Several Interesting Reports on GBS and Sepsis
In doing some background work as I think through some specific economic implications of the N-Assay technology I looked at some information that people on this site might like to view. It helped me better understand the N-Assay potential as well as its medical importance. So I am sharing it with you as a matter of general interest.
Sepsis: use of clinical criteria as well as novel diagnostic tests aim to improve patient outcomes
www.healthgrades.com/physician/dr-jonathan-faro-gdfp2/patient-ratings#QualitySurveyResults_anchor
By Jonathan Faro, MD, April 2014
Sepsis, as defined by Stedman’s Medical Dictionary, is “the presence of various pathogenic organisms, or their toxins, in the blood or tissues.”1 …
When a clinician is confronted with a patient who is possibly septic, multiple criteria and diagnostic tests are used to reach this diagnosis. As the clinical picture may shift rapidly, bringing about sudden decompensation of the patient, the clinician must be prepared to act even before the results of ordered tests are available. This empiric treatment is then adjusted accordingly based on both the patient’s response and the data as it is obtained. Here, we review findings common with sepsis, and the diagnostics that allow us to tailor the treatment and allow for the best possible outcome….
Regardless of the degree of sepsis, at least two or more of the following are required to make the diagnosis: fever, tachycardia, tachypnea, and leukocytosis. Sepsis is notably more severe when it is accompanied by organ dysfunction due to hypotension, which leads to hypoperfusion of organs. This end-organ injury may be made apparent as decreased urine output, altered mental status, or lactic acidosis, and in its more severe state, is associated with multiple organ failure (multiple organ dysfunction syndrome).
With more than 750,000 cases of sepsis occurring annually, and more than 200,000 deaths each year attributable to sepsis, it is important that this condition is promptly recognized.5 An inadequate approach to working up a septic patient may range from the clinician failing to recognize when infection is present, to administering inappropriate empiric antibiotics, to performing an inadequate examination, and even to sending off incorrect laboratory tests or failing to order the correct tests, such as gram stain/culture, which will aid in targeting empiric treatment choices. Equally serious and potentially devastating is the failure to perform surgical intervention in a timely manner when required for adequate treatment.
Once a differential has been narrowed down to an infectious agent as the underlying cause for the patient’s presenting condition, an appropriate antibiotic may be selected based on a few generalities. In obstetrical or gynecological patients, for example, the anatomic location of the infection and the time of onset to recognition of the infection both play important roles. For abdominal incisions, e.g., following cesarean delivery or hysterectomy, gram-positive organisms such as staph aureus and strep pyogenes as well as streptococcus agalactiae are important to consider, along with gram-negative facultative anaerobes. We have seen in our institution an increase in the number of post-operative wounds infected with methicillin-resistant staphylococcus aureus (MRSA), and it is important to include coverage against this organism. It should also be noted that the importance of obtaining culture and gram stain of infected tissue prior to the initiation of empiric treatment cannot be overemphasized.6
Equally important in determining when sepsis is present and its resolution or response to treatment is the rapid identification of the specific pathogen(s) present and their susceptibility to clinically relevant antimicrobials. While gram stain of infected fluid/tissue may be done rapidly and may allow for categorization of a suspected infectious agent, culture and then follow-up determination of antimicrobial resistance may take several days. Recently, the Infectious Diseases Society of America (IDSA) has led a strong push to foster the development of new diagnostic tests that will be easy to use and provide results within an hour.10
Caliendo et al. state that the ideal diagnostic test is accurate; relies on heat-stable reagents with an extended shelf-life; is easily portable; requires minimal technical skills; is rapid (<1 hr), sensitive, and specific; does not require being run in large batches; is cost-effective; and is suitable for use in a broad range of clinical samples. They say that currently PCR-based tests meet some but not all of these criteria.10
In work that my colleagues and I at the University of Texas Health Sciences Center have done on group B streptococcus (GBS), we have developed an antibody-based test (termed the N-Assay) which allows for the simultaneous identification of a microbial pathogen and determination of its antimicrobial susceptibility. By substituting antibodies specific for varying pathogens, one may selectively identify pathogens present in a patient. A similar assay that we developed in 2010 was tested earlier this year in more than 300 patients, and it was found that GBS could be reliably detected in much less time than is typically required for culture.11
We have converted this test to an ELISA format, and as such, have seen preliminary results that allow for identification of GBS in under an hour. Furthermore, by changing the specificity of the capture antibody, we are able to detect vancomycin-resistant enterococcus (VRE), Neisseria gonorrhea, and E.coli, as well as Candida albicans.
