Frecuencia de alteraciones citológicas cervicales y virus papiloma humano en una muestra de estudiantes universitarias en Temuco, Chile / Frequency of cervical cytological alterations and human papilloma virus in a sample of university students in Temuco, Chile

Resumen Introducción: El inicio precoz de actividad sexual puede favorecer el desarrollo de alteraciones cervicales y de infecciones de transmisión sexual, en especial del virus papiloma humano (VPH) muy frecuente en adolescentes y jóvenes. Objetivo: Analizar el estado del cuello uterino, presencia del VPH y conductas sexuales en mujeres menores de 25 años. Material y Métodos: Participaron 182 estudiantes universitarias de 18-24 años, sanas, sexualmente activas y no vacunadas para VPH. Se realizó Papanicolaou (Pap) y clasificación del VPH en alto y bajo riesgo (AR y BR) mediante reacción de polimerasa en cadena en tiempo real. Las conductas sexuales fueron consultadas privadamente. Resultados: El 46,9% de los Pap presentaron alteraciones citológicas (inflamación inespecífica/hemorrágico: 29,4% y frotis atípicos (FA):10,2%). La frecuencia de los VPH-AR fue 24,3%; de éstos, 67,4% presentó un Pap alterado. Hubo asociación entre alteraciones citológicas y presencia de VPH (p < 0,0001) y años de actividad sexual y FA o neoplasia intraepitelial grado I (NIE I) (p = 0,009). El 11,9% de las jóvenes estudiadas (21/177) presentó FA o NIE I, con 66,7% de casos VPH-AR. Conclusiones: Estos hallazgos alertan la vulnerabilidad de estas jóvenes que tendrían un riesgo potencial de persistencia viral, NIE y eventualmente cáncer. Es importante enfatizar consejería y prevención previo a la edad normada de ingreso al programa de cribado para cáncer cérvico uterino en Chile.

Background: The early onset of sexual activity can promote the development of cervical alterations and sexually transmitted infections, especially the human papillomavirus (HPV) very common in adolescents and young people. Aim: The condition of the cervix, HPV and sexual behavior in young women under 25 years of age were analyzed. Methods: 182 university students, healthy, sexually active, 18-24 years old, without vaccine for HPV participated. Papanicolaou (Pap) test and classification of high and low risk HPV (HR and LR) were performed by real time polymerase chain reaction. The sexual behaviors were consulted in private. Results: The 46.9% of Pap presented cytological alterations, non-specific inflammation/hemorrhagic (29.4%) and atypical smear (10.2%) being de most frequent. The overall frequency of HPV-HR was 24.3%, of these 67.4% presented an altered Pap. There was an association between cytological alterations and HPV (p < 0.0001) and years of sexual activity and atypical smear or cervical intraepithelial neoplasia grade I (CIN I) (p = 0.009). 11.9% of young women (21/177) presented atypical smear or CIN I, with 66.7% of cases HPV-HR. Conclusions: These findings alert the vulnerability of these young women who would have a potential risk of viral persistence, CIN and eventually cancer. It is important to emphasize counseling and prevention prior to the regular age of admission to the screening program for cervical cancer. This study was financed by the Universidad de La Frontera through Projects DI15-0047 and DI17-0123.

Virus papiloma humano y Chlamydia trachomatis según número de parejas sexuales y tiempo de actividad sexual en estudiantes universitarias en la Región de La Araucanía, Chile / Human papilloma virus and Chlamydia trachomatis by number of sexual partners and time of sexual activity on university students in the Region of La Araucanía, Chile

