Pre-intervention Prevalence Research Articles

Effectiveness of an intervention to manage occupational stress among bus drivers of Sri Lanka Transport Board in Colombo District, Sri Lanka

Introduction: Occupational stress among bus drivers is on the rise in the world. Mental health promotion programs can be effective in managing job stress in occupational groups.Objectives: To assess the effectiveness of a multi-component intervention to manage occupational stress among bus drivers of Sri Lanka Transport Board of Colombo District.Methods: A cluster randomized control trial was performed to assess the effectiveness of the intervention. Drivers were selected by randomization from all 12 depots in Colombo District. The intervention was carried out in six depots and controlled in the other six depots. Both arms consisted of 72 drivers. The mental health promotion-stress management intervention package was delivered for six months. Outcomes were assessed based on pre- and post-test stress levels. Process indicators were also determined to assess the effectiveness of the intervention.Results: All the participants were males. Response rate in the intervention group was 97.2%. Pre-intervention prevalence of occupational stress in the intervention group was 50% (n=36) and it was 58.33% (n=42) in the control group. This difference was not statistically significant (p=0.316). The post-intervention occupational stress level in the intervention group was 40.28% (n=29) and in the control group was 56.94% (n=41). This difference was statistically significant (p=0.045). In the intervention group, twelve drivers with occupational stress shifted to normal stress levels after the intervention, while five drivers who had normal stress levels, developed occupational stress afterwards (6.94%). This difference within the intervention group was not statistically significant (OR=2.4; 95% CI: 0.845, 6.81; p=0.145). Level of satisfaction on the overall programme was stated as excellent by 86% of the drivers in the intervention group.Conclusions & Recommendations: Stress management intervention was effective in reducing occupational stress among drivers. Mental health promotion programs need to be conducted on the recruitment of bus drivers.

Impact of active case-finding for tuberculosis on case-notifications in Blantyre, Malawi: A community-based cluster-randomised trial (SCALE).

Active case-finding (ACF) for tuberculosis can help find the "missing millions" with undiagnosed tuberculosis. In a cluster-randomised trial, we investigated impact of ACF on case-notifications in Blantyre, Malawi, where ACF has been intensively implemented following 2014 estimates of ~1,000 per 100,000 adults with undiagnosed TB. Following a pre-intervention prevalence survey (May 2019 to March 2020), constrained randomisation allocated neighbourhoods to either door-to-door ACF (sputum microscopy for reported cough >2 weeks) or standard-of-care (SOC). Implementation was interrupted by COVID-19. Cluster-level bacteriologically-confirmed case-notification rate (CNR) ratio within 91 days of ACF was our redefined primary outcome; comparison between arms used Poisson regression with random effects. Secondary outcomes were 91-day CNR ratios comparing all tuberculosis registrations and all non-ACF registrations. Interrupted time series (ITS) analysis of CNRs in the SOC arm examined prevalence survey impact. (ISRCTN11400592). 72 clusters served by 10 study-supported tuberculosis registration centres were randomised to ACF (261,244 adults, 58,944 person-years follow-up) or SOC (256,713 adults, 52,805 person-years). Of 1,192 ACF participants, 13 (1.09%) were smear-positive. Within 91 days, 113 (42 bacteriologically-confirmed) and 108 (33 bacteriologically-confirmed) tuberculosis patients were identified as ACF or SOC cluster residents, respectively. There was no difference by arm, with adjusted 91-day CNR ratios 1.12 (95% CI: 0.61-2.07) for bacteriologically-confirmed tuberculosis; 0.93 (95% CI: 0.68-1.28) for all tuberculosis registrations; and 0.86 (95%CI: 0.63-1.16) for non-ACF (routinely) diagnosed. Of 7,905 ACF and 7,992 SOC pre-intervention survey participants, 12 (0.15%) and 17 (0.21%), respectively, had culture/Xpert-confirmed tuberculosis. ITS analysis showed no survey impact on SOC CNRs. Despite residual undiagnosed tuberculosis of 150 per 100,000 population, there was no increase in tuberculosis notifications from this previously successful approach targeting symptomatic disease, likely due to previous TB ACF and rapid declines in TB burden. In such settings, future ACF should focus on targeted outreach and demand creation, alongside optimised facility-based screening. Trial Registration: ISRCTN11400592.

Cost-effectiveness of treatment strategies for populations from strongyloidiasis high-risk areas globally who will initiate corticosteroid treatment in the USA.

