Genomic surveillance of SARS-CoV-2 and emergence of XBB.1.16 variant in Rajasthan.

PURPOSE: Genomic surveillance of positive SARS-CoV-2 samples is important to monitor the genetic changes occurring in virus, this was enhanced after the WHO designation of XBB.1.16 as a variant under monitoring in March 2023. From 5th February till May 6, 2023 all positive SARS-CoV-2 samples were monitored for genetic changes. METHODS: A total of 1757 samples having Ct value <25 (for E and ORF gene) from different districts of Rajasthan were processed for Next Generation Sequencing (NGS). The FASTA files obtained on sequencing were used for lineage determination using Nextclade and phylogenetic tree construction. RESULTS AND CONCLUSIONS: Sequencing and lineage identification was done in 1624 samples. XBB.1.16 was the predominant lineage in 1413 (87.0%) cases while rest was other XBB (207, 12.74%) and other lineages (4, 0.2%). Of the 1413 XBB.1.16 cases, 57.47% were males and 42.53% were females. Majority (66.53%) belonged to 19-59 year age. 84.15% of XBB.1.16 cases were infected for the first time. Hospitalization was required in only 2.2% cases and death was reported in 5 (0.35%) patients. Most of the cases were symptomatic and the commonest symptoms were fever, cough and rhinorrhea. Co-morbidities were present in 414 (29.3%) cases. Enhanced genomic surveillance helped to rapidly identify the spread of XBB variant in Rajasthan. This in turn helped to take control measures to prevent spread of virus and estimate public health risks of the new variant relative to the previously circulating lineages. XBB variant was found to spread rapidly but produced milder disease.

Outbreak investigation of Dengue like fever in rural area of Rajasthan.

During October 2020, suddenly many cases were reported with Dengue like Illness in Sahawa village, Rajasthan. Blood samples collected from 68 patients were tested for Dengue NS1 antigen and IgM antibodies for Dengue, Chikungunya, Scrub typhus, Leptospira and Brucella by ELISA, Dengue, Chikungunya and Zika viral RNA by multiplex Polymerase Chain Reaction (PCR), 41.17% samples were positive for Dengue; 25% were positive by Dengue PCR, 17.64% for NS1 Ag,14.70% for IgM ELISA, 20.58% were positive for antibodies either for Scrub typhus (4.41%), Leptospira (7.35%) or Brucella (10.29%). Dengue was seen in 41.17% cases and other etiological agents in 20.58% cases.

Co-infection of respiratory pathogens in SARS-CoV-2 positive patients at North West India, Rajasthan.

PURPOSE: Infection due to SARS-CoV-2 shows wide spectrum of disease from asymptomatic to severe disease and death. Coinfection of SARS-CoV-2 with other respiratory pathogens may affect the severity of disease and its outcome. Identification of other respiratory pathogens may help to initiate proper management and avoid unnecessary complications. MATERIALS AND METHODS: Total 250 SARS-COV-2 positive patients admitted in S.M.S hospitalwere included in study. Throat and nasopharyngeal swabs samples were collected in Viral Transport Medium (VTM) and nucleic acid extraction was done by automated EasyMag extractor and tested for 20 respiratory viruses and two bacteria by real time PCR. RESULTS: Out of 250 SARS CoV2 positive samples, 176 (70%) were positive for other respiratory pathogens also. The highest co-infection was due to HCoVOC43 (32.8%) virus followed by bacterial co-infection with S. pneumoniae (14.8%). Six (2.4%) patients with co-infection were on ventilator with age >65yr and three (1.2%) died during treatment. All three cases were found to have other co-morbid diseases like; asthma, Parkinson's and hypertension. CONCLUSION: High number of patients were found to have coinfection with other viruses and bacteria, timely identification and providing specific treatment to these patients can help improve outcome.

Genomic profile of SARS-CoV-2 Omicron variant and its correlation with disease severity in Rajasthan.

Background: Omicron, a new variant of Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2), was first detected in November 2021. This was believed to be highly transmissible and was reported to evade immunity. As a result, an urgent need was felt to screen all positive samples so as to rapidly identify Omicron cases and isolate them to prevent the spread of infection. Genomic surveillance of SARS-CoV-2 was planned to correlate disease severity with the genomic profile. Methods: All the SARS-CoV-2 positive cases detected in the state of Rajasthan were sent to our Lab. Samples received from 24 November 2021 to 4 January 2022 were selected for Next-Generation Sequencing (NGS). Processing was done as per protocol on the Ion Torrent S5 System for 1,210 samples and bioinformatics analysis was done. Results: Among the 1,210 samples tested, 762 (62.9%) were Delta/Delta-like and other lineages, 291 (24%) were Omicron, and 157 (12.9%) were invalid or repeat samples. Within a month, the proportion of Delta and other variants was reversed, 6% Omicron became 81%, and Delta and other variants became 19%, initially all Omicron cases were seen in international travelers and their contacts but soon community transmission was seen. The majority of patients with Omicron were asymptomatic (56.7%) or had mild disease (33%), 9.2% had moderate symptoms, and two (0.7%) had severe disease requiring hospitalization, of which one (0.3%) died and the rest were (99.7%) recovered. History of vaccination was seen in 81.1%, of the previous infection in 43.2% of cases. Among the Omicron cases, BA.1 (62.8%) was the predominant lineage followed by BA.2 (23.7%) and B.1.529 (13.4%), rising trends were seen initially for BA.1 and later for BA.2 also. Although 8.9% of patients with Delta lineage during that period were hospitalized, 7.2% required oxygen, and 0.9% died. To conclude, the community spread of Omicron occurred in a short time and became the predominant circulating variant; BA.1 was the predominant lineage detected. Most of the cases with Omicron were asymptomatic or had mild disease, and the mortality rate was very low as compared to Delta and other lineages.