Changes In Infection Rates Research Articles

Improving hospital environmental hygiene with the use of a targeted multi-modal bundle strategy.

Improving hospital environmental hygiene can reduce environmental contamination and cross-transmission risk, a precursor to healthcare associated infections (HAI). With poor cleaning practice a demonstrated problem, the process of converting evidence into practice requires investigation. The aim of this study was to assess the effectiveness of an environmental hygiene bundle in terms of changes to HAI rates, cleaning performance and environmental services workers (ESW) knowledge and attitudes. A multi-modal bundle was designed and implemented with ESW in eight wards, in a 400-bed metropolitan teaching hospital, using a prospective, before-and-after study design. This consisted of a three-month pre-intervention phase and six-month intervention phase. This research used an implementation science framework to guide the transition from evidence into practice, with data collected in the pre-intervention phase synthesised to design the implementation strategy. There was no statistically significant change in infection rates in the six-month period. Significant improvements in cleaning performance were observed, with the average proportion of ultraviolet markers removed during cleaning across the wards increasing from 61.1% to 95.4%. Results also demonstrate improvements to both the knowledge and attitudes of ESW. By combining infection prevention and implementation science, this bundle was an effective way to engage environmental services staff and improve hospital cleaning.

Examination of Changes in Infection Rates in a Restructured Anaesthesia Intensive Care Unit: A Retrospective Study.

This retrospective study aimed to evaluate the effect of a restructured anaesthesia intensive care unit (ICU) on changes in infection rates and infections. Organisational restructuring was done in the anaesthesia ICU of Firat University Hospital after it was relocated on 14 March 2012. This study was designed to investigate the effect of restructuring on infection rates through a comparison of periods encompassing one year before relocation and one year after relocation. Nosocomial infections were diagnosed according to modified Centers for Disease Control and Prevention (CDC) criteria. In total, 406 patients who were over 18 years old and admitted to the ICU were included; they were hospitalised for 48 h or longer and had non-infectious diseases according to physical examination, laboratory and culture results on admission. The data of 214 patients (Group A) and 192 patients (Group B) were examined. Parameters such as age, gender, primary diagnosis and mean GCS score at admission and mean duration of hospitalisation showed no effect on the rates of infection, but rates of total infection (41.1% vs. 25%), urinary (18.7% vs. 10.4%) and VIP (32.7% vs. 14.6%) were detected in Groups A and B. Statistically significant differences were found for the causative pathogens Pseudomonas (15.4% vs. 6.8%), Acinetobacter (18.2% vs. 12%) and Escherichia (8.9% vs. 2.1%); the mean duration of mechanical ventilation (15.01±16.681 vs. 12.22±17.595) and discharge with improvement (31.8% vs. 44.3%). We detected that restructuring (such as acclimatization, educated staff, hepa filter) caused a significant decline in infection rates. Because ICU staff may be a major cause of infection, we believe that providing education and conducting effective surveillance programs will be the most important factors for reducing infection rates.

Dynamical processes and epidemic threshold on nonlinear coupled multiplex networks

Recently, the interplay between epidemic spreading and awareness diffusion has aroused the interest of many researchers, who have studied models mainly based on linear coupling relations between information and epidemic layers. However, in real-world networks the relation between two layers may be closely correlated with the property of individual nodes and exhibits nonlinear dynamical features. Here we propose a nonlinear coupled information-epidemic model (I-E model) and present a comprehensive analysis in a more generalized scenario where the upload rate differs from node to node, deletion rate varies between susceptible and infected states, and infection rate changes between unaware and aware states. In particular, we develop a theoretical framework of the intra- and inter-layer dynamical processes with a microscopic Markov chain approach (MMCA), and derive an analytic epidemic threshold. Our results suggest that the change of upload and deletion rate has little effect on the diffusion dynamics in the epidemic layer.

