Chikungunya Cases Research Articles

A major chikungunya epidemic with high mortality in northeastern Brazil.

Chikungunya causes fever and severe and persistent joint pain. We reported a chikungunya outbreak that occurred in Ceará State, Brazil between 2016 and 2017 with emphasis on epidemiological characterization of cases, high number of deaths, mortality-associated factors, and spatial and temporal spread of the epidemic among municipalities. In November 2015, the first autochthonous cases of chikungunya were confirmed in Ceará, Brazil. In 2016-2017, 195,993 cases were reported, with an incidence of 2,186.5/100,000 inhabitants and 244 confirmed deaths. Rapid transmission and high mortality rate are serious problems, especially in regions with co-circulating arboviruses.

Simultaneous detection of IgM antibodies against dengue and chikungunya: Coinfection or cross-reactivity?

Background:Dengue and chikungunya sharing same mosquito vector are two most important arboviruses circulating in northern India including Delhi and are responsible for frequent outbreaks. Antigen and antibodies detection ELISA kits are the major tool to diagnose these viral illnesses, and are sometimes associated with cross–reactivity, giving a false picture of coinfection, although simultaneous harboring of both the viruses is not uncommon. Various studies have reported coinfection up to 25% from the same region.Procedure:This study was conducted in the Department of Microbiology, Maulana Azad Medical College, New Delhi, during the month of September 2016 which included 200 blood samples from clinically suspected cases attending Medicine OPD of associated Lok Nayak Hospital, New Delhi. Diagnosis of dengue and chikungunya was made using NS-1 antigen and IgM MAC ELISA for dengue and IgM MAC ELISA for chikungunya as per manufacturer's instructions.Results:Out of 200 suspected cases, 34 (17%) were positive for dengue serology, 77 (38.5%) were positive for chikungunya serology, and 29.9% of positive chikungunya cases were simultaneously affected with dengue. This higher percentage of coinfection might be because of cross-reactivity of the ELISA kits.Discussion:India being a hyperendemic region for dengue and chikungunya, frequent outbreaks are quite common. Circulation of both the virus and huge susceptible population are the major causes for frequent outbreaks. Restricting our attention to diagnose one of them is not sufficient, and coinfection further complicates the illness.Conclusion:Simultaneous diagnosis of dengue and chikungunya is need of time to diagnose dual infection and prevent complications by starting supportive treatment well in time. Molecular technique if ever possible should be employed whenever the coinfection number is higher than expected to rule out cross-reactivity.

Demographic and clinical characteristics of chikungunya patients from six Colombian cities, 2014–2015

In 2014, the chikungunya virus reached Colombia for the first time, resulting in a nationwide epidemic. The objective of this study was to describe the demographics and clinical characteristics of suspected chikungunya cases. Chikungunya infection was confirmed by enzyme-linked immunosorbent assay and 548 patients where included in the study. Of these patients, 295 were positive for antibodies against chikungunya (53.8%), and 27.6% (151/295) were symptomatic for chikungunya infection, with a symptomatic:asymptomatic ratio of 1.04:1. Factors associated with infection included low income and low socio-economic strata (odds ratio [OR]: 1.8; 95% confidence interval [CI]: 1.0–3.2, p = 0.003 and OR: 2.1; CI: 1.3–3.4, p = 0.002, respectively). Confirmed symptomatic cases were associated with symmetric arthritis (OR: 11.7; CI: 6.0–23.0, p < 0.001) of ankles (OR: 8.5; CI: 3.5–20.9, p < 0.001), hands (OR: 8.5; CI: 3.5–20.9, p < 0.001), feet (OR: 6.5; CI: 2.8–15.3, p < 0.001), and wrists (OR: 17.3; CI: 2.3–130.5, p < 0.001). Our study showed that poverty is associated with chikungunya infection. Public health strategies to prevent and control chikungunya should focus on poorer communities that are more vulnerable to infection. The rate of asymptomatic infections among confirmed cases was 48.8%. However, those with symptoms displayed a characteristic rheumatic clinical picture, which could help differentiate chikungunya infection from other endemic viral diseases.

Local transmission of chikungunya in Rome and the Lazio region, Italy.

