Yellow fever virus (YFV) is a zoonotic arbovirus affecting both humans and non-human primates (NHP's) in Africa and South America. Previous descriptions of YF's seasonality have relied purely on ...climatic explanations, despite the high proportion of cases occurring in people involved in agriculture. We use a series of random forest classification models to predict the monthly occurrence of YF in humans and NHP's across Brazil, by fitting four classes of covariates related to the seasonality of climate and agriculture (planting and harvesting), crop output and host demography. We find that models captured seasonal YF reporting in humans and NHPs when they considered seasonality of agriculture rather than climate, particularly for monthly aggregated reports. These findings illustrate the seasonality of exposure, through agriculture, as a component of zoonotic spillover. Additionally, by highlighting crop types and anthropogenic seasonality, these results could directly identify areas at highest risk of zoonotic spillover.
Due to the risk of severe vaccine-associated adverse events, yellow fever vaccination in Brazil is only recommended in areas considered at risk for disease. From September 2008 through June 2009, two ...outbreaks of yellow fever in previously unvaccinated populations resulted in 21 confirmed cases with 9 deaths (case-fatality, 43%) in the southern state of Rio Grande do Sul and 28 cases with 11 deaths (39%) in Sao Paulo state. Epizootic deaths of non-human primates were reported before and during the outbreak. Over 5.5 million doses of yellow fever vaccine were administered in the two most affected states. Vaccine-associated adverse events were associated with six deaths due to acute viscerotropic disease (0.8 deaths per million doses administered) and 45 cases of acute neurotropic disease (5.6 per million doses administered). Yellow fever vaccine recommendations were revised to include areas in Brazil previously not considered at risk for yellow fever.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Howler monkey capture is an arduous and expensive task requiring trained and specialized professionals. We compared strategies and methods to most efficiently capture Alouatta guariba clamitans in ...remnants of the Atlantic Forest in Rio de Janeiro and its bordering states of Minas Gerais and São Paulo. We tested whether or not the success of expeditions in the forest with anesthetic darts, nets, and baited traps differed with and without the support of an information network, a contact chain built with key institutions and inhabitants to continuously monitor howler monkey presence. The influence of forest conditions (vegetation type and fragment size) upon darting success was also evaluated. We captured 24 free‐living A. guariba clamitans. No howler monkey was caught with traps, probably due to the predominantly folivore feeding to high local plant diversity providing a great variety of food options. Captures based on an information network were significantly more efficient in terms of numbers of caught monkeys than without it. Captures with darts were considerably more efficient when performed in semideciduous forests and small forest fragments as opposed to ombrophilous forests or large woods. Although we walked great distances within the forest searching for howler monkeys, all but one animal were captured at the forest fringes. Hindrances to search and the darting method in the Atlantic Forest, for example, the steep terrain, high tree canopies, hunt pressure, and low A. guariba clamitans population density, were mitigated with the use of the information network in this monkey capture. Moreover, the information network enhanced the surveillance of zoonotic diseases, which howler monkeys and other nonhuman primates are reservoirs in Brazil, such as malaria and yellow fever.
Alouatta guariba clamitans crossing the road through the rope, very close to the baited trap in platform 2. Even after 25 weeks, it never entered or examined the platform or the baits, which increases the need to develop better strategies to capture and examine this species in the Atlantic Forest. Panoramic image was assembled using the software Microsoft Image Composite Editor 2.0 (ICE).
HIGHLIGHTS
The construction of an information network with key institution and resident contacts optimize the efforts of howler monkey (Alouatta guariba clamitans) capture.
The network can be easily maintained through mobile message exchange apps.
Focusing howlers searches in small and semideciduous forest fragments are the best strategies to enhance capture efficiency when using anesthetic darts in the Atlantic Forest.
