Dataset Information

Trends and forecasts of leprosy for a hyperendemic city from Brazil's northeast: Evidence from an eleven-year time-series analysis.

ABSTRACT: This study's objective was to estimate the temporal trends of leprosy according to sex and age groups, as well as to estimate and predict the progression of the disease in a hyperendemic city located in the northeast of Brazil. This ecological time-series study was conducted in Imperatriz, Maranhão, Brazil. Leprosy cases diagnosed between 2006 and 2016 were included. Detection rates stratified by sex and age groups were estimated. The study of temporal trends was accomplished using the Seasonal-Trend Decomposition method and temporal modeling of detection rates using linear seasonal autoregressive integrated moving average model according to Box and Jenkins method. Trend forecasts were performed for the 2017-2020 period. A total of 3,212 cases of leprosy were identified, the average incidence among men aged between 30 and 59 years old was 201.55/100,000 inhabitants and among women in the same age group was 135.28/100,000 inhabitants. Detection rates in total and by sex presented a downward trend, though rates stratified according to sex and age presented a growing trend among men aged less than 15 years old and among women aged 60 years old or over. The final models selected in the time-series analysis show the forecasts of total detection rates and rates for men and women presented a downward trend for the 2017-2020 period. Even though the forecasts show a downward trend in Imperatriz, the city is unlikely to meet a significant decrease of the disease burden by 2020.

SUBMITTER: Ramos ACV

PROVIDER: S-EPMC7413479 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

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Trends and forecasts of leprosy for a hyperendemic city from Brazil's northeast: Evidence from an eleven-year time-series analysis.

Ramos Antônio Carlos Vieira ACV Gomes Dulce D Santos Neto Marcelino M Berra Thaís Zamboni TZ de Assis Ivaneliza Simionato IS Yamamura Mellina M Crispim Juliane de Almeida JA Martoreli Júnior José Francisco JF Bruce Alexandre Tadashi Inomata ATI Dos Santos Felipe Lima FL Souza Ludmilla Leidianne Limirio LLL Alves Yan Mathias YM de Andrade Hamilton Leandro Pinto HLP Arcoverde Marcos Augusto Moraes MAM Pieri Flávia Meneguetti FM Arcêncio Ricardo Alexandre RA

PloS one 20200807 8

This study's objective was to estimate the temporal trends of leprosy according to sex and age groups, as well as to estimate and predict the progression of the disease in a hyperendemic city located in the northeast of Brazil. This ecological time-series study was conducted in Imperatriz, Maranhão, Brazil. Leprosy cases diagnosed between 2006 and 2016 were included. Detection rates stratified by sex and age groups were estimated. The study of temporal trends was accomplished using the Seasonal- ...[more]

PMID: 32764785

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Project description:BackgroundCebu has been one of the most leprosy endemic areas in the Philippines. Despite the high coverage rates of multiple drug therapy (MDT) and high BCG-vaccine coverage in children, leprosy control authorities believe that leprosy transmission and incidence (as evidence by continuing new case detection in both adults and children) have not declined as expected, once leprosy had been eliminated. In response to the concerns communicated by the authorities regarding ongoing leprosy transmission in Cebu, this study aims to examine the evidence for the hypothesized ongoing transmission, both in children and adults. Furthermore, it will be assessed which groups and areas are experiencing a continuing risk of leprosy infection; this can form a starting point for more targeted approaches to leprosy control.Methodology & principal findingsCase records from 2000-2010 were retrospectively collected from the Leonard Wood Memorial Clinic archives, and all other clinics on the island where leprosy was treated. Between 2000 and 2010, 3288 leprosy cases were detected. The overall five year case notification rate (CNR) dropped significantly from 47.35 (2001-2005) to 29.21 cases (2006-2010) per 100.000 population. Smaller CNRs were reported for children; however the decline in child-CNR over the same period was minimal. Furthermore, no increase in median age of notification in children or adults was found between 2000 and 2010. Population-adjusted clustering of leprosy cases was mainly detected in urban and peri-urban areas.Conclusions & significanceAlthough the overall CNR declined significantly, CNR seems to be rather static in lower risk populations and areas. Cases are mainly found in urban areas, however CNRs in these areas decline at a much faster rate than in the lower endemic rural areas. A similar situation was found when comparing adults and children: CNRs observed in children were lower than in adults, but further decline (and elimination) of these childhood CNRs was found to be difficult. Moreover, the median age of notification in children has remained stable, suggesting transmission is still on-going. It is unclear why many years of good MDT-coverage and a gradual decline in CNR have not been accompanied by evidence of reduced transmission, especially beyond a certain threshold level of case notification. We believe that a new approach to leprosy control is required to tackle transmission more directly. The most promising approach may involve chemoprophylaxis and/or immunoprophylaxis interventions, targeted at high risk (urban) areas and groups such as household contacts, followed by a different approach once decline in CNR starts to level off. Identified clusters and trends can form the starting point for implementing this approach.