On September 7, 2017, three potentially autochthonous cases of chikungunya were notified in the Lazio region. An Outbreak investigation based on established surveillance system data and molecular analysis of viral variant(s) were conducted. Epidemiological analysis suggested the occurrence of 3 main foci of local transmission. The major focus involved 317 cases with epidemiological link with the area of Anzio. The other two foci occurred in Rome (80 cases) and Latina (8 cases). Cumulative incidence in Anzio and Latina were 331.4 and 7.13 per 100,000 residents, respectively. Cumulative incidences ranged from 1.4 to 14.3/100,000 residents in Rome. This is the first report of a chikungunya outbreak involving a densely populated urban area in a western country. The outbreak probably started in Anzio, spread by continuity to neighbouring villages, and then to the metropolitan area of Rome and to the Latina area favoured by the touristic nature of the Anzio area.

Following in the Footsteps of the Chikungunya Virus in Brazil: The First Autochthonous Cases in Amapá in 2014 and Its Emergence in Rio de Janeiro during 2016

Currently, Brazil lives a triple arboviruses epidemic (DENV, ZIKV and CHIKV) making the differential diagnosis difficult for health professionals. Here, we aimed to investigate chikungunya cases and the possible occurrence of co-infections during the epidemic in Amapá (AP) that started in 2014 when the first autochthonous cases were reported and in Rio de Janeiro (RJ) in 2016. We further performed molecular characterization and genotyping of representative strains. In AP, 51.4% of the suspected cases were confirmed for CHIKV, 71.0% (76/107). Of those, 24 co-infections by CHIKV/DENV, two by CHIKV/DENV-1, and two by CHIKV/DENV-4 were observed. In RJ, 76.9% of the suspected cases were confirmed for CHIKV and co-infections by CHIKV/DENV (n = 8) and by CHIKV/ZIKV (n = 17) were observed. Overall, fever, arthralgia, myalgia, prostration, edema, exanthema, conjunctival hyperemia, lower back pain, dizziness, nausea, retroorbital pain, and anorexia were the predominating chikungunya clinical symptoms described. All strains analyzed from AP belonged to the Asian genotype and no amino acid changes were observed. In RJ, the East-Central-South-African genotype (ECSA) circulation was demonstrated and no E1-A226V mutation was observed. Despite this, an E1-V156A substitution was characterized in two samples and for the first time, the E1-K211T mutation was reported in all samples analyzed.

Chikungunya surveillance in Brazil: challenges in the context of Public Health.

to describe the challenges in implementing the chikungunya surveillance and prevention system in Brazil. 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. 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. 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.

Bionomics and insecticide resistance of the arboviral vector Aedes albopictus in northern Lao PDR.

In the last four decades there has been a staggering increase in the geographical range of the arboviral vector Aedes albopictus (Skuse, 1894). This species is now found in every continent except Antarctica, increasing the distribution of arboviral diseases such as dengue and chikungunya. In Lao PDR dengue epidemics occur regularly, with cases of chikungunya also reported. As treatment methods for arboviral diseases is limited, the control of the vector mosquitoes are essential. There is a paucity of information on the bionomics and resistance status of this mosquito for successful vector control efforts. Here we describe the bionomics and insecticide resistance status of Ae. albopictus in Laos to identify opportunities for control. Adult Ae. albopictus were collected using human-baited double bed net (HDN) traps in forests, villages and rubber plantations and tested for alpha- and flaviviruses with RT-PCR. Surveys were also conducted to identify larval habitats. Seven adult and larval populations originating from Vientiane Capital and Luang Prabang province were tested against DDT, malathion, permethrin, deltamethrin and, temephos following WHO protocols. Aedes albopictus were found throughout the year, but were six-fold greater in the rainy season than the dry season. Adult females were active for 24 hours, with peak of behaviour at 18.00 h. The secondary forest and rubber plantation samples showed evidence of Pan-flaviviruses, while samples from the villages did not. More than half of the emerged Ae. albopictus were collected from mature rubber plantations (53.9%; 1,533/2,845). Most Ae. albopictus mosquitoes emerged from latex collection cups (19.7%; 562/2,845), small water containers (19.7%; 562/2,845) and tyres (17.4%; 495/2,845). Adult mosquitoes were susceptible to pyrethroids, apart from one population in Vientiane city. All populations were resistant to DDT (between 27–90% mortality) and all except one were resistant to malathion (20–86%). Three of the seven larval populations were resistant to temephos (42–87%), with suspected resistance found in three other populations (92–98%).This study demonstrates that rural areas in northern Laos are potential hot spots for arboviral disease transmission. Multiple-insecticide resistance was found. Aedes albopictus control efforts in villages need to expand to include secondary forests and rubber plantations, with larval source management and limited use of insecticides.

