Coinfection accelerates transmission to new hosts despite no effects on virulence and parasite growth.

One of the fundamental aims of ecological, epidemiological and evolutionary studies of host-parasite interactions is to unravel which factors affect parasite virulence. Theory predicts that virulence and transmission are correlated by a trade-off, as too much virulence is expected to hamper transmission owing to excessive host damage. Coinfections may affect each of these traits and/or their correlation. Here, we used inbred lines of the spider mite Tetranychus urticae to test how coinfection with T. evansi impacted virulence-transmission relationships at different conspecific densities. The presence of T. evansi on a shared host did not change the relationship between virulence (leaf damage) and the number of transmitting stages (i.e. adult daughters). The relationship between these traits was hump-shaped across densities, both in single and coinfections, which corresponds to a trade-off. Moreover, transmission to adjacent hosts increased in coinfection, but only at low T. urticae densities. Finally, we tested whether virulence and the number of daughters were correlated with measures of transmission to adjacent hosts, in single and coinfections at different conspecific densities. Traits were mostly independent, meaning that interspecific competitors may increase transmission without affecting virulence. Thus, coinfections may impact epidemiology and parasite trait evolution, but not necessarily the virulence-transmission trade-off.This article is part of the theme issue 'Diversity-dependence of dispersal: interspecific interactions determine spatial dynamics'.

Relevancia a corto plazo de la coinfección viral en pacientes menores de 2 años hospitalizados con infecciones de las vías respiratorias inferiores / Short-term relevance of lower respiratory viral coinfection in inpatients under 2 years of age

Introducción: Avances en el diagnóstico molecular han hecho posible la detección de agentes virales desconocidos en infecciones de las vías respiratorias inferiores (IVRI). Sin embargo, sigue habiendo dudas relativamente a su frecuencia y relevancia. Objetivo: Comparar la clínica y la gravedad entre la infección por virus único y la coinfección en niños admitidos por IVRI. Métodos: Se realizó un estudio durante 3 años consecutivos (2012-2015) que incluyó a niños menores de 2 años ingresados por IVRI. La identificación viral se realizó mediante la técnica de PCR para 16 virus. Los datos clínicos y el uso de los recursos hospitalarios se recogieron de forma estándar durante la estancia hospitalaria y se compararon la infección única con coinfecciones virales. Resultados: Fueron analizadas 524 muestras (451 pacientes); 448 (85,5%) tuvieron al menos un virus identificado. Coinfecciones virales se encontraron en 159 (35,5%). RSV y HRV fueron los virus más frecuentes; bronquiolitis y neumonía, los diagnósticos principales. Los pacientes con coinfecciones virales eran mayores, iban a la guardería, tenían sibilancias recurrentes con más frecuencia y eran más sintomáticos al ingreso. No fueron sometidos a más exámenes, pero les fueron prescritos medicamentos con más frecuencia. El grupo de la coinfección viral no mostró una mayor duración de la estancia hospitalaria, de la necesidad de oxígeno, de UCI o soporte ventilatorio. Discusión: Nuestro estudio mostró una proporción significativa de coinfecciones virales en los niños pequeños ingresados con IVRI y confirma dados previos que muestran que la prescripción es más frecuente en las coinfecciones virales, sin asociación con peor resultado clínico (AU)

Introduction: Advances in molecular diagnosis have made it possible to detect previously unknown viral agents as causative agents of lower respiratory tract infections (LRTI). The frequency and relevance of viral coinfections is still debatable. Objective: compare clinical presentation and severity between single virus infection and viral coinfection in children admitted for LRTI. Methods: A 3-year period observational study (2012-2015) included children younger than two years admitted for LRTI. Viral identification was performed using PCR technique for 16 viruses. Clinical data and use of health resources was gathered during hospital stay using a standard collection form and we compared single virus infection and viral coinfections. Results: The study included 524 samples (451 patients); 448 (85,5%) had at least one virus identified. Viral coinfections were found in 159 (35,5%). RSV and HRV were the most commonly identified virus; bronchiolitis and pneumonia the most frequent diagnosis. Patients with viral coinfections were older, attended day-care centers, had previous recurrent wheezing more frequently and were more symptomatic at admission. These patients did not have more complementary exams performed but were prescribed medications more often. Viral coinfection group did not show longer length of hospital stay and oxygen need, more need for ICU nor ventilatory support. Discussion: Our study showed a significant proportion of viral coinfections in young infants admitted with LRTI and confirmed previous data showing that prescription was more frequent in inpatients with viral coinfections, without an association with worst clinical outcome (AU)

Co-infección por los virus del dengue y chikungunya: revisión narrativa / Coinfection of dengue and chikungunya viruses: narrative review

