5. ISSUES RELATED TO HOME HYGIENE

Selected articles

The impact of home cleaning on quality of life for homes with asthmatic children.
Barnes C, Kennedy K, Gard L, Forrest E, Johnson L, Pacheco F, et al. Allergy Asthma Proc. 2008;Mar 11.
The purpose of this study was to determine if home use of hypochlorite products results in lowered exposure to bacteria, fungi, and protein allergens and improved quality of life (QOL) for asthmatic persons in the home. Asthmatic and nonasthmatic households containing at least three persons (between 2 and 17 years of age) were recruited. Households were supplied one of three sets of cleaning products (regular products, some containing hypochlorite; regular products plus three additional products with dilute hypochlorite; control, no products). Participants were supplied with cleaning instructions and asthma education. The control group was instructed to clean as usual. The results indicated that emphasis on cleaning and cleaning education combined with hypochlorite-based cleaning supplies resulted in significantly improved QOL for families with asthmatic children.

Infections in Child Day Care Centers and Later Development of Asthma, Allergic Rhinitis, and Atopic Dermatitis. Prospective Follow-up Survey 12 Years After Controlled Randomized Hygiene Intervention.
Dunder T,  Tapiainen T, Pokka T, Uhari M. Arch Pediatr Adolesc Med. 2007;161(10):972-7.
The objective of this survey was to evaluate the effect of successful prevention of common infections in child day care centers on the later development of allergic diseases. This was a prospective follow-up survey with a questionnaire administered 12 years after a controlled randomized hygiene intervention.
The survey concluded that the prevention of common respiratory tract and enteric infections during early childhood does not change later allergic morbidity.

Prior Environmental Contamination Increases the Risk of Acquisition of Vancomycin-Resistant Enterococci.
Drees M, Snydman DR, Schmid CH, Barefoot L, Hansjosten K, Vue PM, et al. Clinical Infectious Diseases 2008; 46:678–85.
Patients colonized with vancomycin-resistant enterococci (VRE) frequently contaminate their environment, but the environmental role of VRE transmission remains controversial. During a 14-month study in 2 intensive care units, weekly environmental and twice-weekly patient surveillance cultures were obtained. VRE acquisition was defined as a positive culture result >48 h after admission. To determine risk factors for VRE acquisition, Cox proportional hazards models using time-dependent covariates for colonization pressure and antibiotic exposure were examined. The results led us to conclude that prior room contamination, whether measured via environmental cultures or prior room occupancy by VRE-colonized patients, was highly predictive of VRE acquisition. Increased attention to environmental disinfection is warranted.

How Important Is the Environment in the Emergence of Nosocomial Antimicrobial-Resistant Bacteria?
Harris AD. Clinical Infectious Diseases 2008; 46:686–8.
The paper reviews the role of the environment in the emergence of nosocomial antibiotic resistant bacteria. The authors conclude that potential environmental control interventions need further study before they should be adopted by hospital epidemiologists

Chloraminated drinking water does not generate bacterial resistance to antibiotics in Pseudomonas aeruginosa biofilms.
Jurgens DJ, Sattar SA, Mah TF. Letters in Applied Microbiology. 2008;46(5):562.
This study aimed to determine whether exposure of Pseudomonas aeruginosa biofilms to chloraminated drinking water can lead to individual bacteria with resistance to antibiotics. Biofilms of P. aeruginosa PA14 were grown in drinking water in a Kadouri drip-fed reactor; the biofilms were treated with either 0.5 mg l-1 or 1.0 mg l-1 of chloramine for 15 or 21 days; control biofilms were grown in water without chloramine. Under these test conditions, there was no detectable increase in antibiotic resistance in P. aeruginosa exposed as biofilms to disinfectant residues in chloraminated drinking water. Chloramine in drinking water, while unable to kill biofilm bacteria, does not increase the potential of P. aeruginosa to become resistant to antibiotics.