Human and entomologic investigations of chikungunya outbreak in Mandera, Northeastern Kenya, 2016.

Chikungunya is a reemerging vector borne pathogen associated with severe morbidity in affected populations. Lamu, along the Kenyan coast was affected by a major chikungunya outbreak in 2004. Twelve years later, we report on entomologic investigations and laboratory confirmed chikungunya cases in northeastern Kenya. Patient blood samples were received at the Kenya Medical Research Institute (KEMRI) viral hemorrhagic fever laboratory and the immunoglobulin M enzyme linked immunosorbent assay (IgM ELISA) was used to test for the presence of IgM antibodies against chikungunya and dengue. Reverse transcription polymerase chain reaction (RT-PCR) utilizing flavivirus, alphavirus and chikungunya specific primers were used to detect acute infections and representative PCR positive samples sequenced to confirm the circulating strain. Immature mosquitoes were collected from water-holding containers indoors and outdoors in the affected areas in northeastern Kenya. A total of 189 human samples were tested; 126 from Kenya and 63 from Somalia. 52.9% (100/189) tested positive for Chikungunya virus (CHIKV) by either IgM ELISA or RT-PCR. Sequence analysis of selected samples revealed that the virus was closely related to that from China (2010). 29% (55/189) of the samples, almost all from northeastern Kenya or with a history of travel to northern Kenya, tested positive for dengue IgM antibodies. Entomologic risk assessment revealed high house, container and Breteau indices of, 14.5, 41.9 and 17.1% respectively. Underground water storage tanks were the most abundant, 30.1%, of which 77.4% were infested with Aedes aegypti mosquitoes. These findings confirm the presence of active chikungunya infections in the northeastern parts of Kenya. The detection of dengue IgM antibodies concurrently with chikungunya virus circulation emphasizes on the need for improved surveillance systems and diagnostic algorithms with the capacity to capture multiple causes of arbovirus infections as these two viruses share common vectors and eco-systems. In addition sustained entomological surveillance and vector control programs targeting most productive containers are needed to monitor changes in vector densities, for early detection of the viruses and initiate vector control efforts to prevent possible outbreaks.

Neighborhood Violence Impacts Disease Control and Surveillance: Case Study of Cali, Colombia from 2014 to 2016.

Arboviruses are responsible for a large burden of disease globally and are thus subject to intense epidemiological scrutiny. However, a variable notably absent from most epidemiological analyses has been the impact of violence on arboviral transmission and surveillance. Violence impedes surveillance and delivery of health and preventative services and affects an individual’s health-related behaviors when survival takes priority. Moreover, low and middle-income countries bear a disproportionately high burden of violence and related health outcomes, including vector borne diseases. To better understand the epidemiology of arboviral outbreaks in Cali, Colombia, we georeferenced chikungunya (CHIKV), dengue (DENV), and Zika (ZIKV) viral cases from The National System of Surveillance in Public Health between October 2014 and April 2016. We extracted homicide data from the municipal monthly reports and kernel density of homicide distribution from IdeasPaz. Crucially, an overall higher risk of homicide is associated with increased risk of reported DENV, lower rates of acute testing, and higher rates of lab versus clinical discordance. In the context of high violence as a potential barrier to access to preventive health services, a community approach to improve health and peace should be considered.