We evaluated the duration of neutralizing antibodies and the status of 17DD vaccine-specific T- and B-cell memory following primary and revaccination regimens for yellow fever (YF) in Brazil. We ...observed progressive decline of plaque-reduction neutralization test (PRNT) seropositivity and of the levels of effector memory CD4+ and CD8+ T cells, as well as interferon-γ+CD8+ T cells, 10 years after primary vaccination. Revaccination restored PRNT seropositivity as well as the levels of effector memory CD4+, CD8+, and interferon-γ+CD8+ T cells. Moreover, secondary or multiple vaccinations guarantee long-term persistence of PRNT positivity and cell-mediated memory 10 years after booster vaccination. These findings support the relevance of booster doses to heighten the 17DD-YF-specific immune response to guarantee the long-term persistence of memory components. Secondary or multiple vaccinations improved the correlates of protection triggered by 17DD-YF primary vaccination, indicating that booster regimens are needed to achieve efficient immunity in areas with high risk for virus transmission.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The recent reemergence of yellow fever virus (YFV) in Brazil has raised serious concerns due to the rapid dissemination of the virus in the southeastern region. To better understand YFV genetic ...diversity and dynamics during the recent outbreak in southeastern Brazil, we generated 18 complete and nearly complete genomes from the peak of the epidemic curve from nonhuman primates (NHPs) and human infected cases across the Espírito Santo and Rio de Janeiro states. Genomic sequencing of 18 YFV genomes revealed the estimated timing, source, and likely routes of yellow fever virus transmission and dispersion during one of the largest outbreaks ever registered in Brazil. We showed that during the recent epidemic, YFV was reintroduced from Minas Gerais to the Espírito Santo and Rio de Janeiro states multiple times between 2016 and 2019. The analysis of data from portable sequencing could identify the corridor of spread of YFV. These findings reinforce the idea that continued genomic surveillance strategies can provide information on virus genetic diversity and transmission dynamics that might assist in understanding arbovirus epidemics.
Arbovirus infections in Brazil, including yellow fever, dengue, zika, and chikungunya, result in considerable morbidity and mortality and are pressing public health concerns. However, our understanding of these outbreaks is hampered by the limited availability of genomic data. In this study, we investigated the genetic diversity and spatial distribution of YFV during the current outbreak by analyzing genomic data from areas in southeastern Brazil not covered by other previous studies. To gain insights into the routes of YFV introduction and dispersion, we tracked the virus by sequencing YFV genomes sampled from nonhuman primates and infected patients from the southeastern region. Our study provides an understanding of how YFV initiates transmission in new Brazilian regions and illustrates that genomics in the field can augment traditional approaches to infectious disease surveillance and control.
Due to the importance that Howler monkeys have on the yellow fever (YF) epidemiological sylvatic cycle in Brazil, more accurate morphological diagnostic criteria needs to be established, especially ...considering the differences that may exist between the genera of Brazilian non-human primates (NHPs) involved in yellow fever virus (YFV) epizootics.
Records of YF epizootics in NHPs in Brazil between 2007 and 2009 were obtained from the Brazilian Ministry of Health database to select YF positive (n=98) Howler monkeys (Alouatta sp.) for this study. The changes described in the histopathological reports were categorized by organ and their frequencies calculated.
The most frequent lesions observed in the animals with YF were hepatocyte apoptosis (Councilman body formation), midzonal hepatocyte necrosis, steatosis, liver hemorrhage, inflammatory mononuclear cell infiltration of the liver, renal acute tubular necrosis and interstitial nephritis. Midzonal hepatocyte necrosis, steatosis and hemorrhage presented positive correlations with apoptosis of hepatocytes, suggesting strong YFV pathogenic effect association; they were also the main histopathological changes in the Alouatta sp. A pronounced negative correlation between apoptosis of hepatocytes and hepatic mononuclear cell infiltration pointed to significant histopathological differences between YFV infection in Howler monkeys and humans.
The results warn that NHPs may exhibit different response patterns following YFV infection and require a more careful diagnosis. Presumptive diagnosis based on primate histopathological lesions may contribute to public health service control.
to describe the epidemiological profile of human rabies in Brazil.
this is a descriptive study of human rabies cases reported in 2000-2017, with an estimate of incidence and spatial distribution.
188 ...cases were studied, mostly males (66.5%), rural residents (67.0%), children under 15 years (49.6%), with biting being the most frequent form of exposure (81.9%); frequency was highest in the period 2000-2008 (85.6%), with 46.6% of cases involving dogs and 45.9% bats; median incubation was 50 days, followed by, predominantly, symptoms of fever (92.6%), agitation (85.2%), paresthesia (66.7%), and dysphagia/paralysis (51.9%); the majority (70.2%) did not have prophylaxis and for the rest (29.8%) who did have prophylaxis, it was untimely and/or incomplete; 13 patients were treated according to the Recife Protocol, and two survived.
human rabies incidence reduced and its epidemiological profile changed, with predominance of cases transmitted by bats; we suggest that secondary cases be investigated, and that pre-exposure prophylaxis be made available to populations at greater risk of accidents involving bats.
