Preliminary findings of a randomized trial of non-pharmaceutical interventions to prevent influenza transmission in households

Background

There are sparse data on whether non-pharmaceutical interventions can reduce the spread of influenza. We implemented a study of the feasibility and efficacy of face masks and hand hygiene to reduce influenza transmission among Hong Kong household members.

Methodology/Principal Findings

We conducted a cluster randomized controlled trial of households (composed of at least 3 members) where an index subject presented with influenza-like-illness of <48 hours duration. After influenza was confirmed in an index case by the QuickVue Influenza A+B rapid test, the household of the index subject was randomized to 1) control or 2) surgical face masks or 3) hand hygiene. Households were visited within 36 hours, and 3, 6 and 9 days later. Nose and throat swabs were collected from index subjects and all household contacts at each home visit and tested by viral culture. The primary outcome measure was laboratory culture confirmed influenza in a household contact; the secondary outcome was clinically diagnosed influenza (by self-reported symptoms). We randomized 198 households and completed follow up home visits in 128; the index cases in 122 of those households had laboratory-confirmed influenza. There were 21 household contacts with laboratory confirmed influenza corresponding to a secondary attack ratio of 6%. Clinical secondary attack ratios varied from 5% to 18% depending on case definitions. The laboratory-based or clinical secondary attack ratios did not significantly differ across the intervention arms. Adherence to interventions was variable.

Conclusions/Significance

The secondary attack ratios were lower than anticipated, and lower than reported in other countries, perhaps due to differing patterns of susceptibility, lack of significant antigenic drift in circulating influenza virus strains recently, and/or issues related to the symptomatic recruitment design. Lessons learnt from this pilot have informed changes for the main study in 2008.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00425893","term_id":"NCT00425893"}}NCT00425893 HKClinicalTrials.com HKCTR-365     

Avian influenza H5N1 transmission in households, Indonesia

Background

Disease transmission patterns are needed to inform public health interventions, but remain largely unknown for avian influenza H5N1 virus infections. A recent study on the 139 outbreaks detected in Indonesia between 2005 and 2009 found that the type of exposure to sources of H5N1 virus for both the index case and their household members impacted the risk of additional cases in the household. This study describes the disease transmission patterns in those outbreak households.

Methodology/Principal Findings

We compared cases (n = 177) and contacts (n = 496) in the 113 sporadic and 26 cluster outbreaks detected between July 2005 and July 2009 to estimate attack rates and disease intervals. We used final size household models to fit transmission parameters to data on household size, cases and blood-related household contacts to assess the relative contribution of zoonotic and human-to-human transmission of the virus, as well as the reproduction number for human virus transmission. The overall household attack rate was 18.3% and secondary attack rate was 5.5%. Secondary attack rate remained stable as household size increased. The mean interval between onset of subsequent cases in outbreaks was 5.6 days. The transmission model found that human transmission was very rare, with a reproduction number between 0.1 and 0.25, and the upper confidence bounds below 0.4. Transmission model fit was best when the denominator population was restricted to blood-related household contacts of index cases.

Conclusions/Significance

The study only found strong support for human transmission of the virus when a single large cluster was included in the transmission model. The reproduction number was well below the threshold for sustained transmission. This study provides baseline information on the transmission dynamics for the current zoonotic virus and can be used to detect and define signatures of a virus with increasing capacity for human-to-human transmission.     

Exercises to prevent lower limb injuries in youth sports: cluster randomised controlled trial

Objective To investigate the effect of a structured warm-up programme designed to reduce the incidence of knee and ankle injuries in young people participating in sports.Design Cluster randomised controlled trial with clubs as the unit of randomisation.Setting 120 team handball clubs from central and eastern Norway (61 clubs in the intervention group, 59 in the control group) followed for one league season (eight months).Participants 1837 players aged 15-17 years; 958 players (808 female and 150 male) in the intervention group; 879 players (778 female and 101 male) in the control group.Intervention A structured warm-up programme to improve running, cutting, and landing technique as well as neuromuscular control, balance, and strength.Main outcome measure The rate of acute injuries to the knee or ankle.Results During the season, 129 acute knee or ankle injuries occurred, 81 injuries in the control group (0.9 (SE 0.09) injuries per 1000 player hours; 0.3 (SE 0.17) in training v 5.3 (SE 0.06) during matches) and 48 injuries in the intervention group (0.5 (SE 0.11) injuries per 1000 player hours; 0.2 (SE 0.18) in training v 2.5 (SE 0.06) during matches). Fewer injured players were in the intervention group than in the control group (46 (4.8%) v (76 (8.6%); relative risk intervention group v control group 0.53, 95% confidence interval 0.35 to 0.81).Conclusion A structured programme of warm-up exercises can prevent knee and ankle injuries in young people playing sports. Preventive training should therefore be introduced as an integral part of youth sports programmes.     

