The geographical distribution and socioeconomic risk factors of COVID-19, tuberculosis and leprosy in Fortaleza, Brazil

BACKGROUND

Fortaleza (Brazil) is high endemic for coronavirus disease 2019 (COVID-19), tuberculosis (TB) and leprosy. These three diseases share respiratory droplets through coughing or sneezing as the main mode of transmission but differ in incubation time, with COVID-19 having a short and leprosy a long incubation time. Consequently, contacts of a patient are at higher risk of infection and developing these diseases. There might be scope for combined preventive measures, but a better understanding of the geographical distribution and relevant socioeconomic risk factors of the three diseases is needed first. This study aims to describe the geographic distribution of COVID-19, TB and leprosy incidence and to identify common socioeconomic risk factors.

METHODS

The total number of new cases of COVID-19, TB and leprosy, as well as socioeconomic and demographic variables, were retrieved from official registers. The geographical distribution of COVID-19, TB and leprosy rates per neighbourhood was visualised in Quantum GIS, and spatial autocorrelation was measured with Moran's I in GeoDa. A spatial regression model was applied to understand the association between COVID-19, TB, leprosy rates, and socioeconomic factors.

RESULTS

COVID-19 and TB showed a more homogenous distribution, whereas leprosy is located more in the south and west of Fortaleza. One neighbourhood (Pedras) in the southeast was identified as high endemic for all three diseases. Literacy was a socioeconomic risk factor for all three diseases: a high literacy rate increases the risk of COVID-19, and a low literacy rate (i.e., illiteracy) increases the risk of TB and leprosy. In addition, high income was associated with COVID-19, while low income with TB.

CONCLUSIONS

Despite the similar mode of transmission, COVID-19, TB and leprosy show a different distribution of cases in Fortaleza. In addition, associated risk factors are related to wealth in COVID-19 and to poverty in TB and leprosy. These findings may support policymakers in developing (partially combined) primary and secondary prevention considering the efficient use of resources.

Determining target populations for leprosy prophylactic interventions: a hotspot analysis in Indonesia

Background

Leprosy incidence remained at around 200,000 new cases globally for the last decade. Current strategies to reduce the number of new patients include early detection and providing post-exposure prophylaxis (PEP) to at-risk populations. Because leprosy is distributed unevenly, it is crucial to identify high-risk clusters of leprosy cases for targeting interventions. Geographic Information Systems (GIS) methodology can be used to optimize leprosy control activities by identifying clustering of leprosy cases and determining optimal target populations for PEP.

Methods

The geolocations of leprosy cases registered from 2014 to 2018 in Pasuruan and Pamekasan (Indonesia) were collected and tested for spatial autocorrelation with the Moran’s I statistic. We did a hotspot analysis using the Heatmap tool of QGIS to identify clusters of leprosy cases in both areas. Fifteen cluster settings were compared, varying the heatmap radius (i.e., 500 m, 1000 m, 1500 m, 2000 m, or 2500 m) and the density of clustering (low, moderate, and high). For each cluster setting, we calculated the number of cases in clusters, the size of the cluster (km²), and the total population targeted for PEP under various strategies.

Results

The distribution of cases was more focused in Pasuruan (Moran’s I = 0.44) than in Pamekasan (0.27). The proportion of total cases within identified clusters increased with heatmap radius and ranged from 3% to almost 100% in both areas. The proportion of the population in clusters targeted for PEP decreased with heatmap radius from > 100% to 5% in high and from 88 to 3% in moderate and low density clusters. We have developed an example of a practical guideline to determine optimal cluster settings based on a given PEP strategy, distribution of cases, resources available, and proportion of population targeted for PEP.

Conclusion

Policy and operational decisions related to leprosy control programs can be guided by a hotspot analysis which aid in identifying high-risk clusters and estimating the number of people targeted for prophylactic interventions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07103-0.

The effect of a hand hygiene intervention on infections in residents of nursing homes: a cluster randomized controlled trial

BACKGROUND

The primary goal of hand hygiene is to reduce infectious disease rates. We examined if a nursing home's participation in a hand hygiene intervention resulted in residents having fewer healthcare associated infections (HAIs) when compared to nursing homes without the hand hygiene intervention.

METHODS

This study is a part of a cluster randomized controlled trial (RCT) in 33 nursing homes to improve hand hygiene (HANDSOME). The incidence of five illnesses was followed over 13 months: gastroenteritis, influenza-like illness, pneumonia, urinary tract infections and infections from methicillin-resistant Staphylococcus aureus (MRSA). Incidence rates per study arm were reported for baseline (October-December 2016) and two follow-up periods (January-April 2017, May-October 2017). HAI rates were compared in a Poisson multilevel analysis, correcting for baseline differences (the baseline infection incidence and the size of the nursing home), clustering of observations within nursing homes, and period in the study.

RESULTS

There was statistically significantly more gastroenteritis (p < 0.001) and statistically significantly less influenza-like illness (p < 0.01) in the intervention arm when compared to the control arm. There were no statistically significant differences or pneumonia, urinary tract infections, and MRSA infections in the intervention arm when compared to the control arm. In a sensitivity analysis, gastroenteritis was no longer statistically significantly higher in the intervention arm (p = 0.92).

CONCLUSIONS

As in comparable studies, we could not conclusively demonstrate the effectiveness of an HH intervention in reducing HAIs among residents of nursing homes, despite the use of clearly defined outcome measures, a standardized reporting instrument, and directly observed HH in a multicenter cluster RCT. Trial registration Netherlands Trial Register, trial NL6049 (NTR6188). Registered October 25, 2016, https://www.trialregister.nl/trial/6049 .

Development of a TB vaccine trial site in Africa and lessons from the Ebola experience

Tuberculosis is the deadliest infection of our time. In contrast, about 11,000 people died of Ebola between 2014 and 2016. Despite this manifest difference in mortality, there is now a vaccine licensed in the United States and by the European Medicines Agency, with up to 100% efficacy against Ebola. The developments that led to the trialing of the Ebola vaccine were historic and unprecedented. The single licensed TB vaccine (BCG) has limited efficacy. There is a dire need for a more efficacious TB vaccine. To deploy such vaccines, trials are needed in sites that combine high disease incidence and research infrastructure. We describe our twelve-year experience building a TB vaccine trial site in contrast to the process in the recent Ebola outbreak. There are additional differences. Relative to the Ebola pipeline, TB vaccines have fewer trials and a paucity of government and industry led trials. While pathogens have varying levels of difficulty in the development of new vaccine candidates, there yet appears to be greater interest in funding and coordinating Ebola interventions. TB is a global threat that requires similar concerted effort for elimination.