Resumen Introducción: Los virus del dengue y chikungunya son transmitidos por la hembra de los mosquitos Aedes aegypti y Aedes albopictus, ampliamente distribuidos en zonas tropicales y subtropicales, lo que facilita la co-infección. Objetivo: Determinar la magnitud, la distribución geográfica y el cuadro clínico de la co-infección por dengue y chikungunya. Material y Métodos: Revisión narrativa. Búsqueda en las bases de datos PubMed y Lilacs, utilizando los términos MeSH "Chikungunya", "CHIKV", "DENV", "Dengue" y "coinfection. Se incluyeron los artículos de los últimos 20 años. Resultados: Se incluyeron 45 artículos. El mayor reporte de co-infección fue en Asia seguido de África. En las Américas la información es limitada por la reciente circulación del chikungunya. La magnitud de la co-infección varió entre 0 y 31,9%. No se encontraron diferencias en la distribución de la co-infección por sexo y edad. El cuadro clínico de la mono-infección y la co-infección fue similar. Algunos reportes de caso exponen cuadros graves con afección del sistema nervioso central, manifestaciones hemorrágicas y enfermedad de Still. Conclusión: Las manifestaciones clínicas de la co-infección por dengue y chikungunya son similares a la mono-infección, situación que dificulta el diagnóstico y la medición de su magnitud.

Background: Dengue and chikungunya viruses are transmitted by the female Aedes aegypti and Aedes albopictus, which are widely distributed in tropical and subtropical areas, facilitating coinfection. Aim: To determine the magnitude, geographical distribution and clinical picture of dengue and chikungunya coinfection. Material and Methods: Narrative review. A search in the PubMed and Lilacs databases was made, using the MeSH terms "Chikungunya", "CHIKV", "DENV", "Dengue" and "coinfection. The articles of the last 20 years were included. Results: A total of 45 articles were included. The largest coinfection report was in Asia followed by Africa. In the Americas, the information is limited because of the recent circulation of chikungunya. The magnitude of coinfection varies between 0% and 31.9%. No differences were found in the distribution of coinfection by sex and age. The clinical picture of monoinfection and coinfection was similar. Some case reports show severe cases with central nervous system involvement, hemorrhagic manifestations and Still's disease. Conclusion: The clinical manifestations of coinfection by dengue and chikungunya viruses are similar to those due to monoinfection, which difficult the diagnosis and measurement of its magnitude.

Barriers to control syphilis and HIV vertical transmission in the health care system in the city of Sao Paulo / Entraves no controle da transmissão vertical da sífilis e do HIV no sistema de atenção à saúde do município de São Paulo

OBJECTIVE: The objective of this study was to identify possible barriers to control vertical transmission of syphilis and HIV through the analysis of the orientation process of pregnant women from prenatal care to the obstetric center at an university hospital in Sao Paulo (Reference) and their return (with their exposed babies) for follow-up after hospital discharge (counter-reference). METHODS: It is a retrospective cross-sectional study including interviews with healthcare personnel. Pregnant women with syphilis and/or HIV-infection admitted for labor or miscarriage were identified from August 2006 to August 2007. Routine care for mothers and babies were analyzed. RESULTS: 56 pregnant women were identified: 43 were HIV-infected, 11 had syphilis and two were coinfected (syphilis/HIV); 22 health care professionals were interviewed. Prenatal care was identified in 91.1% of these women: 7/11 (63.6%) with syphilis; 44/45 (97.8%) HIV-infected or coinfected. The reference for delivery was satisfactory for 57.7% of the syphilis-infected women and 97.7% of the HIV-infected ones. The counter-reference was satisfactory for all babies and mothers at hospital discharge, besides the non-adherence to this recommendation. Interviews with health care professionals showed there are better routines for assisting and following-up pregnant women, puerperal women and HIV-infected or exposed babies than for those infected with syphilis. The epidemiological report and surveillance system are also better for HIV-infected patients. CONCLUSION: The difficulties in the reference and counter-reference system of these women and their babies are evident barriers to control the vertical transmission of these infectious diseases. .

