RESUMEN
BACKGROUND: Over the last 5 years (2013-2017), the Caribbean region has faced an unprecedented crisis of co-occurring epidemics of febrile illness due to arboviruses transmitted by the Aedes sp. mosquito (dengue, chikungunya, and Zika). Since 2013, the Caribbean island of Barbados has experienced 3 dengue outbreaks, 1 chikungunya outbreak, and 1 Zika fever outbreak. Prior studies have demonstrated that climate variability influences arbovirus transmission and vector population dynamics in the region, indicating the potential to develop public health interventions using climate information. The aim of this study is to quantify the nonlinear and delayed effects of climate indicators, such as drought and extreme rainfall, on dengue risk in Barbados from 1999 to 2016. METHODS AND FINDINGS: Distributed lag nonlinear models (DLNMs) coupled with a hierarchal mixed-model framework were used to understand the exposure-lag-response association between dengue relative risk and key climate indicators, including the standardised precipitation index (SPI) and minimum temperature (Tmin). The model parameters were estimated in a Bayesian framework to produce probabilistic predictions of exceeding an island-specific outbreak threshold. The ability of the model to successfully detect outbreaks was assessed and compared to a baseline model, representative of standard dengue surveillance practice. Drought conditions were found to positively influence dengue relative risk at long lead times of up to 5 months, while excess rainfall increased the risk at shorter lead times between 1 and 2 months. The SPI averaged over a 6-month period (SPI-6), designed to monitor drought and extreme rainfall, better explained variations in dengue risk than monthly precipitation data measured in millimetres. Tmin was found to be a better predictor than mean and maximum temperature. Furthermore, including bidimensional exposure-lag-response functions of these indicators-rather than linear effects for individual lags-more appropriately described the climate-disease associations than traditional modelling approaches. In prediction mode, the model was successfully able to distinguish outbreaks from nonoutbreaks for most years, with an overall proportion of correct predictions (hits and correct rejections) of 86% (81%:91%) compared with 64% (58%:71%) for the baseline model. The ability of the model to predict dengue outbreaks in recent years was complicated by the lack of data on the emergence of new arboviruses, including chikungunya and Zika. CONCLUSION: We present a modelling approach to infer the risk of dengue outbreaks given the cumulative effect of climate variations in the months leading up to an outbreak. By combining the dengue prediction model with climate indicators, which are routinely monitored and forecasted by the Regional Climate Centre (RCC) at the Caribbean Institute for Meteorology and Hydrology (CIMH), probabilistic dengue outlooks could be included in the Caribbean Health-Climatic Bulletin, issued on a quarterly basis to provide climate-smart decision-making guidance for Caribbean health practitioners. This flexible modelling approach could be extended to model the risk of dengue and other arboviruses in the Caribbean region.
Asunto(s)
Aedes/virología , Clima , Virus del Dengue/patogenicidad , Dengue/epidemiología , Brotes de Enfermedades , Vectores de Enfermedades , Tiempo (Meteorología) , Animales , Barbados/epidemiología , Teorema de Bayes , Dengue/diagnóstico , Dengue/transmisión , Dengue/virología , Sequías , Inundaciones , Calor/efectos adversos , Humanos , Dinámicas no Lineales , Lluvia , Medición de Riesgo , Factores de Riesgo , Factores de TiempoRESUMEN
An emerging mosquito-borne flavivirus, Zika virus (ZIKV) is a significant public health concern because of the syndromes associated with the infection. In addition, ZIKV is considered a major problem due to large-scale spread of the disease and the possible clinical complications for the central nervous system, especially Guillain-Barré syndrome (GBS) and microcephaly. Since the introduction of ZIKV in the Caribbean, molecular detection of the viral RNA has been utilized as a more specific and sensitive approach to demonstrating acute infection. However, it is generally accepted that the virus has a short viremic period, generally less than 5 days. Serologic testing has the inconvenience of strong cross-reactivity among flaviviruses, such as dengue and yellow fever. As part of the laboratory surveillance activities for Zika and other arboviruses at the Caribbean Public Health Agency, in 2016 a sample from a male who was clinically diagnosed with GBS tested positive for Zika virus by real-time polymerase chain reaction (rRT-PCR). The serum sample had been taken on day 21 after the onset of symptoms. The case had initially been characterized as a typical ZIKV infection (mild fever with a generalized maculopapular rash). Later, weakness of limbs and other peripheral neurological symptoms appeared. Enzyme-linked immunoassay (ELISA) showed that the sample was negative for IgM antibodies against Zika, Chikungunya, and dengue viruses. The plaque reduction neutralization test was positive for ZIKV. This indicated parallel development of viremia and immune response against ZIKV. Recent reports have demonstrated a longer duration of the viremia in ZIKV infections. However, our report is the first one that links the infection with extended viremia and the development in parallel of a GBS case.