A randomized controlled trial of interventions to impede date palm sap contamination by bats to prevent nipah virus transmission in bangladesh

Background

Drinking raw date palm sap is a risk factor for human Nipah virus (NiV) infection. Fruit bats, the natural reservoir of NiV, commonly contaminate raw sap with saliva by licking date palm’s sap producing surface. We evaluated four types of physical barriers that may prevent bats from contacting sap.

Methods

During 2009, we used a crossover design and randomly selected 20 date palm sap producing trees and observed each tree for 2 nights: one night with a bamboo skirt intervention applied and one night without the intervention. During 2010, we selected 120 trees and randomly assigned four types of interventions to 15 trees each: bamboo, dhoincha (local plant), jute stick and polythene skirts covering the shaved part, sap stream, tap and collection pot. We enrolled the remaining 60 trees as controls. We used motion sensor activated infrared cameras to examine bat contact with sap.

Results

During 2009 bats contacted date palm sap in 85% of observation nights when no intervention was used compared with 35% of nights when the intervention was used [p<0.001]. Bats were able to contact the sap when the skirt did not entirely cover the sap producing surface. Therefore, in 2010 we requested the sap harvesters to use larger skirts. During 2010 bats contacted date palm sap [2% vs. 83%, p<0.001] less frequently in trees protected with skirts compared to control trees. No bats contacted sap in trees with bamboo (p<0.001 compared to control), dhoincha skirt (p<0.001) or polythene covering (p<0.001), but bats did contact sap during one night (7%) with the jute stick skirt (p<0.001).

Conclusion

Bamboo, dhoincha, jute stick and polythene skirts covering the sap producing areas of a tree effectively prevented bat-sap contact. Community interventions should promote applying these skirts to prevent occasional Nipah spillovers to human.     

Neonatal outcomes after influenza immunization during pregnancy: a randomized controlled trial

Background:

There are limited data about the effect of maternal influenza infection on fetuses and newborns. We performed a secondary analysis of data from the Mother’s Gift project, a randomized study designed to test the effectiveness of inactivated influenza and pneumococcal vaccines during pregnancy.

Methods:

In the Mother’s Gift project, 340 pregnant women in Bangladesh received either inactivated influenza vaccine or 23-valent pneumococcal polysaccharide vaccine (control). This study was performed from August 2004 through December 2005. We performed a secondary analysis of outcomes following maternal influenza immunization during two periods: when influenza virus was not circulating (September 2004 through January 2005) and when influenza virus was circulating (February through October 2005). We assessed gestational age, mean birth weight and the proportion of infants who were small for gestational age.

Results:

During the period with no circulating influenza virus, there were no differences in the incidence of respiratory illness with fever per 100 person-months among mothers and infants in the two groups (influenza vaccine: 3.9; control: 4.0; p > 0.9). The proportion of infants who were small for gestational age and the mean birth weight were similar between groups (small for gestational age: influenza vaccine 29.1%, control 34.3%; mean birth weight: influenza vaccine 3083 g, control 3053 g). During the period with circulating influenza virus, there was a substantial reduction in the incidence per 100 person-months of respiratory illness with fever among the mothers and infants who had received the influenza vaccine (influenza vaccine: 3.7; control: 7.2; p = 0.0003). During this period, the proportion of infants who were small for gestational age was lower in the influenza vaccine group than in the control group (25.9% v. 44.8%; p = 0.03). The mean birth weight was higher among infants whose mothers received the influenza vaccine than among those who received the control vaccine during this period (3178 g v. 2978 g; p = 0.02).

Interpretation:

During the period with circulating influenza virus, maternal immunization during pregnancy was associated with a lower proportion of infants who were small for gestational age and an increase in mean birth weight. These data need confirmation but suggest that prevention of influenza infection in pregnancy can influence intrauterine growth.

