HPV-related oropharyngeal carcinoma remains infrequent over 25 years in a Brazilian Oral Pathology Center: A cross-sectional study with literature review.

BACKGROUND: The aim was to evaluate the frequency, clinicopathological features, and HPV status of oropharyngeal squamous cell carcinoma (OP-SCC) and benign HPV-related epithelial lesions of the oropharynx over the last 25 years. Moreover, a literature review was performed to investigate HPV frequency in OP-SCC samples diagnosed in Brazilian Centers. MATERIAL AND METHODS: A cross-sectional study analyzed OP-SCC, squamous papilloma, verruca vulgaris, and condyloma accuminatum, diagnosed from 1997 to 2021. HPV status of OP-SCC was determined by immunohistochemistry and "in situ" hybridization. Bivariate statistics were performed (p≤0.05). For the literature review, MEDLINE/PubMed, Web of Science, EMBASE, and Scopus were searched. Two independent reviewers assessed the studies for eligibility. RESULTS: Cross-sectional: 211 OP-SCC (63.0%) and 124 benign lesions (37.0%) were included. OP-SCC frequency increased gradually over time, whereas benign lesions had steady trends. OP-SCC affected more males (n= 171; 81.0%), though the relative frequency in females rose over time. Smoking (n= 127; 60.2%) was common in OP-SCC. Nineteen OP-SCC (13.0%) were positive for HPV. HPV-positive and HPV-negative tumors had similar clinicopathological features (p>0.05). Benign lesions predominated in middle-aged (n= 32; 26.7%) women (n= 71; 57.3%), in the soft palate (n=101; 81.5%). LITERATURE REVIEW: 32 studies were included, and in 60% of them, HPV frequency in OP-SCC was less than 25%. CONCLUSIONS: OP-SCC prevalence has been increasing, and it was mostly associated with smoking and alcohol rather than with HPV infection in Brazil. Benign lesions had a stationary frequency over the evaluated period.

Sustainable permeable biobarriers for atrazine removal in packed bed biofilm reactors.

The synergy between two supported bacterial biofilms of S. equisimilis and P. putida and a sustainable biocarrier (raw pine) was studied, working both as biobarriers for the treatment of water contaminated with atrazine. Firstly, the effects of ATZ exposure on bacterial growth were evaluated, with Gram-positive S. equisimilis being a more tolerant bacterium to higher amounts of the herbicide. The bioremoval of ATZ by S. equisimilis concentrated biomass was then assessed, reaching around 83.5% after 15 days due to the potential degradation by the biomass and biosorption by the solids, with overlapping of both mechanisms. The optimization of bacterial biofilm attachment onto raw pine prior to bioremoval assays in lab-scale packed bed biofilm reactors was performed by varying initial biomass concentration, inocula growth time and hydrodynamic conditions. Lastly, the optimized biosystems were tested as sustainable remediation designs to treat water contaminated with the selected herbicide. Results reveal an added beneficial effect towards the bioremoval of atrazine using supported biofilms onto raw pine, reaching 90.42% and 79.71% by S. equisimilis and P. putida biofilms, respectively, over 58.31% increase when compared to sorption on fixed bed of pine. The coupling of biosorption/biodegradation favors the bioremoval process significantly.

Oral amyloidosis: an update.

BACKGROUND: Amyloidosis is a disease characterized by the progressive deposition of abnormal proteins that can occur in any organ. In the oral cavity, the tongue is the most common affected site, usually causing macroglossia. Biopsy is essential for the diagnosis and the occurrence of its systemic form is mandatory to be investigated. This systematic review evaluated the existing information in the literature on Amyloidosis in the oral cavity to allow a more comprehensive and updated analysis of its clinicopathological characteristics, as well as to explore the main forms of treatment and prognostic factors. MATERIAL AND METHODS: Electronic searches were undertaken in five databases supplemented by manual scrutiny. RESULTS: A total of 111 studies were included with 158 individuals. CONCLUSIONS: The disease had a higher prevalence in women, the tongue was the most affected site, as well as the systemic form of the disease. The worst prognosis was for cases of systemic amyloidosis associated with multiple myeloma.