RESUMEN
BACKGROUND: Small island developing states (SIDS) in the Caribbean region are challenged with managing the health outcomes of a changing climate. Health and climate sectors have partnered to co-develop climate services to improve the management of emerging arboviral diseases such as dengue fever, for example, through the development of climate-driven early warning systems. The objective of this study was to identify health and climate stakeholder perceptions and needs in the Caribbean, with respect to the development of climate services for arboviruses. METHODS: Stakeholders included public decision makers and practitioners from the climate and health sectors at the regional (Caribbean) level and from the countries of Dominica and Barbados. From April to June 2017, we conducted interviews (n = 41), surveys (n = 32), and national workshops with stakeholders. Survey responses were tabulated, and audio recordings were transcribed and analyzed using qualitative coding to identify responses by research topic, country/region, and sector. RESULTS: Health practitioners indicated that their jurisdiction is currently experiencing an increased risk of arboviral diseases associated with climate variability, and most anticipated that this risk will increase in the future. National health sectors reported financial limitations and a lack of technical expertise in geographic information systems (GIS), statistics, and modeling, which constrained their ability to implement climate services for arboviruses. National climate sectors were constrained by a lack of personnel. Stakeholders highlighted the need to strengthen partnerships with the private sector, academia, and civil society. They identified a gap in local research on climate-arbovirus linkages, which constrained the ability of the health sector to make informed decisions. Strategies to strengthen the climate-health partnership included a top-down approach by engaging senior leadership, multi-lateral collaboration agreements, national committees on climate and health, and shared spaces of dialogue. Mechanisms for mainstreaming climate services for health operations to control arboviruses included climatic-health bulletins and an online GIS platform that would allow for regional data sharing and the generation of spatiotemporal epidemic forecasts. Stakeholders identified a 3-month forecast of arboviral illness as the optimal time frame for an epidemic forecast. CONCLUSIONS: These findings support the creation of interdisciplinary and intersectoral 'communities of practice' and the co-design of climate services for the Caribbean public health sector. By fostering the effective use of climate information within health policy, research and practice, nations will have greater capacity to adapt to a changing climate.
Asunto(s)
Aedes , Control de Enfermedades Transmisibles , Enfermedades Transmisibles , Salud Pública , Adolescente , Adulto , Aedes/virología , Anciano , Animales , Infecciones por Arbovirus/prevención & control , Barbados , Cambio Climático , Enfermedades Transmisibles/epidemiología , Atención a la Salud , Dengue/prevención & control , Dengue/transmisión , Vectores de Enfermedades , Dominica , Femenino , Política de Salud , Humanos , Masculino , Persona de Mediana Edad , Sector Público , Participación de los Interesados , Encuestas y Cuestionarios , Adulto JovenRESUMEN
Vampire bat-transmitted rabies was first recognized in Trinidad during a major outbreak reported in 1925. Trinidad is the only Caribbean island with vampire bat-transmitted rabies. We conducted a literature review to describe the changing epidemiology of rabies in Trinidad and give a historical perspective to rabies prevention and control measures on the island. The last human case of rabies occurred in 1937 and although no case of canine-transmitted rabies was reported since 1914, sporadic outbreaks of bat-transmitted rabies still occur in livestock to date. Over the last century, seven notable epidemics were recorded in Trinidad with the loss of over 3000 animals. During the 1950s, several measures were effectively adopted for the prevention and control of the disease which led to a significant reduction in the number of cases. These measures include: vampire bat population control, livestock vaccination, and animal surveillance. However, due to lapses in these measures over the years (e.g., periods of limited vampire control and incomplete herd vaccination), epidemics have occurred. In light of the significant negative impact of rabies on animal production and human health, rabies surveillance in Trinidad should be enhanced and cases evaluated towards the design and implementation of more evidence-based prevention and control programs.