The hygiene hypothesis and psychiatric disorders.
Rook G, Lowry CA. Trends in Immunology. 2008;29(4):150-8.
The hygiene hypothesis proposes that several chronic inflammatory disorders (allergies, autoimmunity, and inflammatory bowel disease) are increasing in prevalence in developed countries because a changing microbial environment has perturbed immunoregulatory circuits which normally terminate inflammatory responses. Some stress-related psychiatric disorders, particularly depression and anxiety, are associated with markers of ongoing inflammation, even without any accompanying inflammatory disorder. Therefore, some psychiatric disorders in developed countries might be attributable to failure of immunoregulatory circuits to terminate ongoing inflammatory responses. This is discussed in relation to the effects of the immune system on a specific group of brain serotonergic neurons involved in the pathophysiology of mood disorders.

The hygiene hypothesis and the increasing prevalence of chronic inflammatory disorders.
Rook G. Transactions of the Royal Society of Tropical Medicine and Hygiene. 2007;101(11):1072-4.
The ‘Hygiene’ or ‘Old Friends’ hypothesis suggests that increases in chronic inflammatory disorders (allergies, inflammatory bowel disease and autoimmunity) in developed countries are partly attributable to diminishing exposure to organisms that  were part of mammalian evolutionary history. Crucial organisms, including helminths and saprophytic mycobacteria, are recognised by the innate immune system as harmless or, in the case of helminths, as organisms that once established must be tolerated. This recognition then triggers development of regulatory dendritic cells that drive regulatory T-cell responses to the ‘OldFriends’ themselves and to simultaneously processed ‘forbidden’ target antigens of the chronic inflammatory disorders.

A three-year surveillance of nosocomial infections by methicillin-resistant Staphylococcus haemolyticus in newborns reveals the disinfectant as a possible reservoir.
Ben Saida N, Marzouk M, Ferjeni A, Boukadida J. Pathologie Biologie. May, 2008.
This was a study of the clonality of methicillin-resistant Staphylococcus haemolyticus responsible for epidemic infections in a neonatal intensive care unit.
Methicillin-resistant Staphylococcus haemolyticus isolates were collected during the period from March 2004 to November 2006, from newborns, the clean hands of nurses and from disinfectant bottles used in the unit. Molecular typing by pulsed-field gel electrophoresis (PFGE) was achieved for all isolates.
The results of this study suggest that MRSH neonatal infections are caused by a limited number of clones. Clone B was able to survive in disinfectant bottles and to conserve its ability to infect newborns. We therefore conclude that the disinfectant can serve as a reservoir for MRSH and point out the need to control all disinfectants used in a neonatal intensive care unit.

Infections presenting for clinical care in early life and later risk of hay fever in two UK birth cohorts.
Bremner SA, Carey IM, DeWilde S, Richards N, Maier WC, Hilton SR, et al. Allergy 2008:63:274–83.
The ‘hygiene hypothesis’ proposes that infections in infancy protect against hay fever (HF). We investigated infections during infancy in relation to HF, including rarer ones not previously researched in this context, while examining the role of potential confounding variables. Our results indicated that upper respiratory tract infections, diarrhoea and vomiting and acute otitis media in infancy were each related with a moderately increased risk of HF in both databases, as were BP. Of 30 infectious illnesses investigated, none had strong or consistent associations with HF after adjustment for consultation frequency. Except for bronchiolitis, possibly a chance finding, none of the clinically apparent infections considered appear to have an important role in allergy prevention.

