Staphylococcus aureus Detection in the Mouth of Housekeepers

This study assessed the prevalence of colonization by Staphylococcus aureus in hospital housekeepers, and their knowledge and beliefs regarding this problem. Three saliva samples were collected and a questionnaire regarding knowledge and beliefs was applied. Of the 92 workers, 63 (68.5%) participated in the study; 20 were not and 43 were colonized; 13 by methicillin resistant Staphylococcus aureus and 30 by methicillin sensitive Staphylococcus aureus. Persistent carrier status of methicillin resistant Staphylococcus aureus was detected in 15.4% of cases. Low knowledge and perception of occupational risk were observed. The mouth was identified as an important reservoir of methicillin resistant Staphylococcus aureus. Analyzing knowledge and beliefs, as well as the state of carrier, is an important strategy to be added to educational actions for the prevention of workers’ colonization.


Introduction
One important factor in the epidemiology of infection and colonization cases by methicillinresistant Staphylococcus aureus (MRSA) in the health care environment is workers' physical proximity with colonized or infected patients and their environment.This approximation contributes to professionals' colonization, who become potential reservoirs and disseminators of these bacteria, contributing to their dispersion in the environment and person-to-person (1)(2) , besides the fact that MRSA colonization predicts infection (3) .In this context, not only hospitalized and colonized individuals can show greater risk of developing MRSA infection, but also non-hospitalized people, whether health service workers or not, according to their health conditions.Given the possible dispersion and survival of methicillin-sensitive Staphylococcus aureus (MSSA) and MRSA in the environment (4)(5) and the nature of their work, hospital housekeepers can also be colonized, Rev. Latino-Am.Enfermagem 2011 Jan-Feb;19 (1):90-6.
few studies have investigated this category.This risk is aggravated by their lack of technical preparation and knowledge to perform their functions in the hospital environment (6) .This affects their risk perception and adherence to prevention measures.
The most studied anatomical sites in Staphylococcus aureus and mainly MRSA research are the nasal mucosa and skin, although the mouth has also been studied (7)(8)(9) .
Although Staphylococus aureus are not part of the oral cavity microbiota (10) , genetically identical MRSA have been isolated from the anterior nostrils and tongue of 20 previously colonized patients, suggesting transference from the nasopharynx to the tongue (7) .This research investigated the prevalence of colonization by MRSA and MSSA, knowledge and beliefs associated with the problem among hospital housekeepers.

Study population
This Subjects were considered transitory carriers if only one of the three cultures was positive for S. aureus (carrier index ≤ 0.5); persistent carrier when two or three cultures were positive (carrier index >0.5) (11)and with the same susceptibility pattern to the antimicrobials that were test: or non carrier when the three cultures were negative (carrier index = 0).

Demographic data collection, processing and analysis
Through a confidential interview, demographic data, knowledge and occupation risk perception about MRSA were collected.Perception questions were based on the Health Beliefs model (12) to investigate the susceptibility and severity of colonization, benefits and barriers for the adoption of preventive measures.Answers to the closed questions were inserted in a double-entry database and data were organized and processed in EPI-Info.Answers to the open questions were submitted to quantitative discourse analysis (13) .After the answers had been listed, they were reread, grouped according to similarity and regrouped into categories, based on which the frequency rates were obtained for the characteristics repeated in the answers' contents.

Laboratory data collection, processing and analysis
Three saliva samples were obtained from each participant at three-month intervals.The samples were collected in 12-mL plastic tubes that were sterile and sent to the laboratory.The saliva was grown in mannitol salt agar plates, using the drop technique, and incubated at 37º C for up to 48 hours.Typical colonies of staphylococcus were counted to define the colonyforming units (CFU); S. aureus was identified through the catalase, coagulase, lecithinase, DNase production and mannitol fermentation tests.The isolated colonies were determined by the disk diffusion method, in accordance with recommendations by the Clinical and Laboratory Standards Institute (14) .The following antimicrobials were used: oxacillin, cefoxitin, penicillin, erythromycin, itromycin, clindamycin, tetracycline, riphampicin, cyprofloxacin, gentamycin, trimethropim sulfametoxazole, vancomycin, linezolid and mupirocin (Oxoid-Basingstoke, England).ATCC strains of S. aureus 25923 and 29213 (14) were used for quality control purposes.The data were processed in EPI-Info and analyzed by descriptive statistics.

