Neonatal infection: Difference between revisions
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<ref name=Fanaroff2013>{{cite book | last = Fanaroff | first = Avroy | title = Klaus & Fanaroff's care of the high-risk neonate | publisher = Elsevier/Saunders | location = Philadelphia, PA | year = 2013 | isbn = 9781416040019 |postscript=; Access provided by the University of Pittsburgh }}</ref> --> |
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<!-- <ref name=MacDonald2015>{{cite book | last = MacDonald | first = Mhairi | title = Avery's neonatology : pathophysiology and management of the newborn | publisher = Wolters Kluwer | location = Philadelphia | year = 2015 | isbn = 9781451192681|postscript=; Access provided by the University of Pittsburgh}}</ref> <ref name=Sinha2012>{{cite book | last = Sinha | first = Sunil | title = Essential neonatal medicine | publisher = John Wiley & Sons | location = Chichester, West Sussex | year = 2012 | isbn = 9780470670408|postscript=; Access provided by the University of Pittsburgh }}</ref>--> |
<!-- <ref name=MacDonald2015>{{cite book | last = MacDonald | first = Mhairi | title = Avery's neonatology : pathophysiology and management of the newborn | publisher = Wolters Kluwer | location = Philadelphia | year = 2015 | isbn = 9781451192681|postscript=; Access provided by the University of Pittsburgh}}</ref> <ref name=Sinha2012>{{cite book | last = Sinha | first = Sunil | title = Essential neonatal medicine | publisher = John Wiley & Sons | location = Chichester, West Sussex | year = 2012 | isbn = 9780470670408|postscript=; Access provided by the University of Pittsburgh }}</ref>--> |
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Revision as of 12:45, 3 January 2016
| Neonatal infection |
|---|
Neonatal infections are infections of the newborn. Some of these infections are immediately recognized when the baby is born, some become apparent within the first week of birth and others do not develop until after the first week. Many of the infants may be born before their due date, have a low birth weight, have contracted infections while in the womb or during deliver. Infants born prematurely and have experienced respiratory infections continue to have respiratory issues later in childhood with possible long-term effects on the ability to engage in normal physical activities, have decreased quality of life and increased health care costs. They can have susceptibility to later infections and inflammatory responses related to lung disease. Though antibiotics can be effective, and methods of pathogen identification is faster, mortality remains 20% to 50%. Full term and post-term infants can also develop infection. Neonatal infection is associated with maternal infection and colonization prior to the birth of the infant.
Causes
Neonatal infection can have many causes and is usually quite distressing to the family and it initiates concentrated effort to treat it by clinicians. Treatment for neonatal infections takes place in the neonatal intensive care unit in industrialized countries, and elsewhere in locations that do not have access to NICU's . The causes and reasons for neonatal infection are many. The origin of infectious bacteria pathogens originates often from the maternal gastrointestinal tract and the genitourinary tract. Many of these maternal infections with these organisms are asymptomatic in the mother. Other maternal infections that may be transmitted to the infant in utero or during birth are bacterial and viral sexually transmitted infections.[1] The infant's ability to resist infection is complicated its immature immune system. The causative agents of neonatal infection are bacteria, viruses, and fungi. In addition, the immune system of the neonate may respond in ways that can create problems that complicate treatment, such as the release of inflammatory chemicals. Congenital defects of the immune system also affect the infants ability to fight off the infection.[2]
Bacteria
