Hospital-acquired infection represents a major public health concern worldwide. Hospitals have played a significant role in the spread of emerging infections. In Toronto, 77% of case patients were exposed to severe acute respiratory syndrome (SARS) in hospital settings in 2003 [1]. Hospitals in South Asia can be at particular risk for transmission of emerging infections, specifically Nipah virus [2]–[4]. For example, a large outbreak of Nipah virus was reported among healthcare workers and patients at hospitals in Siliguri, India in 2001 and evidence of Nipah virus transmission in Bangladesh has recently been reported [3]. In addition, patients in Bangladeshi hospitals face substantial risks from endemic infections; studies have shown that hospital-acquired respiratory infections occur at an incidence rate of 6.1 cases per 1000 patient-days [5], and diarrhea with an incidence rate of 3.9 cases among pediatric patients and 2.7 cases among adults per 1000 patient-days [6].

Pathogens in hospital environments can be transmitted through airborne particles, fomites, respiratory droplets or direct contact with bodily fluids [7]–[9]. International infection control guidelines exist [7], [9], but assume a level of basic infrastructure, which may not be available in many low-income settings. Understanding the context of environmental contamination in low-income hospital settings is essential to inform interventions to control the spread of hospital-acquired infection. Using data from a larger study that explored hospital-acquired respiratory illness, this paper describes the physical structure and contamination of the environment in three Bangladeshi hospitals.

Overcrowding, inadequate sanitary facilities, lack of routine cleaning, lack of basic infection control measures and improper waste management combined to create numerous opportunities for transmission of infection in the study wards. This environment posed a threat of infection to all ward occupants.

Crowding in hospitals facilitates the spread of many diseases [12], [13]. The observed crowded environment could facilitate transmission of infectious microorganisms through coughing, sneezing, talking and contact with materials and surfaces. A study conducted in a hospital in Singapore reported higher concentrations of airborne bacteria in the most densely occupied locations, such as the pharmacy and lobby, and an occupant density of 0.5 to one person per 10 m² ward area [14] compared to our reported overall median of 3.7 persons per 10 m². The uncontrolled flow of visitors in our study wards may influence prevalence of hospital-acquired infection, as was noted in a cross-sectional study in surgical wards in a Bangladeshi tertiary hospital [13]. Sharing beds may also facilitate disease transmission; a study reported transmission of Nipah encephalitis from a patient to a caregiver while sharing a bed [15]. A number of diseases, such as SARS, Nipah virus, tuberculosis, measles, influenza, chickenpox, meningitis, mumps and aspergillosis can be spread by airborne or droplet transmission from coughing, sneezing or inadequate ventilation [7], [8], [15], [16]. Exposure to cold air is commonly perceived to be one reason behind acute respiratory diseases in Bangladeshi children [17], hence the restricted airflow in pediatric wards, which led to inadequate ventilation. Frequent uncovered coughing and sneezing occurred among people in close physical proximity in the study wards with suboptimal ventilation, posing a risk to all ward occupants.

Hospital surfaces could be potential reservoirs of nosocomial pathogens that can survive for a few days to several months [8], [18]. Contaminated floors, taps, door handles and walls in toilets could be potential sites for colonization of pathogens and transmission through hand contact of diseases such as cholera [19], hepatitis A [20], vancomycin-resistant enterococci [21] and puerperal fever [22]. The practice of dry sweeping is strongly discouraged in global infection control recommendations, since it can aerosolize particles that may contain microorganisms [7], [9]. Medical equipment such as nebulizers [23], stethoscopes [24] and sphygmomanometers [25] that have been used on multiple patients without disinfection can also act as fomites for pathogens such as gram-negative bacilli, coagulase-negative staphylococci and methicillin-resistant Staphylococcus aureus (MRSA).

Most hospital infections are acquired via direct contact [8], and hand contact is a major route of acquisition [10]. Thus hand hygiene is considered to be the single most effective measure of infection control [26]. Lack of functioning and accessible handwashing stations in study wards is one reason that handwashing with soap was infrequent. In other settings, hand hygiene compliance improved after providing multiple conveniently located handwashing stations [27]–[29]. Given the continuous hand contamination during patient caregiving, waterless hand sanitizers could also play a role in hand disinfection in addition to handwashing with soap, particularly when hands are not soiled with body secretions and excretions. This alternative is more costly than soap and water and may be unacceptable to family caregivers and staff who are unfamiliar with waterless cleaning agents. However, given the logistical constraints to accessing water on these wards, the acceptability and feasibility of waterless sanitizers should be investigated as an alternative.

The presence of animals inside wards poses a threat of transmission of zoonotic diseases. In a geriatric care center, a cat was associated with an outbreak of epidemic MRSA [30]. Evidence of hospitalizations of dengue patients in Bangladesh [31], coupled with an abundance of mosquitoes in wards, creates an opportunity for nosocomial spread of dengue, a major public health concern in Bangladesh [32].

Improper handling and unsafe disposal of hospital waste is a public health concern globally [33] and in Bangladesh [34]. Particular risks include cleaning, packaging and reusing contaminated medical equipment. Disposing of used sharps in open buckets and on open grounds at these hospitals could increase the potential for transmitting HIV [35], hepatitis B [36] and hepatitis C [37] to both healthcare workers who handle waste and the general public who scavenge in open dumpsites.

This study was conducted in only three public tertiary hospitals that were not randomly chosen; therefore the findings cannot be generalized to other government tertiary hospitals, private clinics or other non-government hospitals in Bangladesh. However, our findings are consistent with other studies in Bangladeshi tertiary hospitals that have reported crowding in wards [38], improper waste disposal [34] and poor hygiene and sanitation facilities [10]. There are many hospitals in other low-income countries with similar environments [39]–[41], particularly within South Asia [42]. Since each researcher was assigned to observe and take notes on the activities of multiple persons, we assume that some events could have been missed and the frequency of events reported here could be underestimated.

Public hospitals play a crucial role in ensuring healthcare services for the poor in Bangladesh [43]. Bangladesh has 17 public tertiary hospitals and a population of 150.5 million, 31% of whom are below the poverty line [44]. Our findings indicate the physical structure and environment of the three public hospitals are conducive to spreading infections to all ward occupants. With evidence of diseases like Nipah virus, avian influenza and H1N1 in this country, this environment creates a regional and global risk for wider transmission of emerging infections. Unlike hospitals in high-income settings, hospitals in low-income settings cannot follow many international infection control recommendations due to resource constraints. Furthermore, it is possible that management that extracts unofficial fees in exchange for services, commodities and access may have a vested interest to maintain such poor conditions in some of these public facilities [45]. Interventions focused solely on education or training are unlikely to improve infection control in these hospitals; interventions should also aim to improve infrastructure and to establish administrative initiatives, such as developing and implementing infection control guidelines, monitoring of routine cleaning and providing incentives for infection control activities among healthcare staff. Low-cost interventions on hand hygiene and cleaning procedures for rooms and medical equipment should be developed and evaluated for their practicality and effectiveness.