New report from IFH - Household water storage, handling and point-of-use treatment
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For decades, access to safe water and sanitation has been promoted as an essential step in reducing the global burden of diarrhoeal disease. Despite this, it is estimated that up to 1.1 billion people still do not have access to improved water sources, and many more lack safe water for drinking. Although mortality from diarrhoeal disease has declined, it is estimated that people in developing countries still experience between 5 and 20 episodes of diarrhoea per year.
Water quality is a problem in developing as well as in developed countries, most particularly in Eastern European countries, but also in North America and elsewhere. In the European region it is estimated that 120 million people still lack access to safe drinking water. In Europe and North America, although there are fewer risks of epidemics related to waterborne pathogens such as cholera, typhoid or hepatitis, numerous instances of disease from contaminated drinking water are still reported; it is estimated that as much as 15-30% of community gastroenteritis may be attributable to municipal drinking water, despite state of the art water treatment technology, and no evidence of unacceptable microbial contamination levels.
Although significant advances have been made globally in providing community water supplies and improving the quality of these supplies, there is concern that health gains from investment in water supply are being compromised by contamination which occurs during distribution, or during storage and handling within the home. It is now recognised that a key option for dealing with this is by promotion of point-of-use water treatment and safe storage. It is argued that, by promoting household water treatment and safe storage, it is possible to provide safe water to underserved populations much more quickly and affordably than it takes to design, install and deliver community supplies. Although “safe water for all” remains the ultimate goal, promotion of “point of use” water treatment has the potential to provide immediate benefit to at risk populations until the long-term goal of providing community water supplies can be achieved.
Point-of-use water treatment is important not only as a means to improve access to safe water in disadvantaged communities, it is also key to preventing waterborne disease in emergency situations. It is likely that the year 2005 will be remembered as the year of natural disasters – the Asian Tsunami, hurricane Katrina in New Orleans and the Pakistan earthquake. Emergency situations require prompt response. In these situations, household or community treatment of drinking water and safe storage play a special role in preventing large-scale diarrhoeal disease outbreaks in the immediate aftermath.
In this IFH report, we review the range of simple, low-cost physical and chemical treatment methods and systems for safe collection, handling and storage which have been developed for improving household water quality. Data on the ability of these systems to provide water of acceptable quality is also assessed. The report also reviews the various field studies which show the extent to which point-of-use treatment and safe storage of water in the home can reduce the burden of diarrhoeal and other waterborne diseases in the community.
It is now well accepted that, if promotion of household water treatment and safe storage is to be successful, it must also involve community education, participation and motivation. This means not only teaching families how to implement water treatment and safe storage, but also promoting awareness of the role of contaminated water in disease transmission. The report reviews some of the formative research which is being carried out to determine how best to achieve behaviour change with respect to water handling, treatment and storage in the home. We also review the various practical guides which are now available which give guidance on how to implement hygiene promotion activities.
Amongst public health scientists and practitioners, there is now widespread consensus that, one of the past mistakes in tackling infectious disease, has been to give greater priority to provision of community water supplies over provision of sanitation, and to sanitation over hygiene. Increasingly it is now recognised that, in reality it is hygiene practices such as handwashing and household water treatment, safe handling and cooking of food etc that reduce the burden of infectious disease. Although there is awareness of the need for greater emphasis on hygiene promotion, this does not necessarily translate into commitment to action by national and international governments and by non-government agencies. A significant barrier to progress is the fact that, in most countries, the separate aspects of hygiene (faeces disposal, food and water hygiene, handwashing, care of the sick, childcare etc) are dealt with by separate agencies. If hygiene promotion is to be effective ideally there should be a single lead agency in each country, and appropriate infrastructure at national, district and local level which is specific for actioning programmes that promote hygiene at household level. This problem was also highlighted at the 2005 Global WASH Forum in Dakar Senegal and in the UNICEF/IRC report on School sanitation and hygiene described below.