Is eczema really on the increase worldwide?
Williams H, Stewart A, von Mutius E, Cookson W, Anderson HR. JACI. 2008;121(4):947-54.
It is unclear whether eczema prevalence is truly increasing worldwide.
We sought to investigate worldwide secular trends in childhood eczema.
Children (n = 302,159) aged 13 to 14 years in 105 centers from 55 countries and children aged 6 to 7 years (n = 187,943) in 64 centers from 35 countries were surveyed from the same study centers taking part in Phase One and Three of the International Study of Asthma and Allergies in Childhood by using identical validated and translated questionnaires. The results indicate that the epidemic of eczema seems to be leveling or decreasing in some countries with previously high prevalence rates. The picture elsewhere is mixed, with many formerly low-prevalence developing countries experiencing substantial increases, especially in the younger age group.

Increased Allergen Levels in Homes Linked to Asthma.
Darryl Zeldin. Journal of Allergy and Clinical Immunology, March 2008.
Results from a new national survey demonstrate that elevated allergen levels in the home are associated with asthma symptoms in allergic individuals. The study suggests that asthmatics that have allergies may alleviate symptoms by reducing allergen exposures inside their homes. The work was carried out by researchers at the National Institute of Environmental Health Sciences (NIEHS), the University of Iowa, Rho Inc., and the Constella Group. The team's findings may help millions of Americans who suffer from asthma. Salo and her co-authors, however, point out that more research is needed to understand the complex relationships between genetic and environmental factors that cause asthma, particularly the role that indoor allergen exposure plays in the development of asthma. "Although reducing allergen levels in the home may not prevent individuals from developing asthma, reducing exposure levels is crucial for those whose asthma is allergic in nature." Zeldin concluded.

Cohort study of sibling effect, infectious disease, and risk of atopic dermatitis during the first 18 months of life.
Stabell Benn C, Melbye M, Wolfahrt J, Bjorksten B, Aaby P. BMJ 2004;328:1223-6.
The possibility of a link between infectious disease morbidity and atopy is not supported by the recently published findings of a large-scale study of 24,341 mother-child pairs in Denmark. Although the data confirmed that larger family sizes, early childcare, pet keeping and farm living correlates with decreased risk of atopic dermatitis in children before 18 months, the results suggested that development of ID in early life is associated with increased, rather than reduced, risk of atopic dermatitis.

Recorded infections and antibiotics in early life: associations with allergy in UK children and their parents.
Harris J.M., Mills P., White C., et al. Thorax 2007;62;631-7.
A birth cohort study was undertaken in 642 UK children recruited before birth and seen annually until the age of 8 years. Reported infections and prescribed antibiotics by the age of 5 years were counted from GP records and comparisons were made with a previous study of their parents. Despite very high rates of recorded early life infections and antibiotic prescriptions, no plausibly causative relationships were found with subsequent respiratory allergies.

Microbial content of drinking water in Finnish and Russian Karelia - implications for atopy prevalence.
von Hertzen L., Laatikainen T., Pitkanen T., et al. Allergy 2007;62(3):288-92.
There have been substantial differences found in prevalence of atopy in school children from Finnish and Russian Karelia. This study found that high microbial content in drinking water was inversely associated with atopy and a dose-response relationship was seen. The high microbial content of drinking water may be a surrogate marker for some other unidentified factors associated with poor living condition in Russian Karelia or it is possible that some direct immunomodulatory potential is exerted when the water is consumed. Natural waters may exposure individuals to environmental saprophytes which may play a crucial role in stimulating the innate immunity and the regulatory network involved in the development and maintenance of immunological homeostasis of the gut and respiratory tract mucosa.

Do immune responses to inhaled skin flakes modulate the expression of allergic disease?
Tovey E.R., Kemp A.S., Almqvist C., Sharland A., Marks G.B. Clinical and Experimental Allergy 2007;37(8):1199-203.
We examine the nature of the immune responses to inhaled skin particles and query whether early exposure could play a role in providing protection against the development of allergic disease. Many of the exposures sustaining the hygiene hypothesis involve co-exposure to skin flakes from humans or animals. Such skin flakes contain a complex mixture of antigens, glycolipids and small peptides that may induce immune responses. Should these responses prove relevant to the modulation of allergic diseases, it provides new opportunities to better understand the epidemic of allergic disease and to develop new interventions for its prevention.