Newly identified risk factors for MRSA carriage in The Netherlands

OBJECTIVES

To elucidate new risk factors for MRSA carriers without known risk factors (MRSA of unknown origin; MUO). These MUO carriers are neither pre-emptively screened nor isolated as normally dictated by the Dutch Search & Destroy policy, thus resulting in policy failure.

METHODS

We performed a prospective case control study to determine risk factors for MUO acquisition/carriage (Dutch Trial Register: NTR2041). Cases were MUO carriers reported by participating medical microbiological laboratories to the RIVM from September 1st 2011 until September 1st 2013. Controls were randomly selected from the community during this period.

RESULTS

Significant risk factors for MUO in logistic multivariate analysis were antibiotic use in the last twelve months, aOR 8.1 (5.6-11.7), screened as contact in a contact tracing but not detected as a MRSA carrier at that time, aOR 4.3 (2.1-8.8), having at least one foreign parent, aOR 2.4 (1.4-3.9) and receiving ambulatory care, aOR 2.3 (1.4-3.7). Our found risk factors explained 83% of the MUO carriage.

CONCLUSIONS

Identifying new risk factors for MRSA carriers remains crucial for countries that apply a targeted screening approach as a Search and Destroy policy or as vertical infection prevention measure.

Introducing leprosy post-exposure prophylaxis into the health systems of India, Nepal and Indonesia: a case study

Background

Leprosy has a wide range of clinical and socio-economic consequences. India, Indonesia and Nepal contribute significantly to the global leprosy burden. After integration, the health systems are pivotal in leprosy service delivery. The Leprosy Post Exposure Prophylaxis (LPEP) program is ongoing to investigate the feasibility of providing single dose rifampicin (SDR) as post-exposure prophylaxis (PEP) to the contacts of leprosy cases in various health systems. We aim to compare national leprosy control programs, and adapted LPEP strategies in India, Nepal and Indonesia. The purpose is to establish a baseline of the health system’s situation and document the subsequent adjustment of LPEP, which will provide the context for interpreting the LPEP results in future.

Methods

The study followed the multiple-case study design with single units of analysis. The data collection methods were direct observation, in-depth interviews and desk review. The study was divided into two phases, i.e. review of national leprosy programs and description of the LPEP program. The comparative analysis was performed using the WHO health system frameworks (2007).

Results

In all countries leprosy services including contact tracing is integrated into the health systems. The LPEP program is fully integrated into the established national leprosy programs, with SDR and increased documentation, which need major additions to standard procedures. PEP administration was widely perceived as well manageable, but the additional LPEP data collection was reported to increase workload in the first year.

Conclusions

The findings of our study led to the recommendation that field-based leprosy research programs should keep health systems in focus. The national leprosy programs are diverse in terms of organizational hierarchy, human resource quantity and capacity. We conclude that PEP can be integrated into different health systems without major structural and personal changes, but provisions are necessary for the additional monitoring requirements.

Electronic supplementary material

The online version of this article (10.1186/s12913-017-2611-7) contains supplementary material, which is available to authorized users.

[Mortality due to chronic viral hepatitis B and C infections in the Netherlands]

OBJECTIVE

To estimate mortality due to chronic hepatitis B-virus (HBV) and hepatitis C-virus (HCV) infections in the Netherlands from 2002 to 2015.

DESIGN

A cross-sectional analysis based on cause-of-death statistics.

METHOD

From Statistics Netherlands we obtained detailed data regarding the number of deaths per year in the following ICD-10 categories: chronic viral hepatitis; malignant neoplasm of the liver and intrahepatic bile ducts; fibrosis and cirrhosis of the liver; and alcoholic liver disease. We determined the population-attributable fractions (PAF) of HBV and HCV infections in mortality due to hepatocellular carcinoma (HCC) and cirrhosis of the liver, and added these to the recorded mortality from viral hepatitis in order to calculate total mortality. We used Dutch research as a basis for allocation to HCC, and a range of PAFs from 3 studies for cirrhosis. Poisson regression was used to assess mortality trends over time and any differences in demographic characteristics.

RESULTS

Around 500 Dutch people died annually of chronic viral hepatitis from 2002 to 2015, according to our 'middle' estimate; the 'lowest' estimate yields 340 and the 'highest' 600 people per year. The total mortality due to a chronic HBV and HCV infection did not change over time. The mortality for HCC due to viral hepatitis increased slightly over time and the mortality for cirrhosis decreased slightly. HCC mortality due to viral hepatitis was higher in Dutch people of non-western origin.

CONCLUSION

Mortality from chronic viral hepatitis is mostly the result of cirrhosis of the liver and HCC. About 500 persons died annually from 2002 to 2015 from causes linked to viral hepatitis.

A Qualitative Exploration of Reasons for Poor Hand Hygiene Among Hospital Workers Lack of Positive Role Models and of Convincing Evidence That Hand Hygiene Prevents Cross-Infection

Objective.

To study potential determinants of hand hygiene compliance among healthcare workers in the hospital setting.

Design.

A qualitative study based on structured-interview guidelines, consisting of 9 focus group interviews involving 58 persons and 7 individual interviews. Interview transcripts were subjected to content analysis.

Setting.

Intensive care units and surgical departments of 5 hospitals of varying size in the Netherlands.

Participants.

A total of 65 nurses, attending physicians, medical residents, and medical students.

Results.

Nurses and medical students expressed the importance of hand hygiene for preventing of cross-infection among patients and themselves. Physicians expressed the importance of hand hygiene for self-protection, but they perceived that there is a lack of evidence that handwashing is effective in preventing cross-infection. All participants stated that personal beliefs about the efficacy of hand hygiene and examples and norms provided by senior hospital staff are of major importance for hand hygiene compliance. They further reported that hand hygiene is most often performed after tasks that they perceive to be dirty, and personal protection appeared to be more important for compliance that patient safety. Medical students explicitly mentioned that they copy the behavior of their superiors, which often leads to noncompliance during clinical practice. Physicians mentioned that their noncompliance arises from their belief that the evidence supporting the effectiveness of hand hygiene for prevention of hospital-acquired infections is not strong.

Conclusion.

The results indicate that beliefs about the importance of self-protection are the main reasons for performing hand hygiene. A lack of positive role models and social norms may hinder compliance.