Results
The 63 housekeepers who participated in the study were all women, between 21 and 56 years old, with an average age of 38.8 years and standard deviation of 6.9.
Work time ranged from 3 to 240 months, with a median 19.1 months.As for the work shift, 59 (93.7%) worked during the day and only 1 (1.6%) informed working at another hospital institution.The characterization of colonized and non-colonized housekeepers and their respective demographic variables are shown in Table 1.The variable "not informed" referred to the subject's refusal to answer the question.
Cruz EDA, Pimenta FC, Hayashida M, Eidt M, Gir E. The obtained results contribute to the acknowledgement of the colonization problem, as this condition affects the workers and service users' health, and contribute to the planning of control and prevention actions.
The prevalence level of 20.6% was high as these are healthy people, even if they work in a hospital environment.Although most studies investigate MRSA prevalence in nasal mucosa and skin, some studies have looked at the mouth to investigate S. aureus (7)(8)(9) .
Its relevance is related with the fact that, while talking, countless MRSA-contaminated saliva droplets can be disseminated into the environment and from person-toperson, evidencing the risk of workers becoming colonized with MRSA in the mouth and, thus, disseminating it to patients, the health care environment and the community.The dissemination risk is also related to the persistent or transitory nature of the colonization.A twoyear follow-up study evidenced the transitory nature of S. aureus colonization in 28 (41.8%)out of 67 research subjects (11) .Although the present study results reveal the condition of transitory S. aureus carrier (67.4%) as the most frequent, including MRSA (84.6%), reports exist (15) that transitorily colonized workers can become persistent carriers in case of skin injuries, potentiating transmission risks.
A research of approximately 15,000 patients showed that MRSA infections diagnosed in the community were significantly associated with higher mortality rates when compared with the absence of this agent as an infection cause (16) .Hence, one cannot ignore the meaning of MRSA colonization for workers' health, including housekeepers.In that sense, knowledge on the carrier status, especially when persistent, and institutional policies for decolonization contribute to reduce MRSA dissemination and death risk in case of infection.
Workers' persistent MRSA colonization should be included as an occupational event and supported by labor legislation.Prevalence rates of methicillin resistance higher than 40% are observed in S. aureus isolated from hospital infections in Southern and Eastern Europe (17) .
Rates of 31% in S. aureus isolated from patients with skin and soft tissue infection were reported in Latin America (18) , reaching approximately 65% at Intensive Care Units in North American hospitals (19) .It should be highlighted, however, that these data refer to individuals with infection.
A research of 340 healthy health professionals in São Paulo State showed a prevalence level of 47.6% of subjects colonized with S. aureus and 4.1% for MRSA (20) .
In the present study, the prevalence level of MRSA identified among hospital housekeepers was 20.6%.
With regard to this professional category, they are not sufficiently prepared to work at an unhealthy service involving, among others, biological risks.
They lack elementary technical knowledge regarding microorganism transmission mechanisms and hygiene in hospital environments.Although most of them start working at the hospital without training, investing in education results in knowledge gains, which is a possible factor in infection prevention, according to researchers (6) .
It is highlighted that research involving hospital housekeepers (6,(21)(22) contributes to increase the visibility of different related problems and encourages experts to seek, based on scientific evidence, new guidelines with a view to greater safety and quality in their professional performance.
This research revealed that the research subjects receive only occasional orientations from clinical nurses and the hospital infection control service team.They obviously consider their professional qualification of little importance, based on the study results that revealed the low education level of workers hired in hospital services (21) .
The association between the low education level and In this study, only 12.7% indicated knowledge on MRSA and 58.7% did not know the measures to prevent its dissemination.These results were considered the main factor that is potentially associated with the high prevalence of MRSA colonization.Brazilian legislation recommends that hospital housekeepers be trained to use IPE, prevent biological risk and observe the principles of personal hygiene (23) .Knowledge is acknowledged as essential to prevent MRSA colonization, although it does not determine by itself workers' behavior in daily professional reality.In this sense, the characterization of the workers' health beliefs regarding this problem can help to identify and understand risk attitudes and contribute to outline prevention strategies.One third of the research subjects did not recognize the colonization risk, underestimating their own risk.Greater perception of vulnerability to risks can be a strategy for the adoption of safe practices (24) .A study developed in one American state assessed health professionals' perceptions and knowledge on hospital infection prevention practices, based on the Health Beliefs Model, revealed limited knowledge on hand washing and non-identification of barriers to prevent hospital infection.The results contributed to the construction and review of specific protocols regarding this theme (25) .
The fact that the workers know their colonization condition or MRSA prevalence in their work group can be a motivating elements for educative measures as well as to adopt safe attitudes.In Brazil, no public guideline exists for the decolonization of workers who are MRSA carriers, so that institutions are responsible for determining criteria and their own protocol.