The report will be released and posted on the IFH website on 10 February, on occasion of the National Symposium on Drinking Water and Community Health: Standards, Surveillance and Management organised by the Indian National Science Academy, New Delhi. 10 and 11 February 2006 (see details below). Prior to that date, copies of the report can be obtained by applying to: secretariat@ifh-homehygiene.org
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Cleaning for a healthy indoor environment for children |
 The Simmons Center for Hygiene & Health in Home and Community held its first conference ”Cleaning for a Healthy Indoor Environment for Children” on October 24 and 25 in Boston. Participants came from across the United States, Canada and Europe. The aim of the conference was to offer new information and practical approaches on cleaning children's environments in order to reduce the risks of infections and allergies. The conference was introduced by Dr. Elizabeth Scott (IFH Scientific Advisory Board Member, and Co-director of the Simmons Center).
The keynote address was given by Dr. Syed Sattar, from the University of Ottawa, who described the role of the environment in bacterial and virus transmission in children. He discussed a number of environmental control measures including hand-washing, alcohol based hand sanitizers and cleaning and disinfection. He also stressed the importance of evaluation of antimicrobial chemicals for effectiveness and safety.
The first session was devoted to cleaning for infection control. The topics included cleaning to prevent the spread of cMRSA and other skin pathogens amongst students during school athletic activities (MaryAnn Custer MS, RN, CSMRN), infection control in daycare and schools (Patricia Kludt, MPH), cleaning for asthma and allergy control (Dr. Gary Adankiewicz, Harvard School of Public Health) and cleaning to remove fungal pathogens from the environment of immunocompromised children living at home (Dr. Eugene Cole, Brigham Young University and conference organizing committee).
The second session was devoted to the risks and benefits associated with cleaning. The keynote paper in this session was given by IFH Chairperson Dr. Sally Bloomfield, who talked about the current concerns related to the so-called ‘hygiene hypothesis' and antibiotic resistance. She also described the ‘targeted hygiene' approach developed by the IFH. Dr. Susan Duty (Simmons College) discussed occupational exposure data on some of the health effects associated with certain cleaning chemicals. This was followed by Dr. Carole LeBlanc who discussed the need to develop less toxic solutions for cleaning and disinfection and the work of the Toxics Use Reduction Institute at the University of Massachusetts. Melissa Taylor from Porter Novelli Public Relations wrapped up the conference with a discussion on social marketing of health messages.
The conference was made possible by sponsorship from Lysol, Procter & Gamble Household Care, and the Soap and Detergent Association. Conference materials and presentations will be available at www.simmons.edu/hygieneandhealth
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| Detection of Methicillin-resistant Staphylococcus aureus in the domestic environment |
Since the first strains of methicillin-resistant Staphylococcus aureus (MRSA) were identified in the early 1960's, the prevalence of MRSA as a nosocomial pathogen has steadily increased and is now considered the most common cause of hospital-acquired infections throughout the world. In the past few years it has become apparent however that MRSA infections are by no means confined to the hospital setting. The prevalence of community-acquired (CA-MRSA) infections, even among previously healthy individuals, is increasing and is now recognised as a significant problem1,2. CA-MRSA infections are primarily associated with skin and soft tissue lesions but can lead to hospitalization and death3,4. Little information is available on the prevalence or origin of CA-MRSA in the domestic environment, however, isolation from household pets has been reported5. Recently, researchers from the University of Arizona, Kelly Reynolds and Charles Gerba, surveyed a total of 494 soft surfaces in 27 homes in two U.S. cities for the prevalence of MRSA, using contact plate sampling with selective chromogenic agar. A total of 17 sites in 11 homes were confirmed positive for MRSA following isolation in mannitol salt agar and automated identification and antibiotic susceptibility testing (Vitek, bioMerieux, Durham, NC). MRSA was detected most frequently on bathroom rugs and bed linens but also on fabric couches, draperies, pet beds and children's car seats. Additionally, a gym bag, purse, and kitchen dischcloth tested positive. This study suggests that the prevalence of MRSA is not uncommon in the home environment, however the public health significance of these findings is not yet known. More research is needed to evaluate the virulence factors, antibiotic resistance patterns, and other characteristics of these household isolates, with respect to risk of infection and disease manifestation.
References: 1.National Nosocomial Infections Surveillance (NNIS) System report. Am J Infect Control 2002;30:458–75. 2Diederen, B & Kluytmans, J. The emergence of infections with community-associated methicillin resistant Staphylococcus aureus . J. Infect. 2005. [Epub ahead of print]. 3.CDC Four pediatric deaths from community-acquired methicillinresistant Staphylococcus aureus —Minnesota and North Dakota, 1997–1999. JAMA 1999;282:1123–5. 4.Frazee BW, et al. Fatal community-associated methicillin-resistant Staphylococcus aureus pneumonia in an immunocompetent young adult. Ann Emerg Med. 2005 46:401-4. 5.Rankin S, et al. leukocidin (PVL) toxin positive MRSA strains isolated from companion animals. Vet Microbiol. 2005 108:145-8.