Trial Registration:

ClinicalTrials.gov: {"type":"clinical-trial","attrs":{"text":"NCT 00142389","term_id":"NCT00142389"}}NCT 00142389Influenza infection in young infants is common and results in high rates of hospital admission,¹ but infection can be prevented by immunization of the mother during pregnancy.² There are few prospective studies of the effect of antenatal vaccination against influenza on fetal and neonatal outcomes.³ There is conflicting information about the effect of maternal influenza infection on the fetus and newborn,³ though other antepartum maternal infections have well-described adverse effects on the fetus.⁴The Mother’s Gift project is a randomized trial designed to assess the safety and efficacy of maternal pneumococcal and influenza immunization in Bangladesh. The primary outcomes of this study have been reported.² In the current article, we report the results of a secondary analysis to assess the hypothesis that influenza immunization influenza the outcomes of infants whose mothers were exposed to influenza during pregnancy.     

The effect of supervision on community health workers’ effectiveness with households in rural South Africa: A cluster randomized controlled trial

BackgroundCommunity health workers (CHWs) can supplement professional medical providers, especially in rural settings where resources are particularly scarce. Yet, outcomes of studies evaluating CHWs effectiveness have been highly variable and lack impact when scaled nationally. This study examines if child and maternal outcomes are better when existing government CHWs, who are perinatal home visitors, receive ongoing enhanced supervision and monitoring, compared to standard care.Methods and findingsA cluster randomized controlled effectiveness trial was conducted comparing outcomes over 2 years when different supervision and support are provided. Primary health clinics were randomized by clinic to receive monitoring and supervision from either (1) existing supervisors (Standard Care (SC); n = 4 clinics, 23 CHWs, 392 mothers); or (2) supervisors from a nongovernmental organization that provided enhanced monitoring and supervision (Accountable Care [AC]; n = 4 clinic areas, 20 CHWs, 423 mothers). Assessments were conducted during pregnancy and at 3, 6, 15, and 24 months post-birth with high retention rates (76% to 86%). The primary outcome was the number of statistically significant intervention effects among 13 outcomes of interest; this approach allowed us to evaluate the intervention holistically while accounting for correlation among the 13 outcomes and considering multiple comparisons.The observed benefits were not statistically significant and did not show the AC’s efficacy over the SC. Only the antiretroviral (ARV) adherence effect met the significance threshold established a priori (SC mean 2.3, AC mean 2.9, p < 0.025; 95% CI = [0.157, 1.576]). However, for 11 of the 13 outcomes, we observed an improvement in the AC compared to the SC. While the observed outcomes were not statistically significant, benefits were observed for 4 outcomes: increasing breastfeeding for 6 months, reducing malnutrition, increasing ARV adherence, and improving developmental milestones. The major study limitation was utilizing existing CHWs and being limited to a sample of 8 clinics. There were no major study-related adverse events.ConclusionsSupervision and monitoring were insufficient to improve CHWs’ impact on maternal and child outcomes. Alternative strategies for staff recruitment and narrowing the intervention outcomes to the specific local community problems are needed for consistently high impact.Trial registrationClinicaltrials.gov, {"type":"clinical-trial","attrs":{"text":"NCT02957799","term_id":"NCT02957799"}}NCT02957799.

In a randomised controlled trial, Dr. Mary Jane Rotheram-Borus and colleagues investigate the effect of supervision on community health workers’ effectiveness in households of rural South Africa.     

Improving the quality of care for infants: a cluster randomized controlled trial

Background

We developed and tested a new method, called the Evidence-based Practice for Improving Quality method, for continuous quality improvement.

Methods

We used cluster randomization to assign 6 neonatal intensive care units (ICUs) to reduce nosocomial infection (infection group) and 6 ICUs to reduce bronchopulmonary dysplasia (pulmonary group). We included all infants born at 32 or fewer weeks gestation. We collected baseline data for 1 year. Practice change interventions were implemented using rapid-change cycles for 2 years.

Results

The difference in incidence trends (slopes of trend lines) between the ICUs in the infection and pulmonary groups was − 0.0020 (95% confidence interval [CI] − 0.0007 to 0.0004) for nosocomial infection and − 0.0006 (95% CI − 0.0011 to − 0.0001) for bronchopulmonary dysplasia.

