# One prospective study of physiologic sea saline nasal care on the incidence of acute upper respiratory tract infections and changes of pharyngeal pathogens in children during kindergarten daycare

## TL;DR

Using sea saline nasal spray in kindergartens reduced the spread and bacterial load of upper respiratory infections in children, but had no effect on viruses or mycoplasma.

## Contribution

This study provides empirical evidence that physiologic sea saline nasal care reduces AURTIs incidence and bacterial colonization in children during daycare.

## Key findings

- The intervention group had a significantly lower AURTIs incidence (45.83%) compared to the control group (71.05%).
- The intervention group showed reduced bacterial species and colony counts in throat swabs after AURTIs onset.
- Bacterial load in the intervention group decreased after AURTIs, while it increased in the control group.

## Abstract

To explore the effects of physiologic sea saline nasal spray irrigation on the incidence of acute upper respiratory tract infections (AURTIs) and pharyngeal pathogens during children’s admission to child care, and to provide a theoretical basis for health care in kindergartens.

Healthy children enrolled in a public kindergarten in the region from February to June 2023 were divided into the intervention group and the control group by using cluster random allocation concealment method. The intervention group was given physiological sea saline nasal care twice a day, while the control group received no special intervention. Swab samples were collected for pathogen detection at the time of admission (baseline) and at the time of the first occurrence of AURTIs more than 48 h after admission. The incidence of AURTIs throughout the entire semester of enrollment and the trend of dispersion in different months were compared between the two groups, and the differences of pharyngeal pathogens (bacterial species, colony counts and non-bacterial pathogens) after the first AURTIs during the kindergarten period were compared with the baseline.

A total of 234 children who met the inclusion and exclusion criteria were included in the analysis, with 120 children in the intervention group and 114 children in the control group. The incidence of AURTIs in the intervention group was significantly lower than that in the control group (45.83% vs. 71.05%, x2 = 15.276, P < 0.001), and the occurrence time of the first AURTIs was significantly more dispersed than that in the control group (Z = 25.075, P < 0.01). The number of bacterial species and colonies cultured in the throat swab of children in the intervention group were significantly less than those in the control group after the onset of AURTIs for the first time (t = 8.591, P < 0.001; x2 = 8.432, P = 0.015). Compared with the baseline, the number of pharyngeal bacteria species in the intervention group decreased after the first occurrence of AURTIs, while that in the control group increased, with statistical significance (t = 6.426, P < 0.001; t = 3.28, P = 0.001). There was no significant difference between the two groups in the detection rates of viruses and mycoplasma (x2 = 0.251, P = 0.616; x2 = 0.071, P = 0.790).

Physiologic sea saline water nasal irrigation care can reduce the bacterial loads of pharynx colonization after the onset of AURTIs, reduce the incidence and concentrated incidence trend of AURTIs, but has no effect on the detection rate of non-bacterial pathogens such as viruses and mycoplasma.