This article was submitted by Kelly Reynolds (reynolds@u.arizona.edu)
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The fungal ecology of the home environment – and emphasis on clean and dry |
 Environmental fungi are introduced to the home environment from outdoors through openings between interior and exterior spaces; and from carriage on clothing and track-in from soil. Once indoors, these organisms interact with the inanimate environment by collecting or settling in or on a variety of surfaces or materials. Such collecting places, or “microenvironments” or “reservoirs,” include carpet, upholstered furniture, wood and various painted surfaces such as walls and ceilings, a variety of personal items, and systems for home heating and cooling. In a dry environment subject to routine cleaning, (i.e., dust removal), such reservoirs are normally non-problematic. And if conditions are such that moisture is limited, then these fungi maintain a stable and non-problematic relationship with the inanimate components of this indoor ecosystem.
However, as water intrudes from outdoors, pipes leak, or moisture condenses onto surfaces and materials, the fungal ecology changes and favors rapid growth and amplification of organisms with high moisture requirements, such as species of Aspergillus,Penicillium,Aureobasidium, Trichoderma, Fusarium, and Stachybotrys, among others. This amplification can damage valuable materials, and affect the quality of indoor air, creating health risks for those who live there. This can include the triggering of respiratory allergies and asthma, and the potential for infection in the immunocompromised. Recognition of recent water damage in the home, as well as the presence of musty odors, and the onset of adverse health effects in occupants, are all indicators of a shift in the normal fungal ecology of a home environment.
The two major strategies for reducing fungal reservoirs and resultant airborne fungal contamination in the home environment are:
1) controlling moisture in the air and on surfaces and materials, and
2) cleaning reservoirs, such as carpet and upholstery, by the frequent removal of soil and dusts. Others include the use of appropriate disinfectants or sanitizers on moisture-prone hard surfaces to further reduce the potential for fungal growth; and restricting fungal entry from outside the home, such as reducing track-in on shoes. Controlling moisture involves regularly inspecting for and eliminating damp areas, and rapidly resolving incidents such as plumbing leaks, floods, and the accumulation of extensive condensation. Such occurrences require removal of the water followed by thorough drying/dehumidification within 24 hours. Cleaning involves the physical removal of dusts and soils and their inherent fungal spores from reservoirs that tend to rapidly collect and concentrate them, such as carpet and upholstery. Such cleaning is best done by the use of a high-efficiency vacuum cleaner containing a disposable, double-walled bag, and having extensive exhaust air filtration. Periodic professional cleaning using an extraction method for carpet and upholstery is also recommended.
Adhering to the guidance presented in “A brief Guide to mold, moisture and your home” will help to ensure a normal fungal ecology in the home that will protect its occupants as well as its value.
This article was submitted by Eugene C. Cole, Brigham Young University (gene.cole@byu.edu). Dr Cole's main research interest is the fungal ecology of indoor environments with a focus on generating guidance for reducing the risk for opportunistic fungal infections in homes of the immunocompromised.
Further Reading:
1. A brief Guide to mold, moisture and your home
2. Fungi in the domestic environment and community settings – association with health problems. |
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| Flu, avian flu and hygiene - avian influenza top health issue of 2005 |
The threat of an outbreak of H5N1 avian flu virus adds a new dimension of concern to the 2005 flu season. Recently WHO carried out a survey of over 600 people from more than 20 countries entitled "How healthy is your world?". The survey asked 2 questions: what were the top health issues of 2005? and what global health issues were the most neglected? Avian influenza came out as the top health issue of 2005, tobacco the most neglected issue. Although there seems to be a general assumption that droplet infection is probably the main route for spread of influenza, increasingly there is acceptance that flu is also transmitted by direct contact, or via contaminated hands and surfaces. In view of this, the major health protection agencies such as WHO, CDC and the UK health protection Agency, include advice on hand and surface hygiene in their advice materials on preventing spread of avian flu in hospital and community settings. In response to concerns about flu in the winter of 2000 and about SARS in 2003, IFH produced an information brochure on understanding respiratory infections which provides practical advice on what people could do in their own home to reduce the risks of spread of colds and influenza. These materials can be downloaded from the IFH website:
http://www.ifh-homehygiene.org/2003/2downloadabledoc/SARS.pdf
Further Reading:
1. Boone, SA and Gerba, CP. The occurrence of influenza A virus on household and day care center fomites. Journal of Infection, 2005, 51, 103-109.
