Estandarización de PCR en tiempo real para detección y cuantificación de los oncogenes E7 de seis Virus del Papiloma Humano de Alto Riesgo

El cáncer de cuello uterino es causado por la infección persistente del epitelio cervical con los genotipos de alto riesgo del Virus del Papiloma Humano. Para su detección se realizan pruebas moleculares que detectan el gen L1 del VPH. Este gen puede perderse hasta en el 11 % de los casos durante la integración del ADN viral en el genoma del hospedero originando falsos negativos. Por otra parte, el oncogén E7 se expresa durante todas las etapas de progresión de la enfermedad. El objetivo de este trabajo fue estandarizar una PCR en tiempo real del oncogén E7 (E7-qPCR) para genotipificación y cuantificación de 6 VPH-AR. Los resultados muestran que la E7- qPCR amplificó VPH-16, -18, -31, -33, -35 y -45 con una alta sensibilidad con límites de detección desde 102 copias, eficiencias entre 90 y 110 %, valores R2 > 0,97 y análisis de curva de fusión que revelan productos específicos.

Cervical cancer is caused by persistent infection of the cervical epithelium with the high-risk genotypes of the Human Papilloma Virus (HR-HPV). For its detection, molecular tests are carried out that detect the L1 gene of HPV. This gene can be lost in up to 11 % of cases during the integration of viral DNA into the host genome, causing false negatives. On the other hand, the E7 oncogene is expressed during all stages of disease progression. The aim of this work was to standardize a real-time PCR of the E7 oncogene (E7-qPCR) for genotyping and quantification of 6 HR-HPV. The results show that the E7-qPCR amplified HPV-16, -18, -31, -33, -35 and -45 with high sensitivity with detection limits from 102 copies, efficiencies between 90 and 110 %, R2 values >0,97 and melting curve analysis revealing specific products.

A Novel Strategy for Cervical Cancer Prevention Using Cervical-Vaginal Self-Collected Samples Shows High Acceptability in Women Living in Low-Income Conditions from Bucaramanga, Colombia.

INTRODUCTION: Human papillomavirus molecular detection prevents cervical cancer (CC). To widen its use, cervical-vaginal self-collection devices are proposed. Our aim was to determine the acceptability of self-sampled cervical-vaginal protocol and the reproducibility of results using HPV detection brushes in a low-income Colombian population between 35 and 65 years old. METHODS: Cross-sectional study including women classified as medium to high-risk for developing CC by using a short-standardized survey. After receiving instructions, women self-collected a cervical-vaginal sample. Subsequently, a perception survey was conducted. RESULTS: Four hundred and twenty-three women performed self-collected sampling. The median age was 46.5 years (IQR 40-52), 56.5% were housewives, and 55.1% had finished elementary school. About 99% of the population (n=419) considered that they understood the instructions, 19.4% (n=82) reported having concerns about the self-collected sample, 9.2% (n=39) distrusted the results because of the self-collection, 7.3% (n=31) felt uncomfortable with the procedure, and 9.7% (n=41) reported some pain. The majority would recommend the procedure to others (99%), 88.5% of the sampled population preferred the self-collected method, 4% preferred conventional cytology, and 7.3% were not sure. The reasons behind favoring the self-collected procedure included privacy (n= 149, 40.1%), comfort (n=110, 29.7%), easiness (n=52, 14%), reliability (n=46, 12.4%), and less painful (n=110, 29.7%). The percentage of HPV detection agreement between the self-collected and the healthcare professional-collected procedures was 98.99% (Cohen's Kappa=0.9774). CONCLUSION: Women living in low-income households in Bucaramanga, Colombia preferred the self-sampling procedure because it was easy to use, convenient, and private, resulting in 98% acceptability, and positioning it as an excellent tool for CC prevention.

Correction to 'Complex ecological interactions across a focus of cutaneous leishmaniasis in Eastern Colombia: novel description of Leishmania species, hosts and phlebotomine fauna'.

[This corrects the article DOI: 10.1098/rsos.200266.].

Complex ecological interactions across a focus of cutaneous leishmaniasis in Eastern Colombia: novel description of Leishmania species, hosts and phlebotomine fauna.

