RESUMEN
OBJECTIVES: To determine the prevalence of high risk human papillomavirus (HPV) types in Nicaraguan women with histological proved pre-neoplastic and neoplastic cervical lesions, and to assess its potential impact on preventive strategies. METHODS: 206 women with histopathological confirmed cervical lesions (CIN I or worse) were screened for HPV DNA on a liquid based cytology sample, using an HPV short fragment polymerase chain reaction based assay. HPV positive samples were genotyped with a reverse hybridisation line probe assay (Lipa). HPV negative samples were re-analysed using type specific real time polymerase chain reaction. RESULTS: Of all lesions CIN II or worse, 12% tested negative. Prevalence of high risk HPV increased from 48.1% in cervical intraepithelial neoplasia I (CIN I) to 94.7% in invasive squamous cervical carcinoma (SCC). The most prevalent high risk HPV types were, in order of prevalence rate, HPV 16, 58, 31 and 52. HPV 16 and/or HPV 31 were present in 63.2% of SCC cases. CONCLUSION: Targeting HPV 16 and 31 with prophylactic vaccines could possibly have an important impact on the incidence of invasive cervical carcinoma in Nicaragua. Further research is needed to define the oncogenic potential of other high prevalent HPV genotypes. Meanwhile, primary prevention and cervical cancer screening programmes should be optimised.
Asunto(s)
Infecciones por Papillomavirus/epidemiología , Lesiones Precancerosas/epidemiología , Displasia del Cuello del Útero/epidemiología , Neoplasias del Cuello Uterino/epidemiología , Adolescente , Adulto , Anciano , Femenino , Humanos , Persona de Mediana Edad , Nicaragua/epidemiología , Lesiones Precancerosas/virología , Prevalencia , Factores de Riesgo , Neoplasias del Cuello Uterino/virología , Displasia del Cuello del Útero/virologíaRESUMEN
OBJECTIVE: To assess if visual inspection with acetic acid (VIA) is a useful alternative screening test for cervical cancer, when used in a resource-poor setting with an existing cytology-based screening programme. METHODS: Women living in Rivas district (Nicaragua), who attended the programme, were concurrently screened with VIA and Papanicolau (PAP) smear. Screening was performed by health providers who had received training in VIA and a refresher course in cytology. Women testing positive for either of the results were referred for colposcopy and biopsy when indicated. The performance of VIA was compared with PAP smear, calculating the relative true and false positive rate (RELTPR and RELFPR) and for a high threshold on biopsy (cervical intraepithelial neoplasia grade 2 or a higher grade). We determined the trade-off between both tests by calculating the ratio of extra false positives detected through extra true positives (EFP:ETP ratio). RESULTS: A total of 1076 patients were screened. Nearly 33% had a positive screening test. On biopsy, 7.6% had a low-grade intraepithelial lesion, 4.5% a high-grade intraepithelial lesion (HSIL) and 0.5% invasive cancer. The RELTPR (VIA to PAP) was 1.96, the RELFPR 5.02 and the EFP:ETP ratio 8.04. VIA detected twice as much HSIL and invasive cancers as the PAP smear. Yet, for every extra diagnosis, eight extra false positives had to be examined at the referral level. CONCLUSIONS: The VIA spectacularly increases the number of HSIL and invasive cancers detected. The high FPR is a concern for the organization of the referral level. There is a need to establish uniform criteria on test positivity and to further improve the performance in field conditions.
Asunto(s)
Ácido Acético , Países en Desarrollo , Indicadores y Reactivos , Tamizaje Masivo/métodos , Neoplasias del Cuello Uterino/diagnóstico , Adulto , Femenino , Humanos , Persona de Mediana Edad , Nicaragua , Prueba de Papanicolaou , Estadística como Asunto , Frotis Vaginal , Displasia del Cuello del Útero/diagnósticoRESUMEN
OBJECTIVE: To obtain baseline information for designing a community-based intervention programme aimed at increasing the cervical cancer screening coverage of women most at risk. METHODS: A population-based survey, using proportional stratified two-stage cluster sampling in Rivas, one of the 16 Departments of Nicaragua. The individuals selected were interviewed at home by one of 26 interviewers, using a structured questionnaire. The questionnaire was designed to elicit (1) knowledge, attitudes and practices concerning sexual and reproductive health and behaviour, (2) risk factors for cervical cancer and (3) the use of health and cervical cancer screening services. RESULTS: A total of 612 men and 634 women participated in the survey. Of the women who had been sexually active at least 3 years, only 41.1% had undergone screening within that period and were considered adequately screened. Correlates of inadequate screening status included low educational level, exclusive use of public health facilities and lack of knowledge about prevention and symptoms of cervical cancer. Negligence, absence of medical problems, fear, lack of knowledge and economic reasons were the main reasons given for not being screened. Reluctance to be screened in the future was related to lack of knowledge of the disease, inadequate screening status, older age and low educational level. CONCLUSIONS: The current screening programme is not effective in reaching the majority of the population. Complementary activities such as education and information, as well as a more pro-active approach to invite women for screening are necessary.
