Prevalence and detection of SARS-CoV-2 by RT-PCR: an analytical study

Background: The COVID-19 pandemic has significantly affected the healthcare system. RT-PCR has played a major role in the confirmation of SARS-CoV-2 thus helping in an early diagnosis, clinical interventions and patient isolation. This study was conducted to ascertain the importance of RT-PCR testing among symptomatic and asymptomatic cases in different age groups with association to infection.  Methods: This retrospective cohort study was conducted from August 2020 to August 2021, in the Department of Microbiology, Autonomous State Medical College and Sarojini Naidu Memorial Hospital, Firozabad, Uttar Pradesh, India. Samples were collected from a total of 342, 281 cases which comprised of symptomatic patients (ILI, SARI), asymptomatic contacts, those seeking hospitalization, travelers and were subjected to testing by RT-PCR. The cases were divided into group A of patients presenting with symptoms ≤7 days, group B of patients with signs and symptoms >7 days and group C comprised of asymptomatic cases. The symptoms of patients were associated with the Ct values of the E/N screening gene and the RdRp/ORF1ab confirmatory genes. The Chi-square test was done to test the statistical significance of association of symptomatic patients with the outcome of the test. Results: The number of positive samples were 4,342 showing a prevalence of 1.3%. The maximum prevalence of infection was found in the age group of 20-29 years followed by the age group 30-39 years (p-value <0.05). The maximum positivity and high viral load were seen in the patients who presented with symptoms ≤7 days with Ct values ≤25. Conclusion: The maximum infection was found in the young age group. The screening and confirmatory genes could be detected in the samples of asymptomatic cases also which was helpful in isolating them and breaking the chain of further spread of the virus

Dark secrets behind the shimmer of contact lens: the Indian scenario

<p>Abstract</p> <p>Background</p> <p>We studied the bacteriological profile of soft contact lens and its accessories among the asymptomatic subjects and monitored the compliance level with the lens use and its cleaning protocol.</p> <p>Findings</p> <p>A total of 115 (104 daily wear and 11 extended wear) subjects using contact lens were studied. Data regarding the duration of use and frequency and method of cleaning were recorded. Contact lens, lens cases, preserving solutions and tips of solution bottles were the samples collected. The isolates were identified on the basis of their phenotypic characters. Samples from 24 subjects (21 daily wear and 3 extended wear) were found contaminated. Of the 24 contaminated cases, 23 showed medium adherence to the cleaning protocol. Contamination rate was higher among the 56 daily wear lens users who used same lens for 2 years and more, than the 48 users who used their lenses for less than 2 years. Lens case contamination was found in all the 24 cases. The bacteria isolated were <it>Citrobacter freundii, Escherichia coli</it>, <it>Klebsiella pneumoniae, Pseudomonas aeruginosa</it>, <it>Staphylococcus epidermidis </it>and <it>Streptococcus pneumoniae</it>. In extended wear lens users, there was no change in microbial flora on repeating the cultures on day 7 and 14.</p> <p>Conclusion</p> <p>Non-compliance with contact lens use may lead to invitation of microbial flora. The accumulation of these bacteria may act as a precursor to biofilm formation, thus colonizing the lens accessories as well. The bacteria isolated in this study were similar to the ones causing microbial keratitis thus, predisposing the otherwise asymptomatic subjects to permanent visual damage.</p

A multiattribute utility evaluation of different methods for the detection of enteric protozoa causing diarrhea in AIDS patients