The Issues of Healthcare-Associated Infections — The Economic and Social Perspective

Abstract The aim of the paper was to diagnose and analyse the rates of infections in Polish voivodships, and possible consequences from both economic and social perspectives of the changes in the levels of cases reported. For the analyses, data banks of Central Statistical Office in Warsaw were used, in particular, information on the incidence of infectious diseases and poisonings. The rates of changes and spatial concentration of the phenomena were investigated in the period between 2005 and 2015. For estimates of regional trends, the Shift-Share Analysis was adopted, and the pattern of spatial distribution was defined on the basis of location quotients. Extreme values of location quotients were observed in Warmińsko-Mazurskie for shigellosis, in Lubuskie for trichinellosis, and for AIDS in Dolnośląskie. Location quotient values allowed identifying regions with a higher spatial concentration of infectious diseases incidences, which in turn could indicate areas and cases where preventive actions should be improved or modified. The Shift-Share Analysis resulted in pointing out regions that recorded a positive change in infection rates. The obtained results also demonstrated that in some cases, the impact of structural changes influences the net rates of infections more than the local components. The obtained results directly indicated objects (regions) where attention should be paid to prevention. Especially, the results of spatial distribution and concentration allowed a reliable analysis of the state of population incidence rates, as well as answered questions concerning the origin of rates whether the change derived from structural, local or overall tendencies. Results could be adopted, for instance, in preventive strategies of local governments. The estimates might be beneficial from the perspective of the healthcare system, due to easier predictive scenarios of future infection and possible centres with the increase in incidence.

Effect of 3 years of biannual mass drug administration with albendazole on lymphatic filariasis and soil-transmitted helminth infections: a community-based study in Republic of the Congo

The standard treatment strategy of mass drug administration with ivermectin plus albendazole for lymphatic filariasis cannot be applied in central Africa, because of the risk of serious adverse events in people with high Loa loa microfilaraemia. Thus, alternative strategies are needed. We investigated one such alternative strategy for mass drug administration for elimination of lymphatic filariasis and soil-transmitted helminth infections in Republic of the Congo. In 2012, we started a 3 year community trial of biannual mass administration of albendazole in a village in Republic of the Congo. All volunteering inhabitants aged 2 years or older were offered albendazole (400 mg) every 6 months. Infection with Wuchereria bancrofti was diagnosed with a rapid card immunochromatographic test for antigenaemia. People with antigenaemia were tested for microfilaraemia by night blood smears. Individuals were also tested for soil-transmitted helminth infections (ie, hookworm, Ascaris lumbricoides, Trichuris trichiura) with the Kato-Katz method. Assessment surveys were done at 12, 24, and 36 months. The main outcome measure was change in infection rates from baseline to year 3. Therapeutic coverage was more than 80% in all six rounds of mass administration of albendazole. Between 2012 and 2015, W bancrofti antigenaemia and microfilaraemia rates in the community fell significantly, from 17·3% (95% CI 14·7-20·0) to 4·7% (3·3-6·6; p<0·0001) and from 5·3% (3·9-7·1) to 0·3% (0·1-1·2; p<0·0001), respectively. The geometric mean microfilaria count in microfilaraemic people fell from 199·4 (120·4-330·5) per mL in 2012 to 39·1 (95% CIs not computed) per mL in 2015 (p=0·0095). Hookworm infection was undetectable after 1 year. Between 2012 and 2015, the number of A lumbricoides eggs expelled per g of faeces fell from 9844·6 (8209·0-11 480·0) to 724·4 (340·7-1114·2; p<0·0001), and of T trichiura eggs from 1107·4 (878·5-1336·3) to 366·0 (255·7-476·2; p<0·0001). Our findings strongly support WHO's provisional strategy of biannual mass administration of albendazole to eliminate lymphatic filariasis in areas where loiasis is co-endemic and ivermectin cannot be safely mass administered. Bill & Melinda Gates Foundation.