Aberrant right subclavian artery in a dog - case report / [Ectopia de artéria subclávia direita em cão - relato de caso]

The brachiocephalic trunk and the left subclavian artery originate from the aortic arch, and both supply blood to the head, neck, and thoracic limbs. Anatomical variations, such as an aberrant right subclavian artery, are congenital conditions rarely observed in dogs, Thus, the objective of the present report was to describe a case of aberrant right subclavian artery in a 9-year-old Dalmatian. However, this anomaly was a finding in which the patient was asymptomatic during its 9 years of life and only at this age did he exhibit signs including sialorrhea, vomiting, hyporexia, and noisy deglutition. Blood count, biochemical profile, and thoracic radiography led to a diagnosis of megaesophagus and aspiration pneumonia. Despite the recommended treatment, the patient did not respond well; as such, the owner elected to euthanize the animal. On necropsy, the right subclavian artery originated directly from the aortic arch, followed a route from left to right dorsally to the esophagus, and then formed an impression of the vascular path over the muscular wall of the esophagus. The esophagus, in turn, exhibited a flaccid wall and dilation in the caudal portion to the vascular path made by the ectopic position of the right subclavian artery.(AU)

O tronco braquiocefálico e a artéria subclávia esquerda emergem do arco aórtico e são responsáveis por fazerem o suprimento sanguíneo para cabeça, pescoço e membros torácicos. Variações anatômicas, como a ectopia da artéria subclávia direita, são alterações congênitas raramente encontradas em cães, cujas alterações do sistema digestivo acontecem em pacientes recém-desmamados e não em adultos. Assim, o objetivo deste relato é descrever um caso de ectopia da artéria subclávia direita em uma cadela, Dálmata, de nove anos de idade. No entanto, essa anomalia foi um achado do qual o paciente foi assintomático durante os nove anos de vida e somente com essa idade apresentou sinais como sialorreia, vômito, hiporexia e deglutição ruidosa. O hemograma e os perfis bioquímicos, associados à radiografia torácica, levaram a um diagnóstico de megaesôfago e pneumonia aspirativa. Mesmo seguindo o tratamento recomendado, houve piora clínica do quadro e o animal foi submetido à eutanásia. À macroscopia, a artéria subclávia direita originava-se direto do arco aórtico, fazia um percurso da esquerda para a direita dorsalmente ao esôfago e, então, formava uma impressão do trajeto vascular sobre a parede muscular do esôfago. O esôfago, por sua vez, apresentava parede flácida e dilatação na porção caudal ao trajeto vascular feito pela posição ectópica da artéria subclávia direita.(AU)

Reinforcement omission effects in rats with bilateral lesions in the substantia nigra pars compacta and ventral tegmental area.

Reinforcement omission effects (ROEs) are characterized by higher response rates after reinforcement omission than after reinforcement delivery. This pattern of behavior is interpreted in terms of motivational and attentional processes. Recent studies from our laboratory have shown that the amygdala, nucleus accumbens, and medial prefrontal cortex are involved in ROE modulation. Also, the literature has demonstrated a role of other areas such as substantia nigra pars compacta (SNc) and the ventral tegmental area (VTA) in processes related to surprising events, such as prediction error and presentation or omission of an event (exteroceptive stimulus and reinforcement). Since these structures send projections to areas related to ROE modulation such as the amygdala, nucleus accumbens, and prefrontal cortex, the objective of the present study was to determine whether the SNc and VTA also integrate the circuit involved in ROE modulation. Rats were trained on a fixed-interval 12 s with limited-hold 6 s signaled schedule of reinforcement (Pre-lesion training). After acquisition of stable performance, the rats received bilateral neurotoxic lesions of the SNc (Experiment 1) and VTA (Experiment 2). Following postoperative recovery, the rats were submitted to two refresher sessions (Post-lesion training). Subsequently, the training was changed from a 100 to a 50% schedule of reinforcement (Post-lesion testing). In both experiments, the results showed that there was no difference in performance between sham rats and rats with bilateral lesions of the SNc or the VTA.