This study aimed to analyse the patterns of diversity, blood sources and Leishmania species of phlebotomines in a focus of cutaneous leishmaniasis in Arboledas, Eastern Colombia. In total, 1729 phlebotomines were captured in two localities (62.3% Siravita and 37.7% Cinera) and five environments of Norte de Santander. We identified 18 species of phlebotomines: Pintomyia ovallesi (29.8%), Psychodopygus davisi (20.3%), Pi. spinicrassa (18.5%) and Lutzomyia gomezi (15.8%) showed the highest abundance. Species diversities were compared between Cinera (15.00) and Siravita (20.00) and among five microenvironments: forest remnants (19.49), coffee plantations (12.5), grassland (12.99), cane plantations (11.66) and citrus plantations (12.22). Leishmania DNA was detected in 5.8% (80/1380) of females, corresponding mainly to Pi. ovallesi (22/80; 27.2%), Lu. gomezi (17/80; 21.3%) and Pi. spinicrassa (11/80; 13.8%). Leishmania species were 63.1% L. braziliensis, 18.5% L. panamensis, 13.2% L. infantum and 6.1% L. amazonensis. The most frequent feeding sources were Homo sapiens (50%), Bos taurus (13.8%) and Canis lupus familiaris (10.3%). This focus of cutaneous leishmaniasis has a high diversity of Leishmania-carrying phlebotomines that feed on domestic animals. The transmission of leishmaniasis to human hosts was mainly associated with Lu. gomezi, Pi. ovallesi and L. braziliensis.

Effect of El Niño Southern Oscillation cycle on the potential distribution of cutaneous leishmaniasis vector species in Colombia.

Local anomalies in rainfall and temperature induced by El Niño and La Niña episodes could change the structure of the vector community. We aimed to estimate the effect of the El Niño-La Niña cycle in the potential distribution of cutaneous leishmaniasis (CL) vector species in Colombia and to compare the richness of the vectors with the occurrence of CL in the state of Norte de Santander. The potential distributions of four species were modeled using a MaxEnt algorithm for the following episodes: La Niña 2010-2011, Neutral 2012-2015 and El Niño 2015-2016. The relationship between the potential richness of the vectors and the occurrence of CL in Norte de Santander was evaluated with a log-binomial regression model. During the El Niño 2015-2016 episode, Lutzomyia ovallesi and Lutzomyia panamensis increased their distribution into environmentally suitable areas, and three vector species (Lutzomyia gomezi, Lutzomyia ovallesi and Lutzomyia panamensis) showed increases in the range of their altitudinal distribution. During the La Niña 2010-2011 episode, a reduction was observed in the area suitable for occupation by Lutzomyia gomezi and Lutzomyia spinicrassa. During the El Niño 2015-2016 episode, the occurrence of at least one CL case was related to a higher percentage of rural localities showing a richness of vectors = 4. The anomalies in rainfall and temperature induced by the episodes produced changes in the potential distribution of CL vectors in Colombia. In Norte de Santander, during Neutral 2012-2015 and El Niño 2015-2016 episodes, a higher probability of at least one CL case was related to a higher percentage of areas with a greater richness of vectors. The results help clarify the effect of the El Niño-La Niña cycle in the dynamics of CL in Colombia and emphasize the need to monitor climate variability to improve the prediction of new cases.

Health-Related Quality of Life after Dengue Fever, Morelos, Mexico, 2016-2017.

We adapted the EQ-5D-3L questionnaire and visual analog scale to assess health-related quality of life (HRQOL) and persistent symptoms in 79 patients with laboratory-confirmed dengue in Morelos, Mexico. The lowest HRQOLs were 0.53 and 38.1 (febrile phase). Patients recovered baseline HRQOL in ≈2 months.

Persistence of symptoms in dengue patients: a clinical cohort study.

BACKGROUND: Dengue is commonly considered an acute illness and follows three phases: febrile, critical in some cases and recovery. However, a number of studies have described a continuation of dengue symptoms for weeks or months, extending the recovery phase. Here we evaluate this persistence of dengue symptoms during convalescence. METHODS: Our clinical cohort study included patients who sought medical services 48 to 144 h from the onset of fever at seven hospitals or ambulatory centers in Morelos, Mexico. Seventy-nine laboratory-confirmed dengue patients were followed up regularly using clinic and/or home visits and telephone calls for as long as symptoms persisted or up to 6 mo. RESULTS: In total, 55.7% of patients had dengue-related symptoms 1 mo after the onset of fever; pain and dermatological manifestations were the most common persistent symptoms. Prognostic factors for symptom persistence were: ≥4 d of fever (RR 1.72; 95% CI 1.35 to 2.19), platelet count ≤100 000/mm3 (RR 1.20; 95% CI 1.20 to 2.20), petechiae/bruises (RR 1.97; 95% CI 1.56 to 2.48) and abdominal pain/hepatomegaly (RR 1.79; 95% CI 1.41 to 2.28). CONCLUSIONS: Persistence of dengue symptoms were common in laboratory-confirmed dengue patients. Manifestations related to tissue damage were associated with persistence after 30 d; host characteristics, such as age and health status before infection, were associated with prolonged persistence (>60 d). The burden of dengue may be higher than previously estimated.

