Posts filed under ‘FIEBRE y RASH’

Duration of the Presence of Infectious Zika Virus in Semen and Serum

Journal of Infectious Diseases, 1 January 2019 V.219 N.1  P.31–40

Freddy A Medina; Giselle Torres; Jenny Acevedo; Sharon Fonseca; Leslie Casiano …

Zika virus (ZIKV) has recently caused a large epidemic in the Americas that is associated with birth defects.

Although ZIKV is primarily transmitted by Aedes mosquitoes, ZIKV RNA is detectable in blood and semen of infected individuals for weeks or months, during which sexual and other modes of transmission are possible.

However, viral RNA is usually detectable longer than infectious virus is present.

We determined the frequency of isolation of infectious virus from semen and serum samples prospectively obtained from a cohort of patients in Puerto Rico.

We confirmed isolation of infectious virus on the basis of a tissue culture cytopathic effect, an increase in virus genome copy equivalents (GCE), and positive results of immunofluorescence analysis; virus in infected cells was quantitated by flow cytometry.

These criteria confirmed the presence of infectious virus in semen specimens from 8 of 97 patients for up to 38 days after initial detection when virus loads are >1.4 × 106 genome copy equivalents/mL. Two serum isolates were obtained from 296 patients.

These findings can help guide important prevention guidelines for persons that may potentially be infectious and transmit ZIKV sexually.




January 5, 2019 at 11:55 am

Multistate infestation with the exotic disease–vector tick Haemaphysalis longicornis — United States, August 2017–September 2018.

MMWR Morb Mortal Wkly Rep November 30, 2018 V.67 N.47 P.1310-1313.

Beard CB et al

Haemaphysalis longicornis is a tick indigenous to eastern Asia and an important vector of human and animal disease agents, resulting in such outcomes as human hemorrhagic fever and reduction of production in dairy cattle by 25%.

H. longicornis was discovered on a sheep in New Jersey in August 2017 (1).

This was the first detection in the United States outside of quarantine.

In the spring of 2018, the tick was again detected at the index site, and later, in other counties in New Jersey, in seven other states in the eastern United States, and in Arkansas.

The hosts included six species of domestic animals, six species of wildlife, and humans.

To forestall adverse consequences in humans, pets, livestock, and wildlife, several critical actions are indicated, including expanded surveillance to determine the evolving distribution of H. longicornis, detection of pathogens that H. longicornis currently harbors, determination of the capacity of H. longicornis to serve as a vector for a range of potential pathogens, and evaluation of effective agents and methods for the control of H. longicornis ….


December 6, 2018 at 8:00 am

Cluster of Fatal Group A Streptococcal emm87 Infections in a Single Family: Molecular Basis for Invasion and Transmission.

J Infect Dis. June 1, 2017 V.215 N.11 P.1648-1652.      

La enfermedad hipervirulenta debida a Strep pyogenes puede ser el resultado de cepas con mutaciones que mejoran la expresión del gen de virulencia pero reducen la transmisión posterior.

Los autores utilizan la secuenciación del genoma completo para investigar la diseminación intra-familiar entre 4 hermanos, de una infección debido a una cepa de Strep pyoegenes hipervirulenta que resultó en la muerte de uno de ellos.

Todos los aislamientos de Strep pyoegenes invasivos y faríngeos tenían una mutación idéntica en un gen que codifica una proteína reguladora clave que producía un fenotipo hiperinvasivo.

Estos datos desafían la teoría prevaleciente de la transmisión reducida inducida por mutaciones que conducen a un Strep pyoegenes hipervirulento con alta diseminación grupal.



September 25, 2018 at 8:13 am

Description of the Pathogenic Features of Streptococcus pyogenes Isolates from Invasive and Non-Invasive Diseases in Aichi, Japan.

Jpn J Infect Dis. 2016 Jul 22;69(4):338-41.

Matsumoto M1, Yamada K, Suzuki M, Adachi H, Kobayashi S, Yamashita T, Minagawa H, Tatsuno I, Hasegawa T.


We identified hypervirulent Streptococcus pyogenes in 27 and 420 isolates from patients with invasive and non-invasive diseases, respectively, in Aichi Prefecture, Japan, between 2003 and 2012, in an attempt to understand why the prevalence of streptococcal toxic shock syndrome (STSS) suddenly increased in this location during 2011. Hypervirulent strains belong to the emm1 genotype, with a mutation in the covR/S genes that regulate many other genes, encoding virulence determinants and resulting in the absence of the proteinase streptococcal exotoxin B and the production of virulence factors such as the superantigen streptococcal exotoxin A, the nuclease streptococcal DNase, the cytotoxin NAD-glycohydrolase, and the hemolysin streptolysin O. We found 1 strain from invasive disease and 1 from non-invasive disease with traits similar to those of hypervirulent strains, except that the sda1 gene was absent. We also found 1 non-emm1 strain with phenotypic and genetic traits identical to those of the emm1 hypervirulent strains except that it did not belong to emm1 genotype, from non-invasive diseases cases in 2011. These findings suggested that hypervirulent and hypervirulent-like strains from invasive and non-invasive disease cases could have at least partially contributed to the sudden increase in the number of patients with STSS in Aichi during 2011


September 21, 2018 at 8:21 am

Invasive streptococcal disease: a review for clinicians.