Reinforcement omission effects in rats with bilateral lesions in the substantia nigra pars compacta and ventral tegmental area

Reinforcement omission effects (ROEs) are characterized by higher response rates after reinforcement omission than after reinforcement delivery. This pattern of behavior is interpreted in terms of motivational and attentional processes. Recent studies from our laboratory have shown that the amygdala, nucleus accumbens, and medial prefrontal cortex are involved in ROE modulation. Also, the literature has demonstrated a role of other areas such as substantia nigra pars compacta (SNc) and the ventral tegmental area (VTA) in processes related to surprising events, such as prediction error and presentation or omission of an event (exteroceptive stimulus and reinforcement). Since these structures send projections to areas related to ROE modulation such as the amygdala, nucleus accumbens, and prefrontal cortex, the objective of the present study was to determine whether the SNc and VTA also integrate the circuit involved in ROE modulation. Rats were trained on a fixed-interval 12 s with limited-hold 6 s signaled schedule of reinforcement (Pre-lesion training). After acquisition of stable performance, the rats received bilateral neurotoxic lesions of the SNc (Experiment 1) and VTA (Experiment 2). Following postoperative recovery, the rats were submitted to two refresher sessions (Post-lesion training). Subsequently, the training was changed from a 100 to a 50% schedule of reinforcement (Post-lesion testing). In both experiments, the results showed that there was no difference in performance between sham rats and rats with bilateral lesions of the SNc or the VTA.

Hemostasia e incisão do pedículo ovariano de gatas submetidas à ovariossalpingo-histerectomia eletiva por meio da técnica das três pinças ou do eletrobisturi bipolaar. Estudo comparativo / Hemostasis and incision into the ovary pedicle of cats undergone elective ovariosalpingohysterectomy using the technique of the three bipolar forceps or eletrobisturi. Comparative study

Na cirurgia de ovariossalpingo-histerectomia (OSH), há várias técnicas para realização da hemostasia e da secção do pedículo ovariano, sendo mais comum a técnica das três pinças. O eletrobisturi bipolar pode ser utilizado com eficácia para hemostasia e corte de tecidos. Objetivou-se nesta pesquisa comparar, em gatas, a hemostasia e a secção do pedículo ovariano mediante o uso do eletrobisturi bipolar com a técnica das três pinças, ambas via celiotomia mediana, em relação ao tempo cirúrgico e à eficiência hemostática (hematócrito). Quarenta gatas, com idade de seis meses a sete anos, peso entre 1,68 e 4,14kg, foram submetidas à hemostasia e à secção desse pedículo, sendo 20 pela técnica convencional e 20 por meio do eletrobisturi bipolar. Na análise estatística, observou-se que o uso do eletrobisturi bipolar gera uma diminuição média significativa na duração da cirurgia, quando comparado com o outro método, sem diferenças quanto à comparação de hematócritos pré e pós-cirúrgicos. Por meio do modelo de regressão múltiplo, verificou-se que as variáveis: idade, peso, número de gestações, número de partos e número de cios não influenciaram significativamente no tempo. Concluiu-se, portanto, que o eletrobisturi bipolar oferece eficiência e maior rapidez na realização da hemostasia e da diérese do pedículo ovariano de gatas submetidas à OSH eletiva...

In ovariosalpingohisterectomy (OSH) surgery, there are several techniques for hemostasis and resection of ovarian pedicle, the most common being the three tweezers technique. The bipolar eletrobisturi can be used effectively for hemostasis and cutting tissue. The aim of this research was to compare, in cats, hemostasis and resection of ovarian pedicle eletrobisturi with bipolar forceps and the three techniques, both via median celiotomy, in relation to time and surgical hemostatic efficiency (hematocrit). Forty cats aged six months to seven years, weighing between 1.68 and 4.14kg, underwent hemostasis and pedicle of this section, 20 with the conventional technique and 20 with eletrobisturi bipolar. Statistical analysis showed that the use of bipolar eletrobisturi generates a significant decrease in the mean duration of surgery when compared with a method without differences in hematocrit comparing pre-and post-surgery. Through the multiple regression model we found that the variables age, weight, number of pregnancies, number of births and number of cycles did not significantly influence the time. We conclude, therefore, that the bipolar eletrobisturi is efficient and fast for hemostasis and dieresis ovarian pedicle of cats undergoing elective ovariohysterectomy...

Predictive factors of graft-censored failure in pediatric kidney transplantation.