Asunto(s)
Tamizaje Masivo , Neoplasias del Cuello Uterino/prevención & control , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Conocimientos, Actitudes y Práctica en Salud , Accesibilidad a los Servicios de Salud , Humanos , Masculino , Persona de Mediana Edad , Nicaragua , Pobreza , Factores de Riesgo , Encuestas y Cuestionarios , Frotis Vaginal , Servicios de Salud para MujeresRESUMEN
OBJECTIVES: To determine prevalence and risk factors of sexually transmitted infections (STIs), HIV, and cervical neoplasia in women attending women's health clinics in Nicaragua, and to assess the potential impact of screening for these diseases. METHODS: Consecutive women attending women's health clinics in different regions were interviewed and examined for STI, HIV, and cervical neoplasia. RESULTS: Whereas only 30.4% of the 1185 participating women attended the clinics because of STI related complaints, 77.0% reported symptoms after probing. Clinical cervicitis was diagnosed in 32.8%, Chlamydia trachomatis in 4.1%, gonorrhoea in 0.4%, trichomoniasis in 10.2%. Antibodies for syphilis were found in 0.7%, for hepatitis B in 3.7%, and none were HIV seropositive. The STI prevalence was 21.8% in women offending with complaints, 17.3% in symptomatic women after probing, and 14.8% in asymptomatic women. Abnormal Papanicolaou (Pap) smears were found in 7.7%, with high risk human papilloma virus (HPV) types in almost 60%. Male promiscuity was associated with high grade squamous intraepithelial lesions (HSIL) and reported former screening was not shown to be protective. Young age and being employed were risk factors for C. trachomatis. CONCLUSION: Nearly one out of five women attending women's health clinics in Nicaragua had an STI, and one out of 13 a precancerous lesion of the cervix. These clinics provide an opportunity to improve the reproductive health of women by probing for STI symptoms, especially in young women, and by offering cervical screening to casual attendees. Of concern is the high rate of cervical lesions in women with a screening history, underlining the need for proper quality control.
Asunto(s)
Enfermedades de Transmisión Sexual/epidemiología , Neoplasias del Cuello Uterino/epidemiología , Adolescente , Adulto , Anciano , Cuello del Útero/microbiología , Distribución de Chi-Cuadrado , Estudios Epidemiológicos , Femenino , Humanos , Persona de Mediana Edad , Nicaragua/epidemiología , Enfermedad Inflamatoria Pélvica/epidemiología , Enfermedad Inflamatoria Pélvica/microbiología , Parejas Sexuales , Enfermedades de Transmisión Sexual/complicaciones , Neoplasias del Cuello Uterino/microbiología , Cervicitis Uterina/epidemiología , Cervicitis Uterina/microbiologíaRESUMEN
Restudy of Deep Sea Drilling Project Sites 536 and 540 in the southeast Gulf of Mexico gives evidence for a giant wave at Cretaceous-Tertiary boundary time. Five units are recognized: (1) Cenomanian limestone underlies a hiatus in which the five highest Cretaceous stages are missing, possibly because of catastrophic K-T erosion. (2) Pebbly mudstone, 45 m thick, represents a submarine landslide possibly of K-T age. (3) Current-bedded sandstone, more than 2.5 m thick, contains anomalous iridium, tektite glass, and shocked quartz; it is interpreted as ejecta from a nearby impact crater, reworked on the deep-sea floor by the resulting tsunami. (4) A 50-cm interval of calcareous mudstone containing small Cretaceous planktic foraminifera and the Ir peak is interpreted as the silt-size fraction of the Cretaceous material suspended by the impact-generated wave. (5) Calcareous mudstone with basal Tertiary forams and the uppermost tail of the Ir anomaly overlies the disturbed interval, dating the impact and wave event as K-T boundary age. Like Beloc in Haiti and Mimbral in Mexico, Sites 536 and 540 are consistent with a large K-T age impact at the nearby Chicxulub crater.
Asunto(s)
Geología , Vidrio/análisis , Iridio/análisis , Cuarzo/análisis , Sistema Solar , Animales , Carbonato de Calcio/análisis , Carbonato de Calcio/química , Eucariontes , Fósiles , Fenómenos Geológicos , Haití , Biología Marina , México , Minerales/análisis , Oceanografía , Océanos y Mares , PaleontologíaRESUMEN
The hypothesis of Cretaceous-Tertiary (K-T) boundary impact on Yucatán, Mexico, predicts that nearby sites should show evidence of proximal impact ejecta and disturbance by giant waves. An outcrop along the Arroyo el Mimbral in northeastern Mexico contains a layered clastic unit up to 3 m thick that interrupts a biostratigraphically complete pelagic-marl sequence deposited at more than 400 m water depth. The marls were found to be unsuitable for determining magnetostratigraphy, but foraminiferal biostratigraphy places the clastic unit precisely at the K-T boundary. We interpret this clastic unit as the deposit of a megawave or tsunami produced by an extraterrestrial impact. The clastic unit comprises three main subunits. (1) The basal "spherule bed" contains glass in the form of tektites and microtektites, glass spherules replaced by chlorite-smectite and calcite, and quartz grains showing probable shock features. This bed is interpreted as a channelized deposit of proximal ejecta. (2) A set of lenticular, massive, graded "laminated beds" contains intraclasts and abundant plant debris, and may be the result of megawave backwash that carried coarse debris from shallow parts of the continental margin into deeper water. (3) At the top, several thin "ripple beds" composed of fine sand are separated by clay drapes; they are interpreted as deposits of oscillating currents, perhaps a seiche. An iridium anomaly (921 +/- 23 pg/g) is observed at the top of the ripple beds. Our observations at the Mimbral locality support the hypothesis of a K-T impact on nearby Yucatán.