The risk of developing strongyloidiasis hyperinfection syndrome appears to be elevated among individuals who initiate corticosteroid treatment. Presumptive treatment or treatment after screening for populations from Strongyloides stercoralis-endemic areas has been suggested before initiating corticosteroids. However, potential clinical and economic impacts of preventative strategies have not been evaluated. Using a decision tree model for a hypothetical cohort of 1000 individuals from S. stercoralis-endemic areas globally initiating corticosteroid treatment, we evaluated the clinical and economic impacts of two interventions, 'Screen and Treat' (i.e. screening and ivermectin treatment after a positive test), and 'Presumptively Treat', compared to current practice (i.e. 'No Intervention'). We evaluated the cost-effectiveness (net cost per death averted) of each strategy using broad ranges of pre-intervention prevalence and hospitalization rates for chronic strongyloidiasis patients initiating corticosteroid treatment. For the baseline parameter estimates, 'Presumptively Treat' was cost-effective (i.e. clinically superior with cost per death averted less than a threshold of $10.6 million per life) compared to 'No Intervention' ($532 000 per death averted) or 'Screen and Treat' ($39 000 per death averted). The two parameters contributing the most uncertainty to the analysis were the hospitalization rate for individuals with chronic strongyloidiasis who initiate corticosteroids (baseline 0.166%) and prevalence of chronic strongyloidiasis (baseline 17.3%) according to a series of one-way sensitivity analyses. For hospitalization rates ≥0.022%, 'Presumptively Treat' would remain cost-effective. Similarly, 'Presumptively Treat' remained preferred at prevalence rates of ≥4%; 'Screen and Treat' was preferred for prevalence between 2 and 4% and 'No Intervention' was preferred for prevalence <2%. The findings support decision-making for interventions for populations from S. stercoralis-endemic areas before initiating corticosteroid treatment. Although some input parameters are highly uncertain and prevalence varies across endemic countries, 'Presumptively Treat' would likely be preferred across a range for many populations, given plausible parameters.

Treatment Patterns and Characteristics of Dialysis Facilities Randomly Assigned to the Medicare End-Stage Renal Disease Treatment Choices Model

In 2021, Medicare launched the End-Stage Renal Disease Treatment Choices (ETC) model, which randomly assigned approximately 30% of dialysis facilities to new financial incentives to increase use of transplantation and home dialysis; these financial bonuses and penalties are calculated by comparing living-donor transplantation, transplant wait-listing, and home dialysis use in ETC-assigned facilities vs benchmarks from non-ETC-assigned (ie, control) facilities. Because model participation is randomly assigned, evaluators may attribute any downstream differences in outcomes to facility performance rather than any imbalance in baseline characteristics. To identify preintervention imbalances in dialysis facility characteristics that should be recognized in any ETC model evaluations. This cross-sectional study compared ETC-assigned and control dialysis facility characteristics in the United States from 2017 to 2018. A total of 6062 facilities were included. Data were analyzed from February 2021 to May 2022. Assignment to the ETC model. Dialysis facilities' preintervention transplantations and home dialysis use, facility characteristics (notably, profit and chain status), patient demographic characteristics, and community socioeconomic characteristics. Among 316 927 patients, with 6 178 855 attributed patient-months, the mean (SD) age in January 2017 was 59 (11) years, and 132 462 (42%) were female. Patients in ETC-assigned facilities had 9% (0.2 [95% CI, 0.1-0.2] percentage points) lower prevalence of living donor transplantation, 12% (3.2 [95% CI, 3.0-3.3] percentage points) lower prevalence of transplantation wait-listing, and 4% (0.4 [95% CI, 0.3-0.4] percentage points) lower prevalence of peritoneal dialysis use compared with control facilities. ETC-assigned facilities were 14% (5.1 [95% CI, 0.9-9.4] percentage points) more likely than control facilities to be owned by the second largest dialysis organization. Relative to control facilities, ETC-assigned facilities also treated 34% (6.6 [95% CI, 6.5-6.7] percentage point) fewer patients with Hispanic ethnicity and were located in communities with median household incomes that were 4% ($2500; 95% CI, $500-$4500) lower on average. In this study, dialysis facilities in ETC-assigned regions had lower preintervention prevalence of transplantation wait-listing, living donor transplantation, and peritoneal dialysis use, relative to control facilities. ETC-assigned and control facilities also differed with respect to other facility, patient, and community characteristics. Evaluators should account for these preintervention imbalances to minimize bias in their inferences about the model's association with postintervention outcomes.