A Case Report of Chikungunya Versus Dengue During an Acute Outbreak of Dengue Fever in the Solomon Islands, 2013

The presence of both dengue fever and chikungunya in Pacific Island jurisdictions, as well as other developing settings, such as Southeast Asia, the Caribbean and South America, as well as sub-Saharan Africa, is increasingly common, as is illustrated by this case study from the Solomon Islands in 2013. Given such, it is increasingly important the medical and clinical officers, as well as ancillary staff, such as nursing and laboratory staff, be able to differentiate between the two conditions, given that while chikungunya can be serious, recovery is generally unremarkable; whereas, dengue fever can have serious, life-threatening complications. This case report presents a typical patient presenting during a dengue outbreak in the Solomon Islands in 2013, which was misdiagnosed as dengue fever, given the similar signs of the two diseases, but who in actuality had the first recorded case of chikungunya in the Solomon Islands. The monograph concludes by making recommendations for additional education of clinical personnel to differentiate between the two diseases for both clinical as well as epidemiological reasons.

Burden of dengue among febrile patients at the time of chikungunya introduction in Piedecuesta, Colombia.

ObjectiveTo estimate the age‐specific incidence of symptomatic dengue and chikungunya in Colombia.MethodA passive facility‐based fever surveillance study was conducted among individuals with undifferentiated fever. Confirmatory diagnostics included serological and molecular tests in paired samples, and surveillance's underreporting was assessed using capture–recapture methods.ResultsOf 839 febrile participants 686 completed the study. There were 33.2% (295/839) dengue infections (51% primary infections), and 35.9% (191/532) of negative dengue cases there were chikungunya cases. On average, dengue cases were younger (median = 18 years) than chikungunya cases (median = 25 years). Thrombocytopaenia and abdominal pain were the main dengue predictors, while presence of rash was the main predictor for chikungunya diagnosis. Underreporting of dengue was 31%; the estimated expansion factors indicate an underreporting rate of dengue cases of threefold for all cases and of almost sixfold for inpatients.ConclusionsThese findings highlight the ongoing coexistence of both arboviruses, a distinct clinical profile of each condition in the study area that could be used by clinicians to generate a differential diagnosis, and the presence of underreporting, mostly among hospitalised cases.

Spatial–Temporal Epidemiology Study of Chikungunya Disease in Bolivia

Geospatial technology has become a great tool for epidemiology study because, with this technological advance,we can determine the environment in which transmission occurs, the distribution of the disease and its evolution over time. One of the important diseases related to public health in Bolivia is the chikungunya disease, also known as chikungunya fever. Therefore, the present research aims to analyze an area of Bolivia with a high number of cases of chikungunya based on remote sensing and GIS. Environmental parameters extracted from Landsat 8 satellite image, together with meteorological data extracted from the National Service of Meteorology in Bolivia, and the epidemiological information of chikungunya cases extracted from the Ministry of Health were the data sources included in this study. A principal component analysis of all the parameters obtained will be developed to build the relationship between the environmental parameters and chikungunya outbreaks in certain months of the year. We construct a GIS platform to allow the end user visualize and interact with the different layers. This study will allow us to have a more integrated understanding of this disease, understand the environment in which the transmission happens, identify in which months higher outbreaks occur and the climatic conditions under which it occurs. This will give us new potential to prevent and control this emerging disease in Bolivia.

Excess mortality in Guadeloupe and Martinique, islands of the French West Indies, during the chikungunya epidemic of 2014.

In some chikungunya epidemics, deaths are not completely captured by traditional surveillance systems, which record case and death reports. We evaluated excess deaths associated with the 2014 chikungunya virus (CHIKV) epidemic in Guadeloupe and Martinique, Antilles. Population (784 097 inhabitants) and mortality data, estimated by sex and age, were accessed from the Institut National de la Statistique et des Études Économiques in France. Epidemiological data, cases, hospitalisations and deaths on CHIKV were obtained from the official epidemiological reports of the Cellule de Institut de Veille Sanitaire in France. Excess deaths were calculated as the difference between the expected and observed deaths for all age groups for each month in 2014 and 2015, considering the upper limit of 99% confidence interval. The Pearson correlation coefficient showed a strong correlation between monthly excess deaths and reported cases of chikungunya (R = 0.81, p < 0.005) and with a 1-month lag (R = 0.87, p < 0.001); and a strong correlation was also observed between monthly rates of hospitalisation for CHIKV and excess deaths with a delay of 1 month (R = 0.87, p < 0.0005). The peak of the epidemic occurred in the month with the highest mortality, returning to normal soon after the end of the CHIKV epidemic. There were excess deaths in almost all age groups, and excess mortality rate was higher among the elderly but was similar between male and female individuals. The overall mortality estimated in the current study (639 deaths) was about four times greater than that obtained through death declarations (160 deaths). Although the aetiological diagnosis of all deaths associated with CHIKV infection is not always possible, already well-known statistical tools can contribute to the evaluation of the impact of CHIKV on mortality and morbidity in the different age groups.

