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[Recrudescence of yellow fever in Chad: case report of the last confirmed case in the health district of Lai-Chad].

Yellow fever (YF) is a viral haemorrhagic fever caused by yellow fever virus transmitted by Aedes mosquitoes. Since 2013, in Chad, four cases of yellow fever have been detected and confirmed as part of the national fever surveillance program. We here report the last clinical case confirmed in the health district of Lai. The patient was a 57-year-old man with no significant medical and surgical history and unknown immunisation status. He consulted on April 21st, 2020 for fever, moderate to low abundance jaundice and epistaxis (nosebleed) and painful hepatomegaly. Paraclinical examinations, such…

The effects of corrective information about disease epidemics and outbreaks: Evidence from Zika and yellow fever in Brazil.

Disease epidemics and outbreaks often generate conspiracy theories and misperceptions that mislead people about the risks they face and how best to protect themselves. We investigate the effectiveness of interventions aimed at combating false and unsupported information about the Zika epidemic and subsequent yellow fever outbreak in Brazil. Results from a nationally representative survey show that conspiracy theories and other misperceptions about Zika are widely believed. Moreover, results from three preregistered survey experiments suggest that efforts to counter misperceptions about disease…

Concurrent amplification of Zika, chikungunya, and yellow fever virus in a sylvatic focus of arboviruses in Southeastern Senegal, 2015.

BACKGROUND: Chikungunya (CHIKV), yellow fever (YFV) and Zika (ZIKV) viruses circulate in sylvatic transmission cycles in southeastern Senegal, where they share common hosts and vectors. All three viruses undergo periodic amplifications, during which they are detected in mosquitoes and sometimes in hosts. However, little is known about their spatio-temporal patterns in years in which they undergo concurrent amplification. The aim of this study was to describe the co-amplification of ZIKV, CHIKV, and YFV, and the daily dynamics of these arboviruses and theirs vectors within villages in southeast…

Ensuring the Safety of Yellow Fever Vaccination in Travelers-The Experience at a Large U.S. Academic Medical Center in Colorado.

Background: Yellow fever (YF) virus has the potential to cause fatal outcomes among at-risk individuals visiting endemic areas. Vaccinating travelers who are at risk is necessary to prevent virus-related life-threatening complications. We lack data on the clinical features of persons seeking YF vaccination. We aim to describe the characteristics of a cohort of persons receiving the YF vaccine before travel. Methods: A retrospective analysis of 964 travelers receiving the YF vaccine (Stamaril®) from Oct 2016 to Jul 2019 was performed at the University of Colorado Hospital, U.S. Percentages, mea…

Evaluating the importation of yellow fever cases into China in 2016 and strategies used to prevent and control the spread of the disease.

During the yellow fever epidemic in Angola in 2016, cases of yellow fever were reported in China for the first time. The 11 cases, all Chinese nationals returning from Angola, were identified in March and April 2016, one to two weeks after the peak of the Angolan epidemic. One patient died; the other 10 cases recovered after treatment. This paper reviews the epidemiological characteristics of the 11 yellow fever cases imported into China. It examines case detection and disease control and surveillance, and presents recommendations for further action to prevent additional importation of yellow …

Yellow Fever: Factors Associated with Death in a Hospital of Reference in Infectious Diseases, São Paulo, Brazil, 2018.

Faced with the reemergence of yellow fever (YF) in the metropolitan region of São Paulo, Brazil, we developed a retrospective study to describe the cases of YF attended at the Institute of Infectology Emilio Ribas from January to March 2018 and analyze the factors associated with death, from the information obtained in the hospital epidemiological investigation. A total of 72 cases of sylvatic YF were confirmed, with 21 deaths (29.2% lethality rate). Cases were concentrated in males (80.6%) and in the age group of 30 to 59 years (56.9%). Two logistic regression models were performed, with cont…

[Prescription of Yellow Fever Vaccine: The Experience of the International Vaccination Centre of the Loures-Odivelas Health Centre Group].

