Dataset on the epidemiology and genetic diversification of dengue virus (DENV) serotypes and genotypes in Mexico.

Dengue virus (DENV) evolution has had a significant impact on disease pathogenesis, virulence, and epidemiology in Mexico. Novel genotypic variation in DENV serotypes and genotypes may influence the magnitude and severity of dengue epidemics, as evidenced by 2009 data from Veracruz State. The data presented herein is related to the publication entitled "Epidemiological Implications of the Genetic Diversification of Dengue Virus (DENV) Serotypes and Genotypes in Mexico" [1]. Raw data and trees provide epidemiological data on DENV prevalence and a comprehensive phylogeny of both representative sequences collected from an NCBI repository, and 28 additional isolates from acute-phase plasma samples diagnosed with dengue fever or severe dengue (Raw sequencing data is hosted in the public repository Mendeley Data (http://dx.doi.org/10.17632/bf2kdhhf6x.2). Phylogenetic trees for each DENV serotype (DENV-1, -2, -3 and -4) were constructed using these sequences by a maximum likelihood methodology as well as a Bayesian Markov chain Monte Carlo (MCMC) integration approach. Phylogenetic trees exhibited: (1) DENV-1, genotype V, (2) the DENV-2 Asian/American and Asian II genotypes, (3) DENV-3, genotype III, and (4) DENV-4, genotype I. This data can be beneficial for future analyses on DENV serotype and genotype structure and the introduction of novel DENV genotype sequences in the Americas, for the further elucidation of dengue etiology.

Epidemiological implications of the genetic diversification of dengue virus (DENV) serotypes and genotypes in Mexico.

Variation and clade shifts in dengue virus (DENV) genotypes are responsible for numerous dengue fever outbreaks throughout Latin America in the past decade. Molecular analyses of dengue serotypes have revealed extensive genetic diversification and the emergence of new genotypes in Brazil (DENV-4 genotype I) and elsewhere in tropical and subtropical America. The goal of the present study is to assess the extent to which the adventitious introduction of DENV genotypes and their increasing genetic diversity affects dengue epidemiology in Mexico. A nuanced sequence inspection and phylogenetic analysis of the C-prM nucleotide region of DENV was performed for specimens collecting in 2009 from the Veracruz State, Mexico. Findings were contrasted with specimens collected in adjacent years and analysed based on the epidemiological patterns reported between 1990 and 2019. Additionally, the identification process of various DENV genotypes was assessed, including: (1) DENV-1, genotype V, (2) the DENV-2 Asian/American and Asian II genotypes (3) DENV-3, genotype III, and (4) DENV-4, genotype I. This resulted in the discovery of a distinct genetic cladistic pattern for serotype DENV-2. Lastly, study findings suggest that a correlation exists between the emergence of novel genotypes and genetic diversification, with the increasing incidence of DENV infections in Mexico in 2009.

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.

Expresión clínica del dengue en usuarios del Instituto Mexicano del Seguro Social, Veracruz, México / Clinical expression of dengue in beneficiaries of the Instituto Mexicano del Seguro Social in Veracruz, Mexico

Objective: To describe and compare the clinical behavior of Dengue Fever (DF) and Hemorrhagic Dengue Fever (HDF) in beneficiaries of the Instituto Mexicano del Seguro Social (IMSS). Methods: Transversal study in beneficiaries from Veracruz, selected among those who sought attention at two medical attention units, with probable dengue diagnosis. Surveys were performed to know personal and epidemiological data, as well as a clinical follow up. Blood samples were taken for RT-PCR viral identification and antibodies against Dengue. In the same way, platelet, hemoglobin, and hematocrit tests were performed for their determination. The SPSS 12.0 software was used for the process and analysis of the information, and simple frequencies, proportions, and means were estimated. Results: 109 patients were studied, classified as 72 DF and 37 as HDF. 40 isolations were performed, and the circulation of the four types of dengue virus was identified, although most of the isolations corresponded to serotype 2 (Asian-American genotype). In one patient, a simultaneous infection of dengue viruses 1 and 2 was identified. A group of patients did not present hemorrhages, capillary fragility, or liquid permeation, but with important thrombocytopenia and hemoconcentration, all infected with den-1 and den-2. Conclusions: The presence of cases with atipical behavior of the diseases were identified. The characteristics and immunologic experience of the populations, as well as the simultaneous circulation of various dengue viruses and their changing structure could be related with the current clinical behavior of Dengue in Mexico. It is important to continue the research to confirm these asseverations.

[Smoking habits in beneficiaries of the social security]. / Consumo de tabaco en derechohabientes del IMSS.