Zika might not be acting alone: Using an ecological study approach to investigate potential co-acting risk factors for an unusual pattern of microcephaly in Brazil.

Zika virus infections can cause a range of neurologic disorders including congenital microcephaly. However, while Zika infections have been notified across all regions in Brazil, there has been an unusual number of congenital microcephaly case notifications concentrated in the Northeast of the country. To address this observation, we investigated epidemiological data (2014–2016) on arbovirus co-distribution, environmental and socio-economic factors for each region in Brazil. Data on arbovirus reported cases and microcephaly were collected from several Brazilian Ministry of Health databases for each Federal unit. These were complemented by environmental management, social economic and Aedes aegypti infestation index data, extracted from multiple databases. Spatial time “ecological” analysis on the number of arboviruses transmitted by Aedes mosquitoes in Brazil show that the distribution of dengue and Zika was widespread in the whole country, with higher incidence in the West-Central region. However, reported chikungunya cases were higher in the Northeast, the region also with the highest number of microcephaly cases registered. Social economic factors (human development index and poverty index) and environmental management (water supply/storage and solid waste management) pointed the Northeast as the less wealthy region. The Northeast is also the region with the highest risk of Aedes aegypti house infestation due to the man-made larval habitats. In summary, the results of our ecological analysis support the hypothesis that the unusual distribution of microcephaly might not be due to Zika infection alone and could be accentuated by poverty and previous or co-infection with other pathogens. Our study reinforces the link between poverty and the risk of disease and the need to understand the effect on pathogenesis of sequential exposure to arboviruses and co-viral infections. Comprehensive large-scale cohort studies are required to corroborate our findings. We recommend that the list of infectious diseases screened, particularly during pregnancy, be regularly updated to include and effectively differentiate all viruses from ongoing outbreaks.

Excess mortality profile during the Asian genotype chikungunya epidemic in the Dominican Republic, 2014.

In 2014 there was a large chikungunya epidemic in the Dominican Republic, with 539 099 reported cases and 6 deaths. Although chikungunya is considered a low-mortality disease, studies have suggested this is an underestimation. This study assessed deaths associated with the epidemic. Mortality data were obtained from the National Statistics Office, the surveillance system for acute febrile illnesses, and the National Epidemiological Surveillance System. Expected all-cause mortality by age group was estimated using the years 2010-2012 as the baseline. The excess deaths were calculated as the difference between observed and expected deaths during the epidemic. The mortality rate increased during the chikungunya epidemic in 2014. There was a strong correlation between monthly excess of deaths and chikungunya cases (Pearson's r=0.89). There was an excess of deaths (>99% confidence interval) among individuals <5 y and >40 y of age. The mortality rates were higher among the elderly. The death excess was 2853. Correcting for the estimated underreporting, there were 4952 deaths during the chikungunya epidemic (49.8 deaths/100 000 population). This study suggests that chikungunya is an important cause of death (underlying or contributing). It is urgent to review clinical protocols and investigate the causes associated with deaths during chikungunya epidemics.

Temperature dependent transmission potential model for chikungunya in India

Chikungunya is a major public health problem in tropical and subtropical countries of the world. During 2016, the National Capital Territory of Delhi experienced an epidemic caused by chikungunya virus with >12,000 cases. Similarly, other parts of India also reported a large number of chikungunya cases, highest incidence rate was observed during 2016 in comparison with last 10 years of epidemiological data. In the present study we exploited R0 mathematical model to understand the transmission risk of chikungunya virus which is transmitted by Aedes vectors. This mechanistic transmission model is climate driven and it predicts how the probability and transmission risk of chikungunya occurs in India. The gridded temperature data from 1948 to 2016 shows that the mean temperatures are gradually increasing in South India from 1982 to 2016 when compared with data of 1948–1981 time scale. During 1982–2016 period many states have reported gradual increase in risk of chikungunya transmission when compared with the 1948–1981 period. The highest transmission risk of chikungunya in India due to favourable ecoclimatic conditions, increasing temperature leads to low extrinsic incubation period, mortality rates and high biting rate were predicted for the year 2016. The epidemics in 2010 and 2016 are also strongly connected to El Nino conditions which favours transmission of chikungunya in India. The study shows that transmission of chikungunya occurs between 20 and 34 °C but the peak transmission occurs at 29 °C. The infections of chikungunya in India are due to availability of vectors and optimum temperature conditions influence chikungunya transmission faster in India. This climate based empirical model helps the public health authorities to assess the risk of chikungunya and one can implement necessary control measures before onset of disease outbreak.