Group B Streptococcus are typically identified as the cause of the majority of early-onset infections in the neonate.[1] Enteric bacilli that originate from the digestive system of the mother have become as prevalent as the group B Streptococcus pathogens and are currently as likely to cause infection. Listeria monocytogenes can also cause infection and is present in the mother.[3][4] The presence of this pathogen can sometimes be determined by the symptoms that appear as a gastrointestinal illness in the mother. The mother acquires infection from ingesting food that contains animal products such as hot dogs, unpasteurized milk, delicatessen meats, and cheese. Infections that develop one month after the birth of the infant are more likely due to Gram-positive bacteria and coagulase positive staphylococci.[5] Neonatal infection can also occur in term and post-term infants.[6] Acquired maternal infection and subsequent inflammation from Ureaplasma urealyticum is accompanied by a strong immune response and is correlated with the need for prolonged mechanical ventilation.[1][7]
Neonatal infections with Staphylococcus areus and Escherichia coli are also diagnosed, but not as frequently as Group B streptococcus infections.[8]
Viruses
Sixty percent of mothers of preterm infants are infected with Cytomegalovirus (CMV). Infection is asymptomatic in most instances but 9% to 12% of postnatally infected low birth weight, preterm infants have severe, sepsis-like infection. CMV infection duration can be long and result in pneumonitis in association with fibrosis. CMV infection in infants has an unexpected effect on the cells of the immune system causing them to prematurely age. This leads to a reduced immune response similar to that found in the elderly.[7]
Other viral infections such as Respiratory Syncytial Virus, metapneumovirus (hMPV), rhinovirus, parainfluenza (PIV), and human coronavirus in the neonatal period are associated with recurrent wheezing in later childhood. RSV infections can be prolonged. Premature infants born at less than 32 weeks gestation have more days of cough and wheeze at 1 year of age than those uninfected with RSV.[7]
Fungi
In very low birth weight infants (VLBWI), systemic fungus infection is a Hospital-acquired infection with serious consequences. The pathogens are usually Candida albicans and Candida parapsilosis. Infection is usually late-onset. Up to 9% of VLBI with birth weights of <1,000 g develop these fungus infections leading to sepsis or meningitis. As many as one-third of these infants can die. Candidiasis is associated with retinopathy, prematurity and negative neurodevelopmental consequences. Candida can colonize the gastrointestinal tract of Low Birthweight Infants (LBI). This gastrointestinal colonization is often a precursor to a more serious invasive infection. The risk of serious candida infection increases when multiple factors are present. These are: thrombocytopenia, the presence of candidal dermatitis, the use of systemic steroids, birth weights of <1,000 g, presence of a central catheter, postponing enteral feeding, vaginal delivery, and the amount of time broad-spectrum antibiotics were given.[9]
Mechanism
Inflammation accompanies infection and is likely to complicate treatment and recovery. Inflammation is linked to reduced growth of the lungs of the premature baby.[7]
Pathogenesis
The recent identification of the presence of microorganisms in maternal-infant body fluids that were previously thought to be sterile, has provided one explanation for the presence of the inflammatory response in both the mother and infant. Sixty-one present of pregnant women with chorioamnionitis, or inflammation of the amniotic fluid were found to be infected by microorganisms. Often, more than one pathogen was present In fifteen percent of pregnant women, inflammation was still evident though no evidence of pathogens. This may indicate that there are other causes. A high percentage 51% to 62%, of pregnant women who had chorioamnionitis also had inflammation of the placenta.[7]
Diagnosis
Diagnosis of infection is based upon the recovery of the pathogen or pathogens from the typically sterile sites in the mother or the baby. Samples are obtained from urine, blood or cerebrospinal fluid. Diagnosis of infection can also be aided by the use of more nonspecific tests such as determining the total white blood cell count, cytokine levels and other blood tests and signs.[5]
| Signs of infection | Notes | References |
|---|---|---|