Predictors of HPV vaccination uptake: a longitudinal study among parents

To assess among parents longitudinal predictors of human papillomavirus (HPV) vaccination uptake for their daughters, random samples of parents were identified via municipal services and sent baseline questionnaires in June 2009 and follow-up questionnaires in November 2011 after their uptake decision. Hierarchical logistic regression analysis was used to assess whether demographic characteristics, and affective and social cognitive factors, predicted uptake at follow-up. Response rates of the baseline and follow-up questionnaire were 29.8% (1762/5918) and 74.3% (793/1067), respectively. Uptake was predicted by a later (2011) versus earlier (2010) decision about uptake as HPV vaccination implementation [odds ratio (OR) 2.48; 95% confidence interval (CI) 1.11-5.52], anticipated regret about no uptake (OR 1.43; 95% CI 1.08-1.89) and intention (OR 2.61; 95% CI 1.47-4.61). There was an interaction between ambivalence and attitude (OR 1.68; 95% CI 1.14-2.47); parents with a positive attitude and a high ambivalence toward vaccination were more likely to have their daughter vaccinated than parents with a positive attitude and a low ambivalence. An informed choice about uptake (5/7 correct items) was made by 44%. In conclusion, uptake was predicted by intention, a later (2011) versus earlier (2010) decision and by anticipated regret about no uptake. Decisions regarding new vaccines are difficult to make, we recommend a well-balanced implementation process.

Prevalence and risk factors of syphilis infection among female sex workers in Shenzhen, China: an observational study (2009-2012)

OBJECTIVE

To investigate prevalence and risk factors of syphilis infection among female sex workers (FSWs) in Shenzhen, China.

METHODS

Observational study among (2009-2012) 1653 FSWs recruited by venue-based sampling using questionnaire-based interviews for socio-demographics, behaviours and syphilis testing results. Logistic regression was used to assess risk factors of syphilis infection.

RESULTS

The overall syphilis prevalence was 4.7%, showing a slightly decreasing trend. Factors significantly associated with syphilis infection were inconsistent condom use (OR = 1.87, P = 0.015), illicit drug use (OR = 5.45, P < 0.001) and older age in years (OR = 1.08, P < 0.001). Venues where FSWs were recruited and duration of commercial sex work were not significantly associated with syphilis infection (P > 0.05).

CONCLUSIONS

Syphilis is still common among FSWs in Shenzhen, China. Current comprehensive prevention programmes (e.g. condom promotion and peer education) should be continued to maintain and increase safe sexual practices and to reduce illicit drug use among FSWs. Expanding point-of-care syphilis screening programmes may be an important strategy for early diagnosis. We recommend timely and effective treatment programmes to be linked to such screening programmes.

Educational inequalities in tuberculosis mortality in sixteen European populations

OBJECTIVE

To describe the magnitude of socioeconomic inequalities in tuberculosis (TB) mortality by level of education in male, female, urban and rural populations in several European countries.

DESIGN

Data were obtained from the Eurothine Project, covering 16 populations between 1990 and 2003. Age- and sex-standardised mortality rates, the relative index of inequality and the slope index of inequality were used to assess educational inequalities.

RESULTS

The number of TB deaths reported was 8530, with a death rate of 3 per 100 000 per year, of which 73% were males. Educational inequalities in TB mortality were present in all European populations. Inequalities in TB mortality were greater than in total mortality. Relative and absolute inequalities were large in Eastern European and Baltic countries but relatively small in Southern European countries and in Norway, Finland and Sweden. Inequalities in mortality were observed among both men and women, and in both rural and urban populations.

CONCLUSIONS

Socio-economic inequalities in TB mortality exist in all European countries. Firm political commitment is required to reduce inequalities in the social determinants of TB incidence. Targeted public health measures are called for to improve access to treatment of vulnerable groups and thereby reduce TB mortality.

Emergence of MRSA of unknown origin in the Netherlands

The Netherlands is known for its low methicillin-resistant Staphylococcus aureus (MRSA) prevalence. Yet MRSA with no link to established Dutch risk factors for acquisition, MRSA of unknown origin (MUO), has now emerged and hampers early detection and control by active screening upon hospital admittance. We assessed the magnitude of the problem and determined the differences between MUO and MRSA of known origin (MKO) for CC398 and non-CC398. National MRSA Surveillance data (2008-2009) were analysed for epidemiological determinants and genotypic characteristics (Panton-Valentine leukocidin, spa). A quarter (24%) of the 5545 MRSA isolates registered were MUO, i.e. not from defined risk groups. There are two genotypic MUO groups: CC398 MUO (352; 26%) and non-CC398 MUO (998; 74%). CC398 MUO needs further investigation because it could suggest spread, not by direct contact with livestock (pigs, veal calves), but through the community. Non-CC398 MUO is less likely to be from a nursing home than non-CC398 MKO (relative risk 0.55; 95% CI 0.42-0.72) and Panton-Valentine leukocidin positivity was more frequent in non-CC398 MUO than MKO (relative risk 1.19; 95% CI 1.11-1.29). Exact transmission routes and risk factors for non-CC398 as CC398 MUO remain undefined.

A systematic review of economic evaluation studies of tuberculosis control in high-income countries

Tuberculosis (TB) is a leading cause of death in developing countries and an important health threat in the industrialised world. Ideally, interventions in TB control are effective, acceptable and economically attractive. This review summarises all economic evaluation studies of TB control in high-income countries over the last 20 years. We provide indications on the relative economic attractiveness of TB interventions based on the reported conclusions. A total of 118 studies using different economic evaluation methodologies on a wide range of TB interventions are included. Most studies (70%) were from North America, and about half (47%) concerned interventions among the general population. Even though the large majority of studies (85%) aimed at preventing active TB disease, 44% of these ignored the prevention of secondary infections, thereby under- estimating the benefits of the intervention. Choosing a health care instead of a societal perspective (92% vs. 8%) further underestimated the benefits. Moreover, 74 studies (62%) disregarded discounting, and for 9 of them this led to overestimated future costs. In all, 66% of the studies reported conclusions favouring the evaluated intervention, which is modest given that a publishing bias towards favourable results is to be expected. In conclusion, we demonstrate that many studies in this review have put the evaluated TB intervention at a disadvantage by the choice of methodology, i. e., underestimating benefits and overestimating costs. This may have led to an overly conservative approach to the introduction of new interventions in TB control.

Improving hand hygiene behaviour of nurses using action planning: a pilot study in the intensive care unit and surgical ward

Compliance with hand hygiene guidelines by hospital physicians and nurses is universally low and there is a need to apply powerful intervention methods from social sciences in order to improve compliance. One method is the formation of implementation intentions (or action planning) in which concrete 'if then' plans are formulated to link an environmental cue with performance of an intended behavioural action. This pilot study explored the practicality and effects of action planning on the hand hygiene behaviour (HHB) of nurses in an ICU and surgical ward of a university teaching hospital. A pre-post test design was used, and 17 nurses were invited to participate. A trained researcher observed HHB of nurses before and three weeks after the intervention in which action plans were formulated. Frequencies were calculated and logistic regression analysis was performed to assess changes in HHB. Of the 17 participants, 10 (seven in surgical ward, three in ICU) had complete data and were included in the analyses. In total, 283 potential moments for hand hygiene were identified, 142 in the surgical ward and 141 in the ICU. HHB increased from 9.3% at baseline to 25.4% post intervention (odds ratio: 3.3; confidence interval: 1.7-6.5; P<0.001). Although this was a small scale study, the results show promise for the use of action planning to improve the HHB of nurses in the short term. Action planning has shown success in closing the intention-behaviour gap in other fields, and its use for improving HHB in healthcare should be further investigated.

