Análisis de los servicios de test del VIH de cinco centros comunitarios españoles para la mejora de nuevas estrategias de promoción del diagnóstico precoz

Background: In recent years, the number of people tested for HIV has experienced a significant increase. The purpose of this study is to analyze data obtained in Spain in the HIV testing services of five Community Centres members of Agrupación Prueba de VIHda throughout 2014 and 2015,to determine its effectiveness and to characterize the subpopulation with a HIV reactive result. Study design and methods: agrupación Prueba de VIHda performed free, anonymous and confidential HIV tests according to the Consolidated guidelines on HIV testing services of WHO (2015). Data were collected using the questionnaire of the COBATEST network, developed by the COBATEST Project, and its significance was determined statistically. Results: 3061 HIV tests were performed during 2014 and 2015, with a prevalence of reactive results of 2.5%. Heterosexual and bisexual men got tested at older ages than homosexual men and women. Non-Spanish origin seems to be a risk factor for HIV infection within the sample. Bisexual men showed as high prevalence of reactive test as homosexual men, as well as they reported less previous HIV tests. Finally, index testing performed by HIV positive peer educators to the sexual partners of newly diagnosed patients showed higher prevalence than that of the classical Voluntary Counselling and Testing approach outreach most at risk populations. Conclusion:The analysis of the data shows higher prevalence of reactive results in people of non-Spanish origin compared to that of the Spanish subgroup, the former still facing barriers to access the public health system in Spain. It also demonstrates the need of new and adapted approaches for promoting early diagnosis specifically in bisexual men. Index testing by peer HIV positive educators is a highly effective method for testing people at high risk of acquiring HIV infection.Antecedentes: En los últimos años, el número de personas sometidas a pruebas frente al VIH ha experimentado un aumento significativo. El propósito de este estudio es analizar los datos de prevalencia de la infección por VIH obtenidos por cinco centros comunitarios en España pertenecientes a la Agrupación Prueba de VIHda entre 2014 y 2015, determinar su efectividad y caracterizar la subpoblación con un resultado preliminar reactivo. Diseño experimental y métodos: La Agrupación Prueba de VIHda realizó pruebas de VIH gratuitas, anónimas y confidenciales de acuerdo con las directrices consolidadas por la OMS (2015). Los datos fueron recogidos mediante el cuestionario desarrollado por el Proyecto COBATEST y su significación se determinó estadísticamente. Resultados: Durante 2014 y 2015 se realizaron un total de 3061 pruebas frente al VIH, obteniendo una prevalencia de resultados preliminares positivos del 2,5%. Los hombres heterosexuales y bisexuales se realizaron la prueba a edades más avanzadas que los hombres homosexuales y las mujeres. Las personas de origen no español parecieron mostrar un mayor riesgo de infección frente al VIH. Hombres bisexuales mostraron una prevalencia elevada similar a la de hombres homosexuales, así como declararon menos pruebas anteriores frente al VIH. Finalmente, las pruebas realizadas a través de indextesting por los educadores pares de VIH a parejas sexuales de pacientes recién diagnosticados mostraron una prevalencia superior a la obtenida por el modelo tradicional de counselling y testado voluntario ofrecido desde los centros comunitarios a poblaciones de mayor riesgo. Conclusión: El análisis de los datos muestra mayores prevalencias de resultados preliminares reactivos en personas de origen no español comparadas con aquellas del subgrupo de personas españolas, el primero de ellos todavía enfrentando barreras de acceso al sistema sanitario público en España, El análisis también demuestra la necesidad de nuevos enfoques adaptados para promover el diagnóstico precoz especialmente entre hombres bisexuales. Las pruebas realizadas a través de indextesting por educadores pares VIH positivos es un método muy eficaz para el testado de las personas con alto riesgo de contraer la infección por VIH

Effects of myxoma virus and rabbit hemorrhagic disease virus on the physiological condition of wild European rabbits: Is blood biochemistry a useful monitoring tool?

Myxomatosis and rabbit hemorrhagic disease (RHD) are the major viral diseases that affect the wild European rabbit (Oryctolagus cuniculus). These diseases arrived in Europe within the last decades and have caused wild rabbit populations to decline dramatically. Both viruses are currently considered to be endemic in the Iberian Peninsula; periodic outbreaks that strongly impact wild populations regularly occur. Myxoma virus (MV) and rabbit hemorrhagic disease virus (RHDV) alter the physiology of infected rabbits, resulting in physical deterioration. Consequently, the persistence and viability of natural populations are affected. The main goal of our study was to determine if blood biochemistry is correlated with serostatus in wild European rabbits. We carried out seven live-trapping sessions in three wild rabbit populations over a two-year period. Blood samples were collected to measure anti-MV and anti-RHDV antibody concentrations and to measure biochemical parameters related to organ function, protein metabolism, and nutritional status. Overall, we found no significant relationships between rabbit serostatus and biochemistry. Our main result was that rabbits that were seropositive for both MV and RHDV had low gamma glutamyltransferase concentrations. Given the robustness of our analyses, the lack of significant relationships may indicate that the biochemical parameters measured are poor proxies for serostatus. Another explanation is that wild rabbits might be producing attenuated physiological responses to these viruses because the latter are now enzootic in the study area.Peer Reviewe