| abnormal Complete Blood Count | looking for signs of infection in the blood: increased white cell count;<presence of immature neutrophils |
[10][8] |
| increased C-reactive protein | a chemical in the blood that shows that the baby's immune system is actively reacting to infection |
[10][8] |
| accessory muscle use | [10] | |
| tachycardia | [8] | |
| bradycardia | [8] | |
| chest recesion | when the baby inhales, the ribs do not move but the belly sinks in |
[10] |
| respiratory distress | the baby has trouble breathing | [10][8] |
| nasal flaring | the baby's nostrils expand when it inhales |
[10] |
| expiratory grunt | a sound of effort when the baby exhales | [10][11] |
| apnea | the baby stops breathing | [10][8] |
| rash | [10] | |
| positive urine culture | [8] | |
| positive cerebral spinal fluid | [8] | |
| other positive cultures | from eyes, ear canal, umbilicus axilla anus |
[8] |
| lethargy | the baby seems tired and has slow or no movements | [10][8] |
| hypotonia | the muscles seem flabby and weak | [10][8] |
| hypothermia | [8] | |
| irritability | infant appears uncomfortable and and has difficulty being soothed |
[10][8] |
| weak cry | [10] | |
| pneumonia | [8] | |
| poor perfusion | poor circulation | [10][8] |
| hypotension | low blood pressure | [10] |
| acidosis | pH imbalance in the blood | [10][8] |
| diarrhea | water-like, unformed stools | [10] |
| poor feeding | [8] | |
| oxygen requirement | [8] | |
| bulging fontanel | the soft spot on the head is bulging | [10] |
| seizures | [10][8] | |
| fever | [8] | |
| disseminated intravascular coagulation | widespread clotting of blood | [10] |
| renal failure | kidneys do not function | [10] |
| bacteremia | bacteria cultured from the blood of the newborn |
[8] |
Diagnosis of viral infection
Symptoms and the isolation the virus pathogen the upper respiratory tract is diagnostic. Virus identification is specific immunologic methods and PCR. The presence of the virus can be rapidly confirmed by the detection of the virus antigen. The methods and materials used for identifying the RSV virus has a specificity and sensitivity approaching 85% to 95%. Not all studies confirm this sensitivity. Antigen detection has comparitivly lower sensitivy rates that approach 65% to 75%.[12]
Neonatal sepsis
Neonatal sepsis of the newborn is an infection that has spread through the entire body. The inflammatory response to this systematic infection can be as serious as the infection itself. [7] In infants that weigh under 1500 g, sepsis is the most common cause of death. Three to four percent of infants per 1000 births contract sepsis. The mortality rate from sepsis is near 25%.[4] Infected sepsis in an infant can be identified by by culturing the blood and spinal fluid and if suspected, intravenous antibiotics are usually started. Lumbar puncture is controversial because in some cases it has found not to be necessary while concurrently, without it estimates of missing up to one third of infants with meningitis is predicted.[5]
Prevention
Routine screening of pregnant women for HIV, hepatitis B, syphilis, and rubella susceptibility is required in the UK.[13]
Treatment with an vaginal antibiotic wash prior to birth does not prevent infection with Group B streptococcus bacteria.[14][8] Breast milk protects against necrotizing enterocolitis.[2]
Because GBS bacteria can colonize the lower reproductive tract of 30% of women, typically pregnant women are tested for this pathogen from 35 to 37 weeks of pregnancy. Treatment of the mother with antibiotics reduced the rate of neonatal infection.[8] Prevention of the infection of the baby is done by treating the mother with penicillin. Since the adoption of this prophylatic treatment, infant mortality from GBS infection has decreased by 80%.[4]
Treatment and management
Neonatal infection treatment is typically started before the diagnosis of the cause can be confirmed. Neonatal infection can be prophylactically treated with antibiotics.[1] Maternal treatment with antibiotics is primarily used to protect against group B Streptococcus.[5]
Epidemiology