Introducción: El virus papiloma humano (VPH) y Chlamydia trachomatis son las infecciones de transmisión sexual (ITS) más frecuentes, en adolescentes y jóvenes, con factores de riesgo: vida sexual activa y múltiples parejas. Chlamydia trachomatis puede favorecer el ingreso de VPH y éste el desarrollo del cáncer cérvico uterino. Ambas infecciones pueden dejar secuelas en la salud sexual y reproductiva. Objetivo: Determinar frecuencias VPH y C trachomatis en estudiantes universitarias asinto-máticas bajo 25 años, asociándolas con número de parejas sexuales (n°PSx) y tiempo de actividad sexual (TASx). Material y Método: Se procesaron 151 muestras/exo y endo cervicales para VPH y C. trachomatis, mediante reacción de polimerasa en cadena convencional y en tiempo real. Resultados: La frecuencia fue: VPH 21,8%, C. trachomatis 11,2% y co-infección 4,6%. De las jóvenes con infección por VPH, 80,6% presentó VPH alto riesgo oncogénico. El n°PSx se asoció fuertemente a VPH. Entre las jóvenes con co-infección VPH/C. trachomatis, 71,4% tenían tres o más PSx. Según TASx, C. trachomatis fue más frecuente (64,7%) entre 3-5 años que VPH. Conclusión: Se observó alta prevalencia de VPH y C trachomatis. Mujeres jóvenes con co-infección VPH/C. trachomatis podrían ser un grupo de alto riesgo con necesidad de mo-nitorear sus infecciones. Es sugerida la implementación de programas universitarios en educación, orientación y prevención en ITS.

Background: Human papilloma virus (HPV) and Chlamydia trachomatis are the most prevalent sexually transmitted infections (STIs), among teenagers and young people, with risk factors: active sex life and multiple partners. Chlamydia trachomatis infection may favor HPV infection and this, the development of cervical cancer. Both infections can lead to consequences on sexual and reproductive health. Objective: To determine frequency of HPV and C. trachomatis in asymptomatic university women less than 25 years, associating them with number of sexual partners (n°SxP) and time of sexual activity (TSxA). Material andMethods: 151 cervical samples for HPV and C. trachomatis, were processed by conventional and in real time reaction polymerase chain. Results: HPV 21, 8%, C. trachomatis 11, 2% and co-infection (HPV/C.trachomatis), 4.6%. Aimong HPV +, 80, 6% showed high risk HPV. The n°SxP was strongly associated with HPV. Aimong young coinfected HPV/C. trachomatis, 71.4% had 3 or more PSx. Chlamydia trachomatis was more frequent (64,7%) that HPV within range of 3-5 years according to the TSxA, Discussion: A high prevalence of HPV and C. trachomatis was observed. Young women with coinfection HPV/C. trachomatis could be a high-risk group need to monitor their infections. It suggests the implementation of university programs in education, counseling and prevention in sexual health.

Eficacia del diagnóstico diferencial de tuberculosis mediante reacción de polimerasa en cadena en lesiones granulomatosas de tejidos fijados en formalina e incluidos en parafina / Efficacy of PCR for the differential diagnosis of tuberculosis in granulomatous lesions of paraffin-embedded formalin fixed tissues

Background: Granulomatous lesions occur in tuberculosis (TB), other infections, toxic, allergic, and autoimmune diseases among others. In absence of a an acid-fast bacilli (AFB) confirmation of TB is necessary. Objective: To assess the efficacy of PCR for TB detection and to correlate with granuloma histology and AFB staining. Methods: We analyzed 380 fixed paraffin-embedded tissues (PETs) of granulomas with and without caseous necrosis; suppurative; sarcoidal; or of chronic nonspecific nature. Nested PCR-IS6110 for Mycobacterium tuberculosis complex (MTB) and a nested pan-Mycobacterium for the hsp65 gene were used for Mycobacterium spp detection. Results: PCR was more sensitive than AFB staining for all five catageories of granulomas: G1: PCR 71%, AFB staining 28%. G2: PCR 37%, AFB 8%. G3: PCR 17%, AFB staining 7%. G4: PCR 8%, AFB staining 4%. G5: PCR 6%, AFB staining 0%. Conclusions: Molecular diagnosis of TB using PCR-based testing is a fast, efficacious and sensitive method that increased the accuracy of PET histological diagnosis associated with granulomatous lesions.

