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| Dr Anu Kant Mital |
Healthcare-associated infections are of important wide-ranging concern in the medical field. They can be localised or systemic, can involve any system of the body, be associated with medical devices or blood product transfusions.
Hospital-based programmes of surveillance, prevention and control of healthcare-associated infections have been in place since the 1950s. The Study on the Efficacy of Nosocomial Infection Control Project (SENIC) from the 1970s showed nosocomial rates could be reduced by 32 per cent if infection surveillance were coupled with appropriate infection control programmes. In 2005, the National Healthcare Safety Network (NHSN) was established with the purpose of integrating and succeeding previous surveillance systems at the Centres for Disease Control and Prevention (CDC): National Nosocomial Infections Surveillance (NNIS), Dialysis Surveillance Network (DSN) and National Surveillance System for Healthcare Workers (NaSH).
Both developed and resource-poor countries are faced with the burden of healthcare-associated infections. In a World Health Organization (WHO) cooperative study (55 hospitals in 14 countries from four WHO regions), about 8.7 per cent of hospitalised patients had nosocomial infections.
A six-year surveillance study from 2002-2007 involving intensive care units (ICUs) in Latin America, Asia, Africa, and Europe, using CDC’s NNIS definitions, revealed higher rates of central-line associated blood stream infections (BSI), ventilator associated pneumonias (VAP), and catheter-associated urinary tract infections than those of comparable United States ICUs. The survey also reported higher frequencies of methicillin-resistant Staphylococcus aureus (MRSA), Enterobacter species resistance to ceftriaxone, and Pseudomonas aeruginosa resistance to fluoroquinolones.
A study of bacteremia in African children found distinct differences in the microbiological causes of nosocomial bacteremia compared with community-acquired bacteremia. Nosocomical bacteremia resulted in a higher rate of morbidity and mortality and longer hospital stay. Because it is largely unrecognised in low-income countries, nosocomial infections are likely to become public health priorities as their occurrence increases.
Premier hospital ICUs of India show that HAI rates are high varying from around 14-15 per cent.
With increasing recognition of burden from healthcare-associated infections, national surveillance systems have been developed in various countries; these have shown that nationwide healthcare-associated infection surveillance systems are effective in reducing healthcare-associated infections, continued surveillance, along with sound infection control programs, not only lead to decreased healthcare-associated infections but also better prioritisation of resources and efforts to improving medical care.
Healthcare-associated infections are of important wide-ranging concern in the medical field. They can be localised or systemic, can involve any system of the body, be associated with medical devices or blood product transfusions.
Methicillin-resistant staphylococcus aureus (MRSA) has become a prevalent cause of infections. Traditionally, community-associated MRSA infections have been associated with USA300 or USA400 strains and healthcare-associated infections with USA100 or USA200 strains. However this distinction is becoming less clear with USA300 strains now increasingly identified as a cause of HAI. A population-based study showed MRSA USA300 was not associated with mortality for either central line–associated bloodstream infections or community-onset pneumonia.
Surgical site infections (SSI) occur within 30 days after the operative procedure or within an year if an implant was placed. Criteria for the diagnosis of SSI include purulent drainage at the site of incision, clinical symptoms of infection (such as pain, redness, swelling, etc), presence of an abscess, isolation of organism from the site culture, and clinical diagnosis of SSI by the surgeons.
Clostridium difficile is the most important bacterial cause of healthcare-associated gastroenteritis. Associated clinical conditions include asymptomatic carriage, diarrhea, and pseudomembranous colitis. Diagnosis is suspected in a patient with diarrhea and recent history of antibiotic use (especially cephalosporins and clindamycin).
