Marylin Puerto-Solís

High prevalence of human papillomavirus type 58 in Mexican colposcopy patients

BACKGROUND Cervical cancer is the second most common cancer of the women worldwide. Infection with some genotypes of human papillomavirus is the most important risk factor associated to cervical cancer. OBJECTIVE To determine the prevalence and genotypes of papillomavirus in biopsies of women with squamous intraepithelial lesion and cervical cancer. STUDY DESIGN Two hundred sequential patients of colposcopy clinic were studied. HPV diagnosis was done by polymerase chain reaction using MY09/MY11 primers, for genotyping line blot hybridization was used. RESULTS A total of 186 women were beta globin positive; 104 (55.9%) had histology diagnosis of low-grade squamous intraepitelial lesions (LSIL), 67 (36.0%) high-grade squamous intraepitelial lesions (HSIL) and 15 (8.1%) invasive cervical cancer (IC). The prevalence of HPV was 56.4% (104/185); HPV 58 was founded in 28.5% of all positive women, HPV 16 in 25.7%, HPV 18 in 13.3%, HPV 33 in 11.4% and 31 in 8.5%. In all grades of the lesions HPV 58 was the most frequently. CONCLUSIONS The high prevalence of HPV 58 among Mexican women with HSIL and IC, has important implications in prophylaxis.

Molecular variants of HPV type 16 E6 among Mexican women with LSIL and invasive cancer

BACKGROUND Cervical cancer is the second most common cancer in women worldwide. Infection with human papillomavirus (HPV) 16 is an important risk factor associated with cervical cancer, more than 50% of cervical cancer tissues have DNA of HPV 16. Intratypic variants have been reported, although they differ in prevalence, biological and biochemical properties, their implication in the aetiology of cervical cancer is still uncertain. OBJECTIVE To identify HPV type 16 E6 variants among Mexican women with diagnosis of low-grade squamous intraepithelial lesion (LSIL) or invasive cancer (IC). STUDY DESIGN Forty HPV16-positive samples were included, 15 were from women with LSIL, 25 from women with IC; 610 pb from the E6 gene were amplified by PCR and the variant status subsequently determined by hybridization with 27 biotinilated probes. Statistical analysis was performed with chi2, odds ratio (OR). RESULTS In the LSIL group we only found ten (66%) EP and five (33%) EP350G variants. In the IC group, four variants were found; 11 (44%) AA, seven (28%) EP, six (24%) EP350G, one (4%) Af2. Comparison of the frequency of variants differed from EP in both groups of patients (P=0.01) with an odds ratio (OR) of 5.14 (CI 95% [1.07-26.56]). CONCLUSION This study demonstrates an association between HPV type 16 variants different from prototype (EP) and invasive cervical cancer.

Acute gastroenteritis associated with rotavirus in adults.

BACKGROUND Rotavirus (RV) is an important cause of acute infectious diarrhea in children all over the world. In adults, RV infection tends to be subclinical; however, outbreaks of gastroenteritis have been reported in emergency situations and in closed communities. The aim of this study was to characterize electrophoretically and antigenically the strains of rotavirus that caused acute gastroenteritis in adults and correlate them with the clinical manifestations. METHODS A laboratory-based survey was carried out in which fecal samples from 44 patients over 18 years of age with acute gastroenteritis were studied. Polyacrylamide gels electrophoresis and immunoenzymatic assay with specific antibodies to group A rotavirus, serotypes G1-4, P1A, and P1B were carried out on all the samples. RESULTS Twenty-eight (63.63%) of the 44 samples were positive for group A rotavirus. Of these, 19 (68%) had long pattern and nine (32%) short pattern. Of all positive samples, 15 (54%) were serotype G1, seven (25%) were G2, two (7%) were G4, and four (14%) had no monoclonal reaction; all were serotype P1A. Among the patients with RV infection, 13 (46.4%) required hospitalization and the remaining 15 (53.6%) showed moderate symptoms. CONCLUSIONS The strains that infected the adults were electrophoretically and antigenically the same as those that infected infants in Mérida, Yucatán over the last 10 years. No relationship between the severity of the symptoms and any specific serotype was found.