OBJECTIVE: To determine the prevalence of tobacco consumption (TC) and frequency according to demographics and health aspects. METHODS: A cross-sectional study from the Mexican Family Life Survey Project was conducted. The past and present TC according to sociodemo-graphic variables and the presence of chronic diseases (CD) were achieved. RESULTS: The prevalence of TC in the past was 21.4 % with a male/female ratio of 2.5. Nowadays TC was 15.2 % and the ratio between male/female was 2.6 (23.0: 8.9); exposure levels by age decreased at present. Out of the total smokers in the past 71 % continue with the habit, 75 % began TC before the age of 20. In the 15 to 19 years group, 50 % of them started before the age of 14. The highest cigarette pack consumption mean was 2.5 per week and for the present smokers was 1.8; the prevalence for CD in the smoking population was above 20 %; present smoking diminished in those with a history of CD, especially cancer and heart disease. CONCLUSIONS: The prevalence of past and present TC is lower than that reported in other studies in the Mexican population, because of how the exposure to TC was measure.

[Hemorrhagic dengue without hemorrhaging: a novel diagnostic category?]. / Dengue hemorrágico sin hemorragias: otra categoría?

OBJECTIVE: Compare the clinical course of Dengue Fever (DF) and Dengue Hemorrhagic Fever (DHF). MATERIAL AND METHODS: Cross-sectional study among seropositive cases reported by the Northern Veracruz District IMSS Office in 2004. We analyzed the epidemiology, symptomology, clinical findings and disease progression. We calculated frequencies, proportions and averages. Clinical data and disease progression were compared. RESULTS: We studied 404 patients, divided into three groups: 75 with CD, 120 DHF and 212 cases with no hemorrhagic data although displaying Dengue with Thrombocytopenia (DwT). General symptoms were much less common among Dengue cases. Abdominal pain, hepatomegaly and splenomegaly were more frequent among patients with DHF. Fluid leakage and hemorrhaging were observed in 75% and 46%, respectively, of the latter group. The history of prior infection was proportional. All patients presenting DHF showed thrombocytopenia, though only 3% showed hemoconcentration. The mean value for hematocrit was low (p=0.02) and the platelet count greater (p<0.001) among Dengue cases. Hemoglobin concentration showed no difference. The average time between disease onset and appearance of thrombocytopenia was similar in DHF cases (4.3+/- 1.6 days) and Dengue with Thrombocytopenia (4.3+/-1.6); even though, contrary to these, in the first group fluid leakage (3.7+/-1.8) and hemorrhaging (3.4+/-1.7) were previously identified. CONCLUSIONS: Our results confirm the presence of cases showing atypical disease course, without external hemorrhaging data but showing significant thrombocytopenia that may go unnoticed and worsen disease progression.

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

BACKGROUND: Dengue (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. RESULTS: 1. 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%. CONCLUSION: DENV-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.

Dengue hemorrágico sin hemorragias: otra categoría? / Hemorrhagic dengue without hemorrhaging: a novel diagnostic category?

Objetivo: Comparar el comportamiento clínico del dengue clásico (DC) y dengue hemorrágico (DH). Material y métodos: Estudio transversal en casos seropositivos de la Delegación Veracruz Norte del Instituto Mexicano del Seguro en 2004. Se analizaron antecedentes epidemiológicos, sintomatología, parámetros clínicos y evolución. Se obtuvieron frecuencias, proporciones y promedios. Se compararon datos clínicos y tiempos de evolución. Resultados: Estudiamos 404 pacientes integrados en tres grupos: 75 con DC, 120 con DH y 212 sin datos hemorrágicos pero con plaquetopenia (DcP). Los síntomas generales fueron menos frecuentes en los casos de dengue; el dolor abdominal, hepatomegalia y esplenomegalia fueron más comunes en los que presentaron hemorragias. El escape de líquidos y hemorragias ocurrieron en 75 y 46% de este último grupo. Los antecedentes de infección previa fueron semejantes. Todos los enfermos de DH presentaron plaquetopenia y 3%, hemoconcentración. La media del hematócrito fue menor (p=0.02) y el conteo plaquetario mayor (p<0.01) en los de DC. La hemoglobina no mostró diferencias. El promedio entre el inicio de la enfermedad y la aparición de plaquetopenia fue similar en los casos con DH (4.3±1.6 días) y DcP (4.3±1.6); aunque, a diferencia de éstos, en los primeros el escape de líquidos (3.7±1.8) y hemorragias (3.4±1.7) se identificaron previamente. Conclusiones: Los resultados demuestran la presencia de casos con una evolución atípica, sin datos hemorrágicos externos pero con trombocitopenia importante que puede pasar desapercibida y predisponer el agravamiento del cuadro.

