[Change in serum IgG antibody during the recovery stage of Omicron variant infection in children: an analysis of 110 cases]

OBJECTIVES

To investigate the serum level of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific RBD IgG antibody (SARS-CoV-2 IgG antibody for short) in children with SARS-CoV-2 Omicron variant infection during the recovery stage, as well as the protective effect of SARS-CoV-2 vaccination against Omicron infection.

METHODS

A retrospective analysis was performed on 110 children who were diagnosed with coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 Omicron variant infection in Tianjin of China from January 8 to February 7, 2022. According to the status of vaccination before diagnosis, they were divided into a booster vaccination (3 doses) group with 2 children, a complete vaccination (2 doses) group with 90 children, an incomplete vaccination (1 dose) group with 5 children, and a non-vaccination group with 13 children. The clinical data and IgG level were compared among the 4 groups.

RESULTS

The complete vaccination group had a significantly higher age than the non-vaccination group at diagnosis (P<0.05), and there was a significant difference in the route of transmission between the two groups (P<0.05). There were no significant differences among the four groups in sex, clinical classification, and re-positive rate of SARS-CoV-2 nucleic acid detection (P>0.05). All 97 children were vaccinated with inactivated vaccine, among whom 85 children (88%) were vaccinated with BBIBP-CorV Sinopharm vaccine (Beijing Institute of Biological Products, Beijing, China). At 1 month after diagnosis, the booster vaccination group and the complete vaccination group had a significantly higher level of SARS-CoV-2 IgG antibody than the non-vaccination group (P<0.05), and at 2 months after diagnosis, the complete vaccination group had a significantly higher level of SARS-CoV-2 IgG antibody than the non-vaccination group (P<0.05). For the complete vaccination group, the level of SARS-CoV-2 IgG antibody at 2 months after diagnosis was significantly lower than that at 1 month after diagnosis (P<0.05).

CONCLUSIONS

Vaccination with inactivated SARS-CoV-2 vaccine has a protective effect against Omicron infection in children. For children vaccinated with 2 doses of the vaccine who experience Omicron infection, there may be a slight reduction in the level of SARS-CoV-2 IgG antibody at 2 months after diagnosis. Citation:Chinese Journal of Contemporary Pediatrics, 2022, 24(7): 736-741.

N-acetylcholine receptors regulate cytokines expression and neutrophils recruitment via MAPK/ERK signaling in zebrafish

N-acetylcholine receptors (AChRs) are mainly distributed in the postsynaptic membrane and have been widely studied for their control of muscle contraction by regulating neural action potentials. However, the influences of AChRs on immune responses and potential mechanisms remain unclear. Here, we used the advantages of live imaging of zebrafish to explore the regulation process of AChRs on inflammatory responses. Pharmacologically activating of the receptor, we found that the expression of pro-inflammatory cytokines il-1β, il-6, tnf-α and il-8 was significantly up-regulated and neutrophil migration to injury sites was also significantly increased. However, these phenomena were reversed under antagonism of the receptor activity. Results showed that interfering with nAChRs functions did not significantly affect zebrafish motion behavior. Results also showed that activation and antagonism of nAChRs function could regulate the phosphorylation of ERK protein respectively. We further demonstrated that ERK participated in the regulation of AChRs in cytokines expression and neutrophils migration in zebrafish. This study preliminarily revealed the roles of AChRs in inflammatory processes and their potential mechanism, providing additional evidence of peripheral immune regulation by cholinergic receptors.

Cordycepin inhibits inflammatory responses through suppression of ERK activation in zebrafish

As a natural extract, cordycepin has been shown to play important regulatory roles in many life activities. In the study, the effects of cordycepin on inflammatory responses and the underlying mechanisms was explored using a zebrafish model. In the model of LPS-induced inflammation, cordycepin was found to significantly inhibited the expression of pro-inflammatory cytokines such as tnf-α, il-1β, il-6, and il-8. Using in vivo imaging model, cordycepin significantly inhibited fluorescent-labeled neutrophils migrating towards injury sites. Furthermore, results showed that the phosphorylation level of ERK protein dramatically decreased after cordycepin treatment. Meanwhile, the ERK inhibitor, PD0325901, significantly inhibited the expression of pro-inflammatory cytokines in LPS-induced inflammatory model and neutrophils migration in the caudal fin injury model. This study indicated the important roles of cordycepin in inhibiting LPS and injury-induced inflammation and preliminarily explained the role of ERK protein in this process.

