Dengue fever

About: Dengue fever is a research topic. Over the lifetime, 17463 publications have been published within this topic receiving 485745 citations. The topic is also known as: Dengue & dengue disease.

Guillain-Barré Syndrome after Chikungunya Infection

Abstract: To the Editor: Chikungunya virus is an RNA alphavirus (group A arbovirus) in the family Togaviridae. The known vectors are Aedes aegypti and Ae. albopictus mosqitoes. Chikungunya infection, after an incubation period of 2–10 days, has the main clinical manifestations of fever, polyarthralgia, and rash. Treatment consists of rest and medication for pain. Outcome is marked by incapacitating arthralgia, which can persist for several weeks or months (1). Complications are rare and consist of mild hemorrhage, myocarditis, and hepatitis (2). Neurologic manifestations are less well known (3). Infection is confirmed by the identification of genomic products in acute-phase blood specimens, (reverse transcription–PCR [RT-PCR]) or, more recently, by serum immunoglobulin (Ig) M or a 4-fold increase in other antibodies. In 2006, chikungunya virus was found on Reunion Island; seroprevalence on the island was estimated to be 38.2% among 785,000 inhabitants (95% confidence interval 35.9%–40.6%) (4). Guillain-Barre syndrome (GBS) is an acute inflammatory demyelinating polyneuropathy; incidence worldwide is 0.6–4/100,000 persons/year. In two thirds of patients, neuropathic GBS occurs after an infection (5,6). Cases of GBS have been described in association with the arboviruses dengue and West Nile but not with chikungunya virus. We report 2 cases of acute and severe GBS related to infection with chikungunya virus. The first patient was a 51-year-old woman who in 2006 was admitted to an intensive care unit in Reunion Island’s Centre Hospitalier Departemental for treatment of polyradiculoneuropathy. Her medical history consisted of poorly treated type 2 diabetes and hypertension. Three weeks before hospital admission, she had had fever, arthralgia, rash, and diarrhea. One week later, rapidly progressing motor weakness and sensory disturbances developed, e.g., tingling in all limbs. She had facial diplegia, and her tendon reflexes were absent. Cerebrospinal fluid (CSF) contained increased protein (1.44 g/L) but not increased leukocytes (1/mm3). Electromyography displayed typical signs of demyelinating sensorimotor neuropathy with increased distal motor latency and reduced motor conduction velocity. Sensory nerve action potential was absent. Antichikungunya IgM was found in serum at 15 days after onset of signs and symptoms. This seroconversion confirms an acute infection by an alphavirus. Serum genomic product (RT-PCR, TaqMan method) (7) was negative for chikungunya virus. Antichikungunya IgM and IgG were also found in CSF. The patient’s respiration rapidly deteriorated, and she required tracheal intubation and mechanical ventilation for 12 days. She was given intravenous immunoglobulin for 5 days (TEGELINE; LBF Biomedicaments, Courtaboeuf, France). She recovered and was extubated on day 12. Two months after onset of symptoms, the patient reported a satisfactory recovery; she was able to walk, and her sensory disturbances had rapidly disappeared. The second patient was a 48-year-old woman who in 2006 was admitted to the intensive care unit in Reunion Island’s Centre Hospitalier Departemental unit for a rapidly developing polyradiculoneuropathy. She had no relevant past medical history. Two weeks before her admission, she had been febrile and had had arthralgia and a rash. Later, weakness with facial diplegia and sensory disturbances developed, e.g., tingling in all limbs. Tendon reflexes were absent. CSF contained increased protein but not increased leukocytes. Electromyography displayed signs of a peripheral neuropathy and evidence of a conduction block. At the time of hospital admission, antichikungunya IgM and IgG were detected in 2 serum samples. RT-PCR for chikungunya virus in serum and CSF was negative. The patient’s respiration rapidly deteriorated, and she required tracheal intubation and mechanical ventilation for 9 days. After receiving intravenous immunoglobulin for 5 days, she recovered quickly. Return of a productive cough and satisfactory muscle tone enabled her to be removed from mechanical ventilation on day 9. For the 2 patients reported here, GBS diagnosis was based on a typical clinical acute motor and sensory polyradiculoneuropathy, which evolved in 3 characteristic stages: rapid deterioration, plateau, and slow recovery (6). Also typical of GBS are normal CSF counts, increased CSF proteins, and electromyography data (peripheral neuropathy, conduction block). The widespread screening for organisms known to be associated with GBS produced negative results. However, antichikungunya IgM was found in serum and CSF, although genomic products in serum and CSF were negative, which was not surprising, given the brief period (4–5 days) of viremia (8). These findings strongly supported a disseminated acute chikungunya infection and enabled us to conclude that chikungunya virus was probably responsible for the GBS. Epidemiologic data also support a causal relationship between chikungunya infection and GBS. The incidence rate of GBS increased ≈22% in 2006 (26/787,000 [3.3/100,000] persons) over the rate in 2005 (21/775,000 [2.7/10,000] persons) and then declined to a rate closer to baseline in 2007 (23/800,000 [2.87/100,000] persons). These 2 cases of GBS on Reunion Island were related to an acute and documented chikungunya infection. In the absence of an effective treatment, patients with these suspected infections should receive supportive care for classic GBS.