Clinical manifestations of the rotavirus infection and his relation with the electropherotypes and serotypes detected during 1998 and 1999 in Merida, Yucatan, Mexico

BACKGROUND Group A rotavirus (RV) is associated with acute infectious diarrhea (AID) in children and adults. The clinical manifestations of RV infection are classified as slight, moderate and severe and could be the results of differing rotaviral serotypes. Attempts have been made to correlate the severity of the infection with specific RV groups, subgroups (SG) serotypes and electropherotypes, but the results have been inconclusive. OBJECTIVE To correlate the severity of the RV infection with the strains of RV isolated from the patients. STUDY DESIGN 142 feces were collected from patients with AID caused by RV. The samples were subjected to polyacrylamide gel electrophoresis (PAGE) to determine the electrophoretic pattern and immunoenzymatic assays with monoclonal antibodies specific for serotype, SG and group. The Program EPIINFO 6.0 was used to analyze the correlation. RESULTS The 142 RV strains isolated were from group A and long electrophoretic pattern. Respect to the symptoms were classified, 43 (30%) as slight; the RV isolates corresponding to these patients were 35 of serotype G1P1A SG II; 4 G1P1A SG I and II; 1 G1P1A SG Non I Non I; 1 G3 SG II; 1 G3 SG Non I and Non II and 1 G3 SG I and II. 89 (53%) of patients showed moderate clinical symptoms. 58 isolates of RV were G1P1A SG II; 11 G1P1A SG Non I Non II; 9 G1P1A SG I and II; 1 G1P1B SG II; 1 G4P1A SG II; 1G1 and G4 SG I and II; 6 G3 SG Non I Non II; 2 G3 SG II. The severe RV infection occurred in only 10 (7%). 8 were serotype G1P1A SG II and 2 were G1P1A SG I and II. CONCLUSION This study demonstrated that the severity of AID has no significant statistical relationship to the specific RV strains isolated from the patients.

LOW PREVALENCE OF HIGH RISK HUMAN PAPILLOMAVIRUS IN NORMAL ORAL MUCOSA BY HYBRID CAPTURE 2

High risk human papillomavirus (HR-HPV) are recognized as a necessary factor to development cervical cancer. During the last decade many studies have found HR-HPV in oral squamous cell carcinoma (OSCC) and normal oral mucosa, however the association between HR-HPV and OSCC is still uncertain. The aim of the study was to determine DNA HR-HPV in normal oral cavity of healthy adults. A cross-sectional study was performed; samples from 77 patients with normal oral cavity were collected at the Dentistry school, Autonomous University of Yucatan, Merida, Yucatan, México. HR-HPV was detected by hybrid capture 2. One sample out of 77(1.2%) was positive for HR-PVH. It was from a man of 50 years old. HRHPV is present in low rate among healthy oral mucosa. Hybrid capture 2 could be a good methodology for large epidemiology studies.

Epidemiology of oral HPV in the oral mucosa in women without signs of oral disease from Yucatan, Mexico

High-risk human papillomaviruses (HR-HPV) are considered necessary for the development of cervical cancer. Furthermore, there is no doubt that some types of oral squamous cell carcinoma are associated with HR-HPV. The epidemiology of oral HPV infections in healthy subjects remains unclear due to a lack of knowledge. The objective of this study was to investigate the epidemiology of human papillomavirus infections of the oral mucosa without pathology. A cross-sectional study was performed; samples from 390 women seeking prenatal care, Pap smears, family planning or gynecological diseases were studied. Oral cells were collected by direct swab sampling. Information regarding sociodemographic status, sexual behavior, infectious diseases, contraceptive history and tobacco and alcohol consumption were obtained through direct interviews. HPV and genotypes were detected by type-specific polymerase chain reaction. Our results revealed that 14% of the women studied had an oral HPV infection. Women ≤ 20 years of age had the highest HPV prevalence (24.5%). In total, seven genotypes were identified, including the high-risk genotypes 16, 18, 58 and 59 and the low-risk genotypes 6, 81 and 13, the latter of which is a type exclusive to oral mucosa. Sexual behavior was not associated with the presence of genital HPV types in the oral mucosa. Genital HPV types were present in the oral mucosa of women without associated clinical manifestations; however, sexual behavior was not associated with infection, and therefore others routes of transmission should be explored.

Knowledge about cervical cancer screening among family physicians: cross-sectional survey

BACKGROUND Cervical cancer (CC) is an important public health problem worldwide. In Mexico, there has been a National Cervical Cancer Screening Program (NCCSP) since 1974. Mexican Social Security Institute attended Mexican workers and family physicians are responsible of the primary care of patients. OBJECTIVE To evaluate knowledge about the aetiology and prevention of CC among family physicians working in Yucatan, Mexico, at Mexican Social Security Institute. METHODS A questionnaire was applied to 187 family doctors. Self-administer questionnaire with 10 item previously used by ours and other researchers, was used for the evaluation. Each correctly answered item was given a point. The maximum grade was 10 and the minimum 0. RESULTS The knowledge mean was 6.93 points. Fewer than 50% knew what to do with women who are human papillomavirus (HPV) positive without a precancerous cervical lesion and the appropriate age range for Pap smears. A total of 61.1% identified CC as an important health problem in Mexico; however, 95.1% identified CC as a preventive cause of deaths among Mexican women and recognized that HPV is the main CC aetiological agent, and 90.3% mentioned the Pap smear as the main method of diagnosis of CC. CONCLUSION The family doctors need to have an adequate knowledge of the practical elements of the NCCSP to give an efficient attention to their patients.