Factors associated with the high tuberculosis case rate in an urban area

SETTING

The Rotterdam region, the Netherlands, 1995-2006.

OBJECTIVE

To identify factors associated with the high tuberculosis (TB) case rate in an urban area.

DESIGN

Municipalities were divided into urban and semi-urban/rural municipalities. We compared the characteristics of TB cases and stratified case rates according to age group, immigrant status and place and time of infection between the two areas.

RESULTS

The TB case rate in urban municipalities was 3.8-fold higher than in semi-urban/rural municipalities. After stratification for country of birth, the rate ratios were lower (1.7 for immigrants and 2.8 for non-immigrants). Immigrants had most frequently acquired their infection abroad (47% of urban and 62% of semi-urban/rural immigrant cases). In 40% of urban cases and 27% of semi-urban/rural cases, the infection was recently acquired in the Netherlands, translating into a 5.7-fold higher recent transmission case rate for the urban population.

CONCLUSIONS

The high urban TB case rate was related to the high proportion of urban immigrants who frequently reactivated an infection acquired abroad. Recent transmission also contributed to a substantial part of the TB caseload in urban municipalities among both urban immigrants and non-immigrants. The authors propose a package of targeted interventions to address the identified factors associated with the high urban TB case rate.

Suboptimal care and perinatal mortality in ten European regions: methodology and evaluation of an international audit

BACKGROUND

A European concerted action (the EuroNatal study) investigated differences in perinatal mortality between countries of Europe. This report describes the methods used in the EuroNatal international audit and discusses the validity of the results.

METHODS

Perinatal deaths between 1993 and 1998 in regions of ten European countries were identified. The categories of death chosen for the study were singleton fetal deaths at 28 or more weeks of gestational age, all intrapartum deaths at 28 or more weeks of gestational age and neonatal deaths at 34 or more weeks of gestational age. Deaths with major congenital anomalies were excluded. An international audit panel used explicit criteria to review all cases, which were blinded for region. Subjective interpretation was used in cases of events or interventions where explicit criteria did not exist. Suboptimal factors were identified in the antenatal, intrapartum and neonatal periods, and classified as 'maternal/social', due to 'infrastructure/service organization', or due to 'professional care delivery'. The contribution of each suboptimal factor to the fatal outcome was listed and consensus was reached on a final grade using a procedure that included correspondence and plenary meetings.

RESULTS

In all regions combined, 90% of all known or estimated cases in the selected categories were included in the audit. In total, 1619 cases of perinatal death were audited. Consensus was reached in 1543 (95%) cases. In 75% of all cases, the grade was based on explicit criteria. In the remaining cases, consensus was reached within subpanels without reference to predefined criteria. There was reasonable to good agreement between and within subpanels, and within panel members.

CONCLUSIONS

The international audit procedure proved feasible and led to consistent results. The results that relate to suboptimal care will need to be studied in depth in order to reach conclusions about their implications for assessing the quality of perinatal care in the individual regions.

[Prevention and control of infectious diseases with pandemic potential: the EU-project SARSControl]

INTRODUCTION

The influenza pandemics of the 20th century, the SARS epidemic in 2002/03 and the growing number of human cases infected with the H5N1 avian influenza virus clearly demonstrate that the threat of new pandemics is very real. These events have intensified pandemic prevention and control activities worldwide. "SARSControl" is a three-year project funded by the European Commission with the objective to aid European member states in the public health management of new emerging infections. This article summarises the main research results and recommendations arising from this project.

METHOD

The reports and papers published in the SARSControl project form the basis of this article. In addition, a literature search for SARS and pandemic influenza was conducted and information on pandemic planning and management guidelines obtained from the WHO and EU websites. The project results are discussed in this context.

RESULTS

A lack of knowledge and delayed international communication resulted in the rapid spread of SARS, highlighting the importance of a global system for rapid and transparent information transfer. Epidemiological and economic modelling studies have shown that, in comparison to travel restrictions, applying intervention measures to interrupt local transmission within a country and investing into vaccine research and anti-viral stockpiling, is a more cost-effective and efficient use of resources for the containment of pandemics. A study investigating the perceived threat associated with pandemics showed that the subjective risk perception of people varies among countries. This influences human behaviour and should hence be considered during risk communication and implementation of pandemic control measures.

DISCUSSION

The basic prerequisites of an efficient pandemic management are operationalisable pandemic plans, subjected to regular exercises, backed by adequate resources and a sound health-care infrastructure. At international level cross-border co-operation and information exchange on infection control is the key to pandemic mitigation and containment. Strengthening surveillance systems at the international level, to allow the timely monitoring of infectious agents and outbreaks is essential. Transferring such outbreak information in real time into mathematical models and the resulting essential epidemiological information to policy makers would facilitate a more efficient use of scarce resources. Involvement of the public in decisions regarding the implementation of restrictive control measures which often curtail individual liberty is necessary for the acceptance and ultimate success of pandemic control.

[Hepatitis B virus transmission patterns in the Netherlands, 2004]

OBJECTIVE

To gain insight into hepatitis B virus (HBV) transmission in the Netherlands.

DESIGN

Descriptive.

METHOD

During 2004, epidemiological data and blood samples (if available) were collected for all reported cases of acute HBV infections in the Netherlands. Following DNA isolation and amplification a 648 base pairs fragment of the HBV S gene was sequenced and subjected to phylogenetic analysis. The sequencing details were also linked to epidemiological information.

RESULTS

In 2004, 291 cases ofacute HBV infections were reported. Blood samples were received from 171 patients (59%), and the genotype could be determined for 158 patients (54%). 6 genotypes were identified: A (64%), B (3%), C (3%), D (21%), E (5%) and F (4%). Of all patients with genotype A, 52% had been infected via homosexual or bisexual contact and 16% via heterosexual contact. Of all patients with genotype D, 42% had been infected via heterosexual contact and 15% via homosexual or bisexual contact. The genotype A cluster was extremely homogeneous with many identical sequences, while genotype B-E clusters were more heterogeneous. 4 identical sequences were found within genotype F, but the patients could not be epidemiologically linked.

CONCLUSION

Sexual transmission, particularly via homosexual or bisexual contact in men, formed the most important risk factor for acquiring an acute HBV infection. Genotype A was predominant in the Netherlands, especially among homosexual or bisexual men. Most infections within genotype D occurred as a result of heterosexual contact. The results show that there was ongoing transmission of HBV in homosexual or bisexual men, while in heterosexuals more cases of new introduction were seen, possibly via chronic carriers from areas where HBV is endemic.