Geospatial modeling of pre-intervention nodule prevalence of Onchocerca volvulus in Ethiopia as an aid to onchocerciasis elimination.

BackgroundOnchocerciasis is a neglected tropical filarial disease transmitted by the bites of blackflies, causing blindness and severe skin lesions. The change in focus for onchocerciasis management from control to elimination requires thorough mapping of pre-control endemicity to identify areas requiring interventions and to monitor progress. Onchocerca volvulus nodule prevalence in sub-Saharan Africa is spatially continuous and heterogeneous, and highly endemic areas may contribute to transmission in areas of low endemicity or vice-versa. Ethiopia is one such onchocerciasis-endemic country with heterogeneous O. volvulus nodule prevalence, and many districts are still unmapped despite their potential for onchocerciasis transmission.Methodology/Principle findingsA Bayesian geostatistical model was fitted for retrospective pre-intervention nodule prevalence data collected from 916 unique sites and 35,077 people across Ethiopia. We used multiple environmental, socio-demographic, and climate variables to estimate the pre-intervention prevalence of O. volvulus nodules across Ethiopia and to explore their relationship with prevalence. Prevalence was high in southern and northwestern Ethiopia and low in Ethiopia’s central and eastern parts. Distance to the nearest river (RR: 0.9850, 95% BCI: 0.9751–0.995), precipitation seasonality (RR: 0.9837, 95% BCI: 0.9681–0.9995), and flow accumulation (RR: 0.9586, 95% BCI: 0.9321–0.9816) were negatively associated with O. volvulus nodule prevalence, while soil moisture (RR: 1.0218, 95% BCI: 1.0135–1.0302) was positively associated. The model estimated the number of pre-intervention cases of O. volvulus nodules in Ethiopia to be around 6.48 million (95% BCI: 3.53–13.04 million).Conclusions/SignificanceNodule prevalence distribution was correlated with habitat suitability for vector breeding and associated biting behavior. The modeled pre-intervention prevalence can be used as a guide for determining priorities for elimination mapping in regions of Ethiopia that are currently unmapped, most of which have comparatively low infection prevalence.

Impact of a health educational interventional program on reducing the head lice infestation among pupils in an elementary school of a sub-tropical region: a quasi-experimental study

BackgroundPediculosis is an important social challenge that can be caused by human head louse, Pediculus humanus capitis. This infestation is cosmopolitan, especially in countries with low hygiene and sanitation. Regular health education classes for students and their parents are required to reduce this infestation in schools and families. This study aimed to evaluate the impact of a health education intervention program on reducing head lice among pupils of an elementary school.MethodsIn a quasi-experimental study, a total of 880 elementary school girls were screened for pediculosis in (2017–2018). The prevalence of pediculosis follow-up continued monthly until the end of the school year after a two months educational intervention course. Visual inspection was applied for initial diagnosis of infection. The suspected cases were confirmed by wood lamp and potassium hydroxide (KOH) microscopic examination. Also eight questions about diagnostic, epidemiology, treatment and prevention were answered in a questionnaire by 50 volunteer parents before and after the training intervention course, to evaluate their general knowledge and measure the effectiveness of learning. All data were statistically analyzed using SPSS software (version 20.0, SPSS, Inc., Chicago, IL, USA). McNemar’s test was also applied to investigate the prevalence rate before and after the intervention. A p -value of less than 0.05 was considered as statistically significant.ResultsAt the beginning of study, pre-intervention prevalence of pediculosis among pupils was 8.4% (49/594). The mean age in all pupils was 9.86 ± 1.83 years old and the most infestation was shown in fourth-grade students with 10 years old. Analysis of statistics demonstrated a significant difference between having infestation and the number of members in the families. Post-intervention phase led to a decreased prevalence of pediculosis in pupils to 3% (8/594) (p-value < 0.05). Based on statistical analysis of questions before and after the training in the questionnaire, a significant increase of parental knowledge was observed on the prevention program of pediculosis (p-value < 0.001).ConclusionThe prevalence of pediculosis was significantly reduced following the educational interventions in the school. The applied interventions may be implemented in other residual centers to get rid of this important infestation.

Appraising The Evidence for Conservative versus Surgical Management of Motor Deficits in Degenerative Cervical Radiculopathy.