Kidney transplantation in children has shown steady improvement in graft survival outcome over the last decades. Using data obtained from the transplantation registry of our center between 1984 and 2012, we assessed the independent determinants of graft failure using the Cox proportional hazards regression. Altogether, 128 recipients younger than 18 years of age at the time of kidney transplantation and who had >3 months graft survival were studied. During 9.95 years of medium follow-up, 27 censored graft failures occurred. Censored graft survival rates at 5, 10, 15, and 20 years post-transplantation were 93%, 82%, 70%, and 63%, respectively. Studied factors included recipient and donor age, recipient gender, dialysis vintage, donor/recipient cytomegalovirus (CMV) serology, panel-reactive antibody percentage, human leukocyte antigen mismatching, previous transplantation number, donor type (deceased vs living donation), cold ischemia time, induction therapy with antithymocyte globulin, occurrence of acute tubular necrosis, and development of acute rejection. Using univariate analysis, the significant predictors for graft-censored failure were adult donor (P < .001), recipient age (P = .035), human leukocyte antigen mismatching (P = .025), antithymocyte globulin induction (P = .03), and development of acute rejection (P < .001). Two factors independently predicted graft-censored failure in multivariate analysis. The odds ratios for graft failure in patients with acute rejection and in children who received an organ of an adult were 3.744 and 4.962, respectively. Pediatric recipients should receive the first priority for allografts from pediatric donors and acute rejection should be meticulously prevented.

Assessment of Arthrobacter viscosus as reactive medium for forming permeable reactive biobarrier applied to PAHs remediation.

Polycyclic aromatic hydrocarbons (PAHs) are significant environmental contaminants as they are present naturally as well as anthropogenically in soil, air and water. In spite of their low solubility, PAHs are spread to the environment, and they are present in surface water, industrial effluent or groundwater. Amongst all remediation technologies for treating groundwater contaminated with PAHs, the use of a permeable reactive biobarrier (PRBB) appears to be the most cost-effective, energy efficient, and environmentally sound approach. In this technology, the microorganisms are used as reactive medium to degrade or stabilize the contaminants. The main limits of this approach are that the microorganisms or consortium used for forming the PRBB should show adequate characteristics. They must be retained in the barrier-forming biofilm, and they should also have degradative ability for the target pollutants. The aim of the present work is to evaluate the viability of Arthrobacter viscosus as bioreactive medium for forming PRBB. Initially, the ability of A. viscosus to remove PAHs, benzo[a]anthracene 100 µM and phenanthrene 100 µM was evaluated operating in a batch bench-scale bioreactor. In both cases, total benzo[a]anthracene and phenanthrene removals were obtained after 7 and 3 days, respectively. Furthermore, the viability of the microorganisms was evaluated in the presence of chromium in a continuous mode. As a final point, the adhesion of A. viscosus to sepiolite forming a bioreactive material to build PRBB was demonstrated. In view of the attained results, it can be concluded that A. viscosus could be a suitable microorganism to form a bioreactive medium for PAHs remediation.

Development of permeable reactive biobarrier for the removal of PAHs by Trichoderma longibrachiatum.

In this work, the formation of permeable reactive biobarriers (PRBBs) using Trichoderma longibrachiatum over nylon sponge as bioreactive medium for removal of polycyclic aromatic hydrocarbons (PAHs) was studied. Colony formation was pretested without PAH presence by inoculation of fungus into nylon sponge. The fungus formed a large quantity of strongly adhesive biofilm among nylon sponge. Afterwards, the ability of the developed bioreactive medium was tested to remediate phenanthrene in aqueous medium and in soil. In aqueous medium, a 90% of phenanthrene concentration reduction was observed after 14 d. However, the pollutant removal in soil requires previous fungus colonization and the attained level was around 70% after 28 d. Subsequently, the formed bioreactive material was used in a glass column reactor to evaluate its application as PRBBs. Mixtures of phenanthrene, benzo[a]anthracene and pyrene at several concentrations, from 100 to 400 µM, were treated. In all cases, the performance of the PRBB was satisfactory and total PAH removals were achieved. These results suggest that PRBBs of T. longibrachiatum supported on nylon sponge can be an effective method for the treatment of PAHs.

Removal of hexavalent chromium of contaminated soil by coupling electrokinetic remediation and permeable reactive biobarriers.