2. Transmission of Avian Influenza Viruses to and between Humans Hayden F. and Croisier A Journal of Infectious Diseases 2005:192:1311-1313
3. WHO, Communicable Disease Surveillance & Response, Avian influenza
4. WPRO and WHO, Communicable Disease Surveillance & Response, Avian influenza, frequently asked questions
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Centers for Disease Control and Prevention, Avian influenza
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UK Health Protection Agency. Pandemic flu: important guidance for you and your family
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UNICEF water and sanitation project in the Pakistan quake zone |
UNICEF and the government of Pakistani-administered Kashmir have jointly launched a new US$ 8.2 million project to rehabilitate rural water supply systems and improve sanitation in the two worst quake-affected districts over the next six months. It is expected that the project will benefit more than half a million people in rural and suburban areas of the two districts, including the provision of safe drinking water and sanitation facilities. As part of the earthquake relief operation, UNICEF has distributed around 1 million water purification sachets and about half a million water purification tablets to address the immediate needs of clean water in quake-hit areas. The agency has also provided 46,000 bars of soap, 11,000 buckets and 5,000 jerry cans across the affected areas in addition to construction of about 1,000 latrines serving 20,000 people living in emergency settlements in and around Mansehra and Muzaffarabad.
Contact: Mohammad El-Fatih , Water and Environmental Sanitation Section, Unicef Pakistan, islamabad@unicef.org, http://www.unicef.org/pakistan/index.html
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| World Toilet Day 19 November 2005 |
 There are 35 countries where over 10 million people have no access to hygienic toilets, and 30 countries where more than two thirds of the population lack this basic facility. On the occasion of World Toilet Day, WaterAid has published a roll of shame1 ranking the worst places in the world for sanitation provision. Ethiopia is the country where the highest percentage (94%) of the population lack adequate sanitation facilities while, in absolute numbers, India has the most people (772,400,000) lacking sanitation. The list also includes three European countries – Russia, Turkey and Romania – where more than 10 million people lack sanitation.
References: 1WaterAid (2005). The state of the world's toilets 2005 : WaterAid's bog roll of dishonour.
World Toilet Day is an initiative of the World Toilet Organization, which was established in 2001 in Singapore.
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| The World Health Report 2005 |
This new publication, published both in print and digitally, is a summary of available measures associated with basic health indicators. The print version include a set of country indicator tables grouped by categories such as mortality or health services coverage and a set of metadata sheets in which each indicator is fully defined and described. The on-line version offers various downloading possibilities, in particular a data query system that allows to tabulate, plot (graph), or map data from pre-selected indicators, years and countries.
Download here
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| Water, sanitation and hygiene education for schools: roundtable proceedings and framework for action
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 Unicef/ IRC International Water and Sanitation Centre (2005). This publication is a report of the Water, Sanitation and Hygiene for Schools Roundtable meeting, which took place in Oxford, UK, 24-26 January 2005. It contains two documents. The first, ‘A Call for Action', sets out actions that participants agreed must be taken to ensure that by 2015 – the target date of the Millennium Development Goals (MDGs) – all schools receive a basic quality package of water, sanitation and hygiene (WASH) education. The second, ‘A Package for Water, Sanitation and Hygiene Education: The Oxford Roundtable Statement', is a concise and comprehensive outline of the ‘optimal package' for scaling up with quality the programmes for Water, Sanitation and Hygiene Education in Schools.
Download here
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| Sanitation and hygiene at the World Bank: an analysis of current activities |
| This report, by Kolsky, P et al (2005), reviews the current World Bank portfolio in sanitation and hygiene. The Bank's sanitation activities, ranging from latrine promotion to the construction of wastewater treatment plants, address a number of development objectives including improved health, greater human dignity, and a more sustainable environment. This report looks particularly closely at the degree to which the Bank's activities support the achievement of the Millennium Development Goal (MDG) target of halving the fraction of the world's population without access to basic sanitation by 2015, and the constraints to increasing support to that aim.