Systematic review. Understanding the prevalence and outcome of motor deficits in degenerative cervical radiculopathy is important to guide management. We compared motor radiculopathy outcomes after conservative and surgical management, a particular focus being painful vs painless radiculopathy. MEDLINE and EMBASE databases were searched. We stratified each study cohort into 1 of 6 groups, I-VI, based on whether radiculopathy was painful, painless or unspecified, and whether interventions were surgical or non-surgical. Of 10514 initial studies, 44 matched the selection criteria. Whilst 42 (95.5%) provided baseline motor radiculopathy data, only 22 (50.0%) provided follow-up motor outcomes. Mean baseline prevalence of motor deficits was 39.1% (9.2%-73.3%) in conservative cohorts and 60.5% (18.5%-94.1%) in surgical cohorts. Group VI, 'surgically-managed motor radiculopathy with unclear pain status' had the largest number of cohorts. Conversely, no cohorts were found in Group III, 'conservatively-managed painless motor radiculopathy'. Large disparities in data quality made direct comparison of conservative vs operative management difficult. Overall pre-intervention prevalence of motor deficits in degenerative cervical radiculopathy is 56.4%. Many studies fail to report motor outcomes after intervention, meaning statistical evidence to guide optimal management of motor radiculopathy is currently lacking. Our study highlights the need for more evidence, preferably from a prospective long-term study, to allow direct comparisons of motor outcomes after conservative and surgical management.

Assessing Onchocerciasis Subcriticality from Pre-Intervention Cross-Sectional Surveys.

.Elimination of an infectious disease requires subcritical transmission, or a reproductive number less than one, and can be assessed with cross-sectional surveys conducted by neglected tropical disease programs. Here, we assess the distribution of onchocerciasis prevalence taken from surveys across sub-Saharan Africa before the initiation of ivermectin in mass drug administrations. Pre-intervention nodular palpation cross-sectional surveys were available from 15 countries in the Expanded Special Project for Elimination of Neglected Tropical Diseases (ESPEN) database. We determined whether the distribution of the prevalence over communities in an area was consistent with a geometric distribution, which previous studies have suggested indicates a subcritical disease. If not, we fitted a negative binominal distribution (hypothetically supercritical) or a mixture of two distributions: geometric (hypothetically subcritical) and Poisson (hypothetically supercritical). The overall distribution of community-level onchocerciasis prevalence estimates from the ESPEN dataset from 2005 to 2014 was not consistent with a geometric distribution. By contrast, data from several countries and parts of countries were consistent with the geometric distribution, for example, some areas within Nigeria and Angola. Even if the geometric distribution suggested pre-intervention subcriticality in more localized geographical areas, our model using pooled survey data of all geographic areas suggests that the entire pre-intervention prevalence does not fit a geometric distribution. Further work will be required to confirm the significance of a geometric distribution for onchocerciasis.

Implementation of a multifaceted nurse‐led intervention to reduce indwelling urinary catheter use in four Australian hospitals: A pre‐ and postintervention study

This study aimed to reduce indwelling urinary catheter (IDC) use and duration through implementation of a multifaceted "bundled" care intervention. Indwelling urinary catheters present a risk for patients through the potential development of catheter-associated urinary tract infection (CAUTI), with duration of IDC a key risk factor. Catheter-associated urinary tract infection is considered preventable yet accounts for over a third of all hospital-acquired infections. The most effective CAUTI reduction strategy is to avoid IDC use where ever possible and to remove the IDC as early as appropriate. A cluster-controlled pre- and poststudy at a facility level with a phased intervention implementation approach. A multifaceted intervention involving a "No CAUTI" catheter care bundle was implemented, in 4 acute-care hospitals, 2 in metropolitan and 2 in rural locations, in New South Wales, Australia. Indwelling urinary catheter point prevalence and duration data were collected at the bedside on 1,630 adult inpatients at preintervention and 1,677 and 1,551 at 4 and 9months postintervention. This study is presented in line with the StaRI checklist (see Appendix S1). A nonsignificant trend towards reduction in IDC prevalence was identified, from 12% preintervention to 10% of all inpatients at 4 and 9months. Variability in preintervention IDC prevalence existed across hospitals (8%-16%). Variability in reduction was evident across hospitals at 4months (between -2% and 4%) and 9months (between 0%-8%). Hospitals with higher preintervention prevalence showed larger decreases, up to 50% when preintervention prevalence was 16%. Indwelling urinary catheter duration increased as more of the short-term IDC placements were avoided. Implementation of a multifaceted intervention resulted in reduced IDC use in four acute-care hospitals in Australia. This result was not statistically significant but did reflect a positive trend of reduction. There was a significant reduction in short-term IDC use at 9months postintervention. Clinical nurse leaders can effectively implement change strategies that influence patient outcomes. Implementation of the evidence-based "No CAUTI" bundle increased awareness of appropriate indications and provided nurses with the tools to inform decision-making related to insertion and removal of IDCs in acute inpatient settings. Working in partnership with inpatients and the multidisciplinary team is essential in minimising acute-care IDC use.

