China
Africa
Explore chapters and articles related to this topic
The gastrointestinal system
Published in C. Simon Herrington, Muir's Textbook of Pathology, 2020
Sharon J. White, Francis A. Carey
The oropharynx may be affected by various bacterial and viral infections. Streptococcus pyogenes is a common cause of sore throat in children and streptococcal infection can precede rheumatic fever or glomerulonephritis. Diphtheria, a highly contagious infection caused by Corynebacterium diphtheriae, most frequently affects the oropharynx, particularly in children. The infection may have serious and not infrequently fatal complications. Immunization programmes are largely responsible for the present low incidence of diphtheria in many parts of the world. Infectious mononucleosis – ‘glandular fever’ – is caused by the Epstein–Barr virus and is a cause of cervical lymphadenopathy. It is infectious and can lead to a particularly troublesome sore throat in adolescents and young adults, often with persistent post-viral symptoms.
The pathophysiology of mitral stenosis
Published in Neeraj Parakh, Ravi S. Math, Vivek Chaturvedi, Mitral Stenosis, 2018
Sudheer Arava, Kusuma Harisha, Ruma Ray
Group A streptococcus pyogenes is an important pathogenic bacterium that causes a wide variety of clinical conditions ranging from pharyngitis to severe invasive infections and necrotizing fasciitis. The most common mode of disease transmission is by direct contact of mucus droplets from an infected person. The organisms are gram-positive, non-motile, non-sporing, facultative anaerobes that grow in pairs and chains (Figure 4.7a). According to the Lancefield classification, they are categorized as group A because they display antigen A on their cell wall. They are called β-hemolytic because, on a blood culture agar plate, they typically produce a small zone of complete hemolysis (Figure 4.7b). The outer layer of streptococcus pyogenes is covered by a hyaluronic acid capsule that is chemically similar to the host connective tissue; therefore, it is non-antigenic. This is vital for these bacteria to survive in the host. The cytoplasmic membrane has antigens similar to human cardiac, skeletal, and smooth muscle cells. Some of the important surface antigens of streptococcus are as follows (Figure 4.8):
Acute Otitis Media
Published in John C Watkinson, Raymond W Clarke, Christopher P Aldren, Doris-Eva Bamiou, Raymond W Clarke, Richard M Irving, Haytham Kubba, Shakeel R Saeed, Paediatrics, The Ear, Skull Base, 2018
Streptococcus pneumoniae (pneumococcus) is the most common bacteria isolated from the middle ear in AOM, and it has been reported in 18–55% of cases. There are, however, some 90 serotypes. Haemophilus influenzae has been isolated in 16–37%, and Moraxellacatarrhalis in 11–23% of cases.15 Less frequently reported are Streptococcus pyogenes in up to 13% of cases and Staphylococcus aureus in up to 5%.16
Acute abdomen: a rare presentation of group a streptococcal infection
Published in Acta Chirurgica Belgica, 2023
Jelle Lubach, Marie Vannijvel, Hendrik Stragier, Yves Debaveye, Albert Wolthuis
A distinction from secondary peritonitis is often impossible to make without surgical exploration [4]. It has also been diagnosed in male patients, but this is less common [5]. Especially healthy women of middle age seem to be most at risk. Sakuraba et al. estimated the male to female sex ratio of these patients between 7 and 18, at the median onset at 48 years [5]. Malota et al. [6] reported 35 cases of GAS peritonitis, of which only 6 were male. All presented with acute abdominal pain and the majority had a fever of more than 38.5 °C. Most often Streptococcus pyogenes was found both in the female genital tract and the upper respiratory system [7], with positive vaginal swabs or, as in our case, a recent pharyngeal infection. Most patients with a group A hemolytic streptococcus peritonitis developed Toxic Shock like syndrome (TSLS) [5]. Morbidity and mortality of invasive group A streptococcal infections admitted to the ICU are significant with an overall mortality up to 40% [8]. In spite of this fact, we only found one case report which resulted in a fatal outcome [9]. This could be due to selection or publication bias. Hemodynamic instability due to septic shock should be promptly treated with aggressive fluid resuscitation and vasopressors [10], together with appropriate antibiotic therapy and adequate source control.
Presence of Streptococcus pyogenes in the throat in invasive Group A Streptococcal disease: a prospective two-year study in two health districts, Finland
Published in Infectious Diseases, 2023
Ville Kailankangas, Johanna Vilhonen, Kirsi Gröndahl-Yli-Hannuksela, Kaisu Rantakokko-Jalava, Tapio Seiskari, Kari Auranen, Emilia Lönnqvist, Mirva Virolainen, Hanne-Leena Hyyryläinen, Jarmo Oksi, Jaana Syrjänen, Jaana Vuopio
Streptococcus pyogenes, or Group A Streptococcus (GAS), is an important human pathogen and remains among the top 10 infectious causes of mortality [1]. It may colonize the throat, other mucous membranes or the skin asymptomatically but is also responsible for various infectious diseases. Most commonly these are mild to moderate infections of the throat and tonsillae, or of the skin, such as impetigo and cellulitis [2]. GAS also causes invasive infections, such as septicemia, necrotizing soft-tissue infection (NSTI) and streptococcal toxic shock syndrome (STSS), which are severe and life threatening even when properly treated and may result in adverse sequelae [3]. In high-income countries, the case fatality rate (CFR) of invasive GAS (iGAS) infections is 10–20%, while the most severe forms STSS and NSTI have a CFR as high as 30–50% [4–7].
Epidemiology of infective endocarditis: novel aspects in the twenty-first century
Published in Expert Review of Cardiovascular Therapy, 2022
Verda Arshad, Khawaja M. Talha, Larry M. Baddour
A serial review of the incidence and epidemiology of a disease is critical as one considers burden of disease and strategies to invoke to hopefully reduce disease incidence based on epidemiological findings. IE is no exception. Some success has been achieved with the decades-long attack on RHD. Fortunately, multiple international agencies have accepted the challenge to rid the world of rheumatic fever. Unfortunately, much more needs to be done in low- and middle-income countries to reduce RHD incidence, and IE as a complication of it. Improving hygiene should help reduce the prevalence of underlying rheumatic carditis as a substrate for the subsequent development of IE. The availability of a Streptococcus pyogenes vaccine, which has been the focus of decades of investigation, will be a promising development in IE incidence reduction [112]. The World Health Foundation (WHF) and the World Health Organization (WHO) have set a target to have a vaccine in phase III clinical trials by 2023. If this goal is met, it can help eliminate RHD-IE.