Introducción: Lesiones granulomatosas ocurren en tuberculosis (TBC), otras infecciones, condiciones tóxicas, alérgicas y autoinmunes, entre otras. Con baciloscopia negativa, es necesario confirmar el diagnóstico de TBC. Objetivo: Evaluar la eficacia de la RPC para detectar TBC comparado con baciloscopia en relación a la histología del granuloma. Métodos: Analisis de 380 tejidos fijados en formalina e incluidos en parafina (TFFP) con diferentes tipos de granulomas: con necrosis caseosa; sin necrosis caseosa; supurativo; sarcoidal; a cuerpo extraño/inespecífico. Utilizamos RPC anidada-IS6110 para detección del complejo Mycobacterium tuberculosis (MTB) y una pan-RPC anidada-hsp65 para Mycobacterium spp. Resultados: La detección de TBC mediante RPC fue significativamente superior a baciloscopia en los cinco tipos de granuloma: G1: RPC 71%, baciloscopia 28%; G2: RPC 37%, baciloscopia 8%; G3: RPC 17%, baciloscopia 7%; G4: RPC 8%, baciloscopia 4%; G5: RPC 6%, baciloscopia 0%. Conclusión: El diagnóstico de TBC por RPC es un método rápido, eficaz y de gran sensibilidad, que aumenta la precisión del diagnóstico diferencial de lesiones granulomatosas de TFFP procesados rutinariamente en histopatología.

Detección de norovirus en niños con diarrea adquirida en la comunidad o nosocomial en el Hospital Guillermo Grant Benavente de Concepción, Chile / Norovirus detection in children with community-acquired or nosocomial diarrhea at Guillermo Grant Benavente Hospital in Concepción, Chile

Introduction: Norovirus (NoV) are RNA viruses highly contagious, stable in the environment, genetically variable, and the most common cause of viral sporadic acute gastroenteritis worldwide. This is the first study carried out in Concepcion, Chile, to investigate the presence of NoV as an etiologic agent of viral diarrheas in hospitalized children. Objective. To detect the presence and genogroup of NoV in children with diarrhea and to compare it with rotavirus (RV) and adenovirus (AdV). Material and Methods: A one year descriptive, prospective study in children 0-14 years old. A single diarrheic stool sample per patient was analyzed for the presence of NoV, RV and AdV. Clinical data were unknown at the moment of sampling. Real time RT-PCR with Taqman™ probes for NoV and the immunocromatography VIKIA™ kit for RoV /AV detection were used. Results: Infection for NoV (25.5%) was significantly higher than for RV (15.9%) and AdV (6.2%). It was even greater in infants younger than 2yr. old (n: 103): NoV 34%, RV 17.5%, AdV 7.8%. Children 2-4 yr. old had 11.8% infection of NoV and RV. Children older than 4, only had 12% RV and 4% AdV. Children hospitalized for diarrhea (n: 92) had: 21.7% of both NoV and RV, and 7.6% AdV; whereas children hospitalized for other causes (n: 53) had 32.1% NoV,5.7% RV and 3.8% AV. The proportion of infection due to NoV was significantly higher in males (31.5%) than in females (19.4%). The average frequency during the year was higher for NoV (30.3%) than for RV (14.7%) except in summer. Conclusion: The presence of NoV was higher than RV in children with diarrhea. NoV infection showed defined characteristics regarding age, gender, seasonal occurrence and nosocomial transmission that are important epidemiological features.

Introducción: Los norovirus (NoV) son virus ARN altamente contagiosos, resistentes, variables genéticamente y una de las etiologías más frecuente de gastroenteritis viral esporádica mundial. Este es el primer trabajo en Concepción, Chile, de búsqueda de NoV como etiología viral de diarreas en niños hospitalizados. Objetivo: Determinar la presencia y genogrupo de NoV en niños con diarrea y compararla con la frecuencia de rotavirus (RV) y adenovirus (AdV). Material y Método: Estudio descriptivo, prospectivo de un año, en niños de 0-14 años ingresados por diarrea aguda o que la adquirieron dentro del hospital. La muestra de deposiciones diarreica se tomó una sola vez por paciente. Las fichas clínicas se analizaron al finalizar el estudio etiológico. Para la detección de NoV se utilizó RPC-TR a en tiempo real con sondas Taqman® y para detección de RV/AdV, el kit VIKIA® de inmunocromatografia. Resultados: La infección por NoV (25,5%) fue significativamente más frecuente que por RV (15,9%) y AdV (6,2%). La mayor presencia de infección fue en pacientes bajo2 años de edad (n: 103): NoV 34,0%, RV 17,5%, AdV 7,8%. La detección en niños hospitalizados por diarrea fue: NoV y RV 21,7% cada uno; AdV 7,6%. En niños con diarrea nosocomial hospitalizados por otras causas se detectó NoV en 32,1%, RV en 5,7% y AdV en 3,8%. La presencia de NoV fue significativamente mayor en varones (31,5%) que en niñas (19,4%). El promedio de diarreas durante el año fue mayor para NoV (30,3%) que para RV(14,7%), excepto en verano. Discusión y Conclusión: La presencia de NoV fue mayor que la de RoV en niños con diarrea y con una tendencia nosocomial que podría deberse a las características del virus que favorece infecciones de ambiente confinado, como hospitales, asilos y cruceros. La infección por NoV presentó características definidas, en edad, género, ocurrencia estacional y relevancia nosocomial, que aportan datos epidemiológicos importantes.