Influenza seasonality goes south in the Yucatan Peninsula: The case for a different influenza vaccine calendar in this Mexican region

INTRODUCTION While vaccination may be relatively straightforward for regions with a well-defined winter season, the situation is quite different for tropical regions. Influenza activity in tropical regions might be out of phase with the dynamics predicted for their hemispheric group thereby impacting the effectiveness of the immunization campaign. OBJECTIVE To investigate how the climatic diversity of Mexico hinders its existing influenza immunization strategy and to suggest that the hemispheric vaccine recommendations be tailored to the regional level in order to optimize vaccine effectiveness. METHODS We studied the seasonality of influenza throughoutMexico by modeling virological and mortality data.De-trended time series of each Mexican state were analyzed by Fourier decomposition to describe the amplitude and timing of annual influenza epidemic cycles and to compare with each the timing of the WHOs Northern and Southern Hemispheric vaccination schedule. FINDINGS The timings of the primary (major) peaks of both virological and mortality data for most Mexican states are well aligned with the Northern Hemisphere winter (December-February) and vaccine schedule. However, influenza peaks in September in the three states of the Yucatan Peninsula. Influenza-related mortality also peaks in September in Quintana Roo and Yucatan whereas it peaks in May in Campeche. As the current timing of vaccination in Mexico is between October and November, more than half of the annual influenza cases have already occurred in the Yucatan Peninsula states by the time the Northern Hemispheric vaccine is delivered and administered. CONCLUSION The current Northern Hemispheric influenza calendar adopted for Mexico is not optimal for the Yucatan Peninsula states thereby likely reducing the effectiveness of the immunization of the population. We recommend that Mexico tailor its immunization strategy to better reflect its climatologic and epidemiological diversity and adopt the WHO Southern Hemisphere influenza vaccine and schedule for the Yucatan Peninsula.

Prevalence of anal infection due to high-risk human papillomavirus and analysis of E2 gene integrity among women with cervical abnormalities

BACKGROUND High-risk human papillomaviruses (HR-HPV) infection has been associated with 90% of anal cancer cases. Women with abnormal cytology are a high-risk group to develop anal neoplasia. The aim of this study is to describe the prevalence and epidemiology of HR-HPV 16, 18, 45, and 58 anal infections in women with cervical abnormalities, as well as to assess E2 gene integrity. METHODS A cross-sectional study was performed on 311 cervical and 311 anal samples from patients with abnormal cytology in two colposcopy clinics in Yucatan, Mexico. A specific PCR for oncogenes was performed in order to identify HVP 16, 18, 45 and 58. Real time PCR was used to amplify the whole HPV 16, 18, and 58 E2 gene to verify its integrity in anal samples. RESULTS High risk HPV 16, 18, 58, and/or 45 were found in 41.47% (129/311) of cervical samples, and in 30.8% (96/331) of anal samples, with 18% (57/311) of the patients being positive in both samples. The same genotypes in both anatomical sites were observed in 11.25% (35/311). The E2 gene was disrupted in 82% of all tested samples. The frequency of genome disruption viral integration in anal samples by genotype was: HPV 58 (97.2%); HPV 16 (72.4%), and HPV 18 (0%). CONCLUSION Women with cervical disease have HR-HPV anal infections, and most of them have the E2 gene disrupted, which represents a risk to develop anal cancer.

Analysis of E2 gene integrity in HPV16 and HPV58 viruses isolated from women with cervical pathology

Integration of human papillomavirus (HPV) DNA into human cells accompanied by the disruption of the viral genome has been described as a prerequisite for cancer development. This study aimed to investigate E2 gene integrity of HPV16 and HPV58 viruses isolated from infected women with cervical lesions. Forty-two HPV16- and 31 HPV58-positive samples were analysed. E2 integrity was assumed when all fragments covering the E2 gene were amplified with specific polymerase chain reaction primers. Overall, in 59% of the samples, at least one fragment was not amplified in HPV16- (57%) and HPV58-positive samples (61%). Samples from high-grade squamous intraepithelial lesions had the highest frequency of E2 gene disruptions (73%), followed by samples from low-grade squamous intraepithelial lesions (63%) and, finally, samples from invasive cervical cancer (35%). Association between the integrity status of the E2 gene, and lesion grade was assessed by the chi-squared test applied to the combined set of viruses (p = 0.6555) or to populations of the same virus type (HPV58, p = 0.3101; HPV16, p = 0.3024). In conclusion, in this study, no association was found between the presence of E2 gene disruptions and the grade of cervical lesions caused by HPV16 and HPV58.