**2. HAI is on the rise**

In last century mankind has experienced tremendous advancement in Medical field in understanding the causes and thereby improvement in diagnostic and therapeutic approach of any disease. Similarly, progress in engineering field has changed the look of Health care system. But with all these advancements also, HAIs are on the rise mainly because of -

**i.** Increase in immunocompromised patients


The last one is most dangerous. Though scenario is slightly better in developed world the picture is grim in other developing countries. According to WHO report 2002 [7] worldwide more than 1.4 million people suffer from HAI. Actually HAI vary from 5-25% in developed countries, whereas data from developing country is not available as it is not reported properly. It may be >40% in Asia, Africa and South America [8]. Klevens et al, 2007 had reported that HAIs killed 99,000 patients in American hospital [9] and 37,000 deaths in Europe [10]. In US, 5-10% of all hospitalized patients can get HAI. In India data are sparse, Mukherjee V had reported in 2001 that HAI occurred in 30-35% of all hospital admissions in India [11]. Childs D reported that HAIs kill more patients every year than do AIDS, breast cancer and automobile accidents together worldwide [12]. HAIs are the 8th most common cause of death in US. The mortality rate range from 12-80% in ICUs of developed countries [13].

#### **Impact of HAI**

Health Organisation (WHO) conducted a survey and the results of the survey in 1988 reported that "Hospital Acquired Infection is a considerable problem even in hospitals in which means

British Medical Council established Hospital Infection Control Programme in 1941 and a part time post of "Control Of Infection Officer" was created, which was renamed as "Infection Control Doctor" in 1988. The first full time "Infection Control Nurse" was appointed in 1959 [1]. National Nosocomial Infections Surveillance (NNIS) system of the Centre for Disease Control and Preventions (CDC) was developed in early 1970s to monitor the incidence of

The term nosocomial infection is derived from nosus means disease and komeion means to take care of and has been used for many years. The hospital acquired or nosocomial infections have been defined as infections that occur to patients during hospitalization but are neither present nor incubating during admission to the hospital. In simple words, any infections acquired in a hospital which was not present or in its incubation period during admission to

In the past, nosocomial infections or Hospital Acquired Infections were restricted only to the hospitals, but in recent years, spectrum of health care and interactions of different types of healthcare facilities including hospital, long term care, rehabilitation or ambulatory care facilities have been expanded and nosocomial infections have broadened its horizon. Hence, the term Healthcare Associated Infection (HAI) is a more appropriate term. The Centers for Disease Control and Prevention (CDC) defines HAIs as infections that patients acquire during the course of receiving treatment for other conditions or that Healthcare workers (HCWs) acquire while performing their duties within a healthcare setting [4]. The bacterial HAIs are usually observed, 48 hours after admission to healthcare setup, because for most of the routinely isolated bacteria the incubation period is 48 hours. But each infection must be assessed individually as the incubation period varies with the type of pathogen, dose of inoculum and patient's immune status. Some HAIs may be observed even after discharge of the patient especially, Hepatitis B virus (HBV), Hepatitis C virus (HCV), Human immune deficiency virus (HIV) etc. Even CDC has changed the name of section of Hospital Infections Programme to the Division of Healthcare Quality Promotion [5]. The National Health care safety network (NHSN) of CDC defines HAI as a localized or systemic condition that results from presence of infectious agent or its toxin and that was not present or incubating at the time

In last century mankind has experienced tremendous advancement in Medical field in understanding the causes and thereby improvement in diagnostic and therapeutic approach of any disease. Similarly, progress in engineering field has changed the look of Health care system. But with all these advancements also, HAIs are on the rise mainly because of -

and interests in control of Hospital Acquired Infections exist" [2].

Hospital Acquired Infection, the risk factors and causative organisms [3].

the hospital are called nosocomial infections.

4 Infection Control

of admission to the Hospital / Health care facility [6].

**i.** Increase in immunocompromised patients

**2. HAI is on the rise**

The major impact of HAI are outcome of disease is adversely affected. HAI is the major cause of: i) increased morbidity and mortality, ii) increased average length of stay (ALS) of patients in the Health Care set up, iii) increased diagnostic and therapeutic interventions and iv) increased cost of Health Care. HAI adds financial burden to patients, health care or‐ ganization, State and also National Health Care system. HAI also have negative impact on effectiveness and productivities of Health Care organization. In case of HAI, patients are not protected by Health insurance and the health care organization comes under consumer pro‐ tection act.

The triad of infectious diseases as described in textbooks are i). the affected host ii). an infectious agent and iii). the environment, both animate and inanimate [14]. HAIs also follow the same triad as the affected host may be the patients, health care workers(HCW), patient's relatives, the infectious agent may be Methicillin Resistant Staphylococcus aureus(MRSA), Vancomycin Resistant Enterococci(VRE), Pseudomonas aeruginosa, other Gram negative bacteria or simply Candida, Aspergillus or viral e.g. Cytomegalovirus, HBV, HIV etc and most important the hospital environment.

Hence, the epidemiological triad of HAI are –