National survey of practices to prevent health care-associated infections in Thailand: The role of prevention bundles

We evaluated the practices used in Thai hospitals to prevent catheter-associated urinary tract infection (CAUTI), central line-associated bloodstream infection (CLABSI), and ventilator-associated pneumonia (VAP). From January 1, 2014-November 30, 2014, we surveyed all Thai hospitals with an intensive care unit and at least 250 beds. The use of prevention practices for CAUTI, CLABSI, and VAP was assessed. High compliance (≥75%) with all components of the CLABSI and VAP prevention bundles were determined. CAUTI, CLABSI, and VAP infection rates before and after implementing infection control practices are reported. Multivariable regression was used to examine associations between infection prevention bundle compliance and infection rate changes. Out of 245 eligible hospitals, 212 (86.5%) responded. A total of 120 (56.6%) and 115 hospitals (54.2%) reported ≥75% compliance for all components of the CLABSI and VAP prevention bundles, respectively, and 91 hospitals (42.9%) reported using ≥ 4 recommended CAUTI-prevention practices. High compliance with all of the CLABSI and VAP bundle components was associated with significant infection rate reductions (CLABSI, 38.3%; P < .001; VAP, 32.0%; P < .001). Hospitals regularly using ≥ 4 CAUTI-prevention practices did not have greater reductions in CAUTI (0.02%; P = .99). Compliance with practices to prevent hospital infections was suboptimal. Policies and interventions promoting bundled approaches may help reduce hospital infections for Thai hospitals.

Cross sectional study of mode of delivery and maternal and perinatal outcomes in mainland China.

BackgroundCesarean delivery (CD) rates have risen globally with nearly 50% of the non-indicated CDs worldwide in China and Brazil. In China’s One Child Policy era (1979–2015) most deliveries were women having their only child. Family size is a major determinant of the safety of medically non-indicated CD or CD on maternal request. The goal of this study is to document CD rates, indications, and analyze the relative safety of non-indicated CD compared to SVD and intrapartum CD.MethodsUnivariate and multivariate logistic regression analyses of the association between mode of delivery and short-term maternal and perinatal outcomes were performed on a cross-section of all deliveries at 39 hospitals in 14 provinces of China in 2011, presented as adjusted odds ratio (aOR), 99% confidence intervals (CI).FindingsAmong 108,847 deliveries, 59,415 were CD (54.6%) with 20.8% of deliveries or 38.2% of all cesareans were non-indicated CD. Compared to SVD, antepartum non-indicated CD was associated with a decreased likelihood of post-partum hemorrhage (PPH) (aOR = 0.80, CI = 0.69–0.92) and was not associated with maternal death or combined severe outcomes (maternal death, transfusion, or hysterectomy). Intrapartum indicated CD was associated with an increased risk of PPH (aOR = 1.68, CI = 1.50–1.89) compared to SVD. Compared to SVD, antepartum non-indicated CD was associated with lower likelihood of neonatal death (aOR = 0.14, CI = 0.06–0.34), neonatal ICU admission (aOR = 0.50, CI = 0.36–0.69), 5-minute Apgar<4 (aOR = 0.06, CI = 0.10–0.36), and respiratory distress syndrome (RDS) (aOR = 0.31, CI = 0.16–0.58), but not significantly associated with changes in rates of infection, hypoxic ischemic encephalopathy (HIEE), birth trauma or meconium aspiration rates.ConclusionsIn 2011 when 81% of deliveries were women having their first child antepartum non-indicated CD had short-term maternal and perinatal outcomes as safe as SVD. Now that all Chinese women can have a second child the safety profile may change.

Is the Commercial Antibiotic-Loaded Bone Cement Useful in Prophylaxis and Cost Saving After Knee and Hip Joint Arthroplasty? The Transatlantic Paradox

BackgroundThe use of antibiotic-loaded bone cement (ALBC) has proven to be effective in preventing periprosthetic infection (PPI) after total hip (THA) and knee arthroplasty (TKA). However, the economic benefit of using ALBC routinely remains controversial. MethodsA total of 2518 patients subjected to THA, partial hip arthroplasty, and TKA between 2009 and 2012 were identified in our prospectively collected registry. Two groups were defined: before (2009-2010) and after the introduction of ALBC (2011-2012). The risks of PPI associated with each type of surgery in each group were determined and compared. Patients subjected to THA without cemented implants were used as controls, and possible bias associated with changes in infection rate during the study period and other variables were controlled. The costs of the use of ALBC were calculated, along with the savings per case of PPI avoided. The minimum follow-up for discarding PPI was 2 years. ResultsFollowing the introduction of ALBC, a global decrease of 57% was observed in the risk of PPI (P = .001). By type of surgery, the decrease was 60.6% in the case of TKA (P = .019) and 72.6% in the case of cemented hip arthroplasty (partial and total; P = .009). No decrease in infection rate was noted in uncemented hip arthroplasty (P = .42). The total saving associated with the use of ALBC was €1,123,846 (€992 per patient): €440,412 after TKA (€801 per patient) and €686,644 after cemented hip arthroplasty (€2672 per patient). ConclusionThe use of ALBC has been found to be effective in preventing PPI after TKA and hip arthroplasty, with a favorable cost-efficiency profile using standardized cost and infection rates in our setting.

