Perfil das infecções relacionadas à assistência à saúde em um centro de terapia intensiva de Minas Gerais Profile of healthcare-associated infections in an intensive care unit in Minas Gerais Perfil de las infecciones relacionadas a la asistência de la salude nun centro de terapia intensiva de Minas Gerais

Background and Objectives: Healthcare-Associated Infections (HAI) are one of the major problems in health care units, especially in the intensive care unit (ICU), due to the presence of critical patients. The objective of this study was to describe the occurrence of HAIs in the ICU of a general hospital in the inlands of Minas Gerais in the period from 2014 to 2016. Methods: descriptive and retrospective study with data obtained from the HealthcareAssociated Infection Control Service of the institution. Results: the percentage of HAIs in the years studied was 3.4% in 2014; 2.4% in 2015 and 1.8% in 2016. The highest occurrence of infection was in individuals aged 41-60 years and the highest percentage was in 2014 (39.1%). In relation to the infection site, most records were from respiratory tract infections (RTI); 68.8% in 2014; 54.2% in 2015; and 51.7% in 2016. However, more than 50% of cases in all years did not have records of the type of etiological agent. As for the underlying pathology, the most frequent was traumatic brain injury (TBI) that affected 18.6% in 2015. Another relevant factor was the high mortality rate recorded in all years that reached 63.8% in 2016. Conclusion: data collection on HAIs at the ICU indicated a low prevalence when compared to the literature. This may be associated with underreporting.


INTRODUCTION
The Centers for Disease Control and Prevention (CDC) define Healthcare-Associated Infections (HAIs) as any infection acquired by an individual during treatment at the health facility, whether in the hospital or outpatient care, long-term or short-term care, which may manifest in a systemic or local manner. 1 In Brazil, HAIs are infections acquired after the patient's admission and manifested during hospitalization or after discharge, when related to hospitalization or hospital procedures. 2 On the one hand, scientific and technological advances enabled the creation of new therapeutic procedures that increased the survival of sick patients, but on the other hand, patients were exposed to a higher risk of developing HAIs. 3 Healthcare-Associated Infections represent an imbalance between the body's natural microbiota and the defense mechanisms commonly observed in severely ill patients. 4 The pathogens involved in HAIs are transmitted to the individual either endogenously, that is, through the patient's own microbiota, or through the exogenous route by the hands, salivary secretion, body fluids, air and contaminated materials. 5 Healthcare-Associated Infections are even more significant in the intensive care unit (ICU) due to the presence of critically ill patients. Although this sector represents less than 2% of hospital beds available, it contributes to more than 25% of hospital infections, with significant impact on morbidity and mortality rates. 6 HAIs are associated with clinical severity of patients, immune system disorders, use of numerous invasive procedures, use of immunosuppressants, prolonged hospitalization, colonization by resistant microorganisms, prescription of antimicrobials, therapeutic dehydration and the ICU environment itself that favors the natural selection of microorganisms. 7,8 Another factor directly associated with HAIs is poor hand hygiene, which is considered the most important, inexpensive, and effective measure for the prevention and control of HAIs. Although this procedure is supported by sound scientific evidence, its adherence is still described as insufficient in the literature. 9 The hands of health professionals are known as the most common route of transmission of infectious agents causing HAIs, although the transmission is complex and multifactorial. 10 The most frequent sites of HAI are urinary tract infections (UTI), respiratory tract infections (RTI), surgical site infections (SSI), and bloodstream infections (BSI). 11 HAIs have negative repercussions and serious consequences, such as increased morbidity and mortality and general expenses. In addition, they lead to a longer length of stay of patients and withdrawal from the family environment, negatively impacting the quality of life of all involved. 12,13 In Brazil, the average rate of nosocomial infection is 15.5%, which corresponds to 1.18 episodes of infection per patient hospitalized with HAIs, i.e., the same patient acquired more than one infection. 14 HAIs are considered one of the leading causes of in-hospital mortality. 3 The occurrence of HAI is related to the vulnerability of patients and to the adherence of health professionals for the prevention and control of infection in the hospital environment.
Therefore, it is mandatory that health services/hospitals have a Healthcare-Associated Infection Control Commission to reduce and control the incidence and worsening of HAIs.

