Different longitudinal patterns of nucleic acid and serology testing results based on disease severity of COVID-19 patients.

Effective strategy to mitigate the ongoing pandemic of 2019 novel coronavirus (COVID-19) require a comprehensive understanding of humoral responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the emerging virus causing COVID-19. The dynamic profile of viral replication and shedding along with viral antigen specific antibody responses among COVID-19 patients started to be reported but there is no consensus on their patterns. Here, we conducted a serial investigation on 21 individuals infected with SARS-CoV-2 in two medical centres from Jiangsu Province, including 11 non-severe COVID-19 patients, and 5 severe COVID-19 patients and 5 asymptomatic carriers based on nucleic acid test and clinical symptoms. The longitudinal swab samples and sera were collected from these people for viral RNA testing and antibody responses, respectively. Our data revealed different pattern of seroconversion among these groups. All 11 non-severe COVID-19 patients and 5 severe COVID-19 patients were seroconverted during hospitalization or follow-up period, suggesting that serological testing is a complementary assay to nucleic acid test for those symptomatic COVID-19 patients. Of note, immediate antibody responses were identified among severe cases, compared to non-severe cases. On the other hand, only one were seroconverted for asymptomatic carriers. The SARS-CoV-2 specific antibody responses were well-maintained during the observation period. Such information is of immediate relevance and would assist COVID-19 clinical diagnosis, prognosis and vaccine design.

Characterization of a big family cluster infection associated with SARS-Cov-2 in Nanjing district (preprint)

Background: Outbreak of COVID-19 has brought catastrophe to huge numbers of families. However, even though numerous tragedies occurred, there were few reports about family cluster infection in the academic journals. Methods: The electronic medical records of 10 COVID-19 patients in a big family were retrospectively reviewed and analyzed.Results: These 10 patients, 4 males and 6 females, were infected through two successive family feasts during Spring Festival. The infection source was a family member at asymptomatic state, who lived in Hubei but travelled to Nanjing. The median age of these 10 patients was 61.5, with the oldest 95 and youngest 38. The incubation period varied from 3 to 17 days, with the median of 5.5. Of them, 2 patients were asymptomatic. The most common symptoms at onset were fever (6/10) and dry cough (6/10). All of them displayed lesions on the chest CT. 40% of them had leukopenia, neutropenia and lymphopenia. After anti-virus treatment, all the patients significantly improved and were discharged. Conclusions: SARS-Cov-2 was highly contagious and so crafty that a varied incubation period did exist. Part of patients might be asymptomatic, which was the potential source of transmission. More measures for protection or quarantine should be taken at home if family member had travel history nearby the epidemic area. 

Characterization of a big family cluster infection associated with SARS-Cov-2 in Nanjing district (preprint)

Background: Outbreak of COVID-19 has brought catastrophe to huge numbers of families. However, even though numerous tragedies occurred, there were few reports about family cluster infection in the academic journals. Methods: The electronic medical records of 10 COVID-19 patients in a big family were retrospectively reviewed and analyzed. Results: These 10 patients, 4 males and 6 females, were infected through two successive family feasts during Spring Festival. The infection source was a family member at asymptomatic state, who lived in Hubei but travelled to Nanjing. The median age of these 10 patients was 61.5, with the oldest 95 and youngest 38. The incubation period varied from 3 to 17 days, with the median of 5.5. Of them, 2 patients were asymptomatic. The most common symptoms at onset were fever (6/10) and dry cough (6/10). All of them displayed lesions on the chest CT. 40% of them had leukopenia, neutropenia and lymphopenia. After anti-virus treatment, all the patients significantly improved and were discharged. Conclusions: SARS-Cov-2 was highly contagious and so crafty that a varied incubation period did exist. Part of patients might be asymptomatic, which was the potential source of transmission. More measures for protection or quarantine should be taken at home if family member had travel history nearby the epidemic area. Keywords: COVID-19, SARS-Cov-2, family cluster, asymptomatic, incubation period.

Epidemiological and clinical characteristics of COVID-19 patients in Nanjing (preprint)

Background: Since December 2019, the outbreak of COVID-19 has spread quickly and thumped many countries and regions. The epidemic of central China was under the spotlight and attracted much more attentions. However, there are few reports describing COVID-19 patients in the regions outside of Wuhan, which are undergoing the change from sporadic imported cases to community-acquired transmission.Methods: The electronic medical records of 74 laboratory-confirmed patients of COVID-19 were retrospectively reviewed and analyzed. Their epidemiological, demographic, clinical and radiological characteristics were systematically summarized. The difference between severe patients and non-severe patients were also analyzed statistically.Results: The 74 COVID-19 patients were composed of 4 (5.4%) mild patients, 56 (75.7%) common patients, 13 (17.6%) severe patients and 1 (1.4%) critical patient. 43 were male, and 31 were female, with the average age 48.1±17.5. No significant difference of susceptibility was observed between genders, and almost people with all age were susceptible to SARS-CoV-2 infection. Before Jan 26, only imported sporadic cases were observed. However, from that day onward, family cluster infection cases increased dramatically, up to 70.3% (52/74), which were mainly from 15 family. The incubation period spanned from 0 to 19 days, with the median 5, and 81.4% had symptom onset within 7 days. At admission, 31.1% of patients had underlying diseases and the most common underlying diseases were hypertension (13.5%) and diabetes (5.4%). The most common symptoms were fever (90.5%), cough (75.7%), fatigue (36.5%) and chest distress (32.4%). 36.5% and 16.2% of patients had leukopenia and lymphocytopenia. 43.2% of patients had increased C reactive protein (CRP), and 40.5% had higher erythrocyte sedimentation rate (ESR) and 21.6% had higher calcitonin. 74.3% of patients had obvious lesions in both lung lobes and 56.8% of lesions manifested as ground glass opacity. Compared with non-severe group, the severe/critical group were significantly older and had more underlying diseases. After treatment, all patients improved and were discharged. No medical professional infection and death case were reported.Conclusion: The epidemic of COVID-19 in Nanjing were mainly caused by family cluster infection. The entire prevalence and illness were much milder than those of Wuhan. The disease of COVID-19 could be controlled and cured.