Identifying urban hotspots of dengue, chikungunya, and Zika transmission in Mexico to support risk stratification efforts: a spatial analysis.

BACKGROUND: Effective Aedes aegypti control is limited, in part, by the difficulty in achieving sufficient intervention coverage. To maximise the effect of vector control, areas with persistently high numbers of Aedes-borne disease cases could be identified and prioritised for preventive interventions. We aimed to identify persistent Aedes-borne disease hotspots in cities across southern Mexico. METHODS: In this spatial analysis, geocoded cases of dengue, chikungunya, and Zika from nine endemic Mexican cities were aggregated at the census-tract level. We included cities that were located in southern Mexico (the arbovirus endemic region of Mexico), with a high burden of dengue cases (ie, more than 5000 cases reported during a 10-year period), and listed as high priority for the Mexican dengue control and prevention programme. The Getis-Ord Gi*(d) statistic was applied to yearly slices of the dataset to identify spatial hotspots of each disease in each city. We used Kendall's W coefficient to quantify the agreement in the distribution of each virus. FINDINGS: 128 507 dengue, 4752 chikungunya and 25 755 Zika clinical cases were reported between Jan 1, 2008, and Dec 31, 2016. All cities showed evidence of transmission heterogeneity, with a mean of 17·6% (SD 4·7) of their total area identified as persistent disease hotspots. Hotspots accounted for 25·6% (SD 9·7; range 12·8-43·0) of the population and 32·1% (10·5; 19·6-50·5) of all Aedes-borne disease cases reported. We found an overlap between hotspots of 61·7% for dengue and Zika and 53·3% for dengue and chikungunya. Dengue hotspots in 2008-16 were significantly associated with dengue hotspots detected during 2017-20 in five of the nine cities. Heads of vector control confirmed hotspot areas as problem zones for arbovirus transmission. INTERPRETATION: This study provides evidence of the overlap of Aedes-borne diseases within geographical hotspots and a methodological framework for the stratification of arbovirus transmission risk within urban areas, which can guide the implementation of surveillance and vector control. FUNDING: USAID, the US Centers for Disease Control and Prevention, the Canadian Institutes of Health Research, International Development Research Centre, Fondo Mixto CONACyT (Mexico)-Gobierno del Estado de Yucatan, and the US National Institutes of Health. TRANSLATION: For the Spanish translation of the abstract see Supplementary Materials section.

Case Fatality Rate Related to Microcephaly Congenital Zika Syndrome and Associated Factors: A Nationwide Retrospective Study in Brazil †.

BACKGROUND: The clinical manifestations of microcephaly/congenital Zika syndrome (microcephaly/CZS) have harmful consequences on the child's health, increasing vulnerability to childhood morbidity and mortality. This study analyzes the case fatality rate and child-maternal characteristics of cases and deaths related to microcephaly/CZS in Brazil, 2015-2017. METHODS: Population-based study developed by linkage of three information systems. We estimate frequencies of cases, deaths, case fatality rate related to microcephaly/CZS according to child and maternal characteristics and causes of death. Multivariate logistic regression models were applied. RESULTS: The microcephaly/CZS case fatality rate was 10% (95% CI 9.2-10.7). Death related to microcephaly/CZS was associated to moderate (OR = 2.15; 95% CI 1.63-2.83), and very low birth weight (OR = 3.77; 95% CI 2.20-6.46); late preterm births (OR = 1.65; 95% CI 1.21-2.23), Apgar < 7 at 1st (OR = 5.98; 95% CI 4.46-8.02) and 5th minutes (OR = 4.13; 95% CI 2.78-6.13), among others. CONCLUSIONS: A high microcephaly/CZS case fatality rate and important factors associated with deaths related to this syndrome were observed. These results can alert health teams to these problems and increase awareness about the factors that may be associated with worse outcomes.

Prevention and control of Aedes transmitted infections in the post-pandemic scenario of COVID-19: challenges and opportunities for the region of the Americas.

