Fabián Méndez

Incidence, Duration, and Determinants of Cervical Human Papillomavirus Infection in a Cohort of Colombian Women with Normal Cytological Results

Data on the incidence and determinants of human papillomavirus (HPV) infection in women >30 years old are scarce. To address this, a cohort of 1610 women--15-85 years old, HPV negative, and with normal cytological results at baseline--was monitored every 6 months for an average of 4.1 years. Information on risk factors and cervical samples for cytological testing and detection and typing of HPV DNA were obtained at each visit. The incidence of high-risk types was higher than that of low-risk types (5.0 vs. 2.0 cases/100 woman-years). The age-specific incidence curve for high-risk types was bimodal, whereas the incidence of low-risk types gradually decreased with age. Infections with high-risk types lasted longer than infections with low-risk types (14.8 vs. 11.1 months). In this cohort of cytologically normal women, the incidence of cervical HPV infection was high, and the epidemiological profile of high-risk HPV types was different from that of low-risk types.

Cervical Coinfection with Human Papillomavirus (HPV) Types and Possible Implications for the Prevention of Cervical Cancer by HPV Vaccines

Coinfection with multiple types of human papillomavirus (HPV) and its implications for the development of efficacious HPV vaccines is a subject of great interest. To describe the occurrence of concurrent infection with multiple HPV types and to determine whether genital HPV infection modifies the risk of acquiring a new HPV infection with another HPV type, 1610 subjects were monitored for an average of 4.1 years in Bogota, Colombia. Information on risk factors for HPV infection and cervical cells was collected for detection of HPV DNA of 36 types at study entry and at 6 consecutive 6-month follow-up visits. Clustering or the concurrent acquisition of multiple types occurred more often than would be expected by chance. Subjects with incident HPV-16 or -18 infection had 5-7 times higher odds of acquiring a subsequent HPV-58 infection than subjects not infected with HPV-16 or -18. This might affect the protection conferred by effective HPV vaccines.

Persistence of HPV infection and risk of high-grade cervical intraepithelial neoplasia in a cohort of Colombian women

Little is known about the dynamics of human papillomavirus (HPV) infection and subsequent development of high-grade cervical intraepithelial neoplasia (CIN2/3), particularly in women >30 years of age. This information is needed to assess the impact of HPV vaccines and consider new screening strategies. A cohort of 1728 women 15–85 years old with normal cytology at baseline was followed every 6 months for an average of 9 years. Women with squamous intraepithelial lesions were referred for biopsy and treatment. The Kaplan–Meier method was used to estimate the median duration of infection and Cox regression analysis was undertaken to assess determinants of clearance and risk of CIN2/3 associated with HPV persistence. No difference in the likelihood of clearance was observed by HPV type or womans age, with the exception of lower clearance for HPV16 infection in women under 30 years of age. Viral load was inversely associated with clearance. In conclusion, viral load is the main determinant of persistence, and persistence of HPV16 infections carry a higher risk of CIN2/3.

Risk factors associated with malaria infection in an urban setting.

Incidence of malaria in urban settings is a growing concern in many regions of the world and individual risk factors need to be identified to appropriately adjust control strategies. We carried out a cross-sectional study in 1993/94 in an urban area of the largest port of the Pacific Coast of Colombia, where transmission has had an upward trend over the past 5 years. Prevalence of malaria infection was estimated in areas of the city with the highest incidence of disease, and the association between some characteristics of the population and the risk of malaria infection was assessed. Prevalence of malaria infection was 4.4% among the 1380 studied people and we found that it decreased with older age, and with knowledge of disease and preventive measures directed to elimination of breeding sites. In addition, the infection was positively associated with exposure to the forest (P < 0.05), although most of the cases (57/61, 93%) were likely to have been acquired in the urban area. We also found that individuals receiving antimalarial treatment in the previous month had around twice the risk of being infected as compared with those without treatment. In addition, our results suggest that use of bednets could not be a very effective protective measure in settings such as that of our study, and that environmental interventions may be needed to decrease the risk of infection.

Knowledge, beliefs and practices relevant for malaria control in an endemic urban area of the Colombian Pacific.

Research projects for malaria control must involve communities to elicit strategies to be successful and programs to be sustainable. Therefore, knowledge, beliefs and practices of the population concerned must be taken into account in the design of interventions against malaria transmission. We conducted a KAP study in Buenaventura, a port on the Pacific Coast of Colombia where transmission was on the increase at the beginning of this decade. The purpose of the study was to help in the design and implementation of a primary health care approach for malaria control. Both qualitative and quantitative research methods were used. The focus group technique was applied in five urban and peri-urban communities and a cross sectional survey was conducted on a random sample of 1380 subjects with a structured interview on knowledge, practices and also on demographic and epidemiological aspects. The information obtained by the two methods was comparable on knowledge of symptoms, causes and ways of malaria transmission, and prevention practices like the use of bednets or provision of health services. We discuss the relevance of obtaining this information and analyze the elements that must be taken into account for communities to become more involved in malaria control strategies.

