Antibacterial activity of zinc oxide nanoparticles (ZnO-NPs) has received significant interest worldwide particularly by the implementation of nanotechnology to synthesize particles in the nanometer region. Many microorganisms exist in the range from hundreds of nanometers to tens of micrometers. ZnO-NPs exhibit attractive antibacterial properties due to increased specific surface area as the reduced particle size leading to enhanced particle surface reactivity. ZnO is a bio-safe material that possesses photo-oxidizing and photocatalysis impacts on chemical and biological species. This review covered ZnO-NPs antibacterial activity including testing methods, impact of UV illumination, ZnO particle properties (size, concentration, morphology, and defects), particle surface modification, and minimum inhibitory concentration. Particular emphasize was given to bactericidal and bacteriostatic mechanisms with focus on generation of reactive oxygen species (ROS) including hydrogen peroxide (H₂O₂), OH⁻ (hydroxyl radicals), and O₂ ⁻² (peroxide). ROS has been a major factor for several mechanisms including cell wall damage due to ZnO-localized interaction, enhanced membrane permeability, internalization of NPs due to loss of proton motive force and uptake of toxic dissolved zinc ions. These have led to mitochondria weakness, intracellular outflow, and release in gene expression of oxidative stress which caused eventual cell growth inhibition and cell death. In some cases, enhanced antibacterial activity can be attributed to surface defects on ZnO abrasive surface texture. One functional application of the ZnO antibacterial bioactivity was discussed in food packaging industry where ZnO-NPs are used as an antibacterial agent toward foodborne diseases. Proper incorporation of ZnO-NPs into packaging materials can cause interaction with foodborne pathogens, thereby releasing NPs onto food surface where they come in contact with bad bacteria and cause the bacterial death and/or inhibition.

Respiratory tract infection (RTI) is a major public health challenge during the Muslim pilgrimage to Makkah. This study aims to evaluate the knowledge, attitude, and practice of Malaysian Hajj and Umrah pilgrims towards the prevention of RTIs in 2018 and determine correlations among three domains. A cross-sectional study was conducted among 225 Umrah and Hajj pilgrims. Knowledge, attitude, and practice (KAP) towards RTI prevention was assessed by using a validated self-administered questionnaire among pilgrims attending a weekly orientation course organized by private Hajj/Umrah companies. Out of 225 participants, 65.9% of respondents were female with the mean (SD) age of 46.74 (13.38) years. The interquartile range (IQR) score for knowledge is 18.0 (6.0), the mean scores of attitude and practice are 32.65 (4.72) and 25.30 (4.9). respectively. Significant and negative linear correlations between knowledge and practice (r = −0.232, p < 0.001), and attitude and practice (r = 0.134, p = 0.045) were observed. Results from the current study showed good knowledge of RTIs among Malaysian pilgrims. However, a poor attitude was reflected in their preventive practice behaviors. This will further help in the prevention and management of RTIs during Hajj and Umrah. Therefore, an extensive educational health campaign should be provided to pilgrims to create awareness.

Background: Hajj pilgrimage faces numerous challenges including a high prevalence of respiratory tract infection as well as its prevention strategies. The aim of this study was to develop and validate a questionnaire to evaluate knowledge, attitude and practice (KAP) towards respiratory tract infections (RTIs) prevention among Malaysian Hajj pilgrims. Methods: This study was conducted among Malaysian Umrah pilgrims in Malaysia from Kuala Lumpur and Kelantan. The questionnaire then underwent a series of validation process that included content, face validity and exploratory part. Item response theory (IRT) analysis was utilized for the validation of the knowledge domain. The attitude and practice were validated using the exploratory factor analysis (EFA). Results: The validation process resulted in a questionnaire that comprised of four main sections: demography, knowledge, attitude, and practice. Following IRT analysis of the knowledge domain, all items analyzed were within the acceptable range of difficulty and discrimination. The Kaiser-Meyer-Olkin measure of sampling adequacy (KMO) was 0.72 and 0.84 for attitude and practice domain respectively and Bartlett’s test of Sphericity for both domains were highly significant (P < 0.001). The factor analysis resulted in two factors with total of 12 items in attitude domain, and 2 factors with total of 13 items in the practice domain with satisfactory factor loading (> 0.3). The Cronbach’s alpha for reliability of the knowledge, attitude and practice domains all showed acceptable values of > 0.6 (0.92, 0.77 and 0.85). Conclusion: The findings of this validation and reliability study showed that the developed questionnaire had a satisfactory psychometric property for measuring KAP of Malaysian Hajj pilgrims.

Background. Respiratory symptoms including cough, runny nose, sore throat, and fever are the most common clinical manifestations faced by hajj pilgrims