The spatial distribution of leprosy cases during 15 years of a leprosy control program in Bangladesh: an observational study

BACKGROUND

An uneven spatial distribution of leprosy can be caused by the influence of geography on the distribution of risk factors over the area, or by population characteristics that are heterogeneously distributed over the area. We studied the distribution of leprosy cases detected by a control program to identify spatial and spatio-temporal patterns of occurrence and to search for environmental risk factors for leprosy.

METHODS

The houses of 11,060 leprosy cases registered in the control area during a 15-year period (1989-2003) were traced back, added to a geographic database (GIS), and plotted on digital maps. We looked for clusters of cases in space and time. Furthermore, relationships with the proximity to geographic features, such as town center, roads, rivers, and clinics, were studied.

RESULTS

Several spatio-temporal clusters were observed for voluntarily reported cases. The cases within and outside clusters did not differ in age at detection, percentage with multibacillary leprosy, or sex ratio. There was no indication of the spread from one point to other parts of the district, indicating a spatially stable endemic situation during the study period. The overall risk of leprosy in the district was not associated with roads, rivers, and leprosy clinics. The risk was highest within 1 kilometer of town centers and decreased with distance from town centers.

CONCLUSION

The association of a risk of leprosy with the proximity to towns indicates that rural towns may play an important role in the epidemiology of leprosy in this district. Further research on the role of towns, particularly in rural areas, is warranted.

MUSIDH, multiple use of simulated demographic histories, a novel method to reduce computation time in microsimulation models of infectious diseases

Microsimulation of infectious diseases requires simulation of many life histories of interacting individuals. In particular, relatively rare infections such as leprosy need to be studied in very large populations. Computation time increases disproportionally with the size of the simulated population. We present a novel method, MUSIDH, an acronym for multiple use of simulated demographic histories, to reduce computation time. Demographic history refers to the processes of birth, death and all other demographic events that should be unrelated to the natural course of an infection, thus non-fatal infections. MUSIDH attaches a fixed number of infection histories to each demographic history, and these infection histories interact as if being the infection history of separate individuals. With two examples, mumps and leprosy, we show that the method can give a factor 50 reduction in computation time at the cost of a small loss in precision. The largest reductions are obtained for rare infections with complex demographic histories.

[Chronic hepatitis B virus (HBV) infection: usefulness of the combination of HBeAg and ALT determination to predict a high HBV-DNA level and therefore the necessity of referral to a specialist for possible antiviral treatment]

OBJECTIVE

To assess the usefulness of a simple practical guideline based on hepatitis B e-antigen (HBeAg) status and a single alanine aminotransferase (ALT) determination to predict hepatitis B virus (HBV) load in chronic HBV patients as a criterion for referral to a specialist for possible antiviral therapy.

DESIGN

Prospective observational study.

METHOD

420 patients with chronic HBV infection were seen at the Municipal Health Service (MHS) in Rotterdam between 2002 and 2005. The usefulness ofa guideline based on HBeAg positivity and/or elevated ALT levels to predict high HBV DNA levels (defined as more than 10(5) copies/ml) was determined. Patients with HBeAg or an elevated ALT level were referred to a specialist according to the practical guideline. Positive and negative predictive value, sensitivity, and specificity of the referral guideline for a high HBV-DNA level were calculated.

RESULTS

Less than half, 43% (181/420) of the patients, were eligible for referral to specialist care. The positive predictive value of the referral guideline was 45% (82/181, 95% CI: 38-53). The negative predictive value, i.e. the proportion of patients with low viral loads who were (rightly) not selected for referral, was 95% (227/239; 95% CI: 71-97). The sensitivity was 87% (95% CI: 80-93): the patients selected included 82 of 94 patients with a high HBV DNA level. Of the 12 patients with high viral loads not referred according to the guideline, 11 had a viral load of between 10(5)-10(6) copies/ml.

CONCLUSION

A referral guideline based on HBeAg status and a single ALT determination can successfully predict viral load in chronic HBV patients and can be used in primary care to select patients for referral to specialist care. This guideline may limit the number of unnecessarily referred patients, enhancing the efficiency of the care for patients with chronic HBV infection.

Incidence and completeness of notification of Legionnaires' disease in The Netherlands: covariate capture-recapture analysis acknowledging regional differences

To estimate incidence and completeness of notification of Legionnaires' disease (LD) in The Netherlands in 2000 and 2001, we performed a capture-recapture analysis using three registers: Notifications, Laboratory results and Hospital admissions. After record-linkage, 373 of the 780 LD patients identified were notified. Ascertained under-notification was 52.2%. Because of expected and observed regional differences in the incidence rate of LD, alternatively to conventional log-linear capture-recapture models, a covariate (region) capture-recapture model, not previously used for estimating infectious disease incidence, was specified and estimated 886 LD patients (95% confidence interval 827-1022). Estimated under-notification was 57.9%. Notified, ascertained and estimated average annual incidence rates of LD were 1.15, 2.42 and 2.77/100 000 inhabitants respectively, with the highest incidence in the southern region of The Netherlands. Covariate capture-recapture analysis acknowledging regional differences of LD incidence appears to reduce bias in the estimated national incidence rate.

Transmission routes of hepatitis B virus infection in chronic hepatitis B patients in The Netherlands

The Netherlands is a low endemic country for hepatitis B virus (HBV). Rotterdam, a city in The Netherlands harbors a large group of chronic hepatitis B (CHB) patients of which most are born abroad. The study included 464 consecutive CHB patients who were reported to the Municipal Public Health Service in Rotterdam from January 1, 2002 to September 15, 2005. The HBV genotypes, possible transmission routes of infection and travel history of CHB patients born in The Netherlands, were compared with those CHB patients living in The Netherlands but who were foreign-born, taking into account the ethnicity of the mother. Of the 464 patients with CHB infection, 14% were Dutch-born and 86% were foreign-born. The CHB patients in the Dutch-born group had genotypes A (35%), B (15%), C (11%), D (37%), and G (2%). In the foreign-born group, the distribution of genotypes was A (20%), B (15%), C (11%), D (40%), and E (15%). In the Dutch-born group, sexual transmission accounted for a larger proportion of infections (P < 0.0001) compared to the foreign-born group, whereas perinatal transmission is reported to be higher in the foreign-born group and in the Dutch-born group with a foreign mother. The genotypes of the chronic HBV strains determined corresponded well with the HBV genotypes expected from the countries of origin of the patients or their mothers. Genotypes A and D are predominant in CHB patients in The Netherlands.