Bibliometric assessment of the global scientific production on Sindbis virus: Implications for Surveillance of Emerging Arboviruses in Latin Americas

Background: Sindbis virus (SINV) is an arbovirus (genus Alphavirus) widely distributed in Africa, Asia-Pacific and Europe, causing infections by 6 genotypes. As other emerging zoonotic arbovirus (such as Usutu, Kyasanur, Orthobunyavirus), its potential arrival to Latin America is of concern. Although all of this, there is no bibliometric studies assessing advances in its research. Methods & Materials: Bibliometric studies at 7 databases: Web of Sciences (WoS)®, Scopus®, GoPubMED, SciELO, Google Scholar, LILACS and ScienceDirect®, assessing the global scientific production on SINV, measuring the number of article per countries, productive institutions, number of original articles, published historically and during the last 5 years (2012-2016), productive authors, citations and H index, among other indicators. Results: Those most productive countries in WoS (N = 771): USA (337[43.7%]), France (53 [6.9%]) and UK (53 [6.9%]). At Scopus (N = 3486): USA (1751 [50.23%]), Germany (160 [4.59%]) and Japan (150 [4.3%]). At GoPubMed (N = 2898): USA (353 [12.18%]), Japan (38 [1.31%]) and UK (33 [1.13%]); production during 2012-2016 at WoS: 684 articles; at Scopus: 420 articles; GoPubMed: 296 articles. Countries with higher H-index (Scopus): USA (112, 68,419 citations), France (42, 4,313 citations), Germany (41, 5,075 citations), Japan (37, 5,512 citations), UK (34, 3,629 citations). Most productive cities on the topic: New York, USA (31 articles), Helsinki, Finland (18) and Beijing, China (17). A georeferenced map of scientific production on PubMed was developed. Conclusion: As in other bibliometric studies, scientific production by USA and their groups is predominant. In areas such as Latin America, investigation on SINV should began, particularly related to preparedness, medical education, epidemiology and transmission. At the same time, is necessary to increase its global research and initiate also this in Latin America, a suitable region where other recent arboviruses have emerged, such as was the case of chikungunya and Zika. For these arboviruses, bibliometric assessment helped to WHO to identify needs for research on these emerging infectious diseases.

Investigation of an autochthonous chikungunya outbreak, July–September 2017, France