The drug-resistant Gram-negative bacteria, for the most part, threaten only hospitalised patients whose immune systems are weak. They can survive for a long time on surfaces in the hospital and enter the body through wounds, catheters, and ventilators.[2]
| Routes of contact transmission | |
| Route | Description |
| Direct-contact transmission | This involves a direct body surface-to-body surface contact and physical transfer of microorganisms between a susceptible host and an infected or colonised person, such as when a person turns a patient, gives a patient a bath, or performs other patient-care activities that require direct personal contact. Direct-contact transmission also can occur between two patients, with one serving as the source of the infectious microorganisms and the other as a susceptible host. |
| Indirect-contact transmission | This involves contact of a susceptible host with a contaminated intermediate object, usually inanimate, such as the Touch surfaces in the wards, including the bed rails and dressing trolleys as well as the IV Poles, side tables, contaminated instruments, needles, or dressings, or contaminated gloves that are not changed between patients. In addition, the improper use of saline flush syringes, vials, and bags has been implicated in disease transmission in the US, even when healthcare workers had access to gloves, disposable needles, intravenous devices, and flushes |
Contact transmission is divided into two subgroups: direct-contact transmission and indirect-contact transmission.
Contact transmission: The most important and frequent mode of transmission of nosocomial infections is by direct contact. It is well established fact that proper practices such as Hand washing , Barrier nursing etc with the concomitant use of good disinfectants in cleaning the TOUCH surfaces helps in reduction of many Infections
Droplet Transmission: Transmission occurs when droplets containing microbes from the infected person are propelled a short distance through the air and deposited on the host’s body; droplets are generated from the source person mainly by coughing, sneezing, and talking, and during the performance of certain procedures, such as bronchoscopy.
Airborne transmission: Dissemination can be either airborne droplet nuclei (small- particle residue {5 µm or smaller in size} of evaporated droplets containing microorganisms that remain suspended in the air for long periods of time) or dust particles containing the infectious agent.
Microorganisms carried in this manner can be dispersed widely by air currents and may become inhaled by a susceptible host within the same room or over a longer distance from the source patient, depending on environmental factors; therefore, special air-handling and ventilation are required to prevent airborne transmission. Microorganisms transmitted by airborne transmission include Legionella, Mycobacterium tuberculosis and the rubeola and varicella viruses.
Common vehicle transmission: This applies to micro-organisms transmitted to the host by contaminated items, such as food, water, medications, devices, and equipment. Vector borne transmission This occurs when vectors such as mosquitoes, flies, rats, and other vermin transmit micro-organisms.
However if the reservoirs of infection are reduced or eradicated in the close ward environments then the scope for all the other forms of infection to spread are reduced. The reservoirs are normally formed on the touch surfaces like bed rails, IV poles, dressing trolleys, towel rails, over-bed tables and the bed side cabinets.
Decontamination of touch surfaces: The recent studies done by well known experts of Hospital Infection control around the globe have found that by a simple process of replacing the touch surfaces made of currently popular materials like plastics or steel by alloys of copper that contain at least 60 per cent copper can help in killing 99.9 per cent of all the bacteria that colonise these objects. These studies have been done in Laboratories with plating coupons of all these materials like Stainless Medical steel, Plastics, Brass and Copper alloys, with incubation at 370 C. the results have been encouraging showing that 99.9 per cent of the bacteria ( including MRSA. VRE, Pseudomonas etc. as well as the HINI virus) were dead by 90 minutes of exposure on these coupons made of copper alloys.
These studies were then conducted to determine the reduction in bio-burden in the Hospital settings in countries like UK, US, South Africa, Japan and Chile, the results were the same – the bio burden on the identified touch surfaces like bed rails IV Poles and side tables etc. dropped by 99.9 per cent on the surfaces that were retrofitted with copper alloys.
Then the final test- to check if this reduction in bio-burden in the hospital would translate into reduced infections rates in the wards. The landmark study done in the US over 43 months in three major hospitals including the Memorial Sloane Kettering Cancer Hospital have shown that depending on the number of surfaces that are replaced with copper alloys ( ie Anti Microbial Copper) the infection rates in the ICU have dropped by 47-69 per cent. As compared to similar adjacent ICU which did not replace any items with anti microbial copper. To check the validity and efficacy of these studies results in Indian setting the newly Built ICU of the Iconic Tata Memorial Hospital. Mumbai has been chosen to conduct a similar study recently. The results should be known by the early weeks of January 2013.
In the meantime many hospital equipment manufacturers and suppliers have seen the potential demand for these anti microbial touch surface equipment and have started manufacturing many items that are used in high risk areas in the ICU and the operation theatres. We hope that soon the healthcare service providers will see the benefits of his simple changes in their practice techniques and switch to using more of these anti microbial copper touch surface equipment.
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