Characteristics and outcomes of COVID-19 patients during the BA.5 omicron wave in Tehran, Iran: a prospective observational study

Abstract

Background Omicron (B.1.1.529) is the fifth variant of concern of SARS-CoV-2, which has several subvariants. Clinical features of BA.1 and BA.2 infections have been described in the literature, but we have limited information about the clinical profile of BA.5, which caused the seventh wave in Iran. Methods A prospective observational study was conducted on the BA.5 confirmed patients referred to Imam Khomeini Hospital Complex, Tehran, Iran, from 11th to 31st August 2022. The patients were divided into the two groups of outpatients and hospitalized patients, and their clinical, radiological, and laboratory data and outcomes were recorded and analyzed. Results We included 193 patients with confirmed BA.5 infection, of whom 48 patients (24·8%) were hospitalized. The mean age of the patients was 45·3 ± 16·5 years, and 113 patients (58·5%) were female. The mean number of days patients had symptoms was 6·8 ± 2·4 days. The most common symptoms were weakness (69·9%), sore throat (67·4%), myalgia (66·3%), hoarseness (63·7%), headache (55·4%), fatigue (54·9%), and dry cough (50·3%). Fever and dyspnea were significantly more observed in the hospitalized patients (p < 0·0001). The COVID-19 vaccination rate was significantly lower in hospitalized patients than in outpatients (35/48–72·9% vs. 140/145 − 96·6%, p < 0·0001). The most common underlying diseases were hypertension (16·1%), diabetes mellitus (9·8%), and cardiovascular diseases (9·8%), all of which were significantly more common in hospitalized patients. Lung opacities were observed in 81·2% of hospitalized patients. By the end of our study, 1·5% of patients died despite receiving critical care services. Conclusions Our findings suggested that BA.5 symptoms are more non-respiratory and usually improve within 7 days. Although the proportion of hospitalized patients is still significant, very few patients require intensive care. COVID-19 vaccination is effective in reducing the hospitalization rate. Trial registration Not applicable. This study is not a clinical trial.

Performance characteristics of INDICAID antigen rapid diagnostic test on SARS-CoV-2 samples during the omicron wave in Cameroon

“…This was corrected by collecting two swabs from every participant at enrolment in the study, one for the INDICAID™ Ag-RDT and the other one destined to the RT-PCR. In the meantime, it is important to recall that excellent agreement at CT < 25 was observed in spite of the very few cases at this threshold; which was due to the low pathogenicity of omicron-driven infection as described elsewhere [ 8 , 9 , 32 , 33 ].…”

“…Interestingly, these results also prove that the current state of the pandemic is mostly driven by low-level viremia (CT > 25) and, thus low symptomatology in our context [ 11 , [25] , [26] , [27] ]. This is not surprising at all, as all sequences obtained were omicron BA.1.H sub-variants; which has been associated with very few symptoms worldwide[ 8 , 9 , 32 , 33 ]. However, previous reports highlighted that rapid COVID-19 tests miss 90 % of asymptomatic cases [ [34] , [35] ].…”