The World Health Organization 2030 goals for onchocerciasis: Insights and perspectives from mathematical modelling: NTD Modelling Consortium Onchocerciasis Group.

The World Health Organization (WHO) has embarked on a consultation process to refine the 2030 goals for priority neglected tropical diseases (NTDs), onchocerciasis among them. Current goals include elimination of transmission (EOT) by 2020 in Latin America, Yemen and selected African countries. The new goals propose that, by 2030, EOT be verified in 10 countries; mass drug administration (MDA) with ivermectin be stopped in at least one focus in 34 countries; and that the proportion of the population no longer in need of MDA be equal or greater than 25%, 50%, 75% and 100% in at least 16, 14, 12, and 10 countries, respectively. The NTD Modelling Consortium onchocerciasis teams have used EPIONCHO and ONCHOSIM to provide modelling insights into these goals. EOT appears feasible in low-moderate endemic areas with long-term MDA at high coverage (≥75%), but uncertain in areas of higher endemicity, poor coverage and adherence, and where MDA has not yet, or only recently, started. Countries will have different proportions of their endemic areas classified according to these categories, and this distribution of pre-intervention prevalence and MDA duration and programmatic success will determine the feasibility of achieving the proposed MDA cessation goals. Highly endemic areas would benefit from switching to biannual or quarterly MDA and implementing vector control where possible (determining optimal frequency and duration of anti-vectorial interventions requires more research). Areas without loiasis that have not yet initiated MDA should implement biannual (preferably with moxidectin) or quarterly MDA from the start. Areas with loiasis not previously treated would benefit from implementing test-and(not)-treat-based interventions, vector control, and anti- Wolbachia therapies, but their success will depend on the levels of screening and coverage achieved and sustained. The diagnostic performance of IgG4 Ov16 serology for assessing EOT is currently uncertain. Verification of EOT requires novel diagnostics at the individual- and population-levels.

Using Enhanced Primary Care Services in High-risk Latino Populations to Reduce Disparities in Glycemic Control.

To determine whether enhanced primary care services delivered preferentially to high-risk patients with diabetes (HbA1c >9%) can effectively reduce racial/ethnic disparities in glycemic control. This retrospective study analyzed electronic health records to examine changes in pre-vs. post-intervention disparities in HbA1c among Hispanics/Latinos relative to non-Hispanic Whites. Mean HbA1c and prevalence of poorly controlled diabetes improved in both racial/ethnic groups, but to a greater extent among Hispanics/Latinos. Mean HbA1c dropped 0.43 points further among Hispanics/Latinos than non-Hispanic Whites (95% CI, - 0.57 to - 0.29, p&lt;.001). The change in disparity in prevalence of poorly controlled diabetes, measured as the ratio of post-vs. pre-intervention prevalence ratios, was 0.89 (95% CI, 0.84 to 0.94, p&lt;.001). Both measures indicated greater reduction among Hispanics/Latinos relative to non-Hispanic Whites. Enhanced primary care services directed at high-risk patients may improve glycemic control and reduce racial/ethnic disparities in diabetes-related outcomes in medically underserved communities.

Enhanced Sanitation Standard Operating Procedures Have Limited Impact on Listeria monocytogenes Prevalence in Retail Delis

In a recent longitudinal surveillance study in 30 U.S. retail delicatessens, 9.7% of environmental surfaces were positive for Listeria monocytogenes, and we found substantial evidence of persistence. In this study, we aimed to reduce the prevalence and persistence of L. monocytogenes in the retail deli environment by developing and implementing practical and feasible intervention strategies (i.e., sanitation standard operating procedures; SSOPs). These SSOPs were standardized across the 30 delis enrolled in this study. SSOP implementation was verified by systems inherent to each retailer. Each deli also was equipped with ATP monitoring systems to verify effective sanitation. We evaluated intervention strategy efficacy by testing 28 food and nonfood contact surfaces for L. monocytogenes for 6 months in all 30 retail delis. The efficacy of the intervention on the delis compared with preintervention prevalence level was not statistically significant; we found that L. monocytogenes could persist despite implementation of enhanced SSOPs. Systematic and accurate use of ATP monitoring systems varied widely among delis. The findings indicate that intervention strategies in the form of enhanced daily SSOPs were not sufficient to eliminate L. monocytogenes from highly prevalent and persistently contaminated delis and that more aggressive strategies (e.g., deep cleaning or capital investment in redesign or equipment) may be necessary to fully mitigate persistent contamination.