Genotipificación del Virus de Papiloma Humano en mujeres de la comuna norte de Bucaramanga / Genotypification of Human Papilloma Virus in women of the comuna Norte de Bucaramanga

Resumen Introducción: La infección persistente con Virus de Papiloma Humano de alto riesgo es causa necesaria para la aparición de cáncer de cérvix. Objetivo: Caracterizar molecularmente los genotipos circulantes de Virus de Papiloma Humano en población de la zona Norte de Bucaramanga. Métodos: Estudio de corte transversal en mujeres de 35 a 65 años con riesgo ≥3 puntos para desarrollar cáncer de cérvix determinado por una encuesta estandarizada. En una muestra cervico-vaginal por autotoma se realizaron pruebas moleculares por tecnología HPV Direct Flow CHIP. Resultados: Se encuestaron 810 mujeres, de éstas 435 (53,7%) se realizaron auto-toma por el riesgo presentado. La mediana de edad fue de 47,3 años (RIQ 41-53 años). Casi la totalidad de la población reside en estrato 1 y 2 (98,8%) y en su mayoría son del régimen subsidiado (87,2%). La prevalencia de infección fue de 10,6% (IC 95%: 7,8 - 13,8), para genotipos de alto riesgo fue de 3,9% (IC 95%: 2,3 - 6,2), de bajo riesgo de 3,5% (IC 95%: 1,4 - 5,6) y para genotipo indeterminado de 1,9%. El genotipo de alto riesgo más común fue VPH-59 y de bajo riesgo fue VPH-62/81. Hubo coinfección con genotipos alto/bajo riesgo en cinco mujeres y coinfección con dos genotipos de bajo riesgo en una mujer. Conclusión: la prevalencia de infección por Virus de Papiloma Humano en mujeres que habitan en zonas vulnerables de Bucaramanga es menor a la reportada en Bogotá y Cali (14,9% y 13%, respectivamente). No se encontró predominio de ningún genotipo de alto riesgo en particular.

Abstract Introduction: Persistent infection with high-risk Human Papilloma Virus is a necessary cause for the appearance of cervical cancer. Objective: Molecularly characterize circulating genotypes of Human Papilloma Virus in population of the north of Bucaramanga. Methods: Cross-sectional study in women aged from 35 to 65 years with risk ≥3 points for develop cervical cancer determined by a standardized survey. In a cervico-vaginal self-sampling probe a molecular test was performed by HPV Direct Flow CHIP technology. Results: 810 women were interviewed, of these 435 (53.7%) performed self-sampling due to the risk calculated. The median age was 47.3 years (RIQ 41-53 years). Almost the entire population resides in poor conditions (stratum1 and 2) (98.8%) and most of them are from the Colombian subsidized social security system (87.2%). The prevalence was 10.6% (CI 95%: 7.8 - 13.8), for high risk genotypes it was 3.9% (CI 95%: 2.3 - 6.2), low risk of 3.5% (CI 95%: 1.4 - 5.6) and for indeterminate genotype of 1.9%. HPV-59 was the most common high-risk genotype and HPV-62/81 was a low-risk genotype. There was coinfection with high risk / low risk genotypes in five women and coinfection with two low risk genotypes in a woman. Conclusion: The prevalence of infection by Human Papilloma Virus in women living in vulnerable areas of Bucaramanga is lower than that reported in Bogotá and Cali (14.9% and 13%, respectively). No predominance of any particular high-risk genotype was found.

Determinants of felt demand for dengue vaccines in the North Caribbean region of Colombia.