Project description:ObjectiveTo evaluate antigen-specific immune responses for leprosy diagnosis in a hyperendemic area in China.MethodsEighty-three leprosy patients and 161 non-leprosy controls were enrolled from Hani-yi Autonomous Prefecture of Honghe, Yunnan Province, China. Leprosy patients were divided into multibacillary (MB, n = 38), paucibacillary (PB, n = 23), and post-multi-drug therapy (MDT, n = 22) groups. Controls were divided into the following groups: healthy household contacts (HHC, n = 119), tuberculosis (TB, n = 11), and endemic controls (EC, n = 31). The NDO-LID Rapid Test, M. leprae antigen-specific ELISA and antigen-specific IFN-γ secretion in a whole blood assay (WBA) were used to evaluate these subjects.ResultsThe NDO-LID Rapid Test achieved higher positive response rates in MB than in PB patients[94.7%(36/38) vs 65.2%(15/23)], and these rates were higher than those observed by ELISA using anti-LID-1[92.1%(35/38) vs 52.2%(12/23)], anti-NDO-LID[92.1%(35/38) vs 47.8% (11/23)], and anti-ND-O-BSA[89.5%(34/38) vs 60.9%(14/23)]. However, the NDO-LID Rapid Test also showed a higher positive response rate in the EC group (33.3%,10/31), which was higher than the rates observed for anti-NDO-LID (12.9%,4/31) and anti-ND-O-BSA (16.1%,5/31). M. leprae antigen-specific ELISA demonstrated relatively high specificity (86.84-97.37%) but low sensitivity (15.97-72.73%) in discriminating between leprosy patients and non-leprosy controls by ROC curve analysis. In contrast, M. leprae antigen-specific IFN-γ secretion detection achieved higher positive response rates in PB than in MB patients (positive ratio of MB vs PB: 40% vs 56% for LID-1, 28.6% vs 47.8% for ML89, 31.4% vs 60.7% for ML2044, and 31.4 vs 47.8% for ML2028) and could distinguish MB from EC when stimulated with ML89(AUC = 0.6664) and PB fromTB when stimulated with ML2044 and ML2028(AUC = 0.7549 and 0.7372, respectively).ConclusionThe NDO-LID Rapid Test and M. leprae antigen-specific ELISA are useful tools to assist in the diagnosis of leprosy patients, especially MB patients, although the former had higher sensitivity but lower specificity than the latter. M. leprae antigen-specific IFN-γ release assessed by WBA has diagnostic value for distinguishing PB from TB but not for distinguishing PB from HHC or EC. Screening novel M. leprae-specific antigens, combining different M. leprae antigens and a multi-cytokine analyte model may be needed for more effective diagnosis of leprosy.

Project description:BackgroundMore than 200,000 new cases of leprosy were reported by 105 countries in 2011. The disease is a public health problem in Brazil, particularly within high-burden pockets in the Amazon region where leprosy is hyperendemic among children.MethodologyWe applied geographic information systems and spatial analysis to determine the spatio-temporal pattern of leprosy cases in a hyperendemic municipality of the Brazilian Amazon region (Castanhal). Moreover, we performed active surveillance to collect clinical, epidemiological and serological data of the household contacts of people affected by leprosy and school children in the general population. The occurrence of subclinical infection and overt disease among the evaluated individuals was correlated with the spatio-temporal pattern of leprosy.Principal findingsThe pattern of leprosy cases showed significant spatio-temporal heterogeneity (p<0.01). Considering 499 mapped cases, we found spatial clusters of high and low detection rates and spatial autocorrelation of individual cases at fine spatio-temporal scales. The relative risk of contracting leprosy in one specific cluster with a high detection rate is almost four times the risk in the areas of low detection rate (RR = 3.86; 95% CI = 2.26-6.59; p<0.0001). Eight new cases were detected among 302 evaluated household contacts: two living in areas of clusters of high detection rate and six in hyperendemic census tracts. Of 188 examined students, 134 (71.3%) lived in hyperendemic areas, 120 (63.8%) were dwelling less than 100 meters of at least one reported leprosy case, 125 (66.5%) showed immunological evidence (positive anti-PGL-I IgM titer) of subclinical infection, and 9 (4.8%) were diagnosed with leprosy (8 within 200 meters of a case living in the same area).Conclusions/significanceSpatial analysis provided a better understanding of the high rate of early childhood leprosy transmission in this region. These findings can be applied to guide leprosy control programs to target intervention to high risk areas.

Project description:BackgroundLeprosy and cutaneous leishmaniasis (CL) are neglected tropical diseases (NTDs) affecting the skin. Their control is challenging but the integration of skin NTDs control programs is recommended to improve timely detection and treatment. However, little is known about the occurrence of leprosy and CL in the same individuals, and what are the characteristics of such patients. This study aimed to identify and characterize patients diagnosed with both leprosy and CL (i.e., outcome) in the hyperendemic state of Mato Grosso, Brazil. Also, we investigated the demographic risk factors associated with the period between the diagnosis of both diseases.Methodology/principal findingsA retrospective cohort study was conducted with patients diagnosed between 2008 and 2017. From the leprosy (n = 28,204) and CL (n = 24,771) databases of the national reporting system, 414 (0.8%; 414/52,561) patients presenting both diseases were identified through a probabilistic linkage procedure. This observed number was much higher than the number of patients that would be expected by chance alone (n = 22). The spatial distribution of patients presenting the outcome was concentrated in the North and Northeast mesoregions of the state. Through survival analysis, we detected that the probability of a patient developing both diseases increased over time from 0.2% in the first year to 1.0% within seven years. Further, using a Cox model we identified male sex (HR: 2.3; 95% CI: 1.7-2.9) and low schooling level (HR: 1.5; 95% CI: 1.2-1.9) as positively associated with the outcome. Furthermore, the hazard of developing the outcome was higher among individuals aged 40-55 years.Conclusions/significanceLeprosy and CL are affecting the same individuals in the area. Integration of control policies for both diseases will help to efficiently cover such patients. Measures should be focused on timely diagnosis by following-up patients diagnosed with CL, active case detection, and training of health professionals.

Dataset Information

Trends and forecasts of leprosy for a hyperendemic city from Brazil's northeast: Evidence from an eleven-year time-series analysis.

Publications

Trends and forecasts of leprosy for a hyperendemic city from Brazil's northeast: Evidence from an eleven-year time-series analysis.

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