Molecular epidemiology of acute hepatitis B in the Netherlands in 2004: nationwide survey

To gain insight into hepatitis B virus (HBV) transmission in the Netherlands, epidemiological data and sera were collected from reported cases of acute HBV infections in the Netherlands in 2004. Cases were classified according to mode of transmission. A fragment of the S-gene of HBV (648 bp) was amplified, sequenced, and subjected to phylogenetic analysis. Of the 291 acute HBV cases reported in 2004, 158 (54%) were available for genotyping. Phylogenetic analysis identified 6 genotypes: A (64%), B (3%), C (3%), D (21%), E (5%) and F (5%). Of HBV infected men having sex with men, 86% were infected with genotype A, accounting for 43% of all patients infected with this genotype. There were only three reported cases of injecting drug use of which one was available for sequencing (genotype A). Unlike the genotype A cluster, sequences within the genotype B-E clusters were heterogenic. Within genotype F, several isolates had identical sequences, but patients could not be epidemiologically linked. Sexual transmission, particularly by men having sex with men was the most important transmission route for HBV. Injecting drug use plays a minor role. Genotype A is predominant in the Netherlands, especially among men having sex with men. In addition to imported strains, there seems to be a pool of related but non-identical strains circulating among chronic carriers in the migrant population, from which occasionally new patients are infected, primarily by heterosexual transmission.

Completeness of notification of tuberculosis in The Netherlands: how reliable is record-linkage and capture-recapture analysis?

The aim of this study was to describe a systematic process of record-linkage, cross-validation, case-ascertainment and capture-recapture analysis to assess the quality of tuberculosis registers and to estimate the completeness of notification of incident tuberculosis cases in The Netherlands in 1998. After record-linkage and cross-validation 1499 tuberculosis patients were identified, of whom 1298 were notified, resulting in an observed under-notification of 13.4%. After adjustment for possible imperfect record-linkage and remaining false-positive hospital cases observed under-notification was 7.3%. Log-linear capture-recapture analysis initially estimated a total number of 2053 (95% CI 1871-2443) tuberculosis cases, resulting in an estimated under-notification of 36.8%. After adjustment for possible imperfect record-linkage and remaining false-positive hospital cases various capture-recapture models estimated under-notification at 13.6%. One of the reasons for the higher than expected estimated under-notification in a country with a well-organized system of tuberculosis control might be that some tuberculosis cases, e.g. extrapulmonary tuberculosis, are managed by clinicians less familiar with notification of infectious diseases. This study demonstrates the possible impact of violation of assumptions underlying capture-recapture analysis, especially the perfect record-linkage, perfect positive predictive value and absent three-way interaction assumptions.

Estimating the coverage of a targeted mobile tuberculosis screening programme among illicit drug users and homeless persons with truncated models

Truncated models are indirect methods to estimate the size of a hidden population which, in contrast to the capture-recapture method, can be used on a single information source. We estimated the coverage of a tuberculosis screening programme among illicit drug users and homeless persons with a mobile digital X-ray unit between 1 January 2003 and 31 December 2005 in Rotterdam, The Netherlands, using truncated models. The screening programme reached about two-third of the estimated target population at least once annually. The intended coverage (at least two chest X-rays per person per year) was about 23%. We conclude that simple truncated models can be used relatively easily on available single-source routine data to estimate the size of a population of illicit drug users and homeless persons. We assumed that the most likely overall bias in this study would be overestimation and therefore the coverage of the targeted mobile tuberculosis screening programme would be higher.

Corticosteroids for treating nerve damage in leprosy

BACKGROUND

Leprosy causes nerve damage which can result in nerve function impairment and disability. Corticosteroids are commonly used for treating nerve damage, although the long-term effect is uncertain.

OBJECTIVES

To assess the effects of corticosteroids on nerve damage in leprosy.

SEARCH STRATEGY

We searched the Cochrane Neuromuscular Disease Group Register, the Cochrane Central Register of Controlled Trials (Issue 4), MEDLINE (from 1966), EMBASE (from 1980), CINAHL (from 1980), LILACS (from 1982) in January 2006. We checked reference lists of the studies identified, the Current Controlled Trials Register (www.controlled-trials.com), conference proceedings and contacted trial authors.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials of corticosteroids for nerve damage in leprosy.

DATA COLLECTION AND ANALYSIS

The primary outcome was improvement in sensory and motor nerve function after one year. Secondary outcomes were improvement in nerve function after two years, change in nerve pain and tenderness, and adverse events. Two authors independently extracted data and assessed trial quality. We contacted trial authors for additional information. We collected adverse effects and cost effectiveness information from the trials and non-randomised studies.

MAIN RESULTS

We included three randomised controlled trials involving 513 people. Two trials compared prednisolone with placebo. One trial treated mild sensory impairment of less than six months duration and the other trial treated nerve function impairment of 6 to 24 months duration. Both trials examined an effect twelve months from the start of treatment. There was no significant difference in nerve function improvement between people treated with prednisolone or with placebo. The third trial compared three corticosteroid regimens for severe type 1 reactions. This trial did not report the prespecified outcomes. However, after 12 months, a significantly higher proportion of individuals on a 3-month course of prednisolone required extra corticosteroids compared to the groups with a high-dose and low-dose regimen of five months duration. Diabetes and peptic or infected ulcer were sometimes reported as serious adverse events in the placebo-controlled trials, but not significantly more often in the corticosteroid than placebo groups.

AUTHORS' CONCLUSIONS

Corticosteroids are used for treating acute nerve damage in leprosy, but evidence from randomised controlled trials does not show a significant long-term effect. Randomised controlled trials are needed to establish their effectiveness, the optimal regimens and to examine new therapies.

Estimating infectious diseases incidence: validity of capture-recapture analysis and truncated models for incomplete count data

Capture-recapture analysis has been used to evaluate infectious disease surveillance. Violation of the underlying assumptions can jeopardize the validity of the capture-recapture estimates and a tool is needed for cross-validation. We re-examined 19 datasets of log-linear model capture-recapture studies on infectious disease incidence using three truncated models for incomplete count data as alternative population estimators. The truncated models yield comparable estimates to independent log-linear capture-recapture models and to parsimonious log-linear models when the number of patients is limited, or the ratio between patients registered once and twice is between 0.5 and 1.5. Compared to saturated log-linear models the truncated models produce considerably lower and often more plausible estimates. We conclude that for estimating infectious disease incidence independent and parsimonious three-source log-linear capture-recapture models are preferable but truncated models can be used as a heuristic tool to identify possible failure in log-linear models, especially when saturated log-linear models are selected.

Sequence variations in the MBL gene and their relationship to pulmonary tuberculosis in the Chinese Han population

SETTING

The mannan binding lectin (MBL) gene is thought to play a role in human innate immune response to tuberculosis (TB) infection.

OBJECTIVE

To investigate the possible association between MBL sequence variants and TB infection in the Chinese Han population.