Inestabilidad microsatelital en lesiones preneoplásicas y neoplásicas del cuello uterino: Correlación con el genotipo del virus papiloma humano / Microsatellite instability and human papilloma virus genotypes in preneoplastic and neoplastic uterine cervix lesions

Background: The association between some specific human papilloma virus (HPV) types and cervix cancer is well known. However, the genetic conditions that favor the development of cervical cancer are less well known. Aim: To determine the presence of satellite instability (MSI) in preneoplastic and neoplastic lesions of the cervix and correlate these findings with HPV genotypes. Material and methods: Biopsy samples of cervical lesions were studied. Sixteen had low grade lesions, 22 had high grade lesions and 28 had an epidermoid cancer. Viral types were identified with polymerase chain reaction, dot-blot hybridization and restriction fragment length polymorphism. MSI was determined using a panel of eight highly informative microsatellites. Results: Microsatellite instability in at least one locus was observed in 91, 56 and 69 percent of low grade lesions, high grade lesions and epidermoid carcinomas, respectively. MSI-High grade, MSI-Low grade instability and microsatellite stability were observed in 5, 60 and 46 percent of samples, respectively. Two of three samples with high grade instability had HPV 52 genotype. Other viral subtypes had frequencies that ranged from 78 percent to 100 percent, with the exception of HPV16 that was present in only 53 percent of samples with low grade instability. Conclusions: Two thirds of biopsy samples from cervical lesions had MSI, mechanism that can be involved in the first stages of cervical carcinogenesis. The low frequency of high grade instability, its association with HPV52 and the low frequency of HPV16 in samples with low grade instability, suggest different coadjutant mechanisms in cervical carcinogenesis

Detection of Giardia duodenalis antigen in human fecal eluates by enzyme-linked immunosorbent assay using polyclonal antibodies

The present study developed and standardized an enzime-linked immunosorbent assay (ELISA) to detect Giardia antigen in feces using rabbit polyclonal antibodies. Giardia cysts were purified from human fecal samples by sucrose and percoll gradients. Gerbils (Meriones unguiculatus) were infected to obtain trophozoites. Rabbits were inoculated with either cyst or trophozoite antigens of 14 Colombian Giardia isolates to develop antibodies against the respective stages. The IgG anti-Giardia were purified by sequential caprylic acid and ammonium sulfate precipitation. A portion of these polyclonal antibodies was linked to alkaline phosphatase (conjugate). One hundred and ninety six samples of human feces, from different patients, were tested by parasitologic diagnosis: 69 were positive for Giardia cysts, 56 had no Giardia parasites, and 71 revealed parasites other than Giardia. The optimal concentration of polyclonal antibodies for antigen capture was 40 æg/ml and the optimal conjugate dilution was 1:100. The absorbance cut-off value was 0.24. The parameters of the ELISA test for Giardia antigen detection were: sensitivity, 100 percent (95 percent CI: 93.4-100 percent); specificity, 95 percent (95 percent CI: 88.6-97.6 percent); positive predictive value, 91 percent (95 percent CI: 81.4-95.9 percent); and negative predictive value, 100 percent (95 percent CI: 96.1-100 percent). This ELISA will improve the diagnosis of Giardia infections in Colombia and will be useful in following patients after treatment