The coronavirus disease of 2019 (COVID-19) pandemic challenges public health systems around the world. Tropical countries will face complex epidemiological scenarios involving the simultaneous transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with viruses transmitted by Aedes aegypti. The occurrence of arboviral diseases with COVID-19 in the Latin America and the Caribbean (LAC) region presents challenges and opportunities for strengthening health services, surveillance and control programs. Financing of training, equipment and reconversion of hospital spaces will have a negative effect on already the limited resource directed to the health sector. The strengthening of the diagnostic infrastructure reappears as an opportunity for the national reference laboratories. Sharing of epidemiological information for the modeling of epidemiological scenarios allows collaboration between health, academic and scientific institutions. The fear of contagion by COVID-19 is constraining people with arboviral diseases to search for care which can lead to an increase in serious cases and could disrupt the operation of vector-control programs due to the reluctance of residents to open their doors to health personnel. Promoting intense community participation along with the incorporation of long lasting innovations in vector control offers new opportunities for control. The COVID-19 pandemic offers challenges and opportunities that must provoke positive behavioral changes and encourage more permanent self-care actions.

Patterns of insecticide resistance in Aedes aegypti: meta-analyses of surveys in Latin America and the Caribbean.

BACKGROUND: The re-emergence of worldwide concern with arthropod-borne viruses (arboviruses) draws increasing attention to their mosquito vectors, particularly Aedes aegypti, whose control heavily rely on insecticide use. As a consequence, insecticide resistance is frequent, but the general patterns of occurrence, cross-resistance and prevailing mechanisms remain unrecognized in some areas such as the Neotropical region. Thus, we sought here to recognize the general trends and patterns of insecticide resistance in Latin America and the Caribbean. A systematic literature review (2008-2018) aimed the data-gathering for the region and meta-analyses to address the stated knowledge gap. RESULTS: A high incidence of insecticide resistance prevails in the mosquito populations of the region. Dichlorodiphenyltrichloroethane (DDT), temephos and deltamethrin were the main insecticides evaluated and the meta-analyses indicate a high frequency of DDT-resistant populations (86.7 ± 0.1%), followed by temephos (75.7 ± 0.1%) and deltamethrin (33.0 ± 0.1%). No evidence of cross-resistance was detected among these three insecticides, and the V1016I knockdown (KDR) site mutation does not explain the patterns of deltamethrin resistance in the region. CONCLUSION: Resistance to DDT, temephos and deltamethrin is serious and widespread, and there is no cross-resistance among them. Altered target site sensitivity is not the main pyrethroid resistance mechanism, which is likely due to a mix of mechanisms. Therefore, the replacement of deltamethrin and particularly temephos in the region by alternative insecticides is an important resistance management recommendation, but should be done with compounds out of the cross-resistance spectrum for these populations and insecticides. Nonetheless, the non-recognition of the prevalent resistance mechanisms in the region makes this suggestion more difficult to apply and invites more broad-scale studies of resistance mechanisms to fill this knowledge gap and improve the resistance management recommendations. © 2020 Society of Chemical Industry.

Prevention and control of Aedes transmitted infections in the post-pandemic scenario of COVID-19: challenges and opportunities for the region of the Americas

The coronavirus disease of 2019 (COVID-19) pandemic challenges public health systems around the world. Tropical countries will face complex epidemiological scenarios involving the simultaneous transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with viruses transmitted by Aedes aegypti. The occurrence of arboviral diseases with COVID-19 in the Latin America and the Caribbean (LAC) region presents challenges and opportunities for strengthening health services, surveillance and control programs. Financing of training, equipment and reconversion of hospital spaces will have a negative effect on already the limited resource directed to the health sector. The strengthening of the diagnostic infrastructure reappears as an opportunity for the national reference laboratories. Sharing of epidemiological information for the modeling of epidemiological scenarios allows collaboration between health, academic and scientific institutions. The fear of contagion by COVID-19 is constraining people with arboviral diseases to search for care which can lead to an increase in serious cases and could disrupt the operation of vector-control programs due to the reluctance of residents to open their doors to health personnel. Promoting intense community participation along with the incorporation of long lasting innovations in vector control offers new opportunities for control. The COVID-19 pandemic offers challenges and opportunities that must provoke positive behavioral changes and encourage more permanent self-care actions.

Publisher Correction: Past and future spread of the arbovirus vectors Aedes aegypti and Aedes albopictus.

This Article was mistakenly not made Open Access when originally published; this has now been amended, and information about the Creative Commons Attribution 4.0 International License has been added into the 'Additional information' section.

Publisher Correction: Past and future spread of the arbovirus vectors Aedes aegypti and Aedes albopictus.

