RESUMEN
Zika is a viral disease transmitted mainly by mosquitoes of the genus Aedes. In recent years, it has expanded geographically, changing from an endemic mosquito-borne disease across equatorial Asia and Africa, to an epidemic disease causing large outbreaks in several areas of the world. With the recent Zika virus (ZIKV) outbreaks in the Americas, the disease has become a focus of attention of public health agencies and of the international research community, especially due to an association with neurological disorders in adults and to the severe neurological and ophthalmological abnormalities found in fetuses and newborns of mothers exposed to ZIKV during pregnancy. A large number of studies have been published in the last 3 years, revealing the structure of the virus, how it is transmitted and how it affects human cells. Many different animal models have been developed, which recapitulate several features of ZIKV disease and its neurological consequences. Moreover, several vaccine candidates are now in active preclinical development, and three of them have already entered phase I clinical trials. Likewise, many different compounds targeting viral and cellular components are being tested in in vitro and in experimental animal models. This review aims to discuss the current state of this rapidly growing literature from a multidisciplinary perspective, as well as to present an overview of the public health response to Zika and of the perspectives for the prevention and treatment of this disease.
RESUMEN
Soil-transmitted helminth (STH) infections are widely distributed in tropical and subtropical areas, including Brazil. We performed a nationwide population-based study including all deaths in Brazil from 2000 to 2011, in which STHs (ascariasis, trichuriasis and/or hookworm infection) were mentioned on death certificates, either as underlying or as associated causes of death. Epidemiological characteristics, time trends and spatial analysis of STH-related mortality were analysed. STHs was identified on 853/12 491 280 death certificates: 827 (97·0%) deaths related to ascariasis, 25 (2·9%) to hookworm infections, and 1 (0·1%) to trichuriasis. The average annual age-adjusted mortality rate was 0·34/1 000 000 inhabitants (95% confidence interval: 0·27-0·44). Females, children <10 years of age, indigenous ethnic groups and residents in the Northeast region had highest STH-related mortality rates. Nationwide mortality decreased significantly over time (annual percent change: -5·7%; 95% CI: -6·9 to -4·4), with regional differences. We identified spatial high-risk clusters for STH-related mortality mainly in the North, Northeast and South regions. Diseases of the digestive system and infectious/parasitic diseases were the most commonly associated causes of death mentioned in the STH-related deaths. Despite decreasing mortality in Brazil, a considerable number of deaths is caused by STHs, with ascariasis responsible for the vast majority. There were marked regional differences, affecting mainly children and vulnerable populations.
Asunto(s)
Helmintiasis/mortalidad , Suelo/parasitología , Adolescente , Adulto , Anciano , Ascariasis/epidemiología , Ascariasis/mortalidad , Ascariasis/parasitología , Ascariasis/transmisión , Brasil/epidemiología , Niño , Preescolar , Femenino , Geografía , Helmintiasis/epidemiología , Helmintiasis/parasitología , Helmintiasis/transmisión , Infecciones por Uncinaria/epidemiología , Infecciones por Uncinaria/mortalidad , Infecciones por Uncinaria/parasitología , Infecciones por Uncinaria/transmisión , Humanos , Lactante , Masculino , Persona de Mediana Edad , Enfermedades Desatendidas , Análisis Espacial , Tricuriasis/epidemiología , Tricuriasis/mortalidad , Tricuriasis/parasitología , Tricuriasis/transmisión , Adulto JovenRESUMEN
OBJECTIVE: The Brazilian National Hansen's Disease Control Program recently identified clusters with high disease transmission. Herein, we present different spatial analytical approaches to define highly vulnerable areas in one of these clusters. METHOD: The study area included 373 municipalities in the four Brazilian states Maranhão, Pará, Tocantins and Piauí. Spatial analysis was based on municipalities as the observation unit, considering the following disease indicators: (i) rate of new cases/100,000 population, (ii) rate of cases <15 years/100,000 population, (iii) new cases with grade-2 disability/100,000 population and (iv) proportion of new cases with grade-2 disabilities. We performed descriptive spatial analysis, local empirical Bayesian analysis and spatial scan statistic. RESULTS: A total of 254 (68.0%) municipalities were classified as hyperendemic (mean annual detection rates >40 cases/100,000 inhabitants). There was a concentration of municipalities with higher detection rates in Pará and in the center of Maranhão. Spatial scan statistic identified 23 likely clusters of new leprosy case detection rates, most of them localized in these two states. These clusters included only 32% of the total population, but 55.4% of new leprosy cases. We also identified 16 significant clusters for the detection rate <15 years and 11 likely clusters of new cases with grade-2. Several clusters of new cases with grade-2/population overlap with those of new cases detection and detection of children <15 years of age. The proportion of new cases with grade-2 did not reveal any significant clusters. CONCLUSIONS: Several municipality clusters for high leprosy transmission and late diagnosis were identified in an endemic area using different statistical approaches. Spatial scan statistic is adequate to validate and confirm high-risk leprosy areas for transmission and late diagnosis, identified using descriptive spatial analysis and using local empirical Bayesian method. National and State leprosy control programs urgently need to intensify control actions in these highly vulnerable municipalities.