INTRODUCTION: Yellow fever is a vector-borne disease in sub-Saharan Africa and tropical South America regions which is preventable by an effective and safe vaccine. In some cases, it may cause serious adverse effects and should therefore be prescribed only to individuals at risk of exposure to the yellow fever virus or those traveling to countries requiring proof of vaccination. The aim of this study was to analyze the prescriptions of yellow fever vaccine, based on travel destination and type of referring consultation, according to the international recommendations of the World Health Organiz…

Travel Pattern and Prescription Analysis at a Single Travel Clinic Specialized for Yellow Fever Vaccination in South Korea.

BACKGROUND: Travel-related risks for infectious diseases vary depending on travel patterns such as purpose, destination, and duration. In th … ormed for 3,332 cases for analysis of travel patterns and prescriptions. RESULTS: People receiving yellow fever vaccine (YFV) (n = 2,933) were traveling more frequently for business and tourism and less frequently for providing non-medical service or research/education compared to the 399 people who did not receive the YFV. Overall, most people were traveling …

Spread of yellow fever virus outbreak in Angola and the Democratic Republic of the Congo 2015-16: a modelling study.

BACKGROUND: Since late 2015, an epidemic of yellow fever has caused more than 7334 suspected cases in Angola and the Democratic Republic of the Congo, including 393 deaths. We sought to understand the spatial spread of this outbreak to optimise the use of the limited available vaccine stock. METHODS: We jointly analysed datasets describing the epidemic of yellow fever, vector suitability, human demography, and mobility in central Africa to understand and predict the spread of yellow fever virus. We used a standard logistic model to infer the district-specific yellow fever virus infection risk…

Imidacloprid impairs the post-embryonic development of the midgut in the yellow fever mosquito Stegomyia aegypti (=Aedes aegypti).

The mosquito Stegomyia aegypti (=Aedes aegypti) (Diptera: Culicidae) is a vector for the dengue and yellow fever viruses. As blood digestion occurs in the midgut, this organ constitutes the route of entry of many pathogens. The effects of the insecticide imidacloprid on the survival of St. aegypti were investigated and the sub-lethal effects of the insecticide on midgut development were determined. Third instar larvae were exposed to different concentrations of imidacloprid (0.15, 1.5, 3.0, 6.0 and 15.0 p.p.m.) and survival was monitored every 24 h for 10 days. Midguts from imidacloprid-treate…

Mutual interference on the immune response to yellow fever vaccine and a combined vaccine against measles, mumps and rubella.

A randomized trial was conducted to assess the immunogenicity and reactogenicity of yellow fever vaccines (YFV) given either simultaneously in separate injections, or 30 days or more after a combined measles-mumps-rubella (MMR) vaccine. Volunteers were also randomized to YFV produced from 17DD and WHO-17D-213 substrains. The study group comprised 1769 healthy 12-month-old children brought to health care centers in Brasilia for routine vaccination. The reactogenicity was of the type and frequency expected for the vaccines and no severe adverse event was associated to either vaccine. Seroconvers…

The single kinin receptor signals to separate and independent physiological pathways in Malpighian tubules of the yellow fever mosquito.

In the past, we have used the kinins of the cockroach Leucophaea (the leucokinins) to evaluate the mechanism of diuretic action of kinin peptides in Malpighian tubules of the yellow fever mosquito Aedes aegypti. Now using the kinins of Aedes (the aedeskinins), we have found that in isolated Aedes Malpighian tubules all three aedeskinins (1 microM) significantly 1) increased the rate of fluid secretion (V(S)), 2) hyperpolarized the basolateral membrane voltage (V(bl)), and 3) decreased the input resistance (R(in)) of principal cells, consistent with the known increase in the Cl(-) conductance o…

Effect of body size and sugar meals on oviposition of the yellow fever mosquito, Aedes aegypti (Diptera: Culicidae).