Denominator doesn't matter: standardizing healthcare-associated infection rates by bed days or device days.

To examine the impact on infection rates and hospital rank for catheter-associated urinary tract infection (CAUTI), central line-associated bloodstream infection (CLABSI), and ventilator-associated pneumonia (VAP) using device days and bed days as the denominator Retrospective survey from October 2010 to July 2013 SETTING: Veterans Health Administration medical centers providing acute medical and surgical care Patients admitted to 120 Veterans Health Administration medical centers reporting healthcare-associated infections We examined the importance of using device days and bed days as the denominator between infection rates and hospital rank for CAUTI, CLABSI, and VAP for each medical center. The relationship between device days and bed days as the denominator was assessed using a Pearson correlation, and changes in infection rates and device utilization were evaluated by an analysis of variance. A total of 7.9 million bed days were included. From 2011 to 2013, CAUTI decreased whether measured by device days (2.32 to 1.64, P=.001) or bed days (4.21 to 3.02, P=.006). CLABSI decreased when measured by bed days (1.67 to 1.19, P=.04). VAP rates and device utilization ratios for CAUTI, CLABSI, and VAP were not statistically different across time. Infection rates calculated with device days were strongly correlated with infection rates calculated with bed days (r=0.79-0.94, P<.001). Hospital relative performance measured by ordered rank was also strongly correlated for both denominators (r=0.82-0.96, P<.001). These findings suggest that device days and bed days are equally effective adjustment metrics for comparing healthcare-associated infection rates between hospitals in the setting of stable device utilization.

Changes in healthcare-associated infections after the introduction of a national hand hygiene initiative

Abstract Introduction Interventions that prevent healthcare-associated infections should lead to fewer deaths and shorter hospital stays. Cleaning hands with soap and water or alcohol rub is an effectiveway to prevent the transmission of organisms, but compliance is sometimes low. The National Hand Hygiene Initiative in Australia aimed to improve hand hygiene compliance among healthcare workers, with the goal of reducing rates of healthcare-associated infections. Methods We examined if the introduction of the National Hand Hygiene Initiative was associated with a change in infection rates. Monthly infection rates for six types of healthcare-associated infections were examined in 38 Australian hospitals across six states. Infection categories were: bloodstream infections, centralline associated bloodstream infections, methicillin-resistant and methicillin-sensitive Staphylococcus aureus , Staphylococcus aureus bacteraemia and surgical site infections. Results The National Hand Hygiene Initiative was associated with a statistically significant reduction in infection rates in 11 out of 23 state and infection combinations studied. There was no change in infection rates for nine combinations, and there was an increase in three infection rates in South Australia. Conclusions The intervention was associated with reduced infection rates in many cases. The lack of improvement in nine cases may have been because they already had effective initiatives before the national initiative's introduction.

Changes in healthcare-associated Staphylococcus aureus bloodstream infections after the introduction of a national hand hygiene initiative.

Interventions that prevent healthcare-associated infection should lead to fewer deaths and shorter hospital stays. Cleaning hands (with soap or alcohol) is an effective way to prevent the transmission of organisms, but rates of compliance with hand hygiene are sometimes disappointingly low. The National Hand Hygiene Initiative in Australia aimed to improve hand hygiene compliance among healthcare workers, with the goal of reducing rates of healthcare-associated infection. We examined whether the introduction of the National Hand Hygiene Initiative was associated with a change in infection rates. Monthly infection rates for healthcare-associated Staphylococcus aureus bloodstream infections were examined in 38 Australian hospitals across 6 states. We used Poisson regression and examined 12 possible patterns of change, with the best fitting pattern chosen using the Akaike information criterion. Monthly bed-days were included to control for increased hospital use over time. The National Hand Hygiene Initiative was associated with a reduction in infection rates in 4 of the 6 states studied. Two states showed an immediate reduction in rates of 17% and 28%, 2 states showed a linear decrease in rates of 8% and 11% per year, and 2 showed no change in infection rates. The intervention was associated with reduced infection rates in most states. The failure in 2 states may have been because those states already had effective initiatives before the national initiative's introduction or because infection rates were already low and could not be further reduced.

