Airborne Infection Control in health facilities warrants more attention Airborne transmission of

Airborne Infection Control in health facilities warrants more attention Airborne transmission of infectious disease like tuberculosis (TB), H1N1, severe acute respiratory syndrome (SARS), coronavirus is a major public health concern. India continues to have the highest number of tuberculosis (TB) cases in the world. The airborne transmission becomes even more prevalent in health-care settings because of overburdened and overcrowded hospitals and the presence of patients with immunosuppression. Nosocomial outbreaks of air borne infections in many countries have focused attention on the need to control the transmission of the disease in hospital. Emerging infectious diseases like Nipah virus disease has caused mortality among health care workers and general population with substantial nosocomial transmission. The death of a nurse who treated the patients with Nipah virus disease at recent outbreak in Kerala caught widespread attention. A systematic review of 51 studies conducted in low- to middle-income countries found that TB incidence among health care workers was high, ranging from 69 to 5780 per 100,000. Evidences show that TB is a significant occupational problem among health care professionals. Nosocomial outbreaks of airborne infections like influenza H1N1, drug-susceptible, multidrug-resistant TB (MDR TB), and extensively drug-resistant TB (XDR TB) have been reported and have been linked to the absence or limited application of airborne infection-control strategies in health care facilities.Several factors may facilitate nosocomial transmission in Indian hospitals, although their relative importance in facilitating transmission is unknown. Risk of transmission is highest when there is a high number of cases with poor infection control. Undiagnosed cases especially at medical ICUs and emergency rooms pose great threat for nosocomial transmission. Prevailing infection control practices in India revolve around biomedical waste management and disposal of sharps; while airborne infection control (AIC) measures has not received adequate attention from the health care facilities and practices. National Guidelines on Airborne Infection Control in Health Care and other settings in India were published as the first, formal national guidelines on reducing the risk of airborne infections in health care facilities and special high-risk settings in India.The guideline involves recommendations categorized into three main components; I. Administrative controls.II. Environmental controls.III. Use of Personnel protective equipment.I. Administrative controls: Administrative controls are to classify persons with respiratory symptoms, separate them into appropriate environment, fast-track them through the health care facility to reduce exposure time to others, and diagnose/treat them with minimal delay. A. Outpatient Setting a. Screening: Screening for respiratory symptoms need to occur as early as possible upon patient’s entry at the health care institution. A separate screening counter may be placed, patients can be encouraged to first visit this counter if they have suggestive symptoms, by appropriate advertisements, posters or announcements in the registration area. Even if screening at registration is not possible, screening can occur when patients register at specific clinics or when in waiting areas. b. Education on cough etiquette and respiratory hygiene: physical method that can prove useful for reducing airborne transmission is the provision for patient education on cough hygiene and sputum disposal. This education can easily be imparted to patients through posters and other means in the waiting area. Cough etiquette should be reinforced by all staff members. Masks can be provided to all respiratory symptomatic. Simple surgical masks may not help health care worker from getting air borne diseases but are effective when used by the patients to reduce the production of respiratory droplets of all sizesc. Patient segregation: Segregation of patients with respiratory symptoms can be achieved by having a separate waiting area for chest symptomatics, within the overall outpatient area. This is particularly important in larger institutions with heavy OPD loads. The outpatient area, more so this segregated area, should be well ventilated to reduce overall risk of airborne transmission.d. Fast tracking of patients with respiratory symptoms: Those identified as patients with respiratory symptoms can be further fast-tracked in both their clinical and laboratory evaluation. Patients may be allowed to jump the routine queue and be seen earlier than other patients. The other important area where these patients can be given priority is while performing chest radiography.B. Inpatient areas a. Minimize hospitalization of TB patients: One of the most effective means to reduce the risk of transmission of airborne pathogens such as M. tuberculosis in hospital settings is to manage such patients in the outpatient setting whenever possible.b. Establish separate rooms, wards, or areas within wards for patients with infectious respiratory diseases: patients with infectious respiratory diseases should be physically separated from other patients so that others are not exposed to the infectious droplet nuclei that they generate. Policies on patient separation inevitably generate concern about stigma, but with appropriate measures – such as training and public posting of separation rules – stigma can be minimized. Administrative procedures should ensure that separation happens promptly and automatically, similar to the automatic separation of men and women during inpatient admission. The best choice for infectious or potentially-infectious patients is to house and manage them in airborne precaution rooms.c. Educate inpatients on cough hygiene and provide adequate sputum disposal: Wards housing infectious patients should display sign boards in the ward demonstrating cough hygiene. All patients admitted in the ward/area should be issued surgical masks and counseled on their proper use and adequate measures for safe collection and disposal of sputum. d. Establish safe radiology procedures for patients with infectious respiratory disease like scheduling the procedure during non-busy times II. Environmental Controls: Ventilation should be prioritized to reduce the number of infectious particles in the air. Effective ventilation may be achieved by natural ventilation where ever possible. When clean or fresh air enters a room, it dilutes the concentration of airborne particles, such as droplet nuclei, in room air. Unrestricted openings (i.e. those that cannot be closed) on opposite sides of a room provide the most effective natural ventilation. Openings should constitute at least 20% of the floor areas (10% on either side for effective cross ventilations). In existing health-care facilities that have natural ventilation, when possible, effective ventilation should be achieved by proper operation and maintenance of openings, and by regular checks to see that openings remain free of obstruction at all times.Mechanical ventilation with or without climate control may appropriate where natural ventilation cannot be implemented effectively, or where such systems are inadequate given local conditions (e.g. building structure, climate, regulations, culture, cost and outdoor air quality). If mechanical ventilation is used, the system should be well designed, maintained and operated, to achieve adequate airflow rates and air exchange. Careful attention must be given to ensuring adequate ventilation when installing air conditioners. Minimum number of air changes per hour need to be ensured while using air conditioners. In OPD and registration areas there should be minimum of 6 air changes per hour while in high risk setting it should be 12.In high-risk settings where optimal ventilation cannot be achieved through natural or mechanically-aided means, properly designed, placed and maintained shielded ultraviolet germicidal irradiation devices should be considered as a complementary control.Fig 1. Schematic showing seating arrangement for patient and health care worker (red cross) In (A), natural ventilation would allow potentially infected air to cross health care worker. In (B), with this seating arrangement the chance of such exposure is lessened somewhat. (Picture adapted from NAIC guidelines, 2010)III. Personal protective equipment: Simple surgical masks may not help health care worker from getting air borne diseases but are effective when used by the patients to reduce the production of respiratory droplets of all sizes. Personal protective equipment (e.g. particulate respirators certified as N95 or FFP2) should be available as required in high-risk situation, especially during high-risk aerosol-generating procedures such as bronchoscopy or sputum induction.ConclusionNumerous studies have shown that implementation of recommended air borne infection-control strategies has been associated with reduced outbreaks of air borne infections and preventing its nosocomial transmissions in health care facilities. It is more important to promote implementation of National Air borne Infection Control guidelines in the hospitals. It has been revealed that most of the countries where a significant reduction of air borne diseases including TB has been observed, air borne infection control practices have played a crucial role. Dr Rakesh PSConsultant, TB Elimination