Initial results with VRE have consistently shown that susceptibility to selected antibiotics may be reliably determined after a brief period of culture.
Every effort must be made to stem the development of sepsis. More rapid diagnostic tests will play an increasingly important role in aiding the clinician not only in making the diagnosis, but in tailoring the course of treatment. In addition to improved tests, the clinician will continue to play a central role in determining whether the course of action requires aggressive resuscitation and broad spectrum antibiotics, as well as operative management and aggressive debridement.
Who May Be Affected by Group B Strep?
www.groupbstrep.org/resources/pamphlet.pdf
15,000 to 18,000 newborns and adults in the United States will contract serious GBS disease each year, resulting in bloodstream, respiratory, and other devastating infections. About half of all GBS disease occurs in newborns and is acquired during childbirth when a baby comes into direct contact with the bacteria carried by the mother. GBS causes infections in pregnant women - in the womb, in amniotic fluid, in incisions following cesarean sections, and in the urinary tract. Each year there are over 50,000 cases of such infections in pregnant women. 35-40% of GBS disease occurs in the elderly or in adults with chronic medical conditions.
Approximately 8,000 babies in the United States contract serious GBS disease each year. Up to 800 of these babies may die from it, and up to 20% of the babies who survive GBS-related meningitis are left permanently handicapped. GBS disease is more common than other, better known, newborn problems such as rubella, congenital syphilis, and spina bifida. Some babies that survive, especially those who develop meningitis, may develop long-term medical problems, including hearing or vision loss, varying degrees of physical and learning disabilities, and cerebral palsy.
Birthwise Group
www.birthwisemc.com/group-b-strep.html
Group B Strep (GBS) infection is the leading cause of illness and death among infants in the United States. Current prevention guidelines have reduced the number of babies who get sick from 8000 per year to 1200 per year. Between 10-30% of women carry this bacterium in their vagina or rectum at the time of birth. The bacteria is generally passed from mother to baby during birth during labor or after the membranes rupture although it can happen through intact membranes. ... If certain risk factors are present, the baby is much more likely to get sick. ________________________________________
Additional risk factors:
Membrane rupture >12 hours (6%)
Preterm birth (3-50%)
Fever during labor (15%)
Previous baby with GBS disease (10%)
GBS positive urine culture this pregnancy (4%)
If these factors are present, they mean that the baby is more likely than the 1-2% to get sick. The increased percentage is indicated in the parentheses.
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Most cases (70%) occur in babies born at term. The most common clinical symptom is respiratory distress along with other signs of infection beginning within 24-48 hours of birth. Pneumonia and sepsis (blood infection) are most common but meningitis can also occur.
New Approaches to Preventing, Diagnosing, and Treating Neonatal Sepsis
• Karen Edmond mail,
• Anita Zaidi
• Published: March 09, 2010
• DOI: 10.1371/journal.pmed.1000213
•
• Neonatal sepsis or septicaemia is a clinical syndrome characterized by systemic signs of circulatory compromise (e.g., poor peripheral perfusion, pallor, hypotonia, poor responsiveness) caused by invasion of the bloodstream by bacteria in the first month of life. In the pre-antibiotic era neonatal sepsis was usually fatal. Case fatality rates in antibiotic treated infants now range between 5% and 60% with the highest rates reported from the lowest-income countries [1].
The World Health Organization (WHO) estimates that 1 million deaths per year (10% of all under-five mortality) are due to neonatal sepsis and that 42% of these deaths occur in the first week of life [2]. There are wide disparities in neonatal care between high- and low-income countries. In high-income countries the major concern is the increasing numbers of extremely premature infants with high nosocomial infection rates due to multiresistant organisms in intensive care units. Health facility infections are also a major problem in low-income countries, but the more pressing issues are the high proportion of home deliveries in unclean environments predisposing to sepsis and ensuring that all neonates have access to effective interventions from health care providers in the first days of life2.
Indeed, new strategies that can prevent, diagnose, and treat neonates with sepsis are needed in both low- and high-income settings.
Pathogenesis of Neonatal Infections
• Distal risk factors for neonatal sepsis include poverty and poor environmental conditions. Proximate factors include prolonged rupture of membranes, preterm labour, maternal pyrexia, unhygienic intrapartum and postnatal care, low birth weight, and prelacteal feeding of contaminated foods and fluids [3]–[5].
• The bacteria that cause neonatal sepsis are acquired shortly before, during, and after delivery (Figure 1). They can be obtained directly from mother's blood, skin, or vaginal tract before or during delivery or from the environment during and after delivery. Streptococcus agalactiae (Group B streptococcus, GBS) is the most common cause of neonatal sepsis in many countries, ...