Pathogen Mutation Modeled by Competition Between Site and Bond Percolation

While disease propagation is a main focus of network science, its coevolution with treatment has yet to be studied in this framework. We present a mean-field and stochastic analysis of an epidemic model with antiviral administration and resistance development. We show how this model maps to a coevolutive competition between site and bond percolation featuring hysteresis and both second- and first-order phase transitions. The latter, whose existence on networks is a long-standing question, imply that a microscopic change in infection rate can lead to macroscopic jumps in expected epidemic size.

Effect of Nonpayment for Preventable Infections in U.S. Hospitals

BackgroundIn October 2008, the Centers for Medicare and Medicaid Services (CMS) discontinued additional payments for certain hospital-acquired conditions that were deemed preventable. The effect of this policy on rates of health care–associated infections is unknown.MethodsUsing a quasi-experimental design with interrupted time series with comparison series, we examined changes in trends of two health care–associated infections that were targeted by the CMS policy (central catheter–associated bloodstream infections and catheter-associated urinary tract infections) as compared with an outcome that was not targeted by the policy (ventilator-associated pneumonia). Hospitals participating in the National Healthcare Safety Network and reporting data on at least one health care–associated infection before the onset of the policy were eligible to participate. Data from January 2006 through March 2011 were included. We used regression models to measure the effect of the policy on changes in infection rates, adjusting for baseline trends.ResultsA total of 398 hospitals or health systems contributed 14,817 to 28,339 hospital unit–months, depending on the type of infection. We observed decreasing secular trends for both targeted and nontargeted infections long before the policy was implemented. There were no significant changes in quarterly rates of central catheter–associated bloodstream infections (incidence-rate ratio in the postimplementation vs. preimplementation period, 1.00; P=0.97), catheter-associated urinary tract infections (incidence-rate ratio, 1.03; P=0.08), or ventilator-associated pneumonia (incidence-rate ratio, 0.99; P=0.52) after the policy implementation. Our findings did not differ for hospitals in states without mandatory reporting, nor did it differ according to the quartile of percentage of Medicare admissions or hospital size, type of ownership, or teaching status.ConclusionsWe found no evidence that the 2008 CMS policy to reduce payments for central catheter–associated bloodstream infections and catheter-associated urinary tract infections had any measurable effect on infection rates in U.S. hospitals. (Funded by the Agency for Healthcare Research and Quality.)

Public reporting of HAI rates

PurposeHealth‐care associated infections (HAIs) kill about 100,000 people annually; many are preventable. In response, 18 states currently require hospitals to publicly report their infection rates and national reporting is planned. Yet there is limited evidence on the effects of public reporting on HAI rates, and none on what elements of a reporting plan affect its impact on HAI rates. The author aims to review here what little we know, emphasizing his own case study of Pennsylvania.Design/methodology/approachThe paper contains a narrative description of empirical challenges in attributing changes in infection rates to the introduction of public reporting, and the author's own research findings from a case study of Pennsylvania using both infection rates estimated from administrative (billing) data (“inpatient rates”) and public reported rates.FindingsHospitals, faced with public HAI reporting, may respond both by reducing infection rates and through time‐inconsistent reporting (“gaming”). Both effects are likely to be stronger at hospitals with high reported rates, relative to peers. From 2003‐2008, Pennsylvania inpatient CLABSI rates dropped by 14 per cent, versus a 9 per cent increase in control states. The overall drop comes primarily from hospitals in the highest third of reported rates. Reported CLABSI rates fell much faster, by 40 per cent, from 2005 to 2007. This difference suggests time‐inconsistent reporting.Practical implicationsMuch more research is needed before we can have confidence that public reporting affects HAI rates (and for which HAIs), or know how to design an effective reporting scheme. HAI reporting cannot yet be considered to be “evidence based.” National reporting mandates will foreclose the state experiments needed to address these questions.Originality/valueWhat little we know about impact of public reporting on HAI rates comes in significant part from the case study of Pennsylvania described in this article.