BACKGROUND: The increasing burden associated with dengue in Latin America makes it essential to understand the community's interest in acquiring vaccines, as an input to plan its introduction in endemic regions. The objective of this study is to learn the felt demand for dengue vaccines by estimating the willingness to pay and its associated factors in endemic communities of the North Caribbean region of Colombia. METHODS: A population survey was administered from October to December 2015, including 1037 families in 11 municipalities in Colombia. One adult per family was interviewed on their perception and history of dengue. Participants received a description of four hypothetical scenarios of dengue vaccines, administered in a single dose or in 3 doses, with an effectiveness of 70% for 5 years or 95% for 30 years. The willingness to pay for each one of these vaccines was inquired vs. 5 hypothetical prices in Colombian pesos. RESULTS: Most participants recognized dengue as a serious disease in children (99.3%) and adults (98.6%). 33 (3.2%) of the total respondents reported having suffered dengue and 19 (57.6%) of them required hospitalization. The price of the vaccine was inversely related to the willingness to pay. In addition, single dose vaccines (compared to 3 doses) and one with a protection of 95% for 30 years (compared to an effectiveness of 70% for 5 years), were associated with greater willingness to pay. Greater willingness to pay was observed among the respondents who considered it likely to get the disease, either themselves (OR 1.56; CI 95% 1.08-2.26) or their children (OR 1.89; CI 95% 1.28-2.81), in the next 5 years. The participants who have been diagnosed with dengue also showed greater willingness to pay (OR 1.89; CI 95% 1.01-3.54) compared to those who did not have this history. CONCLUSION: Factors such as price, number of doses and effectiveness can independently influence the decision to purchase a vaccine against an endemic disease, such as dengue. Additionally, this study reveals that background and perceptions of the disease can affect individuals' interest in acquiring this type of preventive interventions.

Day-to-Day Population Movement and the Management of Dengue Epidemics.

Dengue is a growing public health problem in tropical and subtropical cities. It is transmitted by mosquitoes, and the main strategy for epidemic prevention and control is insecticide fumigation. Effective management is, however, proving elusive. People's day-to-day movement about the city is believed to be an important factor in the epidemiological dynamics. We use a simple model to examine the fundamental roles of broad demographic and spatial structures in epidemic initiation, growth and control. We show that the key factors are local dilution, characterised by the vector-host ratio, and spatial connectivity, characterised by the extent of habitually variable movement patterns. Epidemic risk in the population is driven by the demographic groups that frequent the areas with the highest vector-host ratio, even if they only spend some of their time there. Synchronisation of epidemic trajectories in different demographic groups is governed by the vector-host ratios to which they are exposed and the strength of connectivity. Strategies for epidemic prevention and management may be made more effective if they take into account the fluctuating landscape of transmission intensity associated with spatial heterogeneity in the vector-host ratio and people's day-to-day movement patterns.

Persistent Symptoms of Dengue: Estimates of the Incremental Disease and Economic Burden in Mexico.

Dengue is mostly considered an acute illness with three phases: febrile, critical with possible hemorrhagic manifestations, and recovery. But some patients present persistent symptoms, including fatigue and depression, as acknowledged by the World Health Organization. If persistent symptoms affect a non-negligible share of patients, the burden of dengue will be underestimated. On the basis of a systematic literature review and econometric modeling, we found a significant relationship between the share of patients reporting persisting symptoms and time. We updated estimates of the economic burden of dengue in Mexico, addressing uncertainty in productivity loss and incremental expenses using Monte Carlo simulations. Persistent symptoms represent annually about US$22.6 (95% certainty level [CL]: US$13-US$29) million in incremental costs and 28.2 (95% CL: 21.6-36.2) additional disability-adjusted life years per million population, or 13% and 43% increases over previous estimates, respectively. Although our estimates have uncertainty from limited data, they show a substantial, unmeasured burden. Similar patterns likely extend to other dengue-endemic countries.

Contrasting associations of polymorphisms in FcγRIIa and DC-SIGN with the clinical presentation of dengue infection in a Mexican population.

Dengue virus (DENV) causes a spectrum of illness from asymptomatic infection, to a mild febrile illness, to occasional more severe complications including hemorrhage and shock. Dengue is endemic in the state of Morelos, Mexico. Two single nucleotide polymorphisms (SNPs), rs1801274 of FcγRIIa and rs4804803 of DC-SIGN, have been associated with protection from or susceptibility to severe dengue infection. Both of these polymorphisms are located in genes for receptors with important roles in dengue pathogenesis, and their relationship with the clinical presentation of dengue infection in Mexican populations is unknown. In this study, real-time PCR was used to characterize the distribution of rs1801274 and rs4804803 in subjects with asymptomatic dengue infection (n=145), uncomplicated dengue (n=67), and severe dengue (n=36) in Morelos. In contrast with previous studies, the histidine (A) variant of rs1801274 was associated with more mild infection: carrying the histidine allele (either homozygous or heterozygous) was associated with protection from symptomatic infection compared with asymptomatic (OR 0.51, p=0.038). Histidine homozygotes were also less likely to present severe dengue (OR 0.34, p=0.05). Logistic regression models confirm this association (OR 0.48, p=0.04) and also indicate that the G allele of rs4804803 is associated with symptomatic dengue (OR 2.3, p=0.08), after accounting for other biological factors including history of infection. This variant was rare in this study population, with a frequency of 5.4%. These findings reflect the complexity of influences on the development of severe dengue infection. The inclusion of asymptomatic infections and adjusted case definitions likely do not explain the entire disparity with previous findings. Interactions with other polymorphisms may explain why the association of rs1801274 is reversed in this population compared to others. This study demonstrates the importance of genetic association studies in multiple genetically distinct populations.