The effects of dietary sugar and body size on the oviposition of Ae. aegypti were studied under laboratory conditions. In female mosquitoes provided with sugar, the start of maximum fecundity was significantly delayed and the oviposition period was longer than in females provided with water. The peak of oviposition was also delayed in sugar-fed females. Large females oviposited more eggs per day than small females at maximum fecundity and during eight days of observations. Large females also visited significantly more water-containing cups in their cages per day than small females at maximum f

Comparison of the inhibitory effects of interferon alfacon-1 and ribavirin on yellow fever virus infection in a hamster model.

Antiviral compounds were evaluated for efficacy against yellow fever virus (YFV) in a hamster model of YFV-induced liver disease. Challenge with a 10(2) 50% cell culture infectious doses of YFV resulted in a 50-80% mortality rate in female hamsters. Virus was detected by quantitative real-time RT-PCR (QRT-PCR) in liver, kidney, spleen and serum with peak titers on 4-6 days post-viral challenge (dpi). Serum levels of alkaline phosphatase, alanine aminotransferase (ALT), bilirubin, blood urea nitrogen, potassium and creatinine were significantly elevated, while serum levels of albumin, amylase, …

[The city and the death: yellow fever and its impact on funeral customs in Rio de Janeiro (1849-50)].

During the summer of 1849-50, a yellow fever epidemic hit the city of Rio de Janeeiro. In analyzing the epidemic's impact on local funeral customs, the article asked to what extent the subsequent high mortality rate was a catalyst that changed people's attitudes towards death and the deceased. The central hypothesis is that the epidemic was the final argument physicians needed to convince the imperial government and the population to implement these doctors' project, one which would medicalize death and standardize funeral customs.

Однородность штаммов желтой лихорадки, изолированных во время эпидемии и постэпидемического периода в Западной Африке.

Три штамма вируса желтой лихорадки (YFV) были изолированы в 1982 году в Кот-д ' Ивуаре, один из случая с человеком и два из Aedes luteocephalus во время и после эпидемии. Полная геномная последовательность человеческого штамма была определена и сравнилась с последовательности штамма Асиби 1927 года. Наблюдалось расхождение в среднем на уровне 8,3%, в диапазоне от 5,5 до 11,7% в регионе кодирования. Коэффициент перехода на трансверсию составил 5,9. Большинство мутаций (84,3%) произошло в третьем положении кодонов, причем синонимные мутации составляли 92,5%. Однако, когда сопоставлялись час

Совпадение в аннотации оригинала
Three strains of yellow fever virus (YFV) were isolated in 1982 in The Ivory Coast, one from a human case and two from Aedes luteocephalus, during and subsequent to an epidemic. The complete genomic sequence of the human strain was determined and compared to that of the 1927 Asibi strain of YFV. The divergence observed was on average of 8.3%, ranging from 5.…

The yellow fever 17D vaccine virus: molecular basis of viral attenuation and its use as an expression vector.

The yellow fever (YF) virus is the prototype flavivirus. The use of molecular techniques has unraveled the basic mechanisms of viral genome structure and expression. Recent trends in flavivirus research include the use of infectious clone technology with which it is possible to recover virus from cloned cDNA. Using this technique, mutations can be introduced at any point of the viral genome and their resulting effect on virus phenotype can be assessed. This approach has opened new possibilities to study several biological viral features with special emphasis on the issue of virulence/attenuati…

Secondary structure of the 3'-untranslated region of yellow fever virus: implications for virulence, attenuation and vaccine development.

A genetic algorithm-based RNA secondary structure prediction was combined with comparative sequence analysis to construct models of folding for the distal 380 nucleotides of the 3'-untranslated region (3'-UTR) of yellow fever virus (YFV). A number of structural elements that are thermodynamically stable, conserved in shape, and confirmed by compensatory mutations were revealed. At the same time structural polymorphisms were observed among strains of YFV. These polymorphisms showed an association with virulence: all wild and pathogenic strains were likely to be folded in a significantly differe…