How much is not enough? A community randomized trial of a Water and Health Education programme for Trachoma and Ocular C. trachomatis infection in Niger

To determine the impact after 2 years of a water and health education (W/HE) programme on ocular Chlamydia trachomatis infection and trachoma. We randomized 12 trachoma-endemic communities in Maradi, Niger 1:1 to W/HE intervention and control arms and collected data on 10 of the 12 villages. In the intervention villages, at least one clean water well was constructed, and a 3 month, modest health education programme was provided immediately prior to the 2 year survey. We censused all households, and 557 children ages 1-5 years were randomly selected as sentinel children and examined at baseline and at one and 2 years from baseline. Trachoma was clinically assessed and a swab taken and analyzed for C. trachomatis. Tetracycline eye ointment was provided to all children in either arm during the surveys who had signs of trachoma. Infection with C. trachomatis declined slightly, and not significantly, in the children in the control villages over the 2 years, from 15% to 11%. The decline in infection was more pronounced, and significant, in the children in the intervention villages, from 26% to 15%. However, the change in infection rates in the intervention villages was not significantly different from the change in infection rates in the control villages (P = 0.39, and 0.11 for change from baseline to 1 year and 2 year, respectively). There was also no difference in the change in overall trachoma rates between the two arms. These data suggest that the provision of water plus a modest health education programme did not result in a significant difference in trachoma or ocular C. trachomatis infection in endemic communities in Niger. A more substantial health education intervention is likely necessary to produce change.

Investigation into the effect of an alcohol-based hand product on infection rate in a nursing home setting

The study assessed the impact on nursing home (NH) resident infection rates of providing staff with a personal alcohol-based hand product (ABHP) with and without training on its use. Fifteen North Wales NHs were recruited and randomly allocated into one of three groups. All monitored infection rates throughout the study period of 18 weeks (Phase I [weeks 1—9], Phase II [weeks 11—19]). NHs used liquid soap and water for hand washing throughout the study. Groups B and C introduced interventions during week ten: Group B were provided with personal ABHPs without training on use; Group C personal ABHPs with standard training from the sponsoring hand hygiene company. Infection rates between groups and pre- and post-intervention were compared. Infection rates (per 1,000 bed days) for Phase I vs. Phase II of the study were: Group A: 6.99 vs. 7.16; Group B: 6.08 vs. 3.46; and Group C: 5.04 vs. 6.78 respectively. Change in infection rates in Groups B and C pre- and post-intervention did not reach statistical significance, p = 0.097 and p = 0.072 respectively. Comparison of rates in non-intervention Group A with the intervention groups indicated a significantly lower rate after the intervention in Group B ( p = 0.035) but not Group C ( p = 0.765). Findings are limited due to sample size; introduction of personal ABHPs with training did not reduce infection rates. This conflicts with other studies examining education and improvement of hand hygiene compliance. However, infection rates fell in NHs not receiving training, possibly mediated through a sense of `ownership' of the intervention.

New immunosuppressive strategies and the risk of infection

Newer immunosuppressive strategies have resulted in a marked reduction in graft rejection after transplantation, with the price being an increase of infectious complications, such as BK-related nephropathy. The targeting of new immunosuppressive pathways, such as interleukin-2-mammalian target of rapamycin inhibition, may have unexpected consequences for the immune response. Cell-depleting agents have long-lasting effects on cellular recovery and function, with the activation of latent viral infections and late viral and fungal infections. The multitude of different induction and maintenance protocols renders the detection of small increases of often rare infections very difficult. At the same time, preemptive and prophylactic strategies have gained widespread acceptance and may further offset small changes in infection rates. Other factors related to an increase or shift of infections may be of equal importance, such as increased use of marginal donors, older age at transplantation, or more patients receiving a second transplant. Not all the changes observed result in an increased immunosuppression. Steroid- and calcineurin inhibitor-sparing protocols may have a beneficial impact on infectious complications. Antimycotic or antiviral activity has been described for specific immunosuppressive agents, although the in vivo effect of these activities is uncertain. The possible role of specific drugs in the occurrence of infections is discussed, with emphasis on the antibodies and fusion proteins. The unequivocal attribution of a given infection to a specific drug is often impossible, as the risk of infection is dependent on the entirety of immunosuppression and the epidemiological pressure ('net immunosuppression'). It is important to remain vigilant for unexpected infections, not only in the context of clinical studies with selected patients, but also in the routine follow-up of our transplant patients.