Validez y confiabilidad de un instrumento de satisfacción del usuario con síndrome febril agudo / The validity and reliability of an instrument for measuring the satisfaction of users suffering from acute febrile syndrome

Objetivo Determinar la validez y la confiabilidad de un instrumento de satisfacción del paciente con Síndrome Febril Agudo en urgencias y consulta oportuna de la Red Pública de Bucaramanga. Métodos Estudio de evaluación de tecnologías diagnósticas en personas con Síndrome Febril Agudo entre el 2008 y 2009. Se diseñó un cuestionario telefónico a partir de 3 instrumentos en español. Se evaluó validez de contenido mediante sometimiento a expertos y a profesionales de salud y validez facial en una prueba piloto con 30 usuarios. La reproducibilidad fue realizada por dos enfermeras independientemente en 19 encuestas. Resultados Se realizaron 146 encuestas, de estas 75.3 por ciento fueron contestadas por mujeres, 33.6 por ciento por los mismos pacientes y 52.7 por ciento por las madres de estos cuando eran menores de 15 años. Se realizó análisis factorial obteniendo 3 factores: satisfacción con la atención médica, de enfermería y la organización del centro; al modelo final entraron 16 de 26 ítems. El alfa de Cronbach para cada factor fue 0,89 (IC 95 por ciento: 0,86;0,93), 0,78 (IC95 por ciento: 0.67;0.84) y 0,88 (IC95 por ciento: 0.85;0.91) respectivamente; el coeficiente de kappa fue 0.90 (IC95 por ciento: 0.77;0.97) y el coeficiente de correlación intraclase fue 0.955 (IC95 por ciento: 0.862;0.986) El promedio de las diferencias en la sumatoria de los ítems fue -1.3 (DS: 8,5) y los límites de acuerdo de Bland y Altman fueron -18.9 y 15.3. Discusión Este estudio demuestra validez y confiabilidad del instrumento de satisfacción de usuarios de los servicios de urgencias y consulta oportuna y podría aplicarse en la red pública del sistema de salud Colombiano.

Objective Determining the validity and reliability of a user satisfaction instrument applied to patients attending the emergency department and clinic who were suffering from acute febrile syndrome in Bucaramanga's Public Health Network. Methods A diagnostic technology assessment study was conducted between 2008 and 2009 on patients suffering from acute febrile syndrome. A telephone questionnaire was designed using 3 instruments. Content validity was assessed by experts and health professionals and face validity was assessed in a pilot study involving 30 users. Reproducibility was tested in questionnaires independently applied by two nurses to 19 patients. Results Data from 146 surveys was collected; 75.3 percent were answered by women, 33.6 percent were patients and 52.7 percent were their mothers when patients were under 15. Three factors were identified from factor analysis: satisfaction with medical care, nursing and medical centre organisation. The final model included 16 of the 26 items. Cronbach's Alpha for each factor was 0.89 (0.86-0.93 95 percentCI), 0.78 (0.67- 0.84 95 percentCI) and 0.88 (0.85-0.91 95 percentCI), respectively. The Kappa coefficient was 0.90 (0.77-0.97 95 percentCI) and intra-class correlation coefficient was 0.96 (0.86-0.99 95 percentCI). The average difference of the sum of all items was -1.3 (SD: 8.5) and Bland and Altman limits of agreement were -18.9 and 15.3, respectively. Discussion This study established the validity and reliability of a new instrument concerning user satisfaction used with patients suffering from acute febrile syndrome attending emergency health care which that could be applied in the Colombian Public Health System.

[The validity and reliability of an instrument for measuring the satisfaction of users suffering from acute febrile syndrome]. / Validez y confiabilidad de un instrumento de satisfacción del usuario con síndrome febril agudo.