Introduction Chikungunya virus (CHIKV) is an arbovirus that threatens Europe through irreversible spread of vector mosquito Aedes albopictus. In mainland France, three CHIKV local transmission episodes were detected in the last years by sustained surveillance. This surveillance is integrated in a national preparedness and control plan. In August 2017, a real-time reverse transcription-polymerase chain reaction (RT-PCR) confirmed autochthonous case of chikungunya was notified in the Var department, (southeastern France) in the town of Le Cannet-des-Maures (LCDM). Epidemiological and entomological investigations were immediately implemented to determine the source of infection and the extent of the transmission of the CHIKV in order to guide control measures. While these investigations were ongoing, in September, a second episode occurred in Taradeau, a town located ten kilometres from LCDM. Due to the spatial and temporal proximities of these episodes, investigations were also implemented with the additional objective to explore a potential link between them. Methods We conducted door-to-door case-finding in all households within a 200 m-radius around the autochthonous cases’ dwellings. The aim of these investigations was to identify and test any person with symptoms compatible with CHIKV infection, among households’ members as well as visiting relatives or friends, in order to determine the source of infection and the possible link between clusters. We contacted general practitioners (GP), medical laboratories and emergency services in both towns and their surroundings, to request them to quickly report and test any patient with symptoms compatible with CHIKV infection since June 1st. In the same time, we reviewed the surveillance database looking for a possible primary case among the imported chikungunya cases notified at local and national level. For any person with symptoms compatible with CHIKV infection, blood samples were collected and tested for CHIKV infection (RT-PCR and/or serology). Molecular analyses were performed by the National Reference Laboratory on index cases for each transmission episode. Entomological prospections and vector-control measures were implemented in the area of the investigation. Results Eleven cases (seven confirmed by RT-PCR and four with serological evidence of CHIKV infection) were identified in LCDM. Six cases (two confirmed by RT-PCR and four with serological evidence of CHIKV infection) were identified in Taradeau. The surveillance database reviewing has failed to identify imported chikungunya case living or travelling in the Var department. However, thanks to door-to-door investigations, we identified the primary case and a case who was the epidemiological link between the two clusters. All cases had occurred within 60 days after the onset of symptoms of the primary case (July 11th). Genomic characterisation of the virus identified for both clusters the same strain belonging to the “East Central South African” (ECSA) lineage and carrying the adaptive mutation A226 V facilitating transmission by Ae. Albopictus. Despite unfavourable weather conditions, entomological prospections in both towns, detected the presence of adult mosquitoes and breeding sites attributable to a high number of rainwater storage tank in the neighbourhoods. Conclusions This outbreak is the third occurrence in France of local transmission of CHIKV. The two largest episodes involved an ECSA genotype CHIKV harbouring the A226 V mutation facilitating transmission by Ae. albopictus. Thanks to previous information campaigns directed at physicians and biologists, the outbreak was detected early enough to timely implement vector-control measures and to limit its spread. This new outbreak confirms that CHIKV represents an increasing threat in Europe. Regular awareness campaigns targeting physicians and biologists, focusing on arboviruses diagnosis and reporting, have to be conducted to improve the effectiveness of this surveillance.

Tecnologias geoespaciais e o processo de enfermagem em uma unidade sentinela: relato de experiência

Objetivo: relatar a experiência da incorporação da pesquisa dos casos suspeitos de Dengue, Zika vírus e Chikungunya ao processo de enfermagem em uma unidade sentinela de Zika vírus. Método: relato de experiência que utilizou as tecnologias geoespaciais como ferramenta de ensino aprendizagem durante o Estágio Curricular Supervisionado de um curso de graduação em enfermagem feito em uma unidade sentinela. Reuniu-se todas as notificações registradas dos casos e realizou-se o geocodificação do local de residência dos indivíduos. Resultados: novas informações foram produzidas a respeito do endereço de procedência dos indivíduos suspeitos e notou-se que a população atendida reside, em sua maioria, na região compreendida de atendimento já preconizada para a unidade. Conclusões: a experiência contribuiu para a definição de prioridades para as ações relacionadas aos casos de Dengue, Chikungunya e principalmente do Zika vírus, apontando novas possibilidades de uso das tecnologias geoespaciais no desenvolvimento do processo de enfermagem.

The containment of potential outbreaks triggered by imported Chikungunya cases in Italy: a cost utility epidemiological assessment of vector control measures

The arrival of infected travelers from endemic regions can trigger sustained autochthonous transmission of mosquito-borne pathogens in Europe. In 2007 a Chikungunya outbreak was observed in central Italy, mostly affecting two villages characterised by a high density of Aedes albopictus. The outbreak was mitigated through intervention strategies reducing the mosquito abundance. Ten years later, in 2017, sustained Chikungunya transmission was documented in both central and southern Italy. The proposed analysis identifies suitable reactive measures for the containment and mitigation of future epidemics by combining epidemiological modeling with a health economic approach, considering different arrival times of imported infections and possible delays in the notification of cases. Obtained estimates suggest that, if the first notification will occur in the middle of the mosquito breeding season, the combination of larvicides, adulticides and breeding sites removal represents the optimal strategy. In particular, we found that interventions implemented in 2007 were cost-effective, with about 3200 prevented cases, 1450 DALYs averted and €13.5 M saved. Moreover, larvicides are proven to be more cost beneficial in early summer and warmer seasons, while adulticides should be preferred in autumn and colder seasons. Our results provide useful indications supporting urgent decision-making of public health authorities in response to emerging mosquito-borne epidemics.