Multi-event capture-recapture modeling of host-pathogen dynamics among European rabbit populations exposed to myxoma and Rabbit Hemorrhagic Disease Viruses: common and heterogeneous patterns

Host–pathogen epidemiological processes are often unclear due both to their complexity and over-simplistic approaches used to quantify them. We applied a multi-event capture–recapture procedure on two years of data from three rabbit populations to test hypotheses about the effects on survival of, and the dynamics of host immunity to, both myxoma virus and Rabbit Hemorrhagic Disease Virus (MV and RHDV). Although the populations shared the same climatic and management conditions, MV and RHDV dynamics varied greatly among them; MV and RHDV seroprevalences were positively related to density in one population, but RHDV seroprevalence was negatively related to density in another. In addition, (i) juvenile survival was most often negatively related to seropositivity, (ii) RHDV seropositives never had considerably higher survival, and (iii) seroconversion to seropositivity was more likely than the reverse. We suggest seropositivity affects survival depending on trade-offs among antibody protection, immunosuppression and virus lethality. Negative effects of seropositivity might be greater on juveniles due to their immature immune system. Also, while RHDV directly affects survival through the hemorrhagic syndrome, MV lack of direct lethal effects means that interactions influencing survival are likely to be more complex. Multi-event modeling allowed us to quantify patterns of host–pathogen dynamics otherwise difficult to discern. Such an approach offers a promising tool to shed light on causative mechanisms.Funding was provided by an Ingenierıa de Protección Ambiental-Consejo Superior de Investigaciones Científicas (IPA-CSIC) contract through projects 20070687_5 and 20091418. The work reported in this paper complies with standards and procedures promulgated by Spanish legislation.Peer reviewe

Do coccidian and nematode infections influence immunity against myxomatosis and rabbit haemorrhagic disease in European rabbits?

Peer Reviewe

Coccidian and helminth infections influence the sero-conversion against myxoma and rabbit haemorrhagic disease viruses in European wild rabbit

The interaction among several parasites in European rabbits (Oryctolagus cuniculus) is crucial to host fitness and to the epidemiology of myxomatosis and rabbit hemorrhagic disease. These diseases have caused significant reductions in rabbit populations on the Iberian Peninsula. Most studies have focused on the epidemiology and pathogenesis of these viruses individually, and little is known about interactions between these viruses and other parasites. Taking advantage of an experimental restocking program in Spain, the effects of coccidian and nematode infections on the probability of having detectable antibody to myxoma and rabbit hemorrhagic disease viruses were tested in European wild rabbits. For 14 mo, we monitored rabbit abundance and parasite loads (coccidia and nematodes) in three reintroduced rabbit populations. While coccidian and nematode loads explained seasonal antibody prevalences to myxoma virus, the pattern was less clear for rabbit hemorrhagic disease. Contrary to expectations, prevalence of antibody to myxoma virus was inversely proportional to coccidian load, while nematode load seemed to play a minor role. These results have implications for viral disease epidemiology and for disease management intended to increase rabbit populations in areas where they are important for ecosystem conservation.Peer Reviewe

Validated flow cytometry allows rapid quantitative assessment of immune responses in amphibians

Assessments of amphibian immune state have been commonly made through indirect methods like phytohemagglutinin (PHA) injections, or by direct methods like cell counts from blood smears. Here we validate a simple method to assess immune responses in amphibians by means of flow cytometry with a fluorescent lipophilic dye (3,3′ Dipentyloxacarbocyanine), which removes the need for specific antibodies. We experimentally altered the immunological state of Pelobates cultripes tadpoles by exposing some to exogenous corticosterone. We then determined the immune state of each tadpole through both blood smears and flow cytometry. We found that both techniques showed similar patterns of the proportion of white blood cells. Once validated, flow cytometry also allowed quantitation of changes in absolute number of white cells. We discuss the suitability of both techniques attending to the accuracy of each technique, body size requirements, or the tractability in field studies.This study was funded by Ministerio de Economía y Competitividad (grant CGL2012-40044 to I.G.M.) and by fellowship (AP2010-5373) from Ministerio de Educación to P.B