[Epidemiological characteristics and diagnosis of imported malaria cases in Zhejiang Province from 2017 to 2020]

OBJECTIVE

To analyze the epidemiological features and diagnosis of imported malaria cases in Zhejiang Province from 2017 to 2020, so as to provide the scientific evidence for the management of imported malaria in the province.

METHODS

The data of malaria cases reported in Zhejiang Province were captured from the Information Management System for Parasitic Disease Control of China Information System for Disease Control and Prevention from 2017 to 2020, and the temporal, spatial and human distribution, and initial and definitive diagnosis of imported malaria cases were descriptively analyzed.

RESULTS

A total of 593 malaria cases were reported in Zhejiang Province from 2017 to 2020, and all were overseas imported cases, including 532 men and 61 women, with a mean age of 41 years. There were 93.93% of the malaria cases from African countries, and the malaria parasites infecting these cases included Plasmodium falciparum, P. vivax, P. ovale, P. malariae and mixed infections, with P. falciparum as the predominant species (76.73%, 455/593). All malaria cases received totally correct initial diagnoses in county- and city-level centers for disease control and prevention (CDC) and entry-exit inspection and quarantine sectors, and the proportion of malaria cases with confirmation at the day of initial diagnosis was 41.48% (207/499) in medical institutions and 66.18% (45/68) in CDC (χ² = 14.779, P < 0.001). In addition, the median interval [M (Q_R)] of malaria cases was 1 (2) d from onset to initial diagnosis and 1 (2) d from initial diagnosis to confirmation in Zhejiang Province from 2017 to 2020, and the median interval [M (Q_R)] of severe malaria cases was significantly longer than that of non-severe cases [2 (3) d vs. 1 (2) d; Z = -3.002, P < 0.05].

CONCLUSIONS

Zhejiang Province faces great challenges of malaria control, and post-elimination surveillance of malaria still requires to be reinforced. Meanwhile, the awareness of seeking medical services requires to be improved among returners from malaria-endemic regions and the diagnostic capability of malaria requires to be improved among medical professionals.

Veno-venous extracorporeal membrane oxygenation successfully treated a case of severe pulmonary hemorrhage caused by leptospirosis

BACKGROUND

Pulmonary hemorrhage is an important complication of leptospirosis. Once acute respiratory distress syndrome (ARDS) occurs as a secondary condition, treatment is extremely difficult and the mortality rate is very high.

CASE PRESENTATION

The patient was a 49-year-old. He was admitted to the hospital because he had experienced a fever and cough for 4 days. Hemorrhage, respiratory failure, ARDS and other symptoms appeared soon after admission. Due to severe pulmonary hemorrhage secondary to ARDS, mechanical ventilation was performed through tracheal intubation. During intubation, the patient suffered cardiac arrest, and the patient's condition worsened. He was confirmed to have leptospirosis through second-generation sequencing of the alveolar lavage fluid. Finally, we successfully treated the patient with penicillin as an anti-infective medication and venous-venous extracorporeal membrane oxygenation (v-vECMO). To the best of our knowledge, this report is the first to describe the successful application of ECMO in mainland China.

CONCLUSIONS

Leptospirosis can induce serious but transient ARDS with a better prognosis than other causes of ARDS. Our patient was successfully treated with V-vECMO.

[Second sampled survey on the distribution of human parasites in Zhejiang Province]

OBJECTIVE

Twenty-six species of human parasites were recorded in Zhejiang Province in 1987-1989 as a part of the national investigation on the distribution of human parasites, and the total prevalence was 80.2%. In order to find out possible changes on the composition of parasite species and decrease of prevalence after control intervention particularly mass chemotherapy in the past years and provide evidence for an improved control strategy, the second sampled survey was carried out from 1998 to 1999.

METHODS

Ten counties were identified randomly out of 28 counties where the last survey was conducted following the same sampling method. Same technics were used for case detection and data processing.

RESULTS

The total infection rate in a sample of 15,698 was 22.84% was 22.84% in 30 investigation spots in 10 counties, and 17 species of parasites were revealed. The overall prevalence was reduced by 71.51% in comparison to that of 1989, and the number of parasite species was 17, 9 less than that of the last investigation.

CONCLUSIONS

The prevalence of human parasites has greatly declined in this province due to the socioeconomic development and adoption of comprehensive control measures focusing on mass chemotherapy in the past decade.