In the version of this Article originally published, the affiliation for author Catherine Linard was incorrectly stated as '6Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK'. The correct affiliation is '9Spatial Epidemiology Lab (SpELL), Universite Libre de Bruxelles, Brussels, Belgium'. The affiliation for author Hongjie Yu was also incorrectly stated as '11Department of Statistics, Harvard University, Cambridge, MA, USA'. The correct affiliation is '15School of Health, Fudan University, Key Laboratory of Public Health Safety, Ministry of Education, Shanghai, China'. This has now been amended in all versions of the Article.

Past and future spread of the arbovirus vectors Aedes aegypti and Aedes albopictus.

The global population at risk from mosquito-borne diseases-including dengue, yellow fever, chikungunya and Zika-is expanding in concert with changes in the distribution of two key vectors: Aedes aegypti and Aedes albopictus. The distribution of these species is largely driven by both human movement and the presence of suitable climate. Using statistical mapping techniques, we show that human movement patterns explain the spread of both species in Europe and the United States following their introduction. We find that the spread of Ae. aegypti is characterized by long distance importations, while Ae. albopictus has expanded more along the fringes of its distribution. We describe these processes and predict the future distributions of both species in response to accelerating urbanization, connectivity and climate change. Global surveillance and control efforts that aim to mitigate the spread of chikungunya, dengue, yellow fever and Zika viruses must consider the so far unabated spread of these mosquitos. Our maps and predictions offer an opportunity to strategically target surveillance and control programmes and thereby augment efforts to reduce arbovirus burden in human populations globally.

The decline of dengue in the Americas in 2017: discussion of multiple hypotheses.

OBJECTIVE: Since the 1980s, dengue incidence has increased 30-fold. However, in 2017, there was a noticeable reduction in reported dengue incidence cases within the Americas, including severe and fatal cases. Understanding the mechanism underlying dengue's incidence and decline in the Americas is vital for public health planning. We aimed to provide plausible explanations for the decline in 2017. METHODS: An expert panel of representatives from scientific and academic institutions, Ministry of Health officials from Latin America and PAHO/WHO staff met in October 2017 to propose hypotheses. The meeting employed six moderated plenary discussions in which participants reviewed epidemiological evidence, suggested explanatory hypotheses, offered their expert opinions on each and developed a consensus. RESULTS: The expert group established that in 2017, there was a generalised decreased incidence, severity and number of deaths due to dengue in the Americas, accompanied by a reduction in reported cases of both Zika and chikungunya virus infections, with no change in distribution among age groups affected. This decline was determined to be unlikely due to changes in epidemiological surveillance systems, as similar designs of surveillance systems exist across the region. Although sudden surveillance disruption is possible at a country or regional level, it is unlikely to occur in all countries simultaneously. Retrospective modelling with epidemiological, immunological and entomological information is needed. Host or immunological factors may have influenced the decline in dengue cases at the population level through immunity; however, herd protection requires additional evidence. Uncertainty remains regarding the effect on the outcome of sequential infections of different dengue virus (DENV) types and Zika virus (ZIKV), and vice versa. Future studies were recommended that examine the epidemiological effect of prior DENV infection on Zika incidence and severity, the epidemiological effect of prior Zika virus infection on dengue incidence and severity, immune correlates based on new-generation ELISA assays, and impact of prior DENV/other arbovirus infection on ZIKV immune response in relation to number of infections and the duration of antibodies in relation to interval of protection. Follow-up studies should also investigate whether increased vector control intensification activities contributed to the decline in transmission of one or more of these arboviruses. Additionally, proposed studies should focus on the potential role of vector competence when simultaneously exposed to various arboviruses, and on entomological surveillance and its impact on circulating vector species, with a goal of applying specific measures that mitigate seasonal occurrence or outbreaks. CONCLUSIONS: Multifactorial events may have accounted for the decline in dengue seen in 2017. Differing elements might explain the reduction in dengue including elements of immunity, increased vector control, and even vector and\or viruses changes or adaptations. Most of the results of this expert consensus group meeting are hypothetical and based on limited evidence. Further studies are needed.