Interpretation

The results suggest that the Evidence-based Practice for Improving Quality method reduced bronchopulmonary dysplasia in the neonatal ICU and that it may reduce nosocomial infection.Although methods for continuous quality improvement have been used to improve outcomes,^1–3 some, such as the National Institutes of Child Health and Human Development Quality Collaborative,⁴ have reported little or no effect in neonatal intensive care units (ICUs). These methods have been criticized for being based on intuition and anecdotes rather than on evidence.⁵ To address these concerns, researchers have developed methods aimed at improving the use of evidence in quality improvement. Tarnow-Mordi and colleagues,⁶ Sankaran and colleagues⁷ and others^8–10 have used benchmarking instruments^6,8,11 to show risk-adjusted variations in outcomes in neonatal ICUs. Synnes and colleagues¹² reported that variations in the rates of intraventricular hemorrhage could be attributed to practice differences. MacNab and colleagues¹³ showed how multilevel modelling methods can be used to identify practice differences associated with variations in outcomes for targeted interventions and to quantify their attributable risks.Building on these results, we developed the Evidence-based Practice for Improving Quality method for continuous quality improvement. This method is based on 3 pillars: the use of evidence from published literature; the use of data from participating hospitals to identify hospital-specific practices for targeted intervention; and the use of a national network to share expertise. By selectively targeting hospital-specific practices for intervention, this method reduces the reliance on intuition and anecdotes that are associated with existing quality-improvement methods.Our objective was to evaluate the efficacy of the Evidence-based Practice for Improving Quality method by conducting a prospective cluster randomized controlled trial to reduce nosocomial infection and bronchopulmonary dysplasia among infants born at 32 or fewer weeks’ gestation and admitted to 12 Canadian Neonatal Network hospitals¹⁴ over a 36-month period. We hypothesized that the incidence of nosocomial infection would be reduced among infants in ICUs randomized to reduce infection but not among those in ICUs randomized to reduce bronchopulmonary dysplasia. We also hypothesized that the incidence of bronchopulmonary dysplasia would be reduced among infants in the ICUs randomized to reduce this outcome but not among those in ICUs randomized to reduce infections.     

The impact of long-lasting microbial larvicides in reducing malaria transmission and clinical malaria incidence: study protocol for a cluster randomized controlled trial

BackgroundThe massive scale-up of insecticide-treated nets (ITNs) and indoor residual spraying (IRS) has led to a substantial increase in malaria vector insecticide resistance as well as in increased outdoor transmission, both of which hamper the effectiveness and efficiency of ITN and IRS. Long-lasting microbial larvicide can be a cost-effective new supplemental intervention tool for malaria control.Methods/designWe will implement the long-lasting microbial larvicide intervention in 28 clusters in two counties in western Kenya. We will test FourStar controlled release larvicide (6 % by weight Bacillus thuringiensis israelensis and 1 % Bacillus sphaerius) by applying FourStar controlled release granule formulation, 90-day briquettes, and 180-day briquettes in different habitat types. The primary endpoint is clinical malaria incidence rate and the secondary endpoint is malaria vector abundance and transmission intensity. The intervention will be conducted as a two-step approach. First, we will conduct a four-cluster trial (two clusters per county, with one of the two clusters randomly assigned to the intervention arm) to optimize the larvicide application scheme. Second, we will conduct an open-label, cluster-randomized trial to evaluate the effectiveness and cost-effectiveness of the larvicide. Fourteen clusters in each county will be assigned to intervention (treatment) or no intervention (control) by a block randomization on the basis of clinical malaria incidence, vector density, and human population size per site. We will treat each treatment cluster with larvicide for three rounds at 4-month intervals, followed by no treatment for the following 8 months. Next, we will switch the control and treatment sites. The former control sites will receive three rounds of larvicide treatment at appropriate time intervals, and former treatment sites will receive no larvicide. We will monitor indoor and outdoor vector abundance using CO₂-baited CDC light traps equipped with collection bottle rotators. Clinical malaria data will be aggregated from government-run malaria treatment centers.DiscussionSince current first-line vector intervention methods do not target outdoor transmission and will select for higher insecticide resistance, new methods beyond bed nets and IRS should be considered. Long-lasting microbial larviciding represents a promising new tool that can target both indoor and outdoor transmission and alleviate the problem of pyrethroid resistance. It also has the potential to diminish costs by reducing larvicide reapplications. If successful, it could revolutionize malaria vector control in Africa, just as long-lasting bed nets have done.

Trial registration

U.S. National Institute of Health, study ID {"type":"clinical-trial","attrs":{"text":"NCT02392832","term_id":"NCT02392832"}}NCT02392832. Registered on 3 February 2015.     

Involving patients in cardiovascular risk management with nurse-led clinics: a cluster randomized controlled trial

Background

Preventive guidelines on cardiovascular risk management recommend lifestyle changes. Support for lifestyle changes may be a useful task for practice nurses, but the effect of such interventions in primary prevention is not clear. We examined the effect of involving patients in nurse-led cardiovascular risk management on lifestyle adherence and cardiovascular risk.