RESULTS
In the study, were analyzed 181 HAI records notified by the Healthcare-Associated Regarding sociodemographic characteristics, there was a higher frequency in male subjects compared to females. The most frequent age group among individuals with HAIs was 21 to 60 years, especially in patients aged 41 to 60 years (Table 1).  In all years, the most common underlying pathology was traumatic brain injury (TBI),

DISCUSSION
Healthcare-Associated Infections are a serious public health problem, as they increase morbidity and mortality rates, hospitalization costs, the length of stay of patients, and account for the high death rates characteristic of the ICU because this is a critical sector. 15 Of the total number of patients admitted to the ICU, the percentage of HAIs was 3.4% in 2014; 2.4% in 2015 and 1.8% in 2016. Healthcare-Associated Infection rates are higher in large and teaching hospitals and vary according to the type of surveillance used and the degree of complexity of the hospital. Infection rates in the ICU range from 18 to 54% and are five to ten times higher than in other inpatient units. 15 In the institution of the present study, was found a low percentage, possibly because the ICU attends all levels of complexity and the number of beds was duplicated after the renovation performed during the study period. In addition, until 2016, the Healthcare-Associated Infection Control Commission was not active in the institution, since there was no nurse exclusively for the sector and no electronic medical records were used, thus hindering the investigations of HAIs, which may have led to underreporting.
On average, the highest frequency of HAI reports occurred in male subjects (61.8%), corroborating other studies. In a study conducted in a general hospital in Bahia, 85.8% of patients were male 4 and in Belo Horizonte, 54.7% of adult ICU patients were also men. 16 This occurrence seems to be related to the larger number of men admitted to this hospital sector.
Regarding age, there was a higher frequency of HAIs in patients aged 41 to 60 years.
A study conducted in an ICU of a teaching hospital in Fortaleza also found a mean age of 58.3 years. 3 Such age marks the beginning of the elderly phase and the physiological effects of aging that may lead to a higher risk of health problems, especially in ICU patients. 17 The most prevalent infection site was the respiratory tract with an average of 58.5%.
The same result was found in an ICU located in São Paulo (59%). 18 In another study conducted in a public hospital in the inlands of Paraná, RTIs were also more prevalent (36.4%). 19 These results suggest that the use of a mechanical ventilator associated with prolonged use of this device and patients' organic weaknesses may lead to the higher occurrence of HAIs. 14 Considering the reported pathogens, Staphylococcus aureus was the most frequent, with an average of 32.7% over the years, corroborating a study conducted in a public hospital in the inlands of Rondônia that recorded a rate of 23.8%. 20 Studies point out that Staphylococcus aureus is considered one of the major human pathogens, usually present in the nasal cavities, skin and intestine, and most often transmitted by the hands of healthcare professionals when hand hygiene is insufficient. 21 In the present study, TBI was the most prevalent underlying pathology, which is an important risk factor for the development of HAIs because it may depress the immune system and facilitate the pathogen invasion. 22 A study conducted at a university hospital on the characteristics of infections and the health impact of trauma patients showed that 15.6% of patients acquired at least one infection during hospitalization. Economically active individuals are more susceptible to accidents arising from external causes, especially land transport accidents. 23 Although hospital discharge was the most frequent outcome, the registration of deaths, especially in 2016, was relevant (63.8%). In a study on mortality and risks associated with HAIs conducted in a teaching hospital in Paraná, was recorded a mortality rate of 38.4% 24 .
Studies show that mortality in ICUs is generally high, with rates ranging from 9 to 38%. And when it comes to death in patients who develop HAIs, it can reach 70%. 16 The results presented in this investigation should be interpreted with caution. In addition to the limitation of the study design, data comparison may have been impaired due to different data collection techniques. Still, the number of variables reinforces the relevance of the findings.
The survey of data on HAIs at the ICU showed low occurrence compared to the literature. However, specificities in the sector during the study period may explain the strong underreporting. The difficulty of finding information in the notification forms reinforces the need for the complete registration and the importance of active case search.
The eradication of HAIs is an arduous task given the underlying pathology presented by the patient and the HAI etiology. However, prevention and control have proven effective in reducing infections. Actions of permanent and continuing education established by the Healthcare-Associated Infection Control Commission are extremely important tools for the awareness and learning of health professionals. We suggest the continuous dissemination of results obtained by the Healthcare-Associated Infection Control Service through emphasis on the measures that generated positive results with the performance of educational activities.