosis in upstate New York. Drug-resistance patterns were needed as well. In a small upstate community, 79% of 14 isolates tested were resistant to one or more of the antituberculosis drugs. Of 15 isolates with phage types determined, 47% were type 1(13), 27% were type 7(7, 13), and 27% were type 1(7, 12, 13). By combining phage-typing and sensitivity testing, we were able to demonstrate that 4 or possibly 5 of the 7 phage-type 1(13) strains are epidemiologically related.

Postulated sources of Mycobacterium intracellulare and Mycobacterium scrofulaceum infection: isolation of mycobacteria from estuaries and ocean waters

Mycobacteria biochemically and serologically similar to those isolated from humans have been found in estuaries and ocean waters in the south-eastern United States. This is consistent with the hypothesis that aerosols from these waters are one potential source of infection with these mycobacteria.

The tween opacity test as an aid in classification of mycobacteria

The Tween opacity test can be used to differentiate (1) Mycobacterium flavescens from Mycobacterium gordonae and Mycobacterium szulgai, and (2) nonphotochromogenic strains of Mycobacterium kansaii from strains of the Mycobacterium terrae complex.

A mycobacteriology proficiency testing program using simulated sputum specimens

The New York State Department of Health proficiency testing program in mycobacteriology determines the ability of a laboratory to isolate the acid-fast bacillus present in a simulated specimen and to identify the strain. Until 1964 the specimens were autoclaved normal sputa seeded with mycobacteria. When mandatory testing was introduced by law in 1964, more specimens were needed. These have been prepared in simulated sputum bases, first skimmed milk, then granulated hog gastric mucin. The bases are seeded with Mycobacterium tuberculosis and other mycobacteria; Pseudomonas aeruginosa is added to simulate the contamination in clinical specimens. Laboratory performance in general has improved as a result of the proficiency testing and the concomitant educational program, but laboratories processing more than 200 specimens a year continue to perform best.

Enhancing effects of carbon dioxide on the primary isolation of acid-fast bacilli in a modified Lowenstein-Jensen medium

Specimens inoculated on modified Lowenstein-Jensen medium were incubated aerobically and in an atmosphere of 8% CO(2). Sixteen per cent of the positive specimens grew Mycobacterium tuberculosis only after incubation in CO(2).