Transmisión de la malaria urbana en Buenaventura, Colombia: aspectos entomológicos

En los ultimos anos, el numero de casos de malaria urbana en Buenaventura, Colombia, ha aumentado de 576 en 1987 a 3 296 en 1991 y 2 017 en 1992, por lo que se desarrollo un estudio epidemiologico para identificar patrones de transmision de la malaria en este municipio del litoral pacifico colombiano. Se describen los hallazgos entomologicos en relacion con los vectores, los criaderos y el comportamiento de las especies de Anopheles durante el periodo comprendido entre junio de 1993 y mayo de 1994. De los 469 posibles criaderos del area urbana, 28 fueron positivos a anofelinos. En la zona rural vecina de Buenaventura 20 de 80 posibles criaderos fueron positivos a las formas inmaduras del mosquito. Los sitios donde se encontro con mas frecuencia Anopheles albimanus fueron las excavaciones de mineria, los lagos y los estanques para piscicultura. Los criaderos de Anopheles nuneztovari fueron los pozos de lluvia y estanques de peces. Anopheles neivai se recolecto en bromelias. De las capturas intra y peridomiciliarias de mosquitos adultos, 90% correspondieron a Anopheles albimanus. De las hembras, 54,8% habian realizado al menos una ovipostura. Esta especie tuvo una actividad peridomiciliaria maxima entre las 18.00 y 22.00 horas. La mayor tasa de picadura peridomiciliaria fue de 7,1 y correspondio a marzo de 1994. Se espera que esta informacion entomologica permita poner en marcha un importante proceso de participacion comunitaria e implementar medidas de control que esten orientadas por nuestros resultados.

Stakeholders in climate science: Beyond lip service?

Local knowledge coproduction must be rewarded Research models are evolving in response to the need for on-the-ground knowledge of climate change impacts on communities. Partnership between researcher and practitioner is vital for adaptive policy efforts (1). Transdisciplinary research teams present new opportunities by involving academics and local stakeholders, who actively conceive, enact, and apply research on adaptation and mitigation actions (2, 3). In transdisciplinary research, stakeholders are also researchers. But if we want to engage stakeholders in climate research, then we cannot simply pay lip service to the idea while treating them as participants for extractive research.

Defectos eritrocíticos y densidad de la parasitemia en pacientes con malaria por Plasmodium falciparum en Buenaventura, Colombia

OBJECTIVES To determine the prevalence of some erythrocyte defects and to evaluate the relation that that has with parasitemia density in individuals diagnosed with Plasmodium falciparum malaria in a population in the Pacific coastal region of Colombia. METHODS This prevalence study was carried out with 242 persons with P. falciparum malaria who had gone for consultation at the Program of Tropical Diseases diagnostic center in the city of Buenaventura, Colombia. The parasitemia levels were measured, and also determined was the presence of congenital erythrocyte defects (glucose-6-phosphate dehydrogenase (G6PD) deficiency, abnormal hemoglobins, and thalassemias) and of other factors possibly related to parasitemia levels. RESULTS The prevalence of erythrocyte defects was 26.4% (95% confidence interval, 21.0%-32.5%), which was similar to what had been found in previous studies in the same area of Colombia. In the multiple regression models, individuals with sickle cell anemia or a complete deficiency of G6PD had a lower density of parasitemia than did persons without any erythrocyte defect. After adjusting for other variables of interest, the risk of high parasitemias was lower in persons with sickle cell anemia (odds ratio = 0.30) and individuals with a complete deficiency of G6PD (odds ratio = 0.72). CONCLUSIONS Our results confirm the high prevalence of erythrocyte defects in Colombias Pacific coastal region, in a population with ethnic characteristics that are similar to those of some populations in West Africa. Our results also lend support for the existence of innate resistance to malaria among carriers of hemoglobin AS and in persons with G6PD deficiency.

Leishmania (Viannia) Infection in the Domestic Dog in Chaparral, Colombia

Peridomestic transmission of American cutaneous leishmaniasis is increasingly reported and dogs may be a reservoir of Leishmania (Viannia) in this setting. We investigated the prevalence of infection in dogs in Chaparral County, Colombia, the focus of an epidemic of human cutaneous leishmaniasis caused by Leishmania (Viannia) guyanensis. Two (0.72%) of 279 dogs had lesions typical of cutaneous leishmaniasis that were biopsy positive by kinetoplast DNA polymerase chain reaction-Southern blotting. Seroprevalence was 2.2% (6 of 279) by enzyme-linked immunosorbent assay. Buffy coat and ear skin biopsy specimens were positive by polymerase chain reaction-Southern blotting in 7.3% (10 of 137) and 11.4% (12 of 105) of dogs, respectively. Overall 20% of dogs (21 of 105) showed positive results for one or more tests. Amplification and sequencing of the Leishmania 7SL RNA gene identified L. guyanensis in one dog and L. braziliensis in two dogs. No association was identified between the risk factors evaluated and canine infection. Dogs may contribute to transmission but their role in this focus appears to be limited.

Prevalence of Metabolic Syndrome in Urban Colombian Adolescents Aged 10–16 Years Using Three Different Pediatric Definitions

The aim of this study was to evaluate the metabolic syndrome (MetS) prevalence in adolescents using three different definitions for this age group. The evaluated sample consisted of 718 male and 743 female adolescents. Definitions by Cook et al., de Ferranti et al. and International Diabetes Federation (IDF) for adolescents were used to estimate the prevalence of MetS. The prevalence of MetS was 8.5, 2.5 and 1.2% by de Ferranti et al., Cook et al. and IDF definitions, respectively. High fasting glucose component had the lower prevalence whereas high triglycerides levels component was the most prevalent. In obese adolescents, the prevalence of MetS was higher. MetS classification in adolescents strongly depends on the definition chosen. Further research is required for the evaluation of the current definitions (multicentric studies), and for addition or design of new and useful criteria.