Joel Navarrete-Espinosa

Prevalencia de anticuerpos contra dengue y leptospira en la población de Jáltipan, Veracruz

Objective. To discover the prevalence of antibodies against denguevirus and leptospira. Material and Methods. A cross-sectional study was carried out in 500 inhabitants of Veracruz, Mexico through household sampling, administration of a questionnaire and collection of blood samples. The presence of IgG antibodies was determined and factors associated with seroprevalence were evaluated using a logistic regression model. Results. Total denguevirus seroprevalence was 79.6% (IC95% 76-81). The main factors associated with infection were age and residence in neighborhoods with higher vectorial indices (RMP=2.94, IC95% 1.46-6.1). Overall seroprevalence against leptospira was 4% (IC95%

Clinical profile of dengue hemorrhagic fever cases in Mexico

OBJECTIVE Dengue hemorrhagic fever is a public health problem in Mexico since 1994. With four serotypes circulating the risk of epidemic dengue hemorrhagic fever is increasing. MATERIAL AND METHODS We describe the clinical features of confirmed cases in the social security health system (IMSS) from 1995 to 2003. Clinical picture and epidemiological features were compared and a multivariate model was fitted to evaluate associations. RESULTS Cases were divided into two groups: 438 patients with dengue fever, including 109 cases with hemorrhagic manifestations without thrombocytopenia, and 977 cases with dengue hemorrhagic fever, including 79 deaths. The main risk factors associated with mortality were hematemesis (RR 2.6; CI 95% 1.4-4.6) and melena (RR 2.2; Cl 95% 1.2-3.7). CONCLUSIONS Our results characterize the clinical profile of dengue hemorrhagic fever cases in Mexico and identify prognostic factors to alert clinician for the prevention of a fatal evolution.

Obesity and overweight in IMSS female workers in Mexico City

OBJECTIVE To estimate the prevalence and risk factors for overweight (OW) and obesity (OB) in women working at the Mexican Social Security Institute (IMSS, per its abbreviation in Spanish) in Mexico City, using two different classification criteria. MATERIAL AND METHODS A cross-sectional study was performed from July 1999 to September 2000. It included 588 women 20 to 65 years of age and who were working at the IMSS. The criteria used to estimate the prevalence of OW and OB were the WHO criteria and the Mexican Official Norm (NOM) for the integrated management of obesity in Mexico. RESULTS The frequency of OB, according to WHO criteria, was 27.6% (26% adjusted) and for OW 43.2% (40.2% adjusted). According to the NOM, the levels of OB in those with short height (< 1.50 m) increased to 75% and to 52.2% for those with height > 1.50 m. Comparison of BMI between the two height groups showed no differences. The risk factor associated with OB and OW was age. Education and exercise were protective factors. CONCLUSIONS The high prevalences detected in this particular working group highlight the importance of prevention and control of OB in health personnel because it can result in a high number of disability and premature retirement due to disease. The use of the NOM criteria for the identification of women at risk may be useful for early detection of high-risk groups.

Niveles de plomo sanguíneo en madres y recién nacidos derechohabientes del Instituto Mexicano del Seguro Social

OBJETIVO: Establecer la relacion entre el nivel de plomo sanguineo materno (PSM) y el de sangre en cordon umbilical (PSC) al momento del parto, asi como determinar los principales predictores del PSM en derechohabientes del Instituto Mexicano del Seguro Social (IMSS), en el Distrito Federal (D.F.). MATERIAL Y METODOS: Se realizo un estudio transversal en el que se reclutaron voluntarias con embarazo normoevolutivo y se les tomaron muestras de sangre al momento del parto, en cuatro hospitales del IMSS en el D.F., de 1991 a 1993. Se tomo, ademas, muestra de sangre de cordon umbilical. Los datos fueron analizados mediante regresion lineal simple y multiple. RESULTADOS: Se estudiaron un total de 1 404 binomios madre-hijo; el promedio de edad de las madres fue de 25 anos. La media de PSM fue 10.7 ± 6.5 µg/dl; no se encontraron variaciones significativas por hospital, edad o estado civil. Para el PSC la media fue de 10.4 ± 6.2 µg/dl. Por cada aumento en una unidad logaritmica de PSM, el PSC aumenta 0.62 (p<0.01) unidades logaritmicas. La correlacion entre ambos fue de 0.61 (p<0.01). Los principales predictores de PSM fueron el uso de loza vidriada, el consumo de leche y jugo de naranja, estos ultimos se asociaron inversamente con el PSM. Un 47% de las madres y 50% de los ninos tuvieron valores superiores a 10 µg/dl. En 578 recien nacidos se registraron niveles de plomo superiores a los de la madre. CONCLUSIONES: Se sugiere continuar la linea de investigacion para proponer tipos de intervencion.