Bacterial resistance to biocides in the healthcare environment: should it be of genuine concern?
Maillard J.-Y. Journal of Hospital Infection 2007;65(Suppl 2):60-72.
From a review of the evidence base the author concludes that the documented response from bacteria exposed to biocide in conditions close to those found in practice suggests that intrinsic resistance does not adequately describe bacterial survival mechanisms, and that terms such as biofilm resistance and environmental resistance would be more appropriate. The inability to correlate emerging bacterial resistance from in vitro experiments with practical situations is a major drawback when attempting to ascertain whether emerging bacterial resistance in healthcare facilities is of genuine concern. Microbial resistance to in-use biocide concentration has been described in practice, but is uncommon. The efficacy of biocides in healthcare facilities has to be questioned with the increasing use of products with low bactericidal activity, as is the selection of less susceptible bacteria following such exposure.

Acinetobacter lwoffii and Lactococcus lactis strains isolated from farm cowsheds possess strong allergy-protective properties.
Debarry J., Gam H., Hanuszkiewicz H., Dickgreber N., Blümer H., Von Mutius E., Bufe A., Gaterman S., Rens H., Holger H. Journal of Allergy and Clinical Immunology 2007;119:1514-21.
The paper evaluates the potential allergy-protective properties of microbes isolated from the farming environment. Of a number of bacterial species identified in cowsheds of farms, two were selected, namely Acinetobacter lwoffii F78 and Lactococcus lactis G121. Both isolates were able to reduce allergic reactions in mice, to activate mammalian cells in vitro, and to induce a TH1-polarizing program in dendritic cells. The data strongly support the hygiene hypothesis, which states that an environment rich in microbiologic structures, such as a farming environment, might protect against the development of allergies.

Early-life respiratory viral infections, atopic sensitization, and risk of subsequent development of persistent asthma.
Kusel M.H., de Klerk N.H., Kebadze T., Vohma V., Holt P.G., Johnston S.L., Sly P.D. Journal of Allergy and Clinical Immunology 2007; in press
This study suggests that severe viral infections combined with sensitivity to allergies during the first year of a child's life may lead to the development of asthma later in childhood. The researchers studied almost 200 children for 5 years, recording the viruses they were infected with during their first year of life and when they developed allergies. They found that those children who had a lower respiratory viral infection during their first year of life and developed sensitivity to an allergen before they were two were three to four times more likely to suffer from asthma at the age of 5.

Possible hazards of hypochlorite disinfection for feeding equipment for premature infants.
Price E., Awadel-Kariem F.M. , Hateley P. , Harvey J. , Gilks J., Kempley S. Journal of Hospital Infection 2006; 64:90-92.
Caco2 cells were exposed for 30 min to dilutions of 1:200 and 1:2000 of a 2% sodium hypochlorite solution. Upon examination under the electron microscope (EM), control cells appeared normal with a fully structured brush border. However, at both dilutions, treated cell samples showed subcellular damage, including loss of microvilli, slight dilatation of the endoplasmic reticulum and some swelling of the mitochondria. Caution is needed when extrapolating from in vitro models, but this study suggests possible effect on the infant gut mucosa of not rinsing off these disinfectants after treatment of infant feeding utensils.

Effects of chronic triclosan exposure upon the antimicrobial susceptibility of 40 ex-situ environmental and human isolates.
Ledder R.G., Gilbert P., Willis C., McBain A.J. Journal of Applied Microbiology 2006;100:1132-40.
Triclosan (TCS) exposure of Eschenchia coli selects for tolerant clones, mutated in their enoyl-acyl carrier protein reductase. It has been inferred that this phenomenon is widespread amongst bacterial genera and might be associated with resistance to third party agents. These data suggest that selection for high level resistance by TCS exposure is not widespread and appears to be confined to certain enteric bacteria, especially E coli. Change in TCS susceptibility did not affect susceptibility towards chemically unrelated antimicrobials. It is concluded that acquired high-level TCS resistance is not a widespread phenomenon.