RESUMEN
An emerging mosquito-borne flavivirus, Zika virus (ZIKV) is a significant public health concern because of the syndromes associated with the infection. In addition, ZIKV is considered a major problem due to large-scale spread of the disease and the possible clinical complications for the central nervous system, especially Guillain-Barré syndrome (GBS) and microcephaly. Since the introduction of ZIKV in the Caribbean, molecular detection of the viral RNA has been utilized as a more specific and sensitive approach to demonstrating acute infection. However, it is generally accepted that the virus has a short viremic period, generally less than 5 days. Serologic testing has the inconvenience of strong cross-reactivity among flaviviruses, such as dengue and yellow fever. As part of the laboratory surveillance activities for Zika and other arboviruses at the Caribbean Public Health Agency, in 2016 a sample from a male who was clinically diagnosed with GBS tested positive for Zika virus by real-time polymerase chain reaction (rRT-PCR). The serum sample had been taken on day 21 after the onset of symptoms. The case had initially been characterized as a typical ZIKV infection (mild fever with a generalized maculopapular rash). Later, weakness of limbs and other peripheral neurological symptoms appeared. Enzyme-linked immunoassay (ELISA) showed that the sample was negative for IgM antibodies against Zika, Chikungunya, and dengue viruses. The plaque reduction neutralization test was positive for ZIKV. This indicated parallel development of viremia and immune response against ZIKV. Recent reports have demonstrated a longer duration of the viremia in ZIKV infections. However, our report is the first one that links the infection with extended viremia and the development in parallel of a GBS case.
El virus del Zika (ZIKV), un flavivirus emergente transmitido por mosquitos, es una inquietud importante en el ámbito de la salud pública por los síndromes asociados con la infección. Además, el ZIKV se considera un problema acuciante debido a la propagación a gran escala de la enfermedad y a las posibles complicaciones clínicas en el sistema nervioso central, en concreto, el síndrome de Guillain-Barré y la microcefalia. Desde que el ZIKV se introdujera en el Caribe, la detección molecular del ARN viral ha sido el método más específico y sensible utilizado para comprobar una infección aguda. Sin embargo, se cree que el virus tiene un período virémico corto, de menos de 5 días en general. La prueba serológica presenta el inconveniente de la fuerte reactividad cruzada entre los flavivirus, como el dengue y la fiebre amarilla. Como parte de las actividades de vigilancia de laboratorio para el Zika y otros arbovirus del Agencia Caribena de Salud Publica, en el 2016 la muestra de un hombre diagnosticado con la enfermedad de Guillain Barré dio positiva para el virus del Zika por medio de una reacción en cadena de la polimerasa en tiempo real (rRT-RCP). La muestra de suero se había tomado en el día 21 después de la aparición de los síntomas. En un principio, el caso se calificó como una infección por ZIKV típica (fiebre leve con una erupción maculopapular generalizada). Posteriormente, apareció la debilidad de los miembros y otros síntomas neurológicos periféricos. La prueba de inmunoadsorción enzimática (ELISA) fue negativa para los anticuerpos de tipo IgM contra los virus del Zika, el chikunguña y el dengue. La prueba de neutralización por reducción del número de placas dio positivo para el ZIKV, lo que probó que paralelamente se había desarrollado una respuesta virémica e inmune contra el ZIKV. En informes recientes se ha demostrado que en las infecciones de ZIKV el periodo virémico es más largo. Sin embargo, nuestro informe es de los primeros que relaciona un periodo virémico prolongado con el desarrollo paralelo del síndrome de Guillain-Barré.