Specific genetic markers for detecting subtypes of dengue virus serotype-2 in isolates from the states of Oaxaca and Veracruz, Mexico

BackgroundDengue (DEN) is an infectious disease caused by the DEN virus (DENV), which belongs to the Flavivirus genus in the family Flaviviridae. It has a (+) sense RNA genome and is mainly transmitted to humans by the vector mosquito Aedes aegypti. Dengue fever (DF) and dengue hemorrhagic fever (DHF) are caused by one of four closely related virus serotypes (DENV-1, DENV-2, DENV-3 and DENV-4). Epidemiological and evolutionary studies have indicated that host and viral factors are involved in determining disease outcome and have proved the importance of viral genotype in causing severe epidemics. Host immune status and mosquito vectorial capacity are also important influences on the severity of infection. Therefore, an understanding of the relationship between virus variants with altered amino acids and high pathogenicity will provide more information on the molecular epidemiology of DEN. Accordingly, knowledge of the DENV serotypes and genotypes circulating in the latest DEN outbreaks around the world, including Mexico, will contribute to understanding DEN infections.Results1. We obtained 88 isolates of DENV, 27 from Oaxaca and 61 from Veracruz. 2. Of these 88 isolates, 16 were serotype 1; 62 serotype 2; 7 serotype 3; and 2 serotype 4. One isolate had 2 serotypes (DENV-2 and -1). 3. Partial nucleotide sequences of the genes encoding C- prM (14 sequences), the NS3 helicase domain (7 sequences), the NS5 S-adenosyl methionine transferase domain (7 sequences) and the RNA-dependent RNA polymerase (RdRp) domain (18 sequences) were obtained. Phylogenetic analysis showed that DENV-2 isolates belonged to the Asian/American genotype. In addition, the Asian/American genotype was divided into two clusters, one containing the isolates from 2001 and the other the isolates from 2005–2006 with high bootstrap support of 94%.ConclusionDENV-2 was the predominant serotype in the DF and DHF outbreak from 2005 to 2006 in Oaxaca State as well as in the 2006 outbreak in Veracruz State, with the Asian/American genotype prevalent in both states. Interestingly, DENV-1 and DENV-2 were the only serotypes related to DHF cases. In contrast, DENV-3 and DENV-4 were poorly represented according to epidemiological data reported in Mexico. We found that isoleucine was replaced by valine at residue 106 of protein C in the isolates from these 2005–2006 outbreaks and in those from the 1997, 1998 and 2001 outbreaks in the Caribbean islands. We suggested that this amino acid change may be used as a signature for isolates arising in the Caribbean islands and pertaining to the Asian/American genotype. Other amino acid changes are specific for the Asian/American, Asian and American strains.

A DNA Microarray-Based Assay to Detect Dual Infection with Two Dengue Virus Serotypes

Here; we have described and tested a microarray based-method for the screening of dengue virus (DENV) serotypes. This DNA microarray assay is specific and sensitive and can detect dual infections with two dengue virus serotypes and single-serotype infections. Other methodologies may underestimate samples containing more than one serotype. This technology can be used to discriminate between the four DENV serotypes. Single-stranded DNA targets were covalently attached to glass slides and hybridised with specific labelled probes. DENV isolates and dengue samples were used to evaluate microarray performance. Our results demonstrate that the probes hybridized specifically to DENV serotypes; with no detection of unspecific signals. This finding provides evidence that specific probes can effectively identify single and double infections in DENV samples.