Antibiotic use is associated with resistance of environmental organisms in a teaching hospital.
Dancer S.J., Coyne M., Robertson C., Thomson A., Gulerj A., Alcock S. Journal of Hospital Infection 2006;62:200-6.
An intensive care unit (ICU), acute stroke unit (ASU) and medical day bed unit (MDBU) underwent a standardised 4-month environmental screening programme to examine environmental organisms from these wards and to compare bacterial resistances in association with antimicrobial usage. Antibiotic resistance was significantly associated with individual wards for staphylococci and coliforms, and trends were also demonstrated for other gram-negative organisms. Antibiotic consumption on the ICU was six-fold higher than on the ASU and MDBU. Associations were found between the consumption of selected antibiotic groups and the corresponding resistances among staphylococci and gram-negative bacilli. Antibacterial resistance was the only significant difference between environmental bacteria from different wards, and appeared to reflect prescribing pressure.

Antimicrobial drug resistance: “Prediction is very difficult especially about the future”.
Courvalin P. Emerging Infectious Diseases 2005;11:1503-6.
Evolution of bacterial resistance to antimicrobial drugs is unavoidable. The only means of dealing with it is to delay emergence and subsequent dissemination of resistant bacteria or resistance genes. Resistance to antimicrobials can result from mutations in housekeeping structural or regulatory genes, or horizontal acquisition of foreign genetic information. The two phenomena are not mutually exclusive and can be associated in the emergence and more efficient spread of resistance. This review discusses the predictable future of the relationship between antimicrobial drugs and bacteria.

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., Clin.ical 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.

Filthy friends. Hamilton G. New Scientist 2005; April 13^th: 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.

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.

Whither triclosan? Russel A.D. Journal of Antimicrobial Chemotherapy 2004;53:693-5.
Triclosan has activity against gram-negative and gram-positive bacteria, although Pseudomonas aeruginosa is highly resistant. Its growth inhibitory properties probably result from enoyl reductase inhibition, whilst membrane destabilisation is responsible for bactericidal action at higher concentrations. Resistance can arise from mutations in, or over production of, enoyl reductase, impermeability or efflux. The author concludes that whilst triclosan resistance in laboratory experiments may be associated with changes in antibiotic susceptibility, comprehensive surveys have not demonstrated any association between triclosan usage and antibiotic resistance in clinical practice. Triclosan has several important uses and the aim must be to retain these applications whilst eliminating unnecessary ones.

Bacterial adaptation and resistance to antiseptics, disinfectants and preservatives is not a new phenomenon. Russell A.D. Journal of Hospital Infection 2004;57:97-104.
This paper is a historical review on the development of resistance to antibacterial compounds. As reduced susceptibility to biocides has been known for a long time, it might be expected by now to have resulted in the development of highly biocide resistant strains. Since this does not appear to be the case, it might, therefore, be argued that resistance to biocides is unlikely to occur. The author concludes that this conclusion is unwarranted and that biocides should only be incorporated into formulated products where necessary, and only with full appreciation of factors influencing their activity.

Characterization of Staphylococcus aureus mutants expressing reduced susceptibility to common house-cleaners.Davis A.O., O’Leary J.O., Muthaiyan A., Langervin M.J., Delgado A., Abalos A.T., Fajarda A.R., Marek J., Wilkinson B.J., Gustafson J.E. Journal of Applied Microbiology 2005;98:364-72.
Spontaneous mutants of Staph aureus demonstrating reduced susceptibility to one of four house-cleaner formulations were selected and their susceptibility to a range of house-cleaners and their components together with hydrogen peroxide was determined by measuring minimum inhibitory concentrations and minimum bactericidal concentrations. The mutants demonstrated altered susceptibility to multiple antimicrobials. The authors speculate, however, that the reduced susceptibility probably does not pose any threat to efficacy under conditions where products are used at much higher concentrations. Of 76 clinical MRSA, 20 exhibited reduced susceptibility to a house-cleaner.