DESIGN

A total of 152 male pulmonary tuberculosis (PTB) patients and 293 healthy male subjects were recruited. Six MBL single nucleotide polymorphisms (SNPs) (A/B, A/C, A/D, H/L, Y/X and P/Q) were genotyped and haplotyped using the combined analysis of polymerase chain reaction using sequence-specific primers (PCR-SSP) and the PCR-sequence specific oligonucleotide probe (PCR-SSOP) assay. The genotype and haplotype frequencies were compared between TB cases and controls using an unconditional logistic regression model.

RESULTS

Neither the genotypes nor the haplotypes of the five loci were significantly associated with the disease when considered individually. After the haplotypes were regrouped, however, the XB haplotype group coding for diminished MBL levels was present at a significantly higher frequency in the patients compared with the YA group (OR 1.57, 95% CI 1.02-2.41, P < 0.05).

CONCLUSION

No convincing evidence of association between MBL sequence variants and PTB was observed individually, although the low-producing XB haplotype group may serve as a minor risk factor for PTB infection in the male Chinese Han population.

Chlamydia trachomatis infections in multi-ethnic urban youth: a pilot combining STI health education and outreach testing in Rotterdam, Netherlands

BACKGROUND/OBJECTIVES

Testing for Chlamydia trachomatis (Ct) is less accepted in people of non-Dutch ethnicity than Dutch people. We offered additional Ct and gonorrhoea testing through our outreach sexually transmitted infections (STI) prevention programme to determine whether this intervention strategy is feasible and efficient.

METHODS

Outreach workers offered test kits to women and men aged 15-29 years, in group and street settings and in a vocational training school. Demographic and behavioural data and characteristics of non-responders were assessed. DNA was isolated (using the MagNA Pure LC system) from urine and tested using the Cobas Amplicor test.

RESULTS

Among sexually active people, the test rate differed by venue (groups 80% (74/93), school 73% (49/67), street 17% (49/287); p<0.001). There was no difference in test rate between group and school settings by gender or ethnicity. Ct positivity was 14.5% (25/172); women 20.2% (20/99) versus men 6.8% (5/73); p = 0.01. Ct positivity was highest at school (24.5% (12/49)) and among Surinamese/Antillean people (17.5% (14/80)). Treatment rate of index cases and current partners was 100% and 78%, respectively.

CONCLUSIONS

We found a high acceptance of chlamydia testing in group and school settings in both men and women of non-Dutch ethnicity. The prevalence indicates that we have accessed high risk people. Outreach testing and is feasible and most efficient in school and group settings. School screening may have an impact on community prevalence of Ct infections.

Prevalence of urogenital Chlamydia trachomatis infections in the Netherlands suggests selective screening approaches. Results from the PILOT CT Population Study

Chlamydia trachomatis screening is being considered in the Netherlands, but policy recommendations are hampered by the lack of population-based data. We studied the prevalence of chlamydia infection in 15-29-year-old women and men in a national representative sample of 21,000 inhabitants of rural and urban areas in the Netherlands. Of this sample, 41% responded by sending in urine and an answered questionnaire, while 11% returned a refusal card. The overall prevalence of chlamydia infection was 2.0% (CI: 1.7-2.3); 2.5% (CI: 2.0-3.0) in women and 1.5% (1.1-1.8) in men. Chlamydia prevalence was significantly greater in very highly urbanized areas (3.2%, CI: 2.4-4.0) compared to rural areas (0.6%, CI: 0.1-1.1). In very highly urbanized areas the greatest prevalence was found among 15-19-year-old women (4.3%) and among 25-29-year-old men (4.2%). A risk profile could be determined and a prediction rule was developed. These data suggest that nationwide systematic screening is not indicated in the Netherlands and that targeted approaches are a better option. Roll-out of selective screening is recommended.

Acceptability and Consequences of Screening for Chlamydia trachomatis by Home-Based Urine Testing

OBJECTIVE

The objective of this study was to study the acceptability and consequences of home-based chlamydia (CT) screening by Municipal Health Services (MHS) among 15- to 29-year-old participants.

STUDY

This study consisted of a cross-section of 156 CT-positives and 600 random sampled CT-negatives after receiving the result of their CT test.

RESULTS

Thirty-eight percent of the men and 59% of the women responded. The screening method was well-accepted. Seventy percent (52) of the CT-positives were surprised about their result. Infected women more often than men reported a feeling of being dirty and of anxiety about infertility. Curiosity for the CT result was decisive for participation in 68% and perception of personal risk was poor. The willingness to be tested regularly was determined by present chlamydial infection, young age, multiple lifetime partners, short relationship, and earlier test for chlamydia.

CONCLUSIONS

Chlamydia screening organised by MHS is acceptable for future screening. Participants with an elevated risk are interested in screening as long as test kits are easily available. Counseling with focus on effects of CT, especially on women, is essential. Alternative approaches are needed to motivate men and non-Dutch high-risk groups.

A prediction rule for selective screening of Chlamydia trachomatis infection

BACKGROUND

Screening for Chlamydia trachomatis infections is aimed at the reduction of these infections and subsequent complications. Selective screening may increase the cost effectiveness of a screening programme. Few population based systematic screening programmes have been carried out and attempts to validate selective screening criteria have shown poor performance. This study describes the development of a prediction rule for estimating the risk of chlamydial infection as a basis for selective screening.

METHODS

A population based chlamydia screening study was performed in the Netherlands by inviting 21,000 15-29 year old women and men in urban and rural areas for home based urine testing. Multivariable logistic regression was used to identify risk factors for chlamydial infection among 6303 sexually active participants, and the discriminative ability was measured by the area under the receiver operating characteristic curve (AUC). Internal validity was assessed with bootstrap resampling techniques.

RESULTS

The prevalence of C trachomatis (CT) infection was 2.6% (95% CI 2.2 to 3.2) in women and 2.0% (95% CI 1.4 to 2.7) in men. Chlamydial infection was associated with high level of urbanisation, young age, Surinam/Antillian ethnicity, low/intermediate education, multiple lifetime partners, a new contact in the previous two months, no condom use at last sexual contact, and complaints of (post)coital bleeding in women and frequent urination in men. A prediction model with these risk factors showed adequate discriminative ability at internal validation (AUC 0.78).

CONCLUSION

The prediction rule has the potential to guide individuals in their choice of participation when offered chlamydia screening and is a promising tool for selective CT screening at population level.

Prevalence of urogenital Chlamydia trachomatis increases significantly with level of urbanisation and suggests targeted screening approaches: results from the first national population based study in the Netherlands

OBJECTIVES

Chlamydia trachomatis (Chlamydia) is the most prevalent sexually transmitted bacterial infection and can cause considerable reproductive morbidity in women. Chlamydia screening programmes have been considered but policy recommendations are hampered by the lack of population based data. This paper describes the prevalence of Chlamydia in 15-29 year old women and men in rural and urban areas, as determined through systematic population based screening organised by the Municipal Public Health Services (MHS), and discusses the implications of this screening strategy for routine implementation.