Methods

We performed a cluster randomized controlled trial in 25 practices that included 615 patients. The intervention consisted of nurse-led cardiovascular risk management, including risk assessment, risk communication, a decision aid and adapted motivational interviewing. The control group received a minimal nurse-led intervention. The self-reported outcome measures at one year were smoking, alcohol use, diet and physical activity. Nurses assessed 10-year cardiovascular mortality risk after one year.

Results

There were no significant differences between the intervention groups. The effect of the intervention on the consumption of vegetables and physical activity was small, and some differences were only significant for subgroups. The effects of the intervention on the intake of fat, fruit and alcohol and smoking were not significant. We found no effect between the groups for cardiovascular 10-year risk.

Interpretation

Nurse-led risk communication, use of a decision aid and adapted motivational interviewing did not lead to relevant differences between the groups in terms of lifestyle changes or cardiovascular risk, despite significant within-group differences.It is not clear if programs for lifestyle change are effective in the primary prevention of cardiovascular diseases. Some studies have shown lifestyle improvements with cardiovascular rehabilitation programs,^1–3 and studies in primary prevention have suggested small, but potentially important, reductions in the risk of cardiovascular disease. However, these studies have had limitations and have recommended further research.^4,5 According to national and international guidelines for cardiovascular risk management, measures to prevent cardiovascular disease, such as patient education and support for lifestyle change, can be delegated to practice nurses in primary care.^6–8 However, we do not know whether the delivery of primary prevention programs by practice nurses is effective. We also do no know the effect of nurse-led prevention, including shared decision-making and risk communication, on cardiovascular risk.Because an unhealthy lifestyle plays an important role in the development of cardiovascular disease,^9,10 preventive guidelines on cardiovascular disease and diabetes recommend education and counselling about smoking, diet, physical exercise and alcohol consumption for patients with moderately and highly increased risk.^6,11 These patients are usually monitored in primary care practices. The adherence to lifestyle advice ranges from 20% to 90%,^12–15 and improving adherence requires effective interventions, comprising cognitive, behavioural and affective components (strategies to influence adherence to lifestyle advice via feelings and emotions or social relationships and social supports).¹⁶ Shared treatment decisions are highly preferred. Informed and shared decision-making requires that all information about the cardiovascular risk and the pros and cons of the risk-reduction options be shared with the patient, and that the patients’ individual values, personal resources and capacity for self-determination be respected.^17–19 In our cardiovascular risk reduction study,²⁰ we developed an innovative implementation strategy that included a central role for practice nurses. Key elements of our intervention included risk assessment, risk communication, use of a decision aid and adapted motivational interviewing (Box 1).^19,21,22

Box 1.?Key features of the nurse-led intervention

• Risk assessment (intervention and control): The absolute 10-year mortality risk from cardiovascular diseases was assessed with use of a risk table from the Dutch guidelines (for patients without diabetes) or the UK Prospective Diabetes Study risk engine (for patients with diabetes).^6,23 Nurses in the control group continued to provide usual care after this step.
• Risk communication (intervention only): Nurses informed the patients of their absolute 10-year cardiovascular mortality risk using a risk communication tool developed for this study.^24–37
• Decision support (intervention only): Nurses provied support to the patients using an updated decision aid.²⁸ This tool facilitated the nurses’ interaction with the patients to arrive at informed, value-based choices for risk reduction. The tool provided information about the options and their associated relevant outcomes.
• Adapted motivational interviewing (intervention only): Nurses discussed the options for risk reduction. The patient’s personal values were elicited using adapted motivational interviewing.

In the present study, we investigated whether a nurse-led intervention in primary care had a positive effect on lifestyle and 10-year cardiovascular risk. We hypothesized that involving patients in decision-making would increase adherence to lifestyle changes and decrease the absolute risk of 10-year cardiovascular mortality.     

Effectiveness of disseminating consensus management recommendations for ulcer bleeding: a cluster randomized trial

Background:

International guidelines for the management of nonvariceal upper gastrointestinal bleeding have not been widely adopted in clinical practice. We sought to determine whether a national, multifaceted intervention could improve adherence to guidelines, especially for patients at high risk of nonvariceal upper gastrointestinal bleeding.

