Introduction
One of the significant ways of transmitting the infection is by hand, so hand hygiene is highly emphasized. Regarding the importance of handwashing in the wards, different physical and chemical methods are used to disinfect the hands. These methods have advantages and disadvantages and are used depending on the conditions. It has been attempted to provide solutions for solving the problem of inadequate hand hygiene. The first significant step is to highly access the antiseptic solutions that cause less dryness and skin irritation. Irritant contact dermatitis is one of the most common occupational diseases of health care personnel; its symptoms are usually dry skin, redness, and a burning sensation. The use of complementary therapies, unlike drug treatments, has no serious side effects and drug interactions in almost all cases. Also, it is simply applied and well accepted by the individual. The critical concern of hospitals is related to hospital infections, and it is highly attempted to prevent and control pathogens; in other words, care for vulnerable people against pathogens. According to the mentioned cases, the role of hands in transmitting infection, and the importance of minimizing skin complications of hand hygiene factors, we aimed to determine the effect of tea tree oil and lavender on bacterial samples of nurses’ hands.
Methods
This is a quasi-experimental study. All nurses working in the ICU (surgery, neurosurgery, and neurology) wards of Vali Asr Hospital with the characteristics of the research sample were selected by the non-probability sampling method. Finally, we recruited 55 nurses, including 8 men and 47 women. The demographic questionnaire and bacterial culture form were completed by the laboratory expert after taking the consent of the nurses to participate in the study. In the intervention stage, on the first day in the first experimental group, 2 drops of lavender oil, on the second day, 2 drops of tea tree oil, and on the third day, 2 drops of distilled water were poured on the nurse’s palm, and they were asked to rub their hands for 10 seconds. After drying the hand (for 30 seconds), a researcher (Laboratory expert), using a sterile swab, collected the bacteria samples from different parts of the nurses’ hands, the fingers and the palm, in each group.
In this study, blood agar was used. It was poured into a plate and placed at 37 °C in the precision incubator of Vali Asr Hospital, and nutrients were used to grow and multiply bacteria. After 48 hours, the number of colony-forming units (CFU) of plates was counted with a microbial colony counter. The base logarithm of 10 data was calculated for normalization. The data were then analyzed with the Chi-square, paired t test, and ANOVA in SPSS software version 20 at a significant level of less than 0.05.
Results
The results of 330 culture samples in three stages of 55 nurses working in the ICU wards were collected. Most of the nurses were female, and their mean age was 34.8 ±10.6 years. Most nurses were married with an education level of bachelor’s degree, clinical experience of 1 to 5 years, shift work, and contract employment status (Table 1). 


In this study, the most common organisms isolated at the beginning of the study were Staphylococcus epidermidis (76.8%), Staphylococcus aureus (8.8%), Klebsiella spp. (7.9%), and Escherichia coli (6.5%). The use of lavender and tea tree oil has been effective in reducing the microbe of the palm. Hand massage with lavender oil had less effect on reducing germs (P= 0.003); however, tea tree oil caused a more significant reduction of pathogens (P= 0.001) (Table 2).


Discussion
Lavender and tea tree oil reduced the microbial load of nurses’ hands. In other words, both methods were effective. Nevertheless, the effect of tea tree oil was higher. Therefore, it is recommended to apply lavender and tea tree oil for handwashing to remove palm bacteria in special wards. 

Ethical Considerations
Compliance with ethical guidelines
This study has the approval code for the research plan No. 2010 from the Research Council of Arak University of Medical Sciences, and the approval code of ethics (Code: IR.ARAKMU.REC.1393.170.8). The study was performed in accordance with the standards as outlined in the Declaration of Helsinki . This study is according to the moral protocol in research Centre of Health Ministry.

Funding
Arak University of Medical Sciences supported this study.

Authors' contributions
All authors equally contributed to preparing this article.

Conflicts of interest
The authors declare no conflict of interest.

Acknowledgements
Hereby, the researchers would like to sincerely thank all nurses participating in the study. Also, they would like to express their deepest appreciation to the Student Research Committee of Arak University of Medical Sciences for their support and guidance for approving and funding.