<p>Abstract</p> <p>Background</p> <p>Enteric protozoa and sporozoa have emerged as important opportunistic parasites and can cause fatal infections in AIDS patients. The line of treatment being different for them necessitates an accurate and prompt identification of these to avoid empirical treatment. In this study which is the first of its kind from India we did a comprehensive evaluation of different techniques, comparing them on the basis of the attributes like yield, cost, time taken, expertise and infrastructure. For the first time combination of Calcoflour White and DAPI, a nuclear stain, were used to identify <it>Microsporidia </it>spp. Thus, a diagnostic protocol was devised for rapid, sensitive and cost effective identification of the opportunistic enteric protozoa.</p> <p>Results</p> <p>The organisms isolated from the stool samples of the cases (450 HIV patients) were predominantly <it>Cryptosporidium </it>spp., <it>Microsporidia </it>spp. and <it>Cyclospora </it>spp. Interestingly, the control group (200 relatives of the patients who were HIV negative) showed a high incidence (21%) of <it>Cryptosporidium </it>spp. We found a significant increase in the sensitivity of microscopy in detecting <it>Cryptosporidium </it>spp. and <it>Cyclospora </it>spp. after formol ether concentration. Kinyoun's staining was better compared to Modified safranin staining for <it>Cryptosporidium </it>spp. identification. Although ELISA had a sensitivity of 93.25% and specificity of 97% for <it>Cryptosporidium </it>spp. detection, we ranked Kinyoun's staining better than ELISA because it is not affordable to most of our patients. For detecting <it>Cyclospora cayetanensis</it>, autoflourescence was the easiest and most cost effective method followed by Safranin technique. Combination of Calcoflour White stain and DAPI gave good results for the identification of <it>Microsporidia </it>spp. We assessed the above techniques and graded the attributes in the following descending order: cost effectiveness, sensitivity, ease of use and interpretation, time taken for the procedure and batch testing.</p> <p>Conclusion</p> <p>Thus, we conclude that a combination of minimum three procedures should be carried out for the screening of stool specimens of HIV positive patients. Kinyoun's staining should be made mandatory for every diarrheal stool sample from HIV patients. Also every laboratory should assign its own value to the attributes and apply Multiattribute utility theory or the Analytical hierarchy process to decide the most appropriate methodology.</p

Correlation between CD4 counts of HIV patients and enteric protozoan in different seasons – An experience of a tertiary care hospital in Varanasi (India)

<p>Abstract</p> <p>Background</p> <p>Protozoan infections are the most serious among all the superimposed infections in HIV patients and claim a number of lives every year. The line of treatment being different for diverse parasites necessitates a definitive diagnosis of the etiological agents to avoid empirical treatment. Thus, the present study has been aimed to elucidate the associations between diarrhoea and CD4 counts and to study the effect of HAART along with management of diarrhoea in HIV positive patients. This study is the first of its kind in this area where an attempt was made to correlate seasonal variation and intestinal protozoan infestations.</p> <p>Methods</p> <p>The study period was from January 2006 to October 2007 wherein stool samples were collected from 366 HIV positive patients with diarrhea attending the ART centre, inpatient department and ICTC of S.S. hospital, I.M.S., B.H.U., Varanasi. Simultaneously, CD4 counts were recorded to assess the status of HIV infection vis-à-vis parasitic infection. The identification of pathogens was done on the basis of direct microscopy and different staining techniques.</p> <p>Results</p> <p>Of the 366 patients, 112 had acute and 254 had chronic diarrhea. The percentages of intestinal protozoa detected were 78.5% in acute and 50.7% in chronic cases respectively. Immune restoration was observed in 36.6% patients after treatment on the basis of clinical observation and CD4 counts. In 39.8% of HIV positive cases <it>Cryptosporidium </it>spp. was detected followed by <it>Microsporidia </it>spp. (26.7%). The highest incidence of intestinal infection was in the rainy season. However, infection with <it>Cyclospora </it>spp. was at its peak in the summer. Patients with chronic diarrhea had lower CD4 cell counts. The maximum parasitic isolation was in the patients whose CD4 cell counts were below 200 cells/μl.</p> <p>Conclusion</p> <p>There was an inverse relation between the CD4 counts and duration of diarrhea. <it>Cryptosporidium </it>spp. was isolated maximum among all the parasites in the HIV patients. The highest incidence of infection was seen in the rainy season.</p