Methods:

In this randomized trial, we stratified hospitals by region and size and allocated sites to either the control or experimental group. Health care workers in the experimental group were given published guidelines, generic algorithms, stratification scoring systems and written reminders and attended multidisciplinary guideline education groups and case-based workshops. These interventions were implemented over a 12-month period after randomization, with performance feedback and benchmarking. The primary outcome of adherence rates to key guidelines in endoscopic and pharmacologic management, determined by chart review, was adjusted according to site characteristics and possible within-site dependencies. We also report the rates of adherence to other recommendations.

Results:

Forty-three sites were randomized to the experimental (n = 21) or control (n = 22) groups. In our primary analysis, we compared patients before (experimental group: n = 402 patients; control group: n = 424 patients) and after (experimental group: n = 361 patients; control group: n = 389 patients) intervention. Patient-level analysis revealed no significant difference in adherence rates to the guidelines after the intervention (experimental group: 9.8%; control group: 4.8%; p = 0.99) after adjustment for the rate of adherence before the intervention (experimental group: 13.2%; control group: 7.1%). The adherence rates to other guidelines were similar and decreased over time, varying between 5% and 93%.

Interpretation:

This national knowledge translation–based trial suggests poor adherence to guidelines on nonvariceal upper gastrointestinal bleeding. Adherence was not improved by an educational intervention, which highlights both the complexity and poor predictability of attempting to alter the behaviour of health care providers (Trial registration: ClinicalTrials.gov, no. MCT-88113).The care of patients with nonvariceal upper gastrointestinal bleeding has evolved dramatically over the past 10 years, with international consensus recommendations being issued in 2003.¹ National benchmarking initiatives^2,3 suggest that widespread variations in practice persist,^4,5 with poor adherence to published recommendations.⁶ In this randomized knowledge-translation trial, we aimed to assess the effectiveness of a nation-wide active strategy to improve adoption of evidence-based consensus recommendations on nonvariceal upper gastrointestinal bleeding.     

Triple-antiretroviral prophylaxis to prevent mother-to-child HIV transmission through breastfeeding--the Kisumu Breastfeeding Study, Kenya: a clinical trial

Background

Effective strategies are needed for the prevention of mother-to-child HIV transmission (PMTCT) in resource-limited settings. The Kisumu Breastfeeding Study was a single-arm open label trial conducted between July 2003 and February 2009. The overall aim was to investigate whether a maternal triple-antiretroviral regimen that was designed to maximally suppress viral load in late pregnancy and the first 6 mo of lactation was a safe, well-tolerated, and effective PMTCT intervention.

Methods and Findings

HIV-infected pregnant women took zidovudine, lamivudine, and either nevirapine or nelfinavir from 34–36 weeks'' gestation to 6 mo post partum. Infants received single-dose nevirapine at birth. Women were advised to breastfeed exclusively and wean rapidly just before 6 mo. Using Kaplan-Meier methods we estimated HIV-transmission and death rates from delivery to 24 mo. We compared HIV-transmission rates among subgroups defined by maternal risk factors, including baseline CD4 cell count and viral load.Among 487 live-born, singleton, or first-born infants, cumulative HIV-transmission rates at birth, 6 weeks, and 6, 12, and 24 mo were 2.5%, 4.2%, 5.0%, 5.7%, and 7.0%, respectively. The 24-mo HIV-transmission rates stratified by baseline maternal CD4 cell count <500 and ≥500 cells/mm³ were 8.4% (95% confidence interval [CI] 5.8%–12.0%) and 4.1% (1.8%–8.8%), respectively (p = 0.06); the corresponding rates stratified by baseline maternal viral load <10,000 and ≥10,000 copies/ml were 3.0% (1.1%–7.8%) and 8.7% (6.1%–12.3%), respectively (p = 0.01). None of the 12 maternal and 51 infant deaths (including two second-born infants) were attributed to antiretrovirals. The cumulative HIV-transmission or death rate at 24 mo was 15.7% (95% CI 12.7%–19.4%).

Conclusions

This trial shows that a maternal triple-antiretroviral regimen from late pregnancy through 6 months of breastfeeding for PMTCT is safe and feasible in a resource-limited setting. These findings are consistent with those from other trials using maternal triple-antiretroviral regimens during breastfeeding in comparable settings.