METHODS

Stratified national probability survey according to "area address density" (AAD). 21 000 randomly selected women and men in four regions, aged 15-29 years received a home sampling kit. Urine samples were returned by mail and tested by polymerase chain reaction (PCR). Treatment was via the general practitioner, STI clinic, or MHS clinic.

RESULTS

41% (8383) responded by sending in urine and questionnaire. 11% (2227) returned a refusal card. Non-responders included both higher and lower risk categories. Chlamydia prevalence was significantly lower in rural areas (0.6%, 95% CI 0.1 to 1.1) compared with very highly urbanised areas (3.2%, 95% CI 2.4 to 4.0). Overall prevalence was 2.0% (95% CI 1.7 to 2.3): 2.5% (95% CI 2.0 to 3.0%) in women and 1.5% (95% CI 1.1 to 1.8) in men. Of all cases 91% were treated. Infection was associated with degree of urbanisation, ethnicity, number of sex partners, and symptoms.

CONCLUSION

This large, population based study found very low prevalence in rural populations, suggesting that nationwide systematic screening is not indicated in the Netherlands and that targeted approaches are a better option. Further analysis of risk profiles will contribute to determine how selective screening can be done.

A study on transmission and a trial of chemoprophylaxis in contacts of leprosy patients: design, methodology and recruitment findings of COLEP

In this article, we describe the design, methodology and recruitment findings of the COLEP study. The objectives of this study were to determine the effectiveness of chemoprophylaxis with a single dose of rifampicin in the prevention of leprosy among close contacts of leprosy patients, and to find characteristics of contact groups most at risk to develop clinical leprosy. These characteristics should be usable by routine leprosy control programmes. COLEP consists of a cluster randomized, double-blind and placebo-controlled trial, a cohort study to determine risk factors characterizing the sub-groups most at risk within the total contact group of a patient, and a cohort study using a reference group from the general population to determine the prevalence and incidence of leprosy in the total population of the study area. The follow-up period will be 4 years. A coding system was developed describing the physical and genetic distance of the contact person to the patient. This study in Bangladesh includes 1037 newly diagnosed and previously untreated leprosy patients and their 21,867 contacts. The prevalence of leprosy among contacts was 7.3 per 1000. A total of 21,708 contacts without signs and symptoms of clinical leprosy are included in a trial of chemoprophylaxis with single dose rifampicin, and randomized at contact group level in treatment and placebo arms. The results of this large field trial will become available in the years to come.

Risk factors for the development of clinical leprosy among contacts, and their relevance for targeted interventions

Existing knowledge on risk factors for the development of clinical leprosy among contacts of known leprosy patients is reviewed with the aim to identify factors associated with leprosy among contacts that have potential for developing effective targeted interventions in leprosy control. Different definitions of 'contact' have been used and most studies on this subject were among so-called household members. Yet several studies indicate that contacts found in other places than the household are also at risk of developing leprosy. The type of leprosy and the bacterial index are the main patient-related factors involved in transmission, but also contacts of PB patients have a higher risk of contracting leprosy as compared to the general population. The most important contact-related factors are the closeness and intensity of the contact and inherited susceptibility, while the role of age and sex of the contacts is not clear. The role of socio-economic factors is also vague. The significance of immunological and molecular markers in relation to risk of transmitting or developing leprosy is not yet fully understood, but there is an indication that contacts who are sero-positive for anti-PGL-I antibodies are at increased risk of developing clinical leprosy. The presence of a BCG scar is likely to be related to a lower risk. Analogies with tuberculosis suggest that the 'stone-in-the-pond' approach to control may be applicable to leprosy too. Sputum smear negative tuberculosis patients are known to spread the bacteria to others. This analogy strengthens the suggestion that the contacts of paucibacillary leprosy cases should also be included in contact tracing and examination. It is concluded that targeted interventions should be aimed at close contacts of both MB and PB patients inside and outside the household, particularly when genetically related.

Delay in presentation, an indicator for nerve function status at registration and for treatment outcome--the experience of the Bangladesh Acute Nerve Damage Study cohort

The objective of our research was to relate delay in presentation in the Bangladesh Acute Nerve Damage Study cohort to intake status and to treatment outcome. The Bangladesh Acute Nerve Damage Study (BANDS) is a prospective cohort study of 2664 consecutive newly registered patients at clinics run by the Danish-Bangladesh Mission Leprosy (DBLM) project in Nilphamari, northern Bangladesh. The 1-year intake began in April 1995. Three-year follow-up for PB cases and 5 years for MB cases was completed in 2001. Delay in presentation in the BANDS cohort is associated with increased signs of nerve function impairment at registration. Individuals presenting with no nerve impairment and maintaining nerve function to the end of follow-up had the shortest mean delays. Individuals presenting with impairment that did not improve during follow-up had the longest mean delays. Discussion focuses on the value of setting a threshold value defining early presentation. Since the WHO Grade 2 disability rate effectively sanctions lengthy delays where there is no impairment, an indicator relating directly to delay is preferred as an indicator for good practice in leprosy control.

Sensory testing in leprosy: comparison of ballpoint pen and monofilaments

The 10 g monofilament has been replaced by the ballpoint pen in routine sensory testing of nerves in leprosy control in Ethiopia. Results of sensory testing between the ballpoint pen and different monofilaments on hands and feet were compared. Ballpoint pen underdiagnosis of loss of sensation was defined to occur when the pen was felt and the monofilament was not. Differences were evaluated both for individual test points (test point level) and for the test points of extremities collectively (extremity level). An extremity (either a hand or a foot) was defined as having sensory nerve function impairment (SNFI) if a supplying nerve had SNFI, which was the case when sensation was absent in two or more test points in the area supplied by that nerve. At test point level, the percentages with ballpoint pen underdiagnosis relative to the 2, 10, 20 and 50 g monofilaments were 40, 21, 9 and 7%, respectively, in the hands, and 47, 30, 15 and 7% in the feet. Ballpoint pen underdiagnosis percentages of SNFI at extremity level were 32, 18, 8 and 9% in the hands, and 37, 26, 14 and 6% in the feet. The risk of ballpoint pen underdiagnosis appears to be higher in extremities without visible damage. In conclusion, substantial levels of underdiagnosis of sensory loss with the ballpoint pen were observed. However, the consequences for the prognosis of treatment with corticosteroids in patients with the more subtle sensation loss noted here need to be established. Development and testing of guidelines is a prerequisite for the use of the ballpoint pen.