We, as humans, live in a complex environment where we interact with variety of living and non-living creatures. At the microscopic level, there is constant contact with micro-organisms; namely, bacteria, viruses, yeasts, parasites, and others. While most of these microbes are harmless, some are even beneficial to human beings. For example, lactic acid bacteria used to make yogurt; yeasts are involved in leavening of bread; and we derive vaccine substances from some viruses.
On the other hand, these micro-organisms that we can’t see with our naked eyes can lead to serious infectious diseases or even dramatically disrupt civilizations (Myers SS, 2009). A historical example is the Spanish flu pandemic in 1918-1920 where the estimated human death worldwide was 50-100 million (Johnson NP, 2002). Moreover, infectious diseases may also cause devastating economic losses. For instance, the estimated impact of SARS (Severe Acute Respiratory Syndrome) epidemic was close to $40 billion in 2003 (Lee JW, 2004).
Because of improvements in living conditions and advances in medicine, the proportion of infection-related human deaths have been down-trending (Barrett R, 1998). Nonetheless, due to the over-use and inappropriate use of antibiotics, multi-drug resistant pathogens are on the rise, which subsequently lead to high morbidity and mortality. Among these emerging resistant bacteria are Extended-Spectrum Beta-Lactamase (ESBL) and Methicillin-Resistant Staph Aureus (MRSA), which are becoming one of the major global healthcare problems in the twenty-first century (Medina E., 2016). These emerging infectious diseases have not only been problematic in the hospital setting, but also in the community setting (Boucher HW, 2008).
Occupationally acquired MRSA infection is an issue of increasing concern. MRSA colonization and/or infection have been reported in healthcare workers (HCWs), laboratory personnel, veterinarians, professional athletes, firefighters, among school staff and correction facilities. Based on literature published between 1980 and 2006, the estimated prevalence of MRSA colonization among healthcare workers was 5% (Albrich, 2008). Hence, they are likely to act as vectors in MRSA transmission, most frequently through contaminated hands and airborne dispersal in association with an upper respiratory tract infection (Cimolai, 2008). Furthermore, in an environmental surface sampling in thirty-three Washington State fire stations, MRSA was isolated in nineteen fire stations (58%). Also, twelve fire stations (37.5%) reported fire service professionals with MRSA needing medical care (Roberts MC, 2014).
In this paper, we will discuss MRSA as an occupational hazard. First, we will review the the microbiology and pathogenesis of MRSA. Later, will dive into occupational and health impact assessment; vulnerable population; approaches to resolve the problem and protect human health; economic implications; recommendations for research need and policy priorities.
Scientific aspects of the MRSA
Staphylococcus Aureus, commonly called “Staph”, is bacteria normally found in the nose and on the skin of healthy people. MRSA stands for Methicillin-Resistant Staphylococcus Aureus, the most commonly identified antibiotic-resistant microbe in hospitals worldwide (Heuer, 2010). In the United States, the percentage of Methicillin-resistance in isolated Staph aureus approached 60% in 2003, with an average rate of resistance over the period 1998-2002 of nearly 50% (System., 2004).
Individuals colonized with MRSA generally carry this strain of bacteria without having any symptoms. Carrier status can be transient or persistent, with the anterior nares being the main reservoir of MRSA, although other body parts (e.g. hands, skin, axilla) can be colonized too (Albrich, 2008). While 33% of the population is colonized with staph, approximately 1% is colonized with MRSA (NIOSH, 2015).
On the other hand, MRSA can potentially cause a variety of infections that are resistant to several common antibiotics. These can range from localized skin infection to severe deep tissue (e.g. abscess), lung (e.g. pneumonia), heart (e.g. endocarditis), or bone (e.g. osteomyelitis), or bloodstream (bacteremia) infections, which might be life-threatening. MRSA infections occur most frequently amongst people in hospitals and other healthcare facilities, such as dialysis centers and nursing homes who have weakened immune systems (NIOSH, 2015).
Theoretically, anyone can catch MRSA by sharing personal items (e.g. razor, towels) that have touched infected skin, or from direct contact with an infected skin wound. In addition to inpatient medical setting, the risk of contracting MRSA increases in crowded areas where there is skin-to-skin contact or shared equipment or supplies (athletes, military personnel, daycare, schools). As an example, MRSA skin infection may manifest as red, swollen, warm to touch, and painful skin bump that is usually full of pus. This risk of MRSA infection can be lowered by maintaining good hand hygiene, keeping wounds clean and covered, and avoidance of sharing personal items (CDC, 2009).