OBJECTIF: Depuis les années 1980, l'incidence de la dengue a été multipliée par 30. Cependant, en 2017, il y a eu une réduction notable du nombre de cas d'incidence de dengue rapportés dans les Amériques. Nous voulions fournir des explications plausibles à la baisse en 2017. MÉTHODES: Un groupe d'experts constitué de représentants d'institutions scientifiques et académiques, d'officiels des Ministères de la Santé d'Amérique Latine et de membres du personnel de l'OPS/OMS s'est réuni en octobre 2017 pour proposer et évaluer des hypothèses. RÉSULTATS: En 2017, il y a eu une baisse généralisée de l'incidence, de la sévérité et du nombre de décès dus à la dengue dans les Amériques, accompagnée d'une réduction des cas rapportés d'infections par le virus Zika et par le virus du chikungunya, sans modification dans la répartition entre les groupes d'âge affectés. Il a été déterminé que ce déclin était peu probablement dû aux changements dans les systèmes de surveillance épidémiologique, étant donné que des systèmes de surveillance similaires existaient dans toute la région. Bien que des perturbations soudaines dans la surveillance soient possibles au niveau national ou régional, il est peu probable que cela se produise simultanément dans tous les pays. Une modélisation rétrospective avec des informations épidémiologiques, immunologiques et entomologiques est nécessaire. Des facteurs liés à l'hôte ou immunologiques peuvent avoir influencé le déclin des cas de dengue au niveau de la population par le biais de l'immunité; cependant, l'évidence d'une protection conférée par l'effet du troupeau nécessite des données supplémentaires. Une incertitude subsiste quant à l'effet sur le résultat des infections séquentielles de différents types du virus de la dengue (DENV) et du virus Zika (ZIKV), et vice-versa. Les études à venir devraient examiner (1) l'effet épidémiologique d'une infection antérieure par le DENV sur l'incidence et la sévérité du virus Zika, (2) l'effet épidémiologique d'une infection antérieure par le virus Zika sur l'incidence et la sévérité de la dengue, (3) les corrélats immunitaires basés sur des tests ELISA de nouvelle génération, (4) l' impact d'une infection antérieure à DENV/autres arbovirus sur la réponse immunitaire au ZIKV en fonction du nombre d'infections et de la durée des anticorps en fonction de l'intervalle de protection, (5) si des activités d'intensification de la lutte antivectorielle ont contribué à la diminution de la transmission d'un ou plusieurs de ces arbovirus, (6) le rôle potentiel de la compétence vectorielle lorsqu'ils sont exposés simultanément à différents arbovirus, (7) la surveillance entomologique et son impact sur la circulation d'espèces de vecteurs, dans le but d'appliquer des mesures spécifiques qui réduisent l'occurrence saisonnière d'épidémies. CONCLUSIONS: Des événements multifactoriels pourraient expliquer le déclin observé de la dengue en 2017. La plupart des résultats de cette réunion du groupe de consensus d'experts sont hypothétiques, reposent sur des données limitées et requièrent des investigations supplémentaires.

Association and birth prevalence of microcephaly attributable to Zika virus infection among infants in Paraíba, Brazil, in 2015-16: a case-control study.

BACKGROUND: In 2015, the number of infants born with microcephaly increased in Paraíba, Brazil, after a suspected Zika virus outbreak. We did a retrospective case-control investigation to assess the association of microcephaly and Zika virus. METHODS: We enrolled cases reported to the national database for microcephaly and born between Aug 1, 2015, and Feb 1, 2016, on the basis of their birth head circumference and total body length. We identified controls from the national birth registry and matched them to cases by location, aiming to enrol a minimum of two controls per case. Mothers of both cases and controls were asked about demographics, exposures, and illnesses and infants were measured at a follow-up visit 1-7 months after birth. We took blood samples from mothers and infants and classified those containing Zika virus IgM and neutralising antibodies as evidence of recent infection. We calculated prevalence of microcephaly and odds ratios (ORs) using a conditional logistic regression model with maximum penalised conditional likelihood, and combined these ORs with exposure probability estimates to determine the attributable risk. FINDINGS: We enrolled 164 of 706 infants with complete information reported with microcephaly at birth, of whom we classified 91 (55%) as having microcephaly on the basis of their birth measurements, 36 (22%) as small, 21 (13%) as disproportionate, and 16 (10%) as not having microcephaly. 43 (26%) of the 164 infants had microcephaly at follow-up for an estimated prevalence of 5·9 per 1000 livebirths. We enrolled 114 control infants matched to the 43 infants classified as having microcephaly at follow-up. Infants with microcephaly at follow-up were more likely than control infants to be younger (OR 0·5, 95% CI 0·4-0·7), have recent Zika virus infection (21·9, 7·0-109·3), or a mother with Zika-like symptoms in the first trimester (6·2, 2·8-15·4). Once Zika virus infection and infant age were controlled for, we found no significant association between microcephaly and maternal demographics, medications, toxins, or other infections. Based on the presence of Zika virus antibodies in infants, we concluded that 35-87% of microcephaly occurring during the time of our investigation in northeast Brazil was attributable to Zika virus. We estimate 2-5 infants per 1000 livebirths in Paraíba had microcephaly attributable to Zika virus. INTERPRETATION: Time of exposure to Zika virus and evidence of infection in the infants were the only risk factors associated with microcephaly. This investigation has improved understanding of the outbreak of microcephaly in northeast Brazil and highlights the need to obtain multiple measurements after birth to establish if an infant has microcephaly and the need for further research to optimise testing criteria for congenital Zika virus infection. FUNDING: Centers for Disease Control and Prevention.