Effect of antibacterial home cleaning and handwashing products on infectious disease symptoms. A randomised double-blind trial. Larson, E.L., Lin, S.X., Gomez-Pichardo, C. and Della-Latta, P. Ann Intern Med 2004;140:321-329.
The aim of this US study was to evaluate the effect of antibacterial cleaning and handwashing products in 238 households (that included at least one preschool-age child) on the occurrence of infections. Households were randomly assigned to use either antibacterial or nonantibacterial products for general cleaning, laundry, and handwashing. Hygiene practices and infectious disease symptoms were monitored by weekly telephone calls, monthly home visits, and quarterly interviews for 48 weeks. It concluded that antibacterial products, such as soaps, laundry detergents and household cleaners do not reduce infection rates in families. However, the study did not look at how products were used. The study reports no effect on viral illness, but the products tested were antibacterial, and therefore not designed to kill viruses.

Cross-resistance to antibiotics of Escherichia coli adapted to benzalkonium chloride or exposed to stress-inducers. Langsrud, S., Sundheim, G. and Holck, A.L. J Appl Microbiol 2004;96:201-208.
This study looked at the effects of adaptation and stress on the resistance to benzalkonium chloride (BAC) and cross-resistance to antibiotics. Exposure of E. coli to stress inducers (salicylate, chenodeoxycholate and methyl viologen) generally increased the tolerance to BAC and chloramphenicol (CHL). This indicated that adaptation to BAC could be partly attributed to stress responses. Enhanced efflux was one of the observed differences in adapted cells. The authors conclude that provided not taking due precautions, extensive use of disinfectants could lead to emergence of antibiotic-resistant isolates.

Live and let die Gilbert P and Mcbain A. Microbiology Today 2004; 31: 62-63.
In this paper Gilbert and Mcbain argue that the risks associated with biocide use, in relation to microbial resistance, have been overstated. The paper reviews the experimental evidence in support of this statement.

Water, sanitation and hygiene for the health of developing nations. Mara, D.D. Public Health 2003;117:452-456.
An article on water and sanitation needs of the poor in developing countries. To meet the target of water and sanitation for all by the end of 2025, some 2.9 billion people will have to receive improved water supplies, and 4.2billion improved sanitation. The technologies used must be appropriate, simple, affordable and sustainable.

Biocide abuse and antimicrobial resistance – a cause for concern? Fraise, A.P. Journal of Antimicrobial Chemotherapy 2002;49:11-12.
The article outlines work from several researchers on links between biocide resistance and antibiotic resistance. From these links it is suggested that there is a real risk that widespread biocide use could exacerbate the already worrying trend towards increased antimicrobial resistance in clinically relevant organisms. Although it is not yet clear whether there are any real adverse effects, the use of biocides in consumer products is strongly attacked.

Feasibility of national surveillance of health-care–associated infections in home care settings. Manangan, L.P., Pearson, M.L., Tokars, J.I., Miller, E. and Jarvis, W.R. Emerging Infectious Diseases 2002;8(3):233-236.
This article examines the rationale and strategies for surveillance of health-care-associated infections in home-care settings, the challenges of non hospital-based surveillance, and the feasibility of developing a national surveillance system. Home care is often provided by family members who have little or no formal health-care training, which may place patients at increased risk of health care-associated infections not typically seen in hospitals. In the home-care setting, patients with open wounds or central venous catheters may undertake activities of daily living that may increase the risk of infections. A national system for surveillance of health care-associated infections in home care would provide useful data on incidence and types of infections and simplify identification of risk factors for infection and development of national benchmarks for comparing infection rates.