List of amphibian species across the globe whose ranges and macrohabitat overlap with those of L. humile populations

Invasive species cause major ecosystem impacts. To prioritise management, it is first necessary to recognise which invaders have the highest impact, as outlined by the Convention on Biological Diversity’s Strategic Plan 2020. We show for the first time that chemical compounds previously shown to be used in ant defence against other ant species can also be used to prey upon vertebrates of relatively greater size. We estimate the number of amphibian species whose ranges overlap with those of the Argentine ant across the globe and examine the likely global threat to terrestrial amphibians, an already endangered taxonomic group.Peer reviewe

List of amphibian species across the globe whose ranges and macrohabitat overlap with those of L. humile populations

Invasive species have major impacts on biodiversity and are one of the primary causes of amphibian decline and extinction. Unlike other top ant invaders that negatively affect larger fauna via chemical defensive compounds, the Argentine ant (Linepithema humile) does not have a functional sting. Nonetheless, it deploys defensive compounds against competitors and adversaries. We estimated levels of ant aggression toward 3 native terrestrial amphibians by challenging juveniles in field ant trails and in lab ant foraging arenas. We measured the composition and quantities of toxin in L. humile by analyzing pygidial glands and whole-body contents. We examined the mechanisms of toxicity in juvenile amphibians by quantifying the toxin in amphibian tissues, searching for histological damages, and calculating toxic doses for each amphibian species. To determine the potential scope of the threat to amphibians, we used global databases to estimate the number, ranges, and conservation status of terrestrial amphibian species with ranges that overlap those of L. humile. Juvenile amphibians co-occurring spatially and temporally with L. humile die when they encounter L. humile on an ant trail. In the lab, when a juvenile amphibian came in contact with L. humile the ants reacted quickly to spray pygidial-gland venom onto the juveniles. Iridomyrmecin was the toxic compound in the spray. Following absorption, it accumulated in brain, kidney, and liver tissue. Toxic dose for amphibian was species dependent. Worldwide, an estimated 817 terrestrial amphibian species overlap in range with L. humile, and 6.2% of them are classified as threatened. Our findings highlight the high potential of L. humile venom to negatively affect amphibian juveniles and provide a basis for exploring the largely overlooked impacts this ant has in its wide invasive range.This research was partially supported by the Norman and Rose Lederrer Endowed Chair of Biology to A.H. Additional funding came from MINECO and FEDER (projects CGL2012‐36181 and CGL2013‐43660‐P, respectively) and EBD (MINECO Severo Ochoa Program for Centers of Excellence in R + D + I [SEV‐2012‐0262])

Effects of the Argentine ant venom on terrestrial amphibians

Invasive species have major impacts on biodiversity and are one of the primary causes of amphibian decline and extinction. Unlike other top ant invaders that negatively affect larger fauna via chemical defensive compounds, the Argentine ant (Linepithema humile) does not have a functional sting. Nonetheless, it deploys defensive compounds against competitors and adversaries. We estimated levels of ant aggression toward 3 native terrestrial amphibians by challenging juveniles in field ant trails and in lab ant foraging arenas. We measured the composition and quantities of toxin in L. humile by analyzing pygidial glands and whole-body contents. We examined the mechanisms of toxicity in juvenile amphibians by quantifying the toxin in amphibian tissues, searching for histological damages, and calculating toxic doses for each amphibian species. To determine the potential scope of the threat to amphibians, we used global databases to estimate the number, ranges, and conservation status of terrestrial amphibian species with ranges that overlap those of L. humile. Juvenile amphibians co-occurring spatially and temporally with L. humile die when they encounter L. humile on an ant trail. In the lab, when a juvenile amphibian came in contact with L. humile the ants reacted quickly to spray pygidial-gland venom onto the juveniles. Iridomyrmecin was the toxic compound in the spray. Following absorption, it accumulated in brain, kidney, and liver tissue. Toxic dose for amphibian was species dependent. Worldwide, an estimated 817 terrestrial amphibian species overlap in range with L. humile, and 6.2% of them are classified as threatened. Our findings highlight the high potential of L. humile venom to negatively affect amphibian juveniles and provide a basis for exploring the largely overlooked impacts this ant has in its wide invasive range.This research was partially supported by the Norman and Rose Lederrer Endowed Chair of Biology to A.H. Additional funding came from MINECO and FEDER (projects CGL2012‐36181 and CGL2013‐43660‐P, respectively) and EBD (MINECO Severo Ochoa Program for Centers of Excellence in R + D + I [SEV‐2012‐0262])