Download here
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UPCOMING CONFERENCES
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WASH CWG Sulabh International Conference on Solid Waste Management, Kolkata, 1st – 4th February, 2006. Contacts: Mr. Jonathan Hecke SKAT, Switzerland, jonathan.hecke@skat.ch; Prof. K.J. Nath, kumarjyoti@rediffmail.com
National Symposium on Drinking Water and Community Health: Standards, Surveillance and Management
Indian National Science Academy, Bahadur Shah Zafar Marg, New Delhi. To be organized by The National Academy of Sciences, Allahabad, India. Provisional dates: 10- 11 February 2006. For more details contact: Dr. V.P. Sharma: vinodpsharma@gmail.com
School Sanitation and Household Hygiene: promoting a sustainable approach
Nairobi, Kenya, 08 May 06 - 19 May 06, Organised by: Netwas International
Contact: NETWAS International, training, Nairobi, Kenya
IFIC 7th Congress of the International Federation of Infection Control, Stellenbosch, South Africa, 03 July 06 – 06 July 06
Contact: Nelda Rousseau: neldar@sun.ac.z
IWA 5th World Water Congress, Beijing, China, 10 Sep 06 - 14 Sep 06
Organised by: Working Group on Water and Health
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| New Publications in the IFH Reading Rooms |
MRSA bacteraemia in patients on arrival in hospital: a cohort study in Oxfordshire 1997-2003. Wyllie D.H., Peto, T.E.A., Crook D. BMJ 2005 October 29; 331(7523) : 0.
In an Oxford teaching hospital, there were found to be 479 patients with MSSA and 116 with MRSA bacteraemia admitted from the community. Among this group, which comprised 24% of all hospital MRSA cases, at least 91% had been in hospital previously; the median time since discharge was 46 days. About half of cases were in patients in whom MRSA had not been isolated before.
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How to prevent transmission of MRSA in the open community? Vandenesch F. Etienne. Journal of Eurosurveillance 2004; 9: 5.
Demographic characteristics of hospital-acquired (HA) MRSA infections differ from those of CA-MRSA, the former occurring mainly in elderly people and the latter occurring in young people. HA-MRSA infections are particularly associated with surgical wounds or intravenous indwelling catheters. CA-MRSA infections are mainly skin and soft tissue infections occurring in patients with no initial skin wounds. The Panton-Valentine leukocidin (PVL) produced by CA-MRSA strains represents, with its necrotic activity, one of the virulence factors possibly associated with cutaneous tissue destruction. These PVL-positive CA-MRSA are easily transmissible not only within families but also on a larger scale in community settings such as prisons, schools and sport teams. Skin-to-skin contact and indirect contact with contaminated towels, sheets, and sport equipment seem to represent the mode of transmission. The exact prevalence of CA-MRSA is still unknown. Isolates collected at hospitals certainly represent the tip of the iceberg. CA-MRSA strains have been detected in France, Switzerland, Germany, Greece, the Nordic countries, Australasia, Netherlands and Latvia. Where cases of skin and soft tissue infections have been observed in a close-living community of patients, therapeutic and infection control measures have proven successful in controlling the outbreak. The main question is how to prevent transmission of these strains in the open community.
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Hedgehog zoonoses. Riley P.Y., Chomel B.B., Emerging Infectious Diseases 2005; 11: 1-5.
Exotic pets, including hedgehogs, have become popular in recent years among pet owners, especially in North America. Such animals can carry and introduce zoonotic agents, a fact well illustrated by the recent outbreak of monkeypox in pet prairie dogs. This paper reviews known and potential zoonotic diseases that could be carried and transmitted by pet hedgehogs or by wild-caught hedgehogs that have been rescued.
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Are Noroviruses emerging? Widdowson M., Monroe S.S., Glass R.I., Emerging Infectious Diseases 2005; 11: 735-737.