Chikungunya surveillance in Brazil: challenges in the context of Public Health. / Vigilância de chikungunya no Brasil: desafios no contexto da Saúde Pública.

OBJECTIVE: to describe the challenges in implementing the chikungunya surveillance and prevention system in Brazil. METHODS: this was a descriptive study of suspected cases of the disease based on records held on the Notifiable Diseases Information System (Sinan) for the period 2014-2016. RESULTS: more than 100,000 probable chikungunya cases were notified in Brazil in this period, with the largest concentration in the Northeast states (83.3% between 2014 and 2015; 91.0% in 2016); Sinan provided an excellent opportunity for closing records of cases occurring between 2014 and 2015 (85%) and high completeness of obligatory variables. CONCLUSION: given the imminence of the introduction of chikungunya in Brazil in 2014, advance public health preparation took place in order to minimize its effects on society; implementation of the surveillance system improved collection of information regarding the disease, however many challenges can be seen in practice, in view of increasing case incidence. This requires greater handling capacity in this sector.

The risk of urban yellow fever resurgence in Aedes-infested American cities.

Aedes aegypti, historically known as yellow fever (YF) mosquito, transmits a great number of other viruses such as Dengue, West Nile, Chikungunya, Zika, Mayaro and perhaps Oropouche, among others. Well established in Africa and Asia, Aedes mosquitoes are now increasingly invading large parts of the American continent, and hence the risk of urban YF resurgence in the American cities should because of great concern to public health authorities. Although no new urban cycle of YF was reported in the Americas since the end of an Aedes eradication programme in the late 1950s, the high number of non-vaccinated individuals that visit endemic areas, that is, South American jungles where the sylvatic cycle of YF is transmitted by canopy mosquitoes, and return to Aedes-infested urban areas, increases the risk of resurgence of the urban cycle of YF. We present a method to estimate the risk of urban YF resurgence in dengue-endemic cities. This method consists in (1) to estimate the number of Aedes mosquitoes that explains a given dengue outbreak in a given region; (2) calculate the force of infection caused by the introduction of one infective individual per unit area in the endemic area under study; (3) using the above estimates, calculate the probability of at least one autochthonous YF case per unit area produced by one single viraemic traveller per unit area arriving from a YF endemic or epidemic sylvatic region at the city studied. We demonstrate that, provided the relative vector competence, here defined as the capacity to being infected and disseminate the virus, of Ae. aegypti is greater than 0.7 (with respect to dengue), one infected traveller can introduce urban YF in a dengue endemic area.

Febre Chikungunya um desafio para o sistema de vigilância sanitária em saúde: revisão sistemática / Chikungunya Fever, a challenge for the health surveillance system: a systematic review

Introdução: No cenário internacional, o vírus Chikungunya é importante causa de morbidade. Por dispersar-se rapidamente para locais em que são encontrados os mosquitos Aedes aegypti e Aedes albopictus, tornou-se um desafio para a vigilância em saúde mundial. Objetivos: Revisar a literatura científica sobre a ocorrência da Febre do Chikungunya e a resposta da vigilância em saúde frente a surtos e epidemias. Métodos: Revisão sistemática de estudos primários publicados no período de 2005 a 2015, pesquisados nas bases de dados MEDLINE, SCOPUS, Web of Science, TripDatabase e BVS, com estratégia de busca que utilizou descritores em saúde referentes ao vírus Chikungunya e à vigilância em saúde. Resultados: Foram selecionados 13 artigos sobre o tema proposto. Conclusão: Evidenciou-se a necessidade de potencializar a integração das redes de vigilância, instituições de saúde, laboratórios de diagnóstico e ações de combate ao vetor, para acelerar a detecção de casos importados e de transmissão autóctone, bem como eliminação do vetor competente