OBJECTIVE: Compare the clinical course of Dengue Fever (DF) and Dengue Hemorrhagic Fever (DHF). MATERIAL AND METHODS: Cross-sectional study among seropositive cases reported by the Northern Veracruz District IMSS Office in 2004. We analyzed the epidemiology, symptomology, clinical findings and disease progression. We calculated frequencies, proportions and averages. Clinical data and disease progression were compared. RESULTS: We studied 404 patients, divided into three groups: 75 with CD, 120 DHF and 212 cases with no hemorrhagic data although displaying Dengue with Thrombocytopenia (DwT). General symptoms were much less common among Dengue cases. Abdominal pain, hepatomegaly and splenomegaly were more frequent among patients with DHF. Fluid leakage and hemorrhaging were observed in 75% and 46%, respectively, of the latter group. The history of prior infection was proportional. All patients presenting DHF showed thrombocytopenia, though only 3% showed hemoconcentration. The mean value for hematocrit was low (p=0.02) and the platelet count greater (p<0.001) among Dengue cases. Hemoglobin concentration showed no difference. The average time between disease onset and appearance of thrombocytopenia was similar in DHF cases (4.3+/- 1.6 days) and Dengue with Thrombocytopenia (4.3+/-1.6); even though, contrary to these, in the first group fluid leakage (3.7+/-1.8) and hemorrhaging (3.4+/-1.7) were previously identified. CONCLUSIONS: Our results confirm the presence of cases showing atypical disease course, without external hemorrhaging data but showing significant thrombocytopenia that may go unnoticed and worsen disease progression.

[Arbovirus causing hemorrhagic fever at IMSS]. / Arbovirus causales de fiebre hemorrágica en pacientes del Instituto Mexicano del Seguro Social.

OBJECTIVE: To know the arbovirus causing hemorrhagic fever in patients at the Mexican Institute of Social Security. MATERIAL AND METHODS: A follow-up study was made in patients with probable diagnosis of hemorrhagic dengue. Blood samples were taken to look for dengue fever, yellow fever and San Luis, Tonate and Mayaro encephalitis viruses. Frequencies and proportions of the interest variables were analyzed. RESULTS: 35 patients were studied. Isolation and PCR results of the 13 samples were negative in 12 of them and positive to denguevirus-3 in one of them. The determination of IgM was positive for dengue fever in 25 cases; 2 were positive to Mayaro virus and 8 were negative to what was looked for. Hemorrhages and thrombocytopenia were more frequent in patients infected with dengue and Mayaro viruses; jaundice and encephalopathy were more frequent in the latter, and renal dysfunction, in patients with a negative result. Evolution was satisfactory in all cases, except for one (Mayaro), which presented hemorrhages, thrombocytopenia, jaundice and encephalopathy that lead to death. CONCLUSIONS: The results show the risk of appearance and dissemination of several vector-born diseases in Mexico. Thus, they require intensive epidemiological surveillance to identify them and to know their real occurrence and specific clinical profile.

[Prevalence of dengue and leptospira antibodies in the state of Veracruz, Mexico]. / 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% (IC 95% 76-81). The main factors associated with infection were age and residence in neighborhoods with higher vectorial indices (RMP = 2.94, IC 95% 1.46-6.1). Overall seroprevalence against leptospira was 4% (IC 95% 2-6). Prevalence was higher in the 25 to 44 years age group (35%, IC 95% 15-59). Seroprevalence in individuals who referred to living with dogs, pigs, cows and rats was 25% (IC 95% 0.63-80). Eighty-five percent of individuals who were leptospira positive were also dengue positive. CONCLUSIONS: The prevalence of denguevirus antibodies suggests the risk of serious dengue hemorrhagic outbreaks. Although leptospirosis prevalence was low, the coexistence of both agents was confirmed.

Prevalencia de anticuerpos contra dengue y leptospira en la población de Jáltipan, Veracruz / Prevalence of dengue and leptospira antibodies in the state of Veracruz, Mexico

OBJETIVO: Conocer la prevalencia de anticuerpos contra dengue y leptospira en Jáltipan, Veracruz, México MATERIAL Y MÉTODOS: Estudio transversal en 500 habitantes de Jáltipan, Veracruz, mediante un muestreo por hogares, aplicación de cuestionario y toma de muestras sanguíneas. Se buscaron anticuerpos IgG y se evaluaron factores asociados a sus seroprevalencias mediante regresión logística RESULTADOS: La seroprevalencia global para denguevirus fue 79.6 por ciento (IC95 por ciento 76-81); los principales factores vinculados con la infección fueron la edad (p< 0.001) y presencia de larvas en el domicilio (RMP= 2.94; IC95 por ciento 1.46-6.1). La seroprevalencia global contra leptospira fue 4 por ciento (IC95 por ciento 2-6). La mayor prevalencia fue para el grupo en edad productiva (35 por ciento, IC95 por ciento15-59). Quienes refirieron convivir simultáneamente con perros, cerdos, vacas y ratas presentaron una seroprevalencia de 25 por ciento (IC95 por ciento 0.63-80). El 85 por ciento de los positivos a leptospira también fue positivo a dengue CONCLUSIONES: La prevalencia de anticuerpos contra denguevirus demuestra el riesgo de brotes explosivos de dengue hemorrágico. Aunque la prevalencia de leptospirosis fue baja, se confirmó la coexistencia de estos agentes.