Size-dependent pattern of metacercariae accumulation in Macomona liliana: the threshold for infection in a dead-end host

While bivalves can acquire trematode metacercariae over their lifetime, the rate at which this accumulation takes place is not necessarily linear. The present study found that the bivalve Macomona liliana acquires very few or no metacercariae until it reaches 30 mm in size, but thereafter the rate at which it becomes infected increases exponentially. It is likely that this ontogenetic change in infection rate is associated with the increased filtration capacity and siphon diameter of larger M. liliana. The echinostome metacercariae that infect M. liliana also infect a much more common sympatric bivalve, Austrovenus stutchburyi, in which they achieve much higher infection intensity. Due to its deeper burying depth, M. liliana most likely represents a dead-end host for the echinostomes: potential definitive hosts preferentially feed upon A. stutchburyi as they are located closer to the sediment surface than M. liliana. However, due to the low infection intensity and population density of M. liliana, its overall impact as a sink for echinostome populations in the ecosystem is probably negligible.

Reduction in wound infection rates by wound surveillance with postdischarge follow-up and feedback

Surgical wound surveillance with postdischarge follow-up is rarely done in the UK as it is seen as expensive. The aim of this study was to determine whether employing a dedicated team was effective and reduced costs. Infection data were collected prospectively with postdischarge follow-up at 2-3 months, and fed back to surgeons. Wound infection was defined using both ASEPSIS wound scoring and criteria of the US Centers for Disease Control (CDC) definitions. Over 4 years, 15 548 patient episodes were included. Postdischarge surveillance data were available for 79.9 per cent of the 15 154 records of patients who survived. There was a significant reduction in the rate of wound infection between the first and fourth years by ASEPSIS and CDC definitions: odds ratio 0.77 (95 per cent confidence interval (c.i.) 0.64 to 0.92) and 0.69 (95 per cent c.i. 0.57 to 0.83), respectively. The proportion of infections fell significantly in orthopaedic, cardiac and thoracic surgery. The annual budget for wound surveillance was pound 91,600. Changes in infection rates contributed pound 347,491 to the reduction in cost among the patients surveyed. Wound surveillance was associated with a reduction in rates of wound infection within 4 years. The cost reduction as a result of fewer infections exceeded the cost of surveillance after 2 years.

Feline immunodeficiency virus vaccine: A rational paradigm for clinical decision-making

A veterinarian must take into consideration his/her responsibility to prevent disease when assessing the needs of a client's cat that is risk for FIV infection based on its established lifestyle. Cats infected with FIV have debilitated immune functions and exhibit a high level of chronic morbidity impacting on the animal's welfare and the owner's economic abilities to maintain the pet. Attempts to reduce the prevalence of FIV solely by advising clients to maintain their cats indoors has resulted in poor compliance and not impacted on a change in infection rates with outdoor cats. Therapeutics have not impacted on outcomes in infected animals. There has a need for a vaccine for high-risk cats. Options for vaccines that do not confound the current FIV antibody test have not been efficacious against a broad spectrum of isolates. Fel-O-Vax FIV, a conventional non-marker whole virus, has shown good efficacy against heterologous challenges. The intervention should be discussed with cat owners since the vaccine has a reasonable expectation of preventing FIV infection in cats at risk without undue safety issues. Veterinarians who do not initiate this dialogue with owners who have outdoor cats in an environment where 2.5% of cats in the USA are infected may be remiss in their professional responsibilities.