Bacterial Transmission

This study aims to understand how oral bacteria that cause tooth decay and gum disease spread among family members and whether treating multiple family members can reduce the return of these bacteria after dental treatment. Families with children aged 5-12 years will be recruited from university dental clinics. Participants will be assigned to one of three treatment groups: treatment for the child only, treatment for the child and parents, or treatment for all family members. Researchers will collect oral bacterial samples from family members before and after treatment and will monitor close-contact interactions within the household using wearable proximity-tracking devices. The study will also collect information about oral health habits, family interactions, and environmental factors that may influence bacterial transmission. By combining bacterial DNA analysis with information about family contact patterns, researchers hope to better understand how oral bacteria are shared within households and whether family-based treatment approaches can reduce bacterial recolonization after dental therapy. The results of this study may help improve strategies for preventing childhood tooth decay and gum disease by addressing family-level sources of bacterial transmission.

Postoperative respiratory complications, such as bacterial pneumonia, are common and serious problems after general anesthesia. They can lead to longer hospital stays, more complications, and increased mortality. One possible cause is that bacteria from the mouth and throat enter the lower airways during tracheal intubation. The mouth and throat naturally contain many bacteria, including potentially harmful microorganisms. During general anesthesia, coughing and swallowing reflexes are reduced or absent. When a tracheal tube is inserted, secretions from the mouth and throat may be carried into the trachea. The tube may also support the movement of contaminated fluid into the lower airways. ORAL-PROTECT I is a prospective, randomized, controlled study. It investigates whether simple oral hygiene before surgery can reduce the transfer of bacteria into the trachea during airway management under general anesthesia. The study includes patients aged 60 years or older undergoing elective surgery under general anesthesia with tracheal intubation. Participants are randomly assigned to an intervention group or a control group. The intervention group performs oral hygiene immediately before anesthesia. This includes brushing the teeth and tongue for about 3 minutes, followed by rinsing and gargling for about 1 minute with a chlorhexidine antiseptic solution. The control group receives standard care without additional oral hygiene. Oral, pharyngeal, and tracheal swabs will be collected at predefined time points. The primary outcome is based on the perioperative tracheal bacterial load, sampled every 30 minutes and assessed at two hours after induction of anesthesia. The co-primary outcome is based on the oral bacterial load immediately before endotracheal intubation. Secondary outcomes include changes in oral and tracheal bacterial load over time and identification of the microorganisms detected. The study aims to clarify early bacterial transfer during airway management and to evaluate whether a simple preoperative oral hygiene measure can reduce this process.