Dynamics of Naturally-Acquired Immunity Against SARS-CoV-2 in Children and Adolescents

Background
To evaluate the duration of protection against reinfection conferred by a previous SARS-CoV-2 infection in children and adolescents.
Methods
We applied two complementary approaches: a matched test-negative, case-control design and a retrospective cohort design. 458,959 unvaccinated individuals aged 5-18 years were included. Analyses focused on July 1 to December 13, 2021, a period of Delta variant dominance in Israel. We evaluated three SARS-CoV-2-related outcomes: documented PCR confirmed infection or reinfection, symptomatic infection or reinfection, and SARS-CoV-2-related hospitalization or death.
Findings
Overall, children and adolescents who were previously infected acquired durable protection against reinfection with SARS-CoV-2 for at least 18 months. Importantly, no SARS-CoV-2-related deaths were recorded in either the SARS-CoV-2 naïve group or the previously infected group. Effectiveness of naturally-acquired immunity against a recurrent infection reached 89.2% (95% CI: 84.7%-92.4%) three to six months after first infection, mildly declining to 82.5% (95% CI, 79.1%-85.3%) 9-12 months after infection, with a slight non-significant waning trend up to 18 months after infection. Additionally, we found that ages 5-11 years exhibited no significant waning of naturally acquired protection throughout the outcome period, whereas waning protection in the 12-18 year-old age group was more prominent, but still mild.
Interpretation
Children and adolescents who were previously infected with SARS-CoV-2 remain protected to a high degree for 18 months. Further research is needed to examine naturally-acquired immunity against Omicron and newer emerging variants.

Author/s:

Patalon, T., Saciuk, Y., Perez, G., Peretz, A., Ben-Tov, A., Gazit, S.

Role of biofilm in catheter-associated urinary tract infection

Bethie Seay — Thu, 23 Sep 2021 05:00:00 +0000

Date Added:

September 23, 2021

Journal/Publication:

American Journal of Infection Control

Publication Date:

May 19, 2004

Issue:

Volume:

Pages:

177-183

Type:

Meta-analyses, Reviews, and Guidelines

DOI (1):

10.1016/j.ajic.2003.08.005

MeSH

Urinary Catheters

Bacteriuria

Catheters, Indwelling

Reinfection

Urinary Catheterization

urinary tract infections

Biofilms

anti-bacterial agents

Biological Products

A classic article on urinary tract infections in patients with indwelling catheters.

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The predominant form of life for the majority of microorganisms in any hydrated biologic system is a cooperative community termed a “biofilm.” A biofilm on an indwelling urinary catheter consists of adherent microorganisms, their extracellular products, and host components deposited on the catheter. The biofilm mode of life conveys a survival advantage to the microorganisms associated with it and, thus, biofilm on urinary catheters results in persistent infections that are resistant to antimicrobial therapy. Because chronic catheterization leads almost inevitably to bacteriuria, routine treatment of asymptomatic bacteriuria in persons who are catheterized is not recommended. When symptoms of a urinary tract infection develop in a person who is catheterized, changing the catheter before collecting urine improves the accuracy of urine culture results. Changing the catheter may also improve the response to antibiotic therapy by removing the biofilm that probably contains the infecting organisms and that can serve as a nidus for reinfection. Currently, no proven effective strategies exist for prevention of catheter-associated urinary tract infection in persons who are chronically catheterized.

Author/s:

Trautner, B. W., Darouiche, R. O.