Br Med Bull. 2015 Sep;115(1):77-89.

Parks T1, Barrett L2, Jones N3.



Streptococci are a genus of Gram-positive bacteria which cause diverse human diseases. Many of these species have the potential to cause invasive infection resulting from the presence of bacteria in a normally sterile site.


Original articles, reviews and guidelines.


Invasive infection by a streptococcus species usually causes life-threatening illness. When measured in terms of deaths, disability and cost, these infections remain an important threat to health in the UK. Overall they are becoming more frequent among the elderly and those with underlying chronic illness. New observational evidence has become available to support the use of clindamycin and intravenous immunoglobulin in invasive Group A streptococcal disease.


Few interventions for the treatment and prevention of these infections have undergone rigorous evaluation in clinical trials. For example, the role of preventative strategies such as screening of pregnant women to prevent neonatal invasive Group B streptococcal disease needs to be clarified.


Studies of invasive streptococcal disease are challenging to undertake, not least because individual hospitals treat relatively few confirmed cases. Instead clinicians and scientists must work together to build national and international networks with the aim of developing a more complete evidence base for the treatment and prevention of these devastating infections.



September 21, 2018 at 8:20 am

Changes in the clinical and epidemiological features of group A streptococcal bacteraemia in Australia’s Northern Territory.

Trop Med Int Health. 2015 Jan;20(1):40-7.

Gear RJ1, Carter JC, Carapetis JR, Baird R, Davis JS.



Invasive group A streptococcus (iGAS) disease is an important cause of mortality globally. The incidence of iGAS in Australia’s tropical Northern Territory (NT) has been previously reported as 32.2/100 000 in Indigenous people for the period 1991-1996. We aimed to measure the incidence and severity of iGAS disease in the NT since this time.


We collected demographic data for all GAS blood culture isolates over a 12-year period (1998-2009) from the three hospital laboratories serving the tropical NT. We then collected detailed clinical information from hospital records and databases for the subset of these patients who were admitted to Royal Darwin Hospital during 2005-2009.


There were 295 confirmed cases of GAS bacteraemia over the study period, with a mean (SD) age of 42.1 (22.0) years, and 163 (55.0%) were male. The annual age-adjusted incidence was 15.2 (95% CI 13.4-16.9)/100 000 overall and 59.4 (95% CI 51.2-67.6) in Indigenous Australians. For 2005-2009, there were 123 cases with the most common focus of infection being skin/soft tissue [44 (35.6%)]; 29 patients (23.6%) required intensive care unit admission and 20 (16.3%) had streptococcal toxic shock syndrome. Antecedent sore throat or use of non-steroidal anti-inflammatory drugs was rare, but current or recent scabies, pyoderma and trauma were common.


The incidence and severity of iGAS are high and increasing in tropical northern Australia, and urgent attention is needed to improve surveillance and the social determinants of health in this population. This study adds to emerging data suggesting increasing importance of iGAS in low- and middle-income settings globally.



September 21, 2018 at 8:19 am

The contribution of group A streptococcal virulence determinants to the pathogenesis of sepsis.

Virulence. 2014 Jan 1;5(1):127-36.

Reglinski M1, Sriskandan S1.


Streptococcus pyogenes (group A streptococcus, GAS) is responsible for a wide range of pathologies ranging from mild pharyngitis and impetigo to severe invasive soft tissue infections. Despite the continuing susceptibility of the bacterium to β-lactam antibiotics there has been an unexplained resurgence in the prevalence of invasive GAS infection over the past 30 years. Of particular importance was the emergence of a GAS-associated sepsis syndrome that is analogous to the systemic toxicosis associated with TSST-1 producing strains of Staphylococcus aureus. Despite being recognized for over 20 years, the etiology of GAS associated sepsis and the streptococcal toxic shock syndrome remains poorly understood. Here we review the virulence factors that contribute to the etiology of GAS associated sepsis with a particular focus on coagulation system interactions and the role of the superantigens in the development of streptococcal toxic shock syndrome.


September 21, 2018 at 8:18 am

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