PURPOSE: In this study, a novel and ecological alternative have been developed to treat soils contaminated with hexavalent chromium coupling two well-known systems: electrokinetic remediation and permeable reactive biobarriers. The electric field promotes the electromigration of the hexavalent chromium oxyanions towards the anode. The biobarriers were placed before the anode electrode, in order to promote the reduction and retention of the chromium migrating in its direction. Thus, this technology provided a global treatment to soil removal without subsequent treatments of the contaminated effluents. METHODS: The electrokinetic system was coupled with two different permeable reactive biobarriers composed by Arthrobacter viscosus bacteria, supported either in activated carbon or zeolite. An electric field of 10 V was applied and two different treatment times of 9 and 18 days were tested. RESULTS: Removal values of 60% and 79% were obtained when electrokinetic treatment was coupled with zeolite and activated carbon biobarriers, respectively, for a test period of 18 day. The reduction of hexavalent chromium to trivalent chromium was around 45% for both systems. CONCLUSIONS: In this work, two types of biobarriers were efficiently coupled to electrokinetic treatment to decontaminate soil with Cr(VI). Furthermore, the viability of the new coupling technology developed (electrokinetic + biobarriers) to treat low-permeability polluted soils was demonstrated.

Reutilization of Cr-Y zeolite obtained by biosorption in the catalytic oxidation of volatile organic compounds.

This work aims at the reutilization of a Cr-loaded NaY zeolite obtained by biorecovery of chromium from water as catalyst in the oxidation of volatile organic compounds (VOC). Cr-NaY catalysts were obtained after biosorption of Cr(VI) using a bacterium, Arthrobacter viscosus, supported on the zeolite. The biosorption experiments were conducted at different pH values in the range 1-4. The catalysts were characterized by several techniques, namely ICP-AES, SEM-EDS, XRD, XPS, Raman, H(2)-TPR and N(2) adsorption. The zeolite obtained at pH 4 has the highest content of chromium, 0.9%, and was selected as the best catalyst for the oxidation of different VOC, namely ethyl acetate, ethanol and toluene. For all VOC tested, the catalyst with chromium showed higher activity and selectivity to CO(2), in comparison with the starting zeolite NaY. The presence of chromium shifted also the reaction pathways. In terms of selectivity to CO(2), the following sequence was observed: ethyl acetate>toluene>ethanol.

Invited review: physiological properties of bioactive peptides obtained from whey proteins.

Processing of whey proteins yields several bioactive peptides that can trigger physiological effects in the human body: on the nervous system via their opiate and ileum-contracting activities; on the cardiovascular system via their antithrombotic and antihypertensive activities; on the immune system via their antimicrobial and antiviral activities; and on the nutrition system via their digestibility and hypocholesterolemic effects. The specific physiological effects, as well the mechanisms by which they are achieved and the stabilities of the peptides obtained from various whey fractions during their gastrointestinal route, are specifically discussed in this review.

Modelling of the Cr(VI) transport in typical soils of the North of Portugal.

Adsorption of hexavalent chromium [Cr(VI)] onto a loamy sand soil was studied using batch and steady flow tests with contaminant solutions at pH 2, 5 and 7. In all the cases the adsorption of Cr(VI) decreased with increasing pH. The hexavalent chromium speciation and its presence as different oxyanions, according to the solution pH, were the main variables affecting the adsorption process. The influence of the ratio soil/solution concentration was also studied in flow systems at pH 2. Chromium retention increased with the increasing of its concentration in the influent solution. A two-site adsorption model was fitted to the breakthrough curves of hexavalent chromium solutions in order to estimate the Freundlich (k(F)) and Langmuir (S(max)) adsorption parameters, using CXTFIT code. These values were compared to those determined by batch tests and it was concluded that batch tests tended to underestimate these parameters. Nevertheless, they followed the same trend as the parameters determined in opened system, even when the pH of the initial solution was modified.

Treatment of chromium(VI) solutions in a pilot-scale bioreactor through a biofilm of Arthrobacter viscosus supported on GAC.

The aim of this work is to evaluate the applicability of a biofilm to the removal of chromium in solution, at a pilot scale. The effect of the initial concentration of metal on the biosorption behavior of an Arthrobacter viscosus biofilm supported on granular activated carbon, in batch and column essays was also analyzed. Six isotherm equations have been tested in the present study. The best fit was obtained with the Freundlich model. It was observed that as the initial chromium concentration increases, the uptake increases too, but the removal percentage decreases, with values between 95.20% (C(0)=5mg/l) and 38.28% (C(0)=1000 mg/l). The batch adsorption studies were used to develop a pilot bioreactor able to remove chromium from aqueous solutions. Data obtained in a pilot-scale reactor showed an average removal percentage of 99.9%, during the first 30 days, for the initial concentration of 10mg/l and an average removal percentage of 72%, for the same period and for the initial concentration of 100mg/l. Uptake values of 11.35 mg/g and 14.55 mg/g were obtained, respectively, for the initial concentration of 10 and 100mg/l. The results obtained are very promising and encourage the utilization of this biofilm in environmental applications.