Introduction: The Chikungunya virus is an important cause of morbidity in the international scene. It rapidly disperses to the sites where the Aedes aegypti and Aedes albopictus mosquitoes are found. Because this, it is a challenge for global health surveillance. Objectives: To review the scientific literature about Chikungunya fever's incidence and the health surveillance response to outbreaks and epidemics. Methods: Systematic review of primary studies published between 2005 and 2015, searched in databases (MEDLINE, SCOPUS, Web of Science, TripDatabase and BVS) using a strategy with Medical Subject Headings about Chikungunya virus and health Surveillance. Results: Were found 13 articles about the proposed theme of study. Conclusion: It is necessary to strengthen the integration of surveillance networks, health institutions, diagnostic laboratories and anti-vector actions in order to facilitate the early detection of imported cases and autochthonous transmission, and the elimination of the vector

Vigilância de chikungunya no Brasil: desafios no contexto da Saúde Pública / Vigilancia de chikungunya en Brasil: desafíos en el contexto de la Salud Pública / Chikungunya surveillance in Brazil: challenges in the context of Public Health

Objetivo: descrever os desafios da implantação do sistema de vigilância e prevenção de chikungunya no Brasil. Métodos: estudo descritivo dos casos suspeitos da doença notificados no Sistema de Informação de Agravos de Notificação (Sinan) entre 2014 e 2016. Resultados: no período estudado, foram notificados mais de 100 mil casos prováveis de chikungunya no país, com maior concentração nos estados do Nordeste (83,3% entre 2014 e 2015; 91,0% em 2016); o Sinan apresentou excelente oportunidade de encerramento dos casos entre 2014 e 2015 (85%) e alta completitude das variáveis obrigatórias. Conclusão: com a introdução de chikungunya no Brasil em 2014, houve um preparo prévio em termos de Saúde Pública para minimizar seus efeitos na sociedade; a implantação do sistema de vigilância ampliou a coleta de informações da doença, embora muitos desafios mostrem-se evidentes na prática, haja vista a incidência crescente de casos, demandando maior capacidade operante desse setor.

Objetivo: describir los desafíos de la implantación del sistema de vigilancia y prevención de chikungunya en Brasil. Métodos: estudio descriptivo de los casos sospechosos notificados en el Sistema de Notificación de Enfermedades Obligatorias (Sinan) entre 2014 y 2016. Resultados: en el período estudiado se notificaron más de 100 mil casos probables de chikungunya con mayor concentración en los estados del Nordeste (83,3% entre 2014 y 2015 y el 91,0% en 2016); el Sinan presentó una excelente oportunidad de cierre de los casos entre 2014 y 2015 (85%) y alta completitud de las variables obligatorias. Conclusión: con la introducción de chikungunya en Brasil hubo una preparación previa para minimizar sus efectos en la sociedad; la implantación del sistema de vigilancia ha ampliado la recolección de información sobre la enfermedad, sin embargo, muchos desafíos son evidenciados en la práctica, pues la incidencia de casos es creciente, necesitando de mayor capacidad operante de ese sector.

Objective: to describe the challenges in implementing the chikungunya surveillance and prevention system in Brazil. Methods: this was a descriptive study of suspected cases of the disease based on records held on the Notifiable Diseases Information System (Sinan) for the period 2014-2016. Results: more than 100,000 probable chikungunya cases were notified in Brazil in this period, with the largest concentration in the Northeast states (83.3% between 2014 and 2015; 91.0% in 2016); Sinan provided an excellent opportunity for closing records of cases occurring between 2014 and 2015 (85%) and high completeness of obligatory variables. Conclusion: given the imminence of the introduction of chikungunya in Brazil in 2014, advance public health preparation took place in order to minimize its effects on society; implementation of the surveillance system improved collection of information regarding the disease, however many challenges can be seen in practice, in view of increasing case incidence. This requires greater handling capacity in this sector.

