Prospektive Interventionsstudie für die Entwicklung multimodaler Präventionsmaßnahmen zur Risikominimierung von nosokomialen Infektionen in der Pferdeklinik

Prospective intervention study for the development of multimodal prevention measures to minimise the risk of nosocomial infections in the equine clinic

Nosocomial infections and the associated problem of colonisation of patients with multi-resistant pathogens (MRP) is becoming an increasingly serious challenge in both human and veterinary medicine. Especially in equine clinics, nosocomial infections have increased in recent years, which is why hygiene management for the prevention of wound infections is becoming increasingly important. Horse clinics represent a special challenge due to the specific requirements of the species, while small animal clinics can transfer many findings from hominid medicine. This is especially true in connection with wound infections in horses, where the classical opportunistic and zoonotic pathogens such as methicillin-resistant Staphylococcus aureus (MRSA) and extended spectrum beta-lactamase (ESBL-) producing Enterobacteriaceae occur. Against this background, the aim of the work was to develop multimodal hygiene management in connection with Standard Operating Procedures (SOPs), which can be applied effectively and practicably in the equine clinic and thus contribute to a reduction of wound infections.
In this study, a total of 341 equine patients were screened in both 2014 and 2015 using nasal swab samples and faeces for microbiological examination and a status quo of the microbial flora brought along was determined. All patients with the indication colic (n = 233) or with an open injury (n = 108) were included. In addition, a sample was taken from the center of the wound for all injuries within the scope of the screening. The study design was divided into three different sections: Investigation Period A in 2014, a subsequent intervention and the associated introduction of the new hygiene measures developed in Investigation Period A in the form of SOPs, and then Investigation Period B in 2015. The focus of the SOPs for the intervention was placed on improving hand hygiene compliance and the consumption of disinfectants in Investigation Periods A and B was determined. In addition, an active surveillance of postoperative wound infections was conducted in both study periods and all detected infections were subjected to a microbiological follow-up examination. This made it possible to compare the infection rate and exposure to MRP in Investigation Periods A and B. In addition, various risk factors for acquiring a wound infection were included, such as the length of stay, the surgical procedure and the length of the incision, pre-treatment with antibiotics, age and weight.
The evaluations of the initial screening showed that 3,5 % of the patients were already contaminated with MRSA on admission to the clinic and 10,7 % tested positive for ESBL-producing Enterobacteriaceae. The swabs of the wounds showed a germ load of 3,7 % with MRSA, 1,9 % with ESBL and 0,9 % with A. baumanii on admission to the clinic. The study identified several factors that significantly influenced the risk of wound infection. The length of stay was twice as long in patients with a wound infection (p = 0,001), surgical intervention significantly influenced the attainment of infection (p < 0,005) and associated with this, the risk of wound infection was 33,7 times higher. In-patient treatment on the one hand (p < 0,005) and pre-treatment with antibiotics prior to hospitalization (p = 0,002) also influenced the risk. In addition, age (p = 0,006) and weight (p = 0,0037) were determined as risk factors. A total of 42 infections were
detected in IP A and IP B, 69 % of them were colonised with at least one MRP. The introduction of targeted hygiene management and the associated SOPs led to a significant reduction in wound infections (p = 0,033). In the indication colic, of which 48 underwent a laparotomy, 30 % of patients in Investigation Period A succumbed to a wound infection, in Investigation Period B only 17,9 %. In the indication of injuries, 31,7 % of patients developed a wound infection in IP A and only 25 % in IP B. This corresponded to an overall reduction in the infection rate of 8,9 % in IP B after intervention. In addition, the total number of MRP in the follow-up examinations of the infections decreased by 9,5 %. The main conclusion to be drawn from this data was that targeted measures, especially increasing hand hygiene compliance, have a major impact on minimizing the risk of wound infections; in this study, the consumption of disinfectants increased by 190 % in Investigation Period B.