Up to 3.3 million newborns die each year and 23.4% of these die of neonatal infection. About half of the deaths caused by sepsis or pneumonia happen in the first week postpartum. Industrialized countries, prophylactic antibiotic treatment of the mothers identified with Group B streptococcus, early identification of sepsis in the newborn and and administation of antibiotics to the newborn has reduced mortality.[8]
Regions with low neonatal mortality include Europe, the western Pacific and the Americas have sepsis rates that account for 9.1% to 15.3% of the total neonatal deaths worldwide. This is in contrast with the 22.5 to 27.2% percentage of total deaths in resource-poor countries such as Nigeria, the Democratic Republic of the Congo, India, Pakistan and China.[8]
In 2014 Great Britain found 15% (1,018/693,570) of pregnant women screened positive for HIV. This percentage has remained constant since 2011.[15]
In North America, prior to the 1950s, Group A β-hemolytic Streptococcus (GAS) was the most common pathogen associated with neonatal sepsis in North America before the 1960s. In the past twenty years, the most common pathogen causing sepsis is coagulase-negative staphylococci that exist as biofilms associated with infected central venous or arterial catheters.[1] Infections can be fatal and contribute to long-term morbidity and disability among the infants who survive into childhood.[1]Neonatal sepsis effects 128 cases per 1000 live births. Meningitis can occur in the septic infant.[5]
Early-onset infections
Early onset sepsis can occur in the first week of life. It usually is apparent on the first day after birth. This type of infection is usually acquired before the birth of the infant. Premature rupture of membranes and other obstetrical complications can add to the risk of early-onset sepsis. If the amniotic membrane has been ruptured greater than 18 hours before delivery the infant may be at more risk for this complication. Prematurity, low birth weight, chorioamnionitis, maternal urinary tract infection and/or maternal fever are complications that increase the risk for early-onset sepsis. Early onset sepsis is indicated by serious respiratory symptoms. The infant usually suffers from pneumonia, hypothermia, or shock. The mortality rate is 30 to 50%.[5]
Late onset infections
infections that occur after the first week of life but before the age of 30 days are considered late onset infections. Obstetrical and maternal complications are not typically the cause of these late onset infections these infections are usually acquired by the infant in the hospital neonatal intensive care unit. The widespread use use of broad-spectrum antibiotics in the nursery intensive care unit can cause a higher prevalence of invasive antibiotic resistant bacteria.[5] Meconium aspiration syndrome has a mortality rate just over 4%. This accounts for 2% for all neonatal deaths.[6]
Risk factors
Antibiotics can be effective, and methods of pathogen identification is faster, yet mortality remains 20% to 50%.[4]
| Factor | Notes | References |
|---|---|---|
| prematurity | [2] | |
| meconium aspiration | [6] | |
| Postpartum endometritis | [6] | |
| low birth weight | < 40 weeks gestation | [2][5] |
| premature rupture of membranes | <12 hours | [2][5][8] |
| prolonged premature rupture of membranes | >12 hours | [8] |
| pre-term onset of labor | [2][5] | |
| chorioamnionitis | [2] | |
| vaginal discharge | [2] | |
| maternal intrapartum fever | ≥38∘ | [2][10] |
| tender uterus | [10] | |
| rupture of membranes | <12 hours | [8] |
| prolonged rupture of membranes | >12 hours) | [2][10] |
| in utero infection with pathogens | the period of infection allows for the logarithmic growth of pathogens |
[1] |
| maternal urinary tract infection | [2] | |
| prolonged labor | [10] | |
| vaginal examinations during labor | [2][10] | |
| maternal colonization with group B streptococcus | [2][8] | |
| previous baby with early-onset GBS infection | [2][10] | |
| gender | males are more suseptible;This risk declines after respiratory distress syndrome is treated |
[5] |
| multiples | risk is increased for the firstborn | [5] |
| iron supplementation | iron is a growth factor for some bacteria |
[5] |
| maternal intrapartum fever | > 38°C | [2] |
| after insertion of intravenous line |
[5] | |
| immature immune system | [5] | |
| invasive medical procedures | [5] | |
| hypoxia | unexpected resuscitation after birth |
[5][10] |