OBJETIVO: O objetivo deste estudo foi identificar possíveis entraves ao controle da transmissão vertical da sífilis e HIV através da análise do processo de encaminhamento das gestantes desde os serviços de atendimento pré-natal até o Centro Obstétrico de um hospital universitário, no município de São Paulo (referência), e seu retorno, com seus bebês expostos, após alta hospitalar, para acompanhamento (contrarreferência). MÉTODO: Estudo de corte transversal, retrospectivo, acrescido de entrevistas com profissionais de saúde. Gestantes com sífilis e/ou infecção pelo HIV foram identificadas na admissão para o parto de agosto de 2006 a agosto de 2007. A rotina e o fluxo dos encaminhamentos de mães e recém-nascidos foram analisados. RESULTADOS: Foram identificadas 56 gestantes infectadas: 43 com infecção pelo HIV, 11 com sífilis e duas coinfectadas (sífilis/HIV); 22 profissionais de saúde foram entrevistados. Acompanhamento pré-natal foi feito por 91,1% das mulheres: 7/11 (63,6%) com sífilis; 44/45 (97,8%) infectadas pelo HIV ou coinfectadas. A referência para o parto foi adequada para 57,1% das gestantes com sífilis e 97,7% daquelas infectadas pelo HIV. A contrarreferência foi adequada para todas as gestantes, apesar da não aderência a essa recomendação. Entrevistas com os profissionais de saúde revelaram que as rotinas e o fluxo de encaminhamento das gestantes, puérperas e recém-nascidos estão mais bem estabelecidos para HIV do que para sífilis. A vigilância epidemiológica e notificação também foram mais eficazes para o HIV. CONCLUSÃO: As dificuldades no sistema de referência e contrarreferência dessas mulheres e seus bebês são evidentes entraves ao controle da t...

Prevalencia de Trichomonas vaginalis en trabajadores sexuales / Trichomonas vaginalis prevalence in sex workers

La tricomoniasis es una infección de transmisión sexual (ITS) que se asocia a vaginitis, uretritis, cervicitis y enfermedad inflamatoria pélvica pudiendo producir infertilidad tubárica. El objetivo de este trabajo, de tipo retrospectivo longitudinal, fue determinar la prevalencia de Trichomonas vaginalis en una población de trabajadores sexuales en Mendoza, Argentina. Se estudió en forma retrospectiva una población de 720 personas asistidas por el Programa Provincial de ITS de Mendoza. Entre febrero de 2007 y junio de 2009 se procesaron 1692 muestras con un muestreo por reposición. La distribución por sexo fue de 687 mujeres y 33 varones con edades comprendidas entre 15 y 65 años. La prevalencia de tricomoniasis determinada en esta población en riesgo fue de 7.6% para las mujeres, sin encontrarse infecciones en el grupo de los hombres. La prevalencia hallada en este grupo en riesgo muestra una población con alta vulnerabilidad para contraer otras ITS de mayor gravedad. En otro sentido, sugiere una importante falta de adhesión al uso de barreras mecánicas para prevenir infecciones de transmisión sexual. Este trabajo justifica la elaboración de una guía de procedimientos para el manejo de la infección por tricomonas en el marco del Programa de Salud Reproductiva (PROSAR).

Trichomoniasis is a sexually transmitted infection (STI) usually associated to vaginitis, urethritis, cervicitis and pelvic inflammatory disease, which can cause infertility. The aim of this retrospective longitudinal study was to determine Trichomonas vaginalis prevalence in a population of male and female sex workers in Mendoza, Argentina. A cohort of 720 people who attended the STI Program in this province was retrospectively analyzed. From February 2007 up to June 2009, 1692 samples were processed using a reposition sampling method. The age and sex distribution of the population was: 687 women/33 men, from 15 to 65 years old. Trichomoniasis prevalence determined for this population at risk was 7.6% in women only, men did not present infection. The high prevalence shown for this risk group suggests a great vulnerability of this population to contract other more serious STIs. In another sense, it also shows a remarkable lack in the use of mechanical barriers to prevent sexually transmitted diseases (STDs). The present research justifies the elaboration of standardized procedures guide to diagnose T. vaginalis within the framework of the Reproductive Health Program (PROSAR).

Plasmodium species mixed infections in two areas of Manhiça district, Mozambique

We compared the distribution patterns of individual Plasmodium species and mixed-species infections in two geographically close endemic areas, but showing environmental differences. Comparisons concerned circulating Plasmodium infections in both human and mosquito vector populations in the dry and wet seasons, at a micro-epidemiological level (households). Both areas revealed a very high overall prevalence of infection, all year-round and in all age groups. Plasmodium falciparum was the predominant species, being found in the vast majority of infected individuals regardless of the presence of other species. Plasmodium malariae and Plasmodium ovale occurred almost exclusively in mixed infections. Seasonal variation in P. malariae prevalence was observed in one area but not in the other. A decrease in P. malariae prevalence concurred with a marked increase of P. falciparum prevalence. However this was strongly dependent on age and when analysing infections at the individual level, a different pattern between co-infecting species was unveiled. Regarding transmission patterns, in both areas, P. falciparum gametocytes predominated in single infections regardless of age and P. malariae gametocyte carriage increased when its overall prevalence decreased