Trial registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00146380","term_id":"NCT00146380"}}NCT00146380 Please see later in the article for the Editors'' Summary     

Estimating the immunity coverage required to prevent epidemics in a community of households

An estimation of the immunity coverage needed to prevent future outbreaks of an infectious disease is considered for a community of households. Data on outbreak size in a sample of households from one epidemic are used to derive maximum likelihood estimates and confidence bounds for parameters of a stochastic model for disease transmission in a community of households. These parameter estimates induce estimates and confidence bounds for the basic reproduction number and the critical immunity coverage, which are the parameters of main interest when aiming at preventing major outbreaks in the future. The case when individuals are homogeneous, apart from the size of their household, is considered in detail. The generalization to the case with variable infectivity, susceptibility and/or mixing behaviour is discussed more briefly. The methods are illustrated with an application to data on influenza in Tecumseh, Michigan.     

Insecticide impregnated curtains to control domestic transmission of cutaneous leishmaniasis in Venezuela: cluster randomised trial

ObjectiveTo measure the impact on transmission of leishmaniasis of curtains impregnated with insecticide.DesignCluster randomised controlled trial: household interview survey, observational study of people''s behaviour, entomological study with light trap captures of sandflies inside houses.Setting14 urban sectors in Trujillo, Venezuela.Participants2913 inhabitants of 569 houses.InterventionSectors were paired according to their 12 month cumulative incidence of cutaneous leishmaniasis, one sector in each pair was randomly allocated to receive polyester curtains impregnated with lambdacyhalothrin (intervention group) while the other sector received curtains without insecticide or no curtains (control groups). After 12 months a follow up household survey was conducted.ResultsTransmission of cutaneous leishmaniasis occurred mainly in the domestic setting, with the incidence over 12 months of 4%. The mean number of sandflies per trap per night was 16. After follow up the 12 month incidence of cutaneous leishmaniasis was 0% in the intervention group and 8% in the six pairs in the control group that received unimpregnated curtains (mean difference 8, 95% confidence interval 4.22 to 11.78; P=0.001). There were significantly fewer sandflies in the intervention group (2 v 15, mean difference 13 sandflies per trap; 9 to 17; P<0.001).ConclusionCurtains impregnated with insecticide provide a high degree of protection against indoor transmission of cutaneous leishmaniasis.

What is already known on this topic

The transmission of cutaneous leishmaniasis is increasingly in urban and domestic settingsHouse spraying, space spraying, and insecticide treated material reduce the number of vectors

What this paper adds

Pyrethroid impregnated curtains can considerably reduce the incidence rate of cutaneous leishmaniasis in areas where indoor transmission is predominant     

A small change approach to prevent long-term weight gain in adults with overweight and obesity: a randomized controlled trial

Background:Efforts to manage obesity through weight loss are often unsuccessful as most adults are not able to sustain the major changes in behaviour that are required to maintain weight loss long term. We sought to determine whether small changes in physical activity and diet prevent weight gain in adults with overweight and obesity.Methods:We randomized 320 sedentary adults with overweight or obesity to monitoring alone (MA, n = 160) or a small change approach (SCA, n = 160). In Phase I (2 yr), MA participants were asked to maintain their normal lifestyle and SCA participants were counselled to make small changes in diet and physical activity, namely a suggested increase in daily step count of 2000 steps with a decrease in energy intake of 100 kcal per day, with group and individual support. Phase II (1 yr) was a passive follow-up period. The difference in change in body weight between groups at 24 and 36 months from baseline was the primary outcome. Additional outcomes included waist circumference and cardiorespiratory fitness.Results:Overall, 268 participants (83.8%) completed the 2-year intervention, and 239 (74.7%) returned at the end of the follow-up period at 3 years. The difference in body weight change between the SCA and MA groups was significant at 3, 6, 12 and 15 months from baseline, but was no longer significant at 24 months (mean change 0.9 [standard error (SE) 0.5] kg v. −0.4 [SE 0.5] kg; difference −0.6, 95% confidence interval [CI] −1.9 to 0.8) or at 36 months (−1.2 [SE 0.8] v. −0.7 [SE 0.8] kg; difference −0.5, 95% CI −2.2 to 1.2). Changes in waist circumference and cardiorespiratory fitness were not significantly different between groups at 24 or 36 months (both p > 0.1).Interpretation:The SCA did not prevent weight gain compared with monitoring alone at 2 or 3 years in adults with overweight or obesity. On average, we observed prevention of weight gain in both arms of the trial. Trial registration:ClinicalTrials.gov, no. {"type":"clinical-trial","attrs":{"text":"NCT02027077","term_id":"NCT02027077"}}NCT02027077.