The Early Whole-Blood Transcriptional Signature of Dengue Virus and Features Associated with Progression to Dengue Shock Syndrome in Vietnamese Children and Young Adults

Abstract: Dengue is a pantropic public health problem. In children, dengue shock syndrome (DSS) is the most common life-threatening complication. The ability to predict which patients may develop DSS may improve triage and treatment. To this end, we conducted a nested case-control comparison of the early host transcriptional features in 24 DSS patients and 56 sex-, age-, and virus serotype-matched uncomplicated (UC) dengue patients. In the first instance, we defined the "early dengue" profile. The transcriptional signature in acute rather than convalescent samples (≤72 h post-illness onset) was defined by an overabundance of interferon-inducible transcripts (31% of the 551 overabundant transcripts) and canonical gene ontology terms that included the following: response to virus, immune response, innate immune response, and inflammatory response. Pathway and network analyses identified STAT1, STAT2, STAT3, IRF7, IRF9, IRF1, CEBPB, and SP1 as key transcriptional factors mediating the early response. Strikingly, the only difference in the transcriptional signatures of early DSS and UC dengue cases was the greater abundance of several neutrophil-associated transcripts in patients who progressed to DSS, a finding supported by higher plasma concentrations of several canonical proteins associated with neutrophil degranulation (bactericidal/permeability-increasing protein [BPI], elastase 2 [ELA2], and defensin 1 alpha [DEF1A]). Elevated levels of neutrophil-associated transcripts were independent of the neutrophil count and also of the genotype of the infecting virus, as genome-length sequences of dengue virus serotype 1 (DENV-1) (n = 15) and DENV-2 (n = 3) sampled from DSS patients were phylogenetically indistinguishable from those sampled from uncomplicated dengue patients (32 DENV-1 and 9 DENV-2 sequences). Collectively, these data suggest a hitherto unrecognized association between neutrophil activation, pathogenesis, and the development of DSS and point to future strategies for guiding prognosis.

Dengue Type 3 Virus in Plasma Is a Population of Closely Related Genomes: Quasispecies

Abstract: Using reverse transcription-PCR and clonal sequencing of the dengue virus envelope gene derived from the plasma samples of six patients, we reported for the first time that dengue virus circulates as a population of closely related genomes. The extent of sequence diversity varied among patients, with the mean pairwise proportions of difference ranging from 0.21 to 1.67%. Genome-defective viruses were found in 5.8% of the total number of clones analyzed. Our findings on the quasispecies nature of dengue virus and the defective virus in vivo have implications with regard to the pathogenesis of dengue virus.

Natural vertical transmission of dengue virus in Aedes aegypti and Aedes albopictus: a systematic review

Abstract: Dengue is of great concern in various parts of the world, especially in tropical and subtropical countries where the mosquito vectors Aedes aegypti and Aedes albopictus are present The transmission of this virus to humans, by what is known as horizontal transmission, occurs through the bite of infected females of one or other of the two mosquito species Furthermore, an infected female or male parent, by what is known as vertical transmission, can transfer this arbovirus to some part of their offspring Considering that vertical transmission may represent an important strategy for maintaining the circulation of arboviruses in nature, the verification of this phenomenon worldwide is extremely important and necessary to better understand its dynamic In the present study, we conducted a literature review of the presence of natural vertical transmission of dengue virus in Ae aegypti and Ae albopictus worldwide Searches were conducted in MEDLINE, sciELO and Lilacs and all the studies published in Portuguese, English and Spanish were read, evaluated and organized by mosquito species, serotype and the location at which the samples were collected Forty-two studies were included in accordance with the exclusion criteria and methodology The presence of natural vertical transmission in Ae aegypti and Ae albopictus was most clearly evidenced by dengue virus in endemic countries, especially in those in South America and Asia Despite several African countries being considered endemic for dengue, there is a lack of publications on this subject on that continent, which highlights the importance of conducting studies there Furthermore, the finding of natural vertical transmission in Ae albopictus in countries where this species is not yet incriminated as a vector is of great concern as it demonstrates the circulation of this virus in populations of Ae albopictus and alerts to the possibility of some other mosquito species playing a role in the transmission dynamics of this arbovirus Parallel to this, the small number of studies of natural vertical transmission of chikungunya and Zika virus in the world may be explained by the recent entry of these arboviruses into most of the countries concerned