Today, noroviruses are recognized as the most common cause of infectious gastroenteritis among persons of all ages. They are responsible for around 50% of all foodborne gastroenteritis outbreaks in the United States. Noroviruses have been detected in 35% of persons with sporadic gastroenteritis of known cause and in 14% of all children < years old hospitalized for gastroenteritis. However, a fundamental question remains—is the increased detection of norovirus the result of better application of improved diagnostics, or does evidence exist that norovirus disease is an emergent problem? Despite a lack of consistent retrospective data to definitively answer this question, several factors suggest that norovirus disease may actually be more common today. This paper reviews the evidence for this. |
Transmission of avian influenza viruses to and between humans. Hayden F., Croisier A., Journal of Infectious Diseases 2005;192:1311-1314.
Recent research raises questions about the routes of transmission of avian viruses to and between humans. Data indicate possible differences in transmission patterns between human and avian influenza viruses, and implications for prevention in health care, household, and community settings. Transmission of human virus occurs by inhalation of infectious droplets or airborne droplet nuclei and, perhaps, by indirect (fomite) contact followed by self-inoculation of the upper respiratory tract or conjunctival mucosa. The relative importance of these routes is debated, and there is evidence to support each of them. It is likely that each route contributes to transmission under appropriate circumstances and that the manifestations of illness, respiratory tract viral loads, and, perhaps, the type of infecting influenza virus influence the likelihood of transmission by a particular route. The multiple potential routes for the spread of avian influenza viruses, particularly H5N1, indicate that, in addition to protection for the respiratory tract and eyes, proper hand hygiene may be especially important in preventing infection. In households in which illness has occurred, specific protective measures would be advisable for known household contacts. In affected countries, public education regarding simple precautionary measures for food preparation, poultry handling, and avoidance of contaminated water are essential until effective human vaccines for H5N1 viruses become available. |
The occurrence of influenza A virus on household and day care center fomites. Boone S.A.. Gerba C.P.. Journal of Infection 2005; 51:103-109.
During two and a half years, 218 fomites were tested from 14 different day care centers. Ten different fomites from bathrooms, kitchens and play areas were sampled. In addition, 92 fomites from eight different homes with children were tested. Fourteen different household fomites from bathrooms, kitchens and living areas were sampled. Influenza was detected on 23% of day care fomites sampled during the fall and 53% of fomites sampled during the spring. No influenza was detected on home fomites sampled during the summer. In contrast, influenza was detected on 59% of home fomites sampled during March. |
Occurrence of bacteria and biochemical markers on public surfaces. Reynolds K.A., Watt P.M., Boone S.A., and Gerba C.P., International Journal of Environmental Health Research 2005;15: 225-234.
From 1999 – 2003, the hygiene of 1,061 environmental surfaces from shopping, daycare, and office environments, personal items, and miscellaneous activities (i.e., gymnasiums, airports, movie theaters, restaurants, etc.), in four US cities, was monitored. Samples were analyzed for fecal and total coliform bacteria, protein, and biochemical markers. Biochemical markers, i.e., hemoglobin (blood marker), amylase (mucus, saliva, sweat, and urine marker), and urea (urine and sweat marker) were detected on 3%, 15% and 6% of the surfaces, respectively. Protein (general hygiene marker) was present on 26% of surfaces. Surfaces from children’s playground equipment and daycare centers were the most frequently contaminated. Half and one-third of the sites positive for biochemical markers were also positive for total and fecal coliforms, respectively. Artificial contamination of public surfaces with an invisible fluorescent tracer showed that contamination from outside surfaces was transferred to 86% of exposed individual’s hands and 82% tracked the tracer to their home or personal
belongings hours later. Results provide information on the relative hygiene of commonly encountered public surfaces and aid in the identification of priority environments where contaminant occurrence and risk of exposure may be greatest. |
Transmission of influenza: implications for control in health care settings. Bridges C.B., Kuehnert M.J., and Hall C.B. Clinical Infectious Diseases 2003; 37, 1094-1101.
Annual influenza epidemics in the United States result in an average of 136,000 deaths and 114,000 hospitalizations. Although droplet transmission is thought to be the primary mode of influenza transmission, limited evidence is available to support the relative clinical importance of contact, droplet, and droplet nuclei (airborne) transmission of influenza. In this article, the results of studies on the modes of influenza transmission and their relevant isolation precautions are reviewed. |
The potential spread of infection caused by aerosol contamination of surfaces after flushing a domestic toilet. Barker J., Jones M.V., Journal of Applied Microbiology 2005; 99: 339-347.