Overweight and obesity contribute to chronic diseases and present a major public health challenge¹ as more than 63% of adults in Canada currently live with overweight or obesity.² Despite the urgent need to address the obesity problem, few strategies designed to reduce obesity have been broadly successful.Results from randomized controlled trials show that most adults are not able to sustain the major changes in behaviour that are required to maintain weight loss long term.^3,4 A more reasonable and achievable goal may be to focus on the prevention of weight gain. Preventing further weight gain is clinically important as even modest weight gain (0.5–1.0 kg/yr) in adults with overweight and obesity has negative associations with adverse outcomes, such as cancer,⁵ all-cause and cardiovascular disease–related death⁶ and poor health-related quality of life.⁷It has been estimated that, for 90% of the adult population, a reduction of about 100–150 kcal/d would be required to prevent positive energy balance.^8,9 Two separate pilot studies have shown that a small change approach (SCA, defined as an increase in daily step count of 2000 steps or a decrease in energy intake of 100 kcal) prevented weight gain in a small group of adults and children with overweight over 13 weeks.^9,10 More recently SCA was shown to be associated with reduced weight gain in young adults with overweight at 2 years, compared with controls.¹¹We sought to determine the effectiveness of the SCA to prevent weight gain in adults with overweight (defined as a body mass index [BMI] 25–29.9) and obesity (defined as a BMI of ≥ 30) at 2 and 3 years. We hypothesized that the SCA would prevent weight gain in comparison with monitoring of body weight alone.     

The Chronic CARe for diAbeTes study (CARAT): a cluster randomized controlled trial

Background

Diabetes is a major challenge for the health care system and especially for the primary care provider. The Chronic Care Model represents an evidence-based framework for the care for chronically ill. An increasing number of studies showed that implementing elements of the Chronic Care Model improves patient relevant outcomes and process parameters. However, most of these findings have been performed in settings different from the Swiss health care system which is dominated by single handed practices.

Methods/Design

CARAT is a cluster randomized controlled trial with general practitioners as the unit of randomization (trial registration: ISRCTN05947538). The study challenges the hypothesis that implementing several elements of the Chronic Care Model via a specially trained practice nurse improves the HbA1c level of diabetes type II patients significantly after one year (primary outcome). Furthermore, we assume that the intervention increases the proportion of patients who achieve the recommended targets regarding blood pressure (<130/80), HbA1c (=<6.5%) and low-density lipoprotein-cholesterol (<2.6 mmol/l), increases patients' quality of life (SF-36) and several evidence-based quality indicators for diabetes care. These improvements in care will be experienced by the patients (PACIC-5A) as well as by the practice team (ACIC). According to the power calculation, 28 general practitioners will be randomized either to the intervention group or to the control group. Each general practitioner will include 12 patients suffering from diabetes type II. In the intervention group the general practitioner as well as the practice nurse will be trained to perform care for diabetes patients according to the Chronic Care Model in teamwork. In the control group no intervention will be applied at all and patients will be treated as usual. Measurements (pre-data-collection) will take place in months II-IV, starting in February 2010. Follow-up data will be collected after 1 year.

Discussion

This study challenges the hypothesis that the Chronic Care Model can be easily implemented by a practice nurse focused approach. If our results will confirm this hypothesis the suggestion arises whether this approach should be implemented in other chronic diseases and multimorbid patients and how to redesign care in Switzerland.

     

Facemasks, hand hygiene, and influenza among young adults: a randomized intervention trial

Limited vaccine availability and the potential for resistance to antiviral medications have led to calls for establishing the efficacy of non-pharmaceutical measures for mitigating pandemic influenza. Our objective was to examine if the use of face masks and hand hygiene reduced rates of influenza-like illness (ILI) and laboratory-confirmed influenza in the natural setting. A cluster-randomized intervention trial was designed involving 1,178 young adults living in 37 residence houses in 5 university residence halls during the 2007–2008 influenza season. Participants were assigned to face mask and hand hygiene, face mask only, or control group during the study. Discrete-time survival models using generalized estimating equations to estimate intervention effects on ILI and confirmed influenza A/B infection over a 6-week study period were examined. A significant reduction in the rate of ILI was observed in weeks 3 through 6 of the study, with a maximum reduction of 75% during the final study week (rate ratio [RR] = 0.25, [95% CI, 0.07 to 0.87]). Both intervention groups compared to the control showed cumulative reductions in rates of influenza over the study period, although results did not reach statistical significance. Generalizability limited to similar settings and age groups. Face masks and hand hygiene combined may reduce the rate of ILI and confirmed influenza in community settings. These non-pharmaceutical measures should be recommended in crowded settings at the start of an influenza pandemic.

Trail Registration

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