Dengue in pregnant women: characterization of cases in Brazil, 2007-2015. / Dengue em gestantes: caracterização dos casos no Brasil, 2007-2015.

OBJECTIVE: to characterize the probable cases of dengue in pregnant women reported in Brazil, from 2007 to 2015. METHODS: descriptive study of sociodemographic, epidemiological, clinical and laboratory characteristics, with data from the Information System for Notifiable Diseases (Sinan). RESULTS: the annual incidence of dengue in pregnant women ranged from 3.3 (2009) to 816.6 (2010) cases per 100 thousand live births; of the 43,772 probable cases of dengue in pregnant women, 81.6% were investigated, 34.1% were confirmed by laboratory tests, and 1.7% were severe cases; hospitalization and fatality rates were of 5.4% and 1.6‰, respectively; the risk of death due to dengue was higher in pregnant women than in the population of non-pregnant women at reproductive age (ratio=3.95; 95%CI=3.07;5.08), and higher in the third trimester of pregnancy (ratio=8.55; 95%CI=6.08;12.02). CONCLUSION: the results show the burden of dengue in pregnant women and their vulnerability to worsening of the disease and death.

Dengue em gestantes: caracterização dos casos no Brasil, 2007-2015 / Dengue en embarazadas: caracterización de casos en Brasil, 2007-2015 / Dengue in pregnant women: characterization of cases in Brazil, 2007-2015

OBJETIVO: caracterizar os casos prováveis de dengue em gestantes notificados no Brasil, de 2007 a 2015. MÉTODOS: estudo descritivo das características sociodemográficas, epidemiológicas, clínicas e laboratoriais, com dados do Sistema de Informação de Agravos de Notificação (Sinan). RESULTADOS: a incidência anual de dengue em gestantes variou de 3,3 (2009) a 816,6 (2010) casos por 100 mil nascidos vivos; dos 43.772 casos prováveis de dengue em gestantes, 81,6% foram investigados, 34,1% confirmados laboratorialmente e 1,7% graves; as taxas de hospitalização e letalidade foram de 5,4% e 1,6‰, respectivamente; o risco de óbito por dengue foi maior na população de gestantes do que na população de mulheres em idade fértil não gestantes (razão=3,95; intervalo de confiança de 95% ou IC95%=3,07;5,08), superior no terceiro trimestre da gestação (razão=8,55; IC95%=6,08;12,02). CONCLUSÃO: os resultados evidenciam a carga da dengue entre gestantes, sua vulnerabilidade ao agravamento e óbito pela doença.

OBJETIVO: caracterizar los casos probables de dengue en las mujeres embarazadas reportados en Brasil entre 2007 y 2015. MÉTODOS: estudio descriptivo de los datos de las enfermedades de declaración obligatoria del Sistema de Información (Sinan). RESULTADOS: la incidencia anual de dengue osciló entre 3,3 (2009) a 816,6 (2010) casos por cada 100 mil nacidos vivos; de los 43.772 casos probables de dengue, el 81,6% fueron investigados, 34,1% confirmados en laboratorio y 1,7% grave; las tasas de hospitalización y letalidad fueron 5,4% y 1,6%, respectivamente; el riesgo de muerte por dengue fue mayor en embarazadas que en mujeres en edad fértil no embarazadas (ratio=3,95 [IC95%=3,07;5,08]), y mayor en el tercer trimestre (ratio=8,55; [IC95%=6.08;12.02]). CONCLUSIÓN: los resultados muestran la carga de dengue en embarazadas y la vulnerabilidad de éstas al agravamiento y muerte por esta enfermedad.

OBJECTIVE: to characterize the probable cases of dengue in pregnant women reported in Brazil, from 2007 to 2015. METHODS: descriptive study of sociodemographic, epidemiological, clinical and laboratory characteristics, with data from the Information System for Notifiable Diseases (Sinan). RESULTS: the annual incidence of dengue in pregnant women ranged from 3.3 (2009) to 816.6 (2010) cases per 100 thousand live births; of the 43,772 probable cases of dengue in pregnant women, 81.6% were investigated, 34.1% were confirmed by laboratory tests, and 1.7% were severe cases; hospitalization and fatality rates were of 5.4% and 1.6‰, respectively; the risk of death due to dengue was higher in pregnant women than in the population of non-pregnant women at reproductive age (ratio=3.95; 95%CI=3.07;5.08), and higher in the third trimester of pregnancy (ratio=8.55; 95%CI=6.08;12.02). CONCLUSION: the results show the burden of dengue in pregnant women and their vulnerability to worsening of the disease and death.