A semisolid agar carrier containing either Serratia marcesens or MS2 bacteriophage was used to contaminate the side walls and bowl water of a domestic toilet to mimic the effects of soiling after an episode of acute diarrhoea. Although a single flush reduced the level of micro-organisms in the toilet bowl water when contaminated at concentrations reflecting pathogen shedding, large numbers of micro-organisms persisted on the toilet bowl surface and in the bowl water which were disseminated into the air by further flushes. Many individuals may be unaware of the risk of air-borne dissemination of microbes when flushing the toilet and the consequent surface contamination that may spread infection within the household, via direct surface-to-hand-to mouth contact. Some enteric viruses could persist in the air after toilet flushing and infection may be acquired after inhalation and swallowing. |
Disinfection of feline calicivirus (a surrogate for Norovirus) in wastewaters. Tree J.A., Adams M.R., and Lees D.N.. Journal of Applied Microbiology 2005; 98: 155-162.
Feline calicivirus and E. coli seeded in primary wastewater were very susceptible to chlorination compared with poliovirus and MS2. In contrast, FCV seeded in secondary wastewater was more resistant to u.v. irradiation than E. coli but more sensitive than poliovirus and MS2. |
Effect of handwashing on child health: a randomised controlled trial. Luby S.P., Agboatwalla M., Feikin D.R., Painter J., Billhimer W., Arshad Altaf M.R., Hoekstra R.M.. Lancet 2005; 366: 225 – 233.
Luby et al. undertook a randomised controlled trial to assess the effect of handwashing promotion with soap on the incidence of acute respiratory infection, impetigo, and diarrhoea in adjoining squatter settlements in Karachi, Pakistan. Fieldworkers visited households weekly for 1 year to encourage handwashing by residents in households and to record symptoms in all households. Children younger than 5 years in households that received plain soap and handwashing promotion had a 50% lower incidence of pneumonia than controls (95% CI –65% to –34%). Also compared with controls, children younger than 15 years in households with plain soap had a 53% lower incidence of diarrhoea (–65% to –41%) and a 34% lower incidence of impetigo (–52% to –16%). Incidence of disease did not differ significantly between households given plain soap compared with those given antibacterial soap containing 1·2% triclocarban.
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A randomized, controlled trial of a multifaceted intervention including alcohol-based hand sanitizer and hand-hygiene education to reduce illness transmission in the home. Sandora T.J., Taveras E.M., Shih M. ,Resnick, E.A., Lee G.M., Ross-Degnan M., Goldmann D.A., Pediatrics 2005; 116; 587-594.
A trial was conducted of homes of 292 families with children who were enrolled in out-of-home child care in 26 child care centers. Intervention families received a supply of hand sanitizer and biweekly hand-hygiene educational materials for 5 months; control families received only materials promoting good nutrition. A total of 252 GI illnesses occurred during the study; 11% were secondary illnesses. The secondary GI-illness rate was significantly lower in intervention families compared with control families (incidence rate ratio: 0.41). The overall rate of secondary respiratory illness was not significantly different between groups (IRR: 0.97). However, families with higher sanitizer usage had a marginally lower secondary respiratory illness rate than those with less usage (IRR: 0.81).
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Efficacy of three ethanol-based handrubs against feline calicivirus, a surrogate for norovirus Journal of Hospital Infection 2005; 60: 144-149.
In an earlier study Gehrke et al showed that 70% alcohol was the most effective agent against FCV in vivo with a log reduction factor (RF) of 3.78 compared with 70% 1-propanol (RF 3.58) and 70% 2-propanol (RF 2.15) (exposure time 30s) (Gehrke, C. Steinman, J. Goroncy-Bermes, P., J Hosp Infect, 2004, 56: 49-55). These values however were not obtained in this repeat study by these workers In this study the log reduction after 30secs was 2.66.and 1.53 for 70% ethanol and 70% 1-propanol respectively. Activity against calicivirus has also been determined by Kampf et al 2005 J Hosp. Infection 2005, 60: 144-149.
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Selection for high-level resistance by chronic triclosan exposure is not universal. McBain A.J., Ledder R.G., Sreenivasan P., Gilbert P. Journal of Antimicrobial Chemotherapy 2004; 53: 772-777.
These data fail to demonstrate biologically significant drug resistance in triclosan-exposed bacteria and suggest that markedly decreased triclosan susceptibility, although confirmed for E. coli, is not a universal phenomenon. Other bacteria possibly possess more susceptible targets than FabI that are highly conserved, which may govern triclosan activity.