O vírus zika é um flavivírus emergente transmitido por mosquitos e tem sido motivo de grande preocupação em saúde pública por causa das síndromes associadas à infecção. É também considerado um importante problema devido à propagação em grande escala e possíveis complicações clínicas no sistema nervoso central decorrentes da infecção, sobretudo síndrome de Guillain-Barré e microcefalia. Desde a introdução do vírus zika no Caribe, a detecção molecular do RNA viral tem sido usada como método mais específico e sensível para demonstrar infecção aguda. Porém, admite-se em geral que o vírus tem um curto período virêmico, inferior a 5 dias. O teste sorológico tem o inconveniente de produzir intensa reação cruzada com outros flavivírus, como os vírus da dengue e febre amarela. Como parte da vigilância laboratorial do vírus zika e outros arbovírus pela Agência de Saúde Pública do Caribe, em 2016, foi examinada uma amostra de um paciente do sexo masculino com diagnóstico clínico de síndrome de Guillain-Barré e o resultado foi positivo para o vírus zika com a técnica de reação em cadeia da polimerase em tempo real. A amostra sérica havia sido coletada no dia 21 após o início dos sintomas. O caso foi inicialmente descrito como infecção típica pelo vírus zika (febre baixa com erupção cutânea maculopapular generalizada) e, posteriormente, o paciente apresentou fraqueza dos membros e outros sintomas neurológicos periféricos. A amostra foi testada com a técnica de imunoensaio enzimático (ELISA) e foi negativa para anticorpos da classe IgM contra o zika vírus, vírus chikungunya e vírus da dengue. O teste de neutralização por redução de placas foi positivo para o vírus zika, indicando aumento em paralelo da viremia e resposta imunológica ao vírus. Informes recentes têm demonstrado viremia de duração mais prolongada em infecções por vírus zika. Porém, este é o primeiro relato que associa a infecção com viremia prolongada ao surgimento em paralelo da síndrome de Guillain-Barré.
Asunto(s)
Síndrome de Guillain-Barré , Reacción en Cadena de la Polimerasa , Virus Zika , Trinidad y TobagoRESUMEN
ABSTRACT An emerging mosquito-borne flavivirus, Zika virus (ZIKV) is a significant public health concern because of the syndromes associated with the infection. In addition, ZIKV is considered a major problem due to large-scale spread of the disease and the possible clinical complications for the central nervous system, especially Guillain-Barré syndrome (GBS) and microcephaly. Since the introduction of ZIKV in the Caribbean, molecular detection of the viral RNA has been utilized as a more specific and sensitive approach to demonstrating acute infection. However, it is generally accepted that the virus has a short viremic period, generally less than 5 days. Serologic testing has the inconvenience of strong cross-reactivity among flaviviruses, such as dengue and yellow fever. As part of the laboratory surveillance activities for Zika and other arboviruses at the Caribbean Public Health Agency, in 2016 a sample from a male who was clinically diagnosed with GBS tested positive for Zika virus by real-time polymerase chain reaction (rRT-PCR). The serum sample had been taken on day 21 after the onset of symptoms. The case had initially been characterized as a typical ZIKV infection (mild fever with a generalized maculopapular rash). Later, weakness of limbs and other peripheral neurological symptoms appeared. Enzyme-linked immunoassay (ELISA) showed that the sample was negative for IgM antibodies against Zika, Chikungunya, and dengue viruses. The plaque reduction neutralization test was positive for ZIKV. This indicated parallel development of viremia and immune response against ZIKV. Recent reports have demonstrated a longer duration of the viremia in ZIKV infections. However, our report is the first one that links the infection with extended viremia and the development in parallel of a GBS case.(AU)