OBJECTIVE: Determining the validity and reliability of a user satisfaction instrument applied to patients attending the emergency department and clinic who were suffering from acute febrile syndrome in Bucaramanga's Public Health Network. METHODS: A diagnostic technology assessment study was conducted between 2008 and 2009 on patients suffering from acute febrile syndrome. A telephone questionnaire was designed using 3 instruments. Content validity was assessed by experts and health professionals and face validity was assessed in a pilot study involving 30 users. Reproducibility was tested in questionnaires independently applied by two nurses to 19 patients. RESULTS: Data from 146 surveys was collected; 75.3 % were answered by women, 33.6 % were patients and 52.7 % were their mothers when patients were under 15. Three factors were identified from factor analysis: satisfaction with medical care, nursing and medical centre organisation. The final model included 16 of the 26 items. Cronbach's Alpha for each factor was 0.89 (0.86-0.93 95 %CI), 0.78 (0.67- 0.84 95 %CI) and 0.88 (0.85-0.91 95 %CI), respectively. The Kappa coefficient was 0.90 (0.77-0.97 95 %CI) and intra-class correlation coefficient was 0.96 (0.86-0.99 95 %CI). The average difference of the sum of all items was -1.3 (SD: 8.5) and Bland and Altman limits of agreement were -18.9 and 15.3, respectively. DISCUSSION: This study established the validity and reliability of a new instrument concerning user satisfaction used with patients suffering from acute febrile syndrome attending emergency health care which that could be applied in the Colombian Public Health System.

Pluviosidad como predictor de consulta por síndrome febril agudo en un área endémica de dengue / Rainfall and acute febrile syndrome in a dengue-endemic area

Objetivo Describir los patrones de consulta por SFA asociado al dengue y evaluar su asociación con la pluviosidad. Métodos En dos clínicas, durante un periodo de 7 meses (de marzo a septiembre) se identificaron 318 casos de SFA indiferenciado que se incluyeron en un seguimiento clínico sistemático. El 31 por ciento (81/281) fueron IgM positivos para dengue. Se evaluó la pluviosidad (litros/metro cuadrado por día) previa como variable explicatoria del patrón de consultas. Resultados Los meses con más casos de SFA fueron junio, julio y septiembre. Los casos de dengue sólo fueron significativamente más frecuentes en julio. Al evaluar los patrones de pluviosidad de las semanas anteriores, la consulta por SFA estuvo asociada con la pluviosidad promedio registrada 5 semanas antes y esta asociación fue independiente de la institución y del mes (Razón de tasas de incidencia ajustada: RTI=1,04; IC95 por ciento 1-1,08; p=0,045). Por otra parte, un promedio de la pluviosidad de 5 semanas consecutivas fue un predictor independiente de consulta por dengue, 4 semanas después (RTI=1,6; IC95 por ciento 1,15-2,22; p=0.006). Se evidenció una relación lineal entre la pluviosidad y las consultas por dengue: pluviosidad (promedio de 5 semanas) x 0,72 (IC95 por ciento 0,60-0,84; p<0,001)=casos por cada 100 000 habitantes en una semana (4 semanas después). Conclusiones La pluviosidad podría predecir el patrón de consulta por dengue en una región endémica.

Objective Describing patterns of acute febrile syndrome (AFS) consultation related to dengue and evaluating association with rainfall. Methods 318 undifferentiated AFS patients were detected in two clinics during a 7-month period (March to September) and then included in systematic clinical follow-up. 31 percent of them (81/281) were IgM positive for dengue. Rainfall (litres/square meter-day) during the previous weeks was evaluated as a variable for predicting consultation patterns. Results June, July and September were the months in which the greatest number of AFS cases occurred. Cases of dengue were only significantly more frequent during July. When evaluating the previous weeks' rainfall patterns, consultation for AFS was seen to be associated with the average rainfall registered 5 weeks beforehand and such association was independent of the institution and/or month (incidence rate ratio IRR=1,04; 1-1.08 95 percentCI, p=0.045). On the other hand, 5 consecutive weeks' average rainfall was an independent predictor of consultation for dengue 4 weeks later on (RTI=1 ,6 ; 1,15-2,22 95 percentCI, p=0.006). A linear relationship was thus proposed (regarding these sentinel clinics) between consultation for dengue and rainfall: lt/mt-day (5 weeks' average rainfall) X 0 ,72 (0,60-0,84 95 percentCI, p<0.001) = cases for each 100 000 habitants per week (4 weeks later). Conclusions: Studying rainfall could predict the pattern of consultation for dengue in endemic regions.