Conclusion
study was carried out between April 2006 and June 2008, involving housekeepers from a university hospital in the South of Brazil, after approval by the institutional review board.Out of 92 workers, 63 (68.5%) participated in the research because they formally consented and complied with the inclusion criteria: cleaning the environment and utensils at hospital care units for adults patients, collecting three saliva samples at three-month intervals and answering questions through an individual interview.Research subjects working at the institution at the end of the study were collectively and individually informed about the results, and also about the institutional routine for the decolonization of workers colonized by MRSA.
lack of technical knowledge to work in an unhealthy environment enhances occupational risks.Although these workers do not have direct contact with patients, they are Cruz EDA, Pimenta FC, Hayashida M, Eidt M, Gir E. www.eerp.usp.br/rlaeexposed to the high load of environmental contaminants and to the risk of colonization, similarly to professionals in direct contact with patients.
Staphylococcus aureus could be detected in the mouth.This condition can entail risks for workers' health, environmental and person-to-person dissemination.Hospital housekeepers can be MRSA carriers and disseminators to the environment and potentially to the team and patients, as the study results show colonization prevalence rates of 20.6%.As the carrier status is a predictive factor of infection, knowing the condition of MRSA carrier is the workers' right and permits reflecting on their practice and even on the decolonization decision, in accordance with the institutional protocol.As such, it is useful to change attitudes and achieve greater adherence to prevention measures.Low knowledge and colonization risk perception levels in view of MRSA prevalence rates among housekeepers appoint the need to plan educative interventions to prevent colonization.Nurses are directly involved in this problem because they frequently lead and command these workers.Considering that behavior depends on knowledge and beliefs attributed to prevention measures, this study contributes to a better understanding of the context of MRSA colonization.Moreover, it aroused reflections on possible colonization in the workers' mouth and highlighted the need to value this theme in health education actions for hospital housekeepers, promoting knowledge and encouraging risk prevention actions.

Table 1 -
Characterization of housekeepers at a large public hospital according to colonization by Staphylococcus aureus, Curitiba, 2006-8

Table 2 -
Characterization of 13 housekeepers at a large public hospital colonized by methicillin resistant Staphylococcus aureus (MRSA), Curitiba, 2006-8 and the adoption of isolation measures (2.9%).Only 29 (46%) subjects related IPE use with occupational exposure prevention.The influence of colleagues' behavior who do not adopt safety measures on the other professionals' behavior was investigated, and 47 (74.6%) affirmed that this attitude does not interfere in www.eerp.usp.br/rlaemeasures associated with health care services.Their importance for Nursing relates to the fact that they are frequently hired by outsourced services and led by nurses.