Biosorption of Cr(VI) by three different bacterial species supported on granular activated carbon: a comparative study.

The ability of three different bacterial species supported on granular activated carbon (GAC) to remove hexavalent chromium from low concentration liquid solutions was investigated, in batch and column studies. The microorganisms tested were Cr(VI) reducing types: Streptococcus equisimilis (CECT 926), Bacillus coagulans (CECT 12) and Escherichia coli (CECT 515). The results showed metal uptake values of 5.82, 5.35 and 4.12 mg/g(bios.), respectively, for S. equisimilis, B. coagulans and E. coli, for an initial metal concentration of 100 mg/l. In the same order and for the initial concentration of 50 mg/l, metal uptake values were 2.33, 1.98 and 3.60 mg/g(bios.). Finally, for the initial metal concentration of 10 mg/l, those values were, respectively, 0.66, 1.51 and 1.12 mg/g(bios.). Studies made with an industrial effluent, with the aim of testing these biofilms in a real situation, showed values of Cr uptake of 0.083, 0.090 and 0.110 mg/g(bios.), respectively, for S. equisimilis, B. coagulans and E. coli, for an initial concentration of 4.2 mg/l of total Cr. The quantification of polysaccharides, playing a key role in the whole process, was made and it was concluded that the production of polysaccharides is higher for B. coagulans followed by S. equisimilis and E. coli (9.19, 7.24 and 4.77 mg/g(bios.)). The batch studies data were described using the Freundlich, Langmuir, Redlich-Peterson, Dubinin-Radushkevich, Sips and Toth model isotherms. The best fit was obtained with Sips and Toth model isotherms, respectively, for the S. equisimilis and for the B. coagulans biofilms. For the E. coli biofilm the Freundlich, Redlich-Peterson, Sips and Toth models fitted very well to the experimental data. The Adams-Bohart, Wolborska and Yoon and Nelson models were applied to column studies data. Those models were found suitable for describing the dynamic behaviour of the columns with respect to the inlet chromium concentration. Obtained results showed that the biofilms tested are very promising for the removal of Cr(VI) in diluted industrial wastewater. Despite differences in the cell wall structure and composition, the three bacteria exhibit comparable sorption affinities towards chromium, in the open systems studies. The Gram-positive bacteria tested (B. coagulans and S. equisimilis) presented best metal removal percentages in batch studies.

Purification and characterization of a new lectin from the red marine alga Hypnea musciformis.

A lectin from the red marine alga Hypnea musciformis (HML) was purified by extraction with 20 mM PBS, precipitation with 70% saturated ammonium sulphate, ion-exchange DEAE-Cellulose chromatography and RP-HPLC. The 9.3 kDa polypeptide agglutinates erythrocytes from various sources and shows oligomerization tendencies under certain MALDI-TOF/MS conditions. Preliminary N-terminal sequencing and biological assays strongly suggest that the HML may belong to a new class of algae lectins.

Leprosy elimination campaign, Amazonas-Brazil 1997.

A leprosy elimination campaign (LEC) was carried out in 15 endemic areas of Amazonas State, Brazil, in 1997. The LEC concentrated effort to detect leprosy cases during a multi-vaccination national campaign for serious public health problems other than leprosy, such as polio, diphtheria, hepatitis, measles, etc. The national campaign involved intensive population mobilization, giving a valuable opportunity to examine people for leprosy. The LEC personnel included 2964 individuals (municipal and state health workers and community volunteers), distributed in 688 health units and 53 reference health centres. As a result of the LEC, 74,814 person-to-person communications in the community were given; 10,297 clinical skin examinations were conducted, and 40 new leprosy cases were detected on the day of the campaign in urban areas of the municipalities. This total was low, compared to results in other states of Brazil, possibly due to the development of health education activities and regular community services in the state of Amazonas since 1987 and to the early implementation of WHO multiple drug therapy (MDT) from 1982 onwards. Despite the fact that the LEC was carried out only in the urban areas of the municipalities, the finding of no cases of leprosy in 7 out of 15 of them was surprising and may indicate that the prevalence of hidden cases of leprosy is not all that high, at least in these areas of the Amazonas State.