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Antibacterial cleaning products and drug resistance. Aiello, A.E.. Marshall B.. Levy S.B.. Della-Latta P., Lin S,X., Larson E. Emerging Infectious Diseases 2005; 11: 1565-1570.
This study examined whether household use of antibacterial cleaning and hygiene products is an emerging risk factor for carriage of antimicrobial drug–resistant bacteria on hands of household members. Households (N = 224) were randomized to use of antibacterial or non-antibacterial cleaning and hygiene products for 1 year. Antibacterial product use did not lead to a significant increase in antimicrobial drug resistance after 1 year (odds ratio 1.33), nor did it have an effect on bacterial susceptibility to triclosan. However, more extensive and longer term use of triclosan might provide a suitable environment for emergence of resistant species. |
A REVIEW - Clinical significance of emergence of bacterial antimicrobial resistance in the hospital environment Cookson B. Journal of Applied Microbiology 2005; 99: 989-996.
In this paper the many issues relating to biocide resistance are examined, the paradigm with antiseptic use are explored and ways in which biocide resistance could threaten the prevention and control of HAIs are described. Several proposals to inform the need and nature of surveillance, prevention and control measures are made. |
Old friends for breakfast. Rook G.A.W., and Brunet L. R., Clinical and Experimental Allergy 2005; 35: 841-842.
These workers suggest that the hygiene hypothesis, although essentially correct, has spawned 3 untenable interpretations that delayed its acceptance. First the suggestion that diminished exposure to microorganisms fails to drive Th1 cells, with a consequent overproduction of Th2 cells. It is now clear that the critical balance is not Th1/Th2 but rather regulatory T cells (Treg)/Teffector. Secondly, the suggestion that we must suffer infections such as TB or childhood virus infections, in order to be protected from chronic inflammatory disorders. This view has little epidemiological support, and several studies have shown that these infections do not protect from allergies. Thirdly, there was the view, largely created by the media, that home hygiene itself is in some way to blame. Again, a detailed recent report has rejected this simplistic concept. Rook and Brunet suggest that the answer lies in the ‘Old Friends' mechanism. Certain harmless micro-organisms that are part of our evolutionary history are recognized as ‘Old Friends' by the innate immune system; hence, rather than priming aggressive immune responses, they prime immunoregulation, mediated in part by release of IL-10 and transforming growth factor (TGF)-b. Rook and Brunet speculate that stimulation of innate immunity with components of saprophytic mycobacteria, lactobacilli and certain helminths (the ‘Old Friends') will form the basis of treatment in the future by driving both specific and bystander immunoregulation.
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Filthy friends. Hamilton G. New Scientist 2005; April 13th: 35-30.
This paper gives an overview of the hygiene hypothesis. In particular it evaluates data on the nature of the microbial exposure which may be the critical factor in preventing immune dysregulation. |
The asthma epidemic and our artificial habitats. Maziak W. BMC Pulmonary Medicine 2005; 5:5, 1-7.
This paper discusses the “artificial habitats notion” as a generalised scheme for the study of asthma. According to this perspective there is no single answer to the asthma epidemic, but different factors have different relevance depending on the population and environment. In addition to being free from the hygiene hypothesis one-dimensional approach, this view is evolutionary driven allowing us to place the asthma epidemic within the wider perspective of increasing discordance between us and our dramatically changing environment. Sedentary lifestyles, static indoor environments, and automation of the food chain are not only predisposing us to obesity and cardiovascular disease but also depriving our respiratory system from many stimuli necessary for the development of normal airway resistance. |
A model of hygiene practices and consumption patterns in the consumer phase. Christensen B.B.,, Rosenquist H., Sommer H.M., Nielsen N.L., Fagt S., Andersen N.L. and Nørrung B. Risk analysis 2005; 25: 49-60.
A mathematical model is presented, which addresses individual hygiene practices during food preparation and consumption patterns in private homes. The simulated results show that the probability of ingesting a chicken risk meal at home does not only depend on the hygiene practices of the persons preparing the food, but also on the consumption patterns of consumers, and the relationship between people preparing and ingesting food. This finding supports the need of including information on consumer behaviour and preparation hygiene in the consumer phase of exposure assessments. |
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