[Clinical characteristics in patients with persistent positive pharyngeal swab of omicron variant and analysis on nucleic acid testing of anal swabs].

OBJECTIVE

To analyze the clinical characteristics in patients with persistent positive pharyngeal swab of 2019 novel coronavirus Omicron variant and results of nucleic acid testing of anal swabs to provide basis for prevention and control measures.

METHODS

This study included 93 patients whose pharyngeal swab nucleic acid test were persistent positive and admitted to the ward of Daping Hospital in the National Exhibition and Convention Center (Shanghai) Makeshift Hospital from May 1 to May 24, 2022. The gender, age, underlying diseases, vaccination status, clinical symptoms, interval between infection onset and anal sampling, length of hospital stay, the nucleic acid test result of pharyngeal swabs and anal swabs and the time turning negative were collected and analyzed.

RESULTS

The age of 93 patients ranged from 8 to 72 years old with a median of (46.0±16.0) years old. Among them, 30 cases (32.3%) were male and 63 cases (67.7%) were female. Sixty-five patients (69.9%) received 2-3 shots of vaccine, 2 patients (2.1%) received 1 shot, and 26 patients (28.0%) did not receive any vaccination. Twenty patients (21.5%) had underlying diseases, of which hypertension (13 cases, 14.0%) and type 2 diabetes mellitus (6 cases, 6.5%) were the most common. Twenty-four patients (25.8%) had asymptomatic infection and the rest (69 cases, 74.2%) had mild symptoms. Cough (50 cases, 53.8%) and sore throat (28 cases, 30.1%) were the most common clinical manifestations of the upper respiratory tract in these patients. Only 6 patients (6.5%) had gastrointestinal symptoms (including diarrhea in 5 patients and diarrhea with vomiting in 1 patient). Pharyngeal and anal swabs were collected simultaneously from all 93 patients at 8-16th days [(11.55±2.27) days] after 2019 novel coronavirus Omicron variant infection. The pharyngeal swabs were positive in 79 patients (85.0%) and the anal swabs were positive in 5 patients (5.4%). The time of pharyngeal swabs turning negative was (14.7±2.9) days, and that of anal swab turning positive was (14.2±1.9) days. The median length of hospital stay was (16.7±2.9) days.

CONCLUSIONS

In patients with persistent positive nucleic acid of the 2019 novel coronavirus Omicron variant, there were more mild infection than asymptomatic. The upper respiratory tract symptoms such as cough and sore throat were the most. The likelihood of transmission of 2019 novel coronavirus Omicron variant through the digestive tract may be low. The correlation between gastrointestinal symptoms and 2019 novel coronavirus Omicron variant RNA in the digestive tract is uncertain.