Increased rates of Guillain-Barré syndrome associated with Zika virus outbreak in the Salvador metropolitan area, Brazil.

In mid-2015, Salvador, Brazil, reported an outbreak of Guillain-Barré syndrome (GBS), coinciding with the introduction and spread of Zika virus (ZIKV). We found that GBS incidence during April-July 2015 among those ≥12 years of age was 5.6 cases/100,000 population/year and increased markedly with increasing age to 14.7 among those ≥60 years of age. We conducted interviews with 41 case-patients and 85 neighborhood controls and found no differences in demographics or exposures prior to GBS-symptom onset. A higher proportion of case-patients (83%) compared to controls (21%) reported an antecedent illness (OR 18.1, CI 6.9-47.5), most commonly characterized by rash, headache, fever, and myalgias, within a median of 8 days prior to GBS onset. Our investigation confirmed an outbreak of GBS, particularly in older adults, that was strongly associated with Zika-like illness and geo-temporally associated with ZIKV transmission, suggesting that ZIKV may result in severe neurologic complications.

Taking innovative vector control interventions in urban Latin America to scale: lessons learnt from multi-country implementation research.

Prior to the current public health emergency following the emergence of chikungunya and Zika Virus Disease in the Americas during 2014 and 2015, multi-country research investigated between 2011 and 2013 the efficacy of novel Aedes aegypti intervention packages through cluster randomised controlled trials in four Latin-American cities: Fortaleza (Brazil); Girardot (Colombia), Acapulco (Mexico) and Salto (Uruguay). Results from the trials led to a scaling up effort of the interventions at city levels. Scaling up refers to deliberate efforts to increase the impact of successfully tested health interventions to benefit more people and foster policy and program development in a sustainable way. The different scenarios represent examples for  a 'vertical approach' and a 'horizontal approach'. This paper presents the analysis of a preliminary process evaluation of the scaling up efforts in the mentioned cites, with a focus on challenges and enabling factors encountered by the research teams, analysing the main social, political, administrative, financial and acceptance factors.

Dengue prediction by the web: Tweets are a useful tool for estimating and forecasting Dengue at country and city level.

BACKGROUND: Infectious diseases are a leading threat to public health. Accurate and timely monitoring of disease risk and progress can reduce their impact. Mentioning a disease in social networks is correlated with physician visits by patients, and can be used to estimate disease activity. Dengue is the fastest growing mosquito-borne viral disease, with an estimated annual incidence of 390 million infections, of which 96 million manifest clinically. Dengue burden is likely to increase in the future owing to trends toward increased urbanization, scarce water supplies and, possibly, environmental change. The epidemiological dynamic of Dengue is complex and difficult to predict, partly due to costly and slow surveillance systems. METHODOLOGY / PRINCIPAL FINDINGS: In this study, we aimed to quantitatively assess the usefulness of data acquired by Twitter for the early detection and monitoring of Dengue epidemics, both at country and city level at a weekly basis. Here, we evaluated and demonstrated the potential of tweets modeling for Dengue estimation and forecast, in comparison with other available web-based data, Google Trends and Wikipedia access logs. Also, we studied the factors that might influence the goodness-of-fit of the model. We built a simple model based on tweets that was able to 'nowcast', i.e. estimate disease numbers in the same week, but also 'forecast' disease in future weeks. At the country level, tweets are strongly associated with Dengue cases, and can estimate present and future Dengue cases until 8 weeks in advance. At city level, tweets are also useful for estimating Dengue activity. Our model can be applied successfully to small and less developed cities, suggesting a robust construction, even though it may be influenced by the incidence of the disease, the activity of Twitter locally, and social factors, including human development index and internet access. CONCLUSIONS: Tweets association with Dengue cases is valuable to assist traditional Dengue surveillance at real-time and low-cost. Tweets are able to successfully nowcast, i.e. estimate Dengue in the present week, but also forecast, i.e. predict Dengue at until 8 weeks in the future, both at country and city level with high estimation capacity.