The yellow fever virus (YFV) caused a severe outbreak in Brazil in 2016-2018 that rapidly spread across the Atlantic Forest in its most populated region without viral circulation for almost 80 years. ...A comprehensive entomological survey combining analysis of distribution, abundance and YFV natural infection in mosquitoes captured before and during the outbreak was conducted in 44 municipalities of five Brazilian states. In total, 17,662 mosquitoes of 89 species were collected. Before evidence of virus circulation, mosquitoes were tested negative but traditional vectors were alarmingly detected in 82% of municipalities, revealing high receptivity to sylvatic transmission. During the outbreak, five species were found positive in 42% of municipalities. Haemagogus janthinomys and Hg. leucocelaenus are considered the primary vectors due to their large distribution combined with high abundance and natural infection rates, concurring together for the rapid spread and severity of this outbreak. Aedes taeniorhynchus was found infected for the first time, but like Sabethes chloropterus and Aedes scapularis, it appears to have a potential local or secondary role because of their low abundance, distribution and infection rates. There was no evidence of YFV transmission by Aedes albopictus and Aedes aegypti, although the former was the most widespread species across affected municipalities, presenting an important overlap between the niches of the sylvatic vectors and the anthropic ones. The definition of receptive areas, expansion of vaccination in the most affected age group and exposed populations and the adoption of universal vaccination to the entire Brazilian population need to be urgently implemented.
Raiva humana no Brasil: estudo descritivo, 2000-2017 Vargas, Alexander; Romano, Alessandro Pecego Martins; Merchán-Hamann, Edgar
Epidemiologia e serviços de saúde,
7/2019, Letnik:
28, Številka:
2
Journal Article
Odprti dostop
Resumo Objetivo: descrever o perfil epidemiológico da raiva humana no Brasil. Métodos: estudo descritivo dos casos de raiva humana notificados em 2000-2017; estimou-se a incidência e distribuição ...espacial. Resultados: 188 casos humanos observados, na maioria homens (66,5%), residentes rurais (67,0%), menores de 15 anos de idade (49,6%), com exposição mais frequente por mordedura (81,9%); o período 2000-2008 apresentou maior frequência (85,6%), com 46,6% dos casos envolvendo cães e 45,9% morcegos; incubação mediana de 50 dias, seguida de sintomatologia predominante de febre (92,6%), agitação (85,2%), parestesia (66,7%) e disfagia/paralisia (51,9%); a maioria (70,2%) não fez profilaxia, os demais (29,8%) realizaram-na de forma inoportuna e/ou incompleta; 13 pacientes foram tratados pelo Protocolo de Recife e dois sobreviveram. Conclusão: houve redução na incidência de raiva humana e mudança no perfil epidemiológico, predominando casos transmitidos por morcegos; sugere-se investigar casos secundários e viabilizar a profilaxia pré-exposição em populações sob maior risco de acidentes com morcegos.
Although malaria cases have substantially decreased in Southeast Brazil, a significant increase in the number of Plasmodium vivax-like autochthonous human cases has been reported in remote areas of ...the Atlantic Forest in the past few decades in Rio de Janeiro (RJ) state, including an outbreak during 2015-2016. The singular clinical and epidemiological aspects in several human cases, and collectively with molecular and genetic data, revealed that they were due to the non-human primate (NHP) parasite Plasmodium simium; however, the understanding of the autochthonous malarial epidemiology in Southeast Brazil can only be acquired by assessing the circulation of NHP Plasmodium in the foci and determining its hosts.
A large sampling effort was carried out in the Atlantic forest of RJ and its bordering states (Minas Gerais, São Paulo, Espírito Santo) for collecting and examining free-living NHPs. Blood and/or viscera were analyzed for Plasmodium infections via molecular and microscopic techniques.
In total, 146 NHPs of six species, from 30 counties in four states, were tested, of which majority were collected from RJ. Howler monkeys (Alouatta clamitans) were the only species found infected. In RJ, 26% of these monkeys tested positive, of which 17% were found to be infected with P. simium. Importantly, specific single nucleotide polymorphisms-the only available genetic markers that differentiate P. simium from P. vivax-were detected in all P. simium infected A. clamitans despite their geographical origin of malarial foci. Interestingly, 71% of P. simium infected NHPs were from the coastal slope of a mountain chain (Serra do Mar), where majority of the human cases were found. Plasmodium brasilianum/malariae was initially detected in 14% and 25% free-living howler monkeys in RJ and in the Espírito Santo (ES) state, respectively. Moreover, the malarial pigment was detected in the spleen fragments of 50% of a subsample comprising dead howler monkeys in both RJ and ES. All NHPs were negative for Plasmodium falciparum.
Our data indicate that howler monkeys act as the main reservoir for the Atlantic forest human malarial parasites in RJ and other sites in Southeast Brazil and reinforce its zoonotic characteristics.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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