O06.5 An Exploratory Evaluation of Universal Opt-Out Chlamydia Testing During Clinical Encounters For Young Women in the United States

BackgroundChlamydia testing rates are low, with only about a third of sexually active young women tested at clinical encounters. Even fewer sexually active female adolescents are tested. Interventions to increase...

Survey of iodine deficiency and intestinal parasitic infections in school-going children: Bie Province, Angola

To obtain baseline pre-intervention prevalence levels of iodine deficiency and parasitic and helminth infections in school-going children in Bie Province, Angola. A cross-sectional study conducted in randomly selected schools. The target population was children aged 6-10 years. Bie Province, Angola. A total of 1029 children sampled, with 791 stool samples and 826 urine samples collected from twenty-four schools. Widespread severe and moderate deficiencies in iodine. Children in five schools were severely iodine deficient. All sampled schoolchildren were iodine deficient to a greater or lesser extent. In all, 80 % of all children across the twenty-four schools were infected with one or a combination of intestinal helminths and intestinal protozoa. These findings have serious implications for the cognitive development of Angolan children, as well as for Angola's development in terms of productivity and economic potential. It is strongly recommended that the provincial and national Ministries of Health, in collaboration with international health agencies, immediately plan and implement a strategy to provide sufficient iodine through iodised oil capsules and iodised salt to the iodine-deficient population. National coalitions need to be strengthened among the government, partners and salt producers. It is also recommended that all the children in schools be de-wormed for multiple helminth species at least twice a year.

Onchocerca Volvulus: Effects of Annual Treatment with Ivermectin on Prevalence and of infection

Vector control is practical and effective in only a circumscribed region of West Africa. As an alternative to vector control, chemotherapy – based control has been revolutionized by the finding that ivermectin, a novel semi synthetic macrocyclic lactone, is safe and acceptable for mass distribution at the community level. In this study, the effect of ivermectin treatment was evaluated by comparing the pre- and post-treatment intervention prevalence and intensity, over a 3 year period. The pre-intervention prevalence and intensity were 53.5% and 3 mf/mg skin snip respectively. There was significant decrease (p

TRYPANOSOMA BRUCEI GAMBIENSE TRYPANOSOMIASIS IN TEREGO COUNTY, NORTHERN UGANDA, 1996: A LOT QUALITY ASSURANCE SAMPLING SURVEY

We estimated the pre-intervention prevalence of Trypanosoma brucei gambiense (Tbg) trypanosomiasis using the lot quality assurance sampling (LQAS) methods in 14 parishes of Terego County in northern Uganda. A total of 826 participants were included in the survey sample in 1996. The prevalence of laboratory confirmed Tbg trypanosomiasis adjusted for parish population sizes was 2.2% (95% confidence interval =1.1-3.2). This estimate was consistent with the 1.1% period prevalence calculated on the basis of cases identified through passive and active screening in 1996-1999. Ranking of parishes in four categories according to LQAS analysis of the 1996 survey predicted the prevalences observed during the first round of active screening in the population in 1997-1998 (P < 0.0001, by chi-square test). Overall prevalence and ranking of parishes obtained with LQAS were validated by the results of the population screening, suggesting that these survey methods may be useful in the pre-intervention phase of sleeping sickness control programs.

Are insecticide-impregnated dog collars a feasible alternative to dog culling as a strategy for controlling canine visceral leishmaniasis in Brazil?

In a zoonotic visceral leishmaniasis (ZVL)-endemic area in Brazil, deltamethrin-impregnated collars (DMC) were fitted to 136 dogs for 5 months and significantly reduced the odds of increasing their anti- Leishmania antibody titer during this period by 50% (95% confidence interval 29–87%, P=0.01), as compared with a population of 97 uncollared dogs with pre-intervention prevalence within the same town. Mathematical modeling suggests that under typical Brazilian ZVL-endemic conditions, the epidemiological impact of community-wide DMC application should be greater than the currently practiced dog culling strategy, but that its impact will be dependent on collar coverage and loss rate. Both interventions should have a higher proportional impact in regions of lower endemicity, but the relative advantage of DMC over culling increases with transmission rate. Sensitivity analyses indicate that the impact of either intervention is not significantly affected by variation in the biology of the sandfly vector, but is greatly influenced by variation in dog mortality and serorecovery rates.