RESUMEN El virus del Zika (ZIKV), un flavivirus emergente transmitido por mosquitos, es una inquietud importante en el ámbito de la salud pública por los síndromes asociados con la infección. Además, el ZIKV se considera un problema acuciante debido a la propagación a gran escala de la enfermedad y a las posibles complicaciones clínicas en el sistema nervioso central, en concreto, el síndrome de Guillain-Barré y la microcefalia. Desde que el ZIKV se introdujera en el Caribe, la detección molecular del ARN viral ha sido el método más específico y sensible utilizado para comprobar una infección aguda. Sin embargo, se cree que el virus tiene un período virémico corto, de menos de 5 días en general. La prueba serológica presenta el inconveniente de la fuerte reactividad cruzada entre los flavivirus, como el dengue y la fiebre amarilla. Como parte de las actividades de vigilancia de laboratorio para el Zika y otros arbovirus del Agencia Caribena de Salud Publica, en el 2016 la muestra de un hombre diagnosticado con la enfermedad de Guillain Barré dio positiva para el virus del Zika por medio de una reacción en cadena de la polimerasa en tiempo real (rRT-RCP). La muestra de suero se había tomado en el día 21 después de la aparición de los síntomas. En un principio, el caso se calificó como una infección por ZIKV típica (fiebre leve con una erupción maculopapular generalizada). Posteriormente, apareció la debilidad de los miembros y otros síntomas neurológicos periféricos. La prueba de inmunoadsorción enzimática (ELISA) fue negativa para los anticuerpos de tipo IgM contra los virus del Zika, el chikunguña y el dengue. La prueba de neutralización por reducción del número de placas dio positivo para el ZIKV, lo que probó que paralelamente se había desarrollado una respuesta virémica e inmune contra el ZIKV. En informes recientes se ha demostrado que en las infecciones de ZIKV el periodo virémico es más largo. Sin embargo, nuestro informe es de los primeros que relaciona un periodo virémico prolongado con el desarrollo paralelo del síndrome de Guillain-Barré.(AU)
RESUMO O vírus zika é um flavivírus emergente transmitido por mosquitos e tem sido motivo de grande preocupação em saúde pública por causa das síndromes associadas à infecção. É também considerado um importante problema devido à propagação em grande escala e possíveis complicações clínicas no sistema nervoso central decorrentes da infecção, sobretudo síndrome de Guillain-Barré e microcefalia. Desde a introdução do vírus zika no Caribe, a detecção molecular do RNA viral tem sido usada como método mais específico e sensível para demonstrar infecção aguda. Porém, admite-se em geral que o vírus tem um curto período virêmico, inferior a 5 dias. O teste sorológico tem o inconveniente de produzir intensa reação cruzada com outros flavivírus, como os vírus da dengue e febre amarela. Como parte da vigilância laboratorial do vírus zika e outros arbovírus pela Agência de Saúde Pública do Caribe, em 2016, foi examinada uma amostra de um paciente do sexo masculino com diagnóstico clínico de síndrome de Guillain-Barré e o resultado foi positivo para o vírus zika com a técnica de reação em cadeia da polimerase em tempo real. A amostra sérica havia sido coletada no dia 21 após o início dos sintomas. O caso foi inicialmente descrito como infecção típica pelo vírus zika (febre baixa com erupção cutânea maculopapular generalizada) e, posteriormente, o paciente apresentou fraqueza dos membros e outros sintomas neurológicos periféricos. A amostra foi testada com a técnica de imunoensaio enzimático (ELISA) e foi negativa para anticorpos da classe IgM contra o zika vírus, vírus chikungunya e vírus da dengue. O teste de neutralização por redução de placas foi positivo para o vírus zika, indicando aumento em paralelo da viremia e resposta imunológica ao vírus. Informes recentes têm demonstrado viremia de duração mais prolongada em infecções por vírus zika. Porém, este é o primeiro relato que associa a infecção com viremia prolongada ao surgimento em paralelo da síndrome de Guillain-Barré.(AU)