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.

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

OBJETIVO: Estimar la prevalencia de obesidad (OB) y sobrepeso (SP) en mujeres trabajadoras del IMSS en la Ciudad de México, aplicando dos criterios de clasificación y su asociación con algunos factores de riesgo. MATERIAL Y MÉTODOS: Estudio transversal realizado entre julio de 1999 y septiembre de 2000 que incluyó a 588 mujeres trabajadoras en el IMSS entre 20 y 65 años. Los criterios utilizados para medir la prevalencia de OB y SP fueron los propuestos por la OMS y la Norma Oficial Mexicana para el manejo integral de la obesidad (NOM).RESULTADOS: La frecuencia de OB fue 27.6% (26% ajustada) y de SP de 43.2% (40.2% ajustada) al aplicar los criterios de la OMS. Conforme a la NOM, los niveles de OB en el grupo de talla baja (<1.50 m) se elevaron a 75% y en el de talla mayor a 1.50 m a 52.2%. Sin embargo, al comparar el índice de masa corporal de talla baja y talla normal no se aprecian diferencias. El factor de riesgo para OB y SP fue la edad. En forma protectora resultaron la educación y el ejercicio. CONCLUSIONES: Las altas prevalencias de OB y SP en la población estudiada constituyen un riesgo importante para la salud de este grupo de población, que se puede traducir en altos niveles de discapacidad y pensiones con un alto costo para la Institución. Estos resultados demandan la realización de intervenciones que permitan identificar precozmente a mujeres con índices de masa corporal de riesgo. Los rangos propuestos por la NOM pueden ser de utilidad para la identificación precoz de las mujeres en riesgo.

Clinical profile of dengue hemorrhagic fever cases in Mexico

OBJETIVO: El dengue hemorrágico en México es una enfermedad emergente desde 1994. La circulación de los cuatro serotipos incrementa el riesgo de epidemias de dengue hemorrágico. MATERIAL Y MÉTODOS: Se reportan los datos clínicos y epidemiológicos de los casos de dengue hemorrágico confirmados y notificados por el IMSS de 1995 a 2003. Se analizaron las características clínicas y epidemiológicas entre grupos. Para el control y la evaluación final de las variables se utilizó un modelo multivariado. RESULTADOS: Los casos fueron asignados en dos grupos: 438 con dengue clásico, que incluye 109 casos con manifestaciones hemorrágicas sin trombocitopenia, y 977 casos de dengue hemorrágico con 79 defunciones. Los factores de riesgo asociados a las defunciones fueron: hematemesis (RR 2.6; IC 95 por ciento 1.4-4.6) y melena (RR 2.2; IC 95 por ciento 1.2-3.7). CONCLUSIONES: El cuadro clínico descrito para la población del Instituto Mexicano del Seguro Social permite identificar factores pronósticos que ayuden al clínico a prevenir y manejar adecuadamente los casos severos de dengue hemorrágico.

Validación de la prueba de coproparasitoscopía de Faust con preservador a base de fenol, alcohol y formol (PAF) / Validation of the coproparasitoscopic Faust test with preservative made up of phenol, aocohol and formol (PAF)

Se comparó la prueba de coproparasitoscopia con preservador PAF (fenol, alcohol y formol), con el método directo utilizado rutinariamente en unidades médicas de atención rural. Se estudiaron 50 niños de Jamiltepec, Oaxaca. Se les realizaron cuatro exámenes coproparasitoscópicos, tres por el método directo y el último con la técnica de PAF. Al comparar ambas pruebas, y tomando como estandar de oro el método directo, se obtuvo una sensibilidad para el PAF del 91 por ciento, especificidad de 85 por ciento, y valor predictivo positivo del 96 por ciento. La técnica evaluada permite optimizar los recursos, por lo que se propone como método diagnóstico alterno al directo. Cuando esté indicada una prueva tamiz, la técnica de PAF puede ser una alternativa eficiente, sobre todo en poblaciones rurales con prevalencia alta de parasitosis intestinal