Asunto(s)
Diagnóstico Tardío/estadística & datos numéricos , Enfermedades Endémicas/estadística & datos numéricos , Lepra/epidemiología , Lepra/transmisión , Población Rural/estadística & datos numéricos , Brasil/epidemiología , Análisis por Conglomerados , Control de Enfermedades Transmisibles/organización & administración , Femenino , Estado de Salud , Humanos , Lepra/diagnóstico , Masculino , Mycobacterium leprae/aislamiento & purificación , Vigilancia de la Población , Medición de Riesgo , Factores de RiesgoRESUMEN
OBJECTIVE: To provide an evidence base for improvement of leprosy control in Brazil's high transmission areas. DESIGN: We obtained data from municipalities in a major disease cluster from databases for notifiable diseases of four states (Maranhão, Parâ, Tocantins, Piauí), including notifications from 2001 to 2009. Indicators for monitoring and evaluation of leprosy according to the World Health Organization were evaluated with emphasis on the rates of new cases presenting grade-2 disabilities and among children < 15 years of age, indicating late diagnosis and active transmission, respectively. RESULTS: A total of 82,463 leprosy cases were detected in the area (mean annual case detection rate: 95.9/100,000; RR = 4.56 as compared to the rest of Brazil; 95% CI: 4.45-4.66, P < 0.0001). There was a steady decrease of detection rates in the study period, from 100.8 to 75.6/100,000 inhabitants. In children <15 years of age, 9,009 cases of leprosy were detected (28.40/100,000), significantly more than in the rest of Brazil (RR = 5.80; 95% CI: 5.39-6.25, P < 0.0001). New cases with grade-2 disabilities/100,000 population maintained a stable trend at a high level (4.43 cluster vs. 1.28 rest of country; RR = 3.46; 95% CI: 3.11-3.84, P < 0.0001), whereas the proportion of new cases with grade-2 was slightly lower than the country's average (5.51% vs. 6.75%; RR = 0.84; 95% CI: 0.81-0.86, P < 0.0001). CONCLUSIONS: Despite recently improved leprosy control measures, there is still major active transmission and late diagnosis in the cluster. Further specific actions are needed to improve early case detection and prompt treatment with the aim to reduce disease burden in the population, considering social inequities.
Asunto(s)
Enfermedades Endémicas/prevención & control , Lepra/diagnóstico , Lepra/epidemiología , Lepra/transmisión , Adolescente , Adulto , Anciano , Brasil/epidemiología , Niño , Preescolar , Diagnóstico Tardío , Femenino , Humanos , Incidencia , Lactante , Masculino , Persona de Mediana Edad , Índice de Severidad de la EnfermedadRESUMEN
The presence of pathogens or predators in water may alter oviposition behaviour of gravid female Aedes aegypti mosquitoes. We evaluated the oviposition behaviour of A. aegypti in recipients containing larvivorous fish (Betta splendens and Poecilia reticulata). In four breeders, fish specimens were placed in 15 l of dechlorined water. Four control breeders only contained dechlorined water. Breeders with eucatex ovitraps and approximately 100 male and female mosquitoes were placed in wire netting cages. During a period of 7 weeks, eggs on the ovitraps were counted weekly. The median number of eggs laid in recipients with B. splendens (32.5/week) was lower than in those with P. reticulata (200.5/week) and the control group (186.5/week; P < 0.0001). The oviposition activity index (OAI) for P. reticulata did not show any considerable difference between posture in deposits with and without fish (-0005). Deposits with B. splendens showed a lower position than those used as controls (-0627). We conclude that B. splendens can be used to effectively prevent gravid A. aegypti females from laying eggs in large water containers.