| low socioeconomic status | [5] | |
| hypothermia | [5] | |
| metabolic acidosis | [5] | |
| obstetrical complications | [5] | |
| prevalence of resistant bacteria in the neonatal intensive care unit | [5] |
| Factor | Notes | References |
|---|---|---|
| after insertion of an intravenous line | hypothermia | |
| poor feeding | ||
| lethargy | ||
| more likely to develop osteoarthritis | ||
| soft tissue infection | ||
| meningitits | [5] |
The risk for developing catheter-related infections is offset by the increased survival rate of premature infants that have early onset sepsis. Intravenous administration of prophylactic immunoglobin enhances immunity of the immature infant and is used for treatment. [5]
Society and culture
Neonatal infections are more likely to occur among black infants. Early onset sepsis is twice as common among black infants compared to white infants. [5]
Research
The susceptibility to continued risk of infection and the and immune deficiencies are active areas of research. Studies regarding the role of viruses in neonatal infections are lacking. Research also continues into the role and protective effect of gut, skin and other human microbiomes and the colonization during the neonatal period.[7][5] The comparison between resource rich countries and resource poor countries makes it somewhat difficult to compare the diagnosis success since industrialized regions are able to confirm the diagnosis and presence of pathogens in the clinical laboratory. Clinical testing may not be available in all settings and clinicians must rely on the signs of infection in the newborn. Research data from Africa and Southeast Asia is scarce.[8]
The result of some research has been the identification of diagnostic tools and procedures that will identify mothers with Group B streptococcus infection in resource-poor regions. These procedures would be easy to use and inexpensive. Those mothers who are indentified as being infected could then be prophylactly treated prior to the birth of the baby.[8]
References
- ^ a b c d e f g MacDonald, Mhairi (2015). Avery's neonatology : pathophysiology and management of the newborn. Philadelphia: Wolters Kluwer. ISBN 9781451192681; Access provided by the University of Pittsburgh
{{cite book}}: CS1 maint: postscript (link) - ^ a b c d e f g h i j k l m n o Isaacs, David (2014). Evidence-based neonatal infections. Chichester, West Sussex, UK: Wiley Blackwell. ISBN 978-0-470-65460-6; Access provided by the university of Pittsburgh
{{cite book}}: CS1 maint: postscript (link) - ^ "Listeria (Listeriosis)". Centers for Disease Control and Prevention. 22 October 2015. Retrieved 2015-12-23.
- ^ a b c d Florin, Todd (2011). Netter's pediatrics. Philadelphia, Pa: Elsevier Saunders. ISBN 978-1437711554; Access provided by the University of Pittsburgh
{{cite book}}: CS1 maint: postscript (link) - ^ a b c d e f g h i j k l m n o p q r s t u v w x y z Fanaroff, Avroy (2013). Klaus & Fanaroff's care of the high-risk neonate. Philadelphia, PA: Elsevier/Saunders. ISBN 9781416040019; Access provided by the University of Pittsburgh
{{cite book}}: CS1 maint: postscript (link) - ^ a b c d Siriwachirachai, Thitiporn; Sangkomkamhang, Ussanee S; Lumbiganon, Pisake; Laopaiboon, Malinee; Siriwachirachai, Thitiporn (2014). "Antibiotics for meconium-stained amniotic fluid in labour for preventing maternal and neonatal infections". doi:10.1002/14651858.CD007772.pub3.
{{cite journal}}: Cite journal requires|journal=(help) - ^ a b c d e f g Pryhuber, Gloria S. (2015). "Postnatal Infections and Immunology Affecting Chronic Lung Disease of Prematurity". Clinics in Perinatology. 42 (4): 697–718. doi:10.1016/j.clp.2015.08.002. ISSN 0095-5108; Access provided by the University of Pittsburgh
{{cite journal}}: CS1 maint: postscript (link) - ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af Santosham, Mathuram; Chan, Grace J.; Lee, Anne CC; Baqui, Abdullah H.; Tan, Jingwen; Black, Robert E. (2013). "Risk of Early-Onset Neonatal Infection with Maternal Infection or Colonization: A Global Systematic Review and Meta-Analysis". PLoS Medicine. 10 (8): e1001502. doi:10.1371/journal.pmed.1001502. ISSN 1549-1676.
{{cite journal}}: CS1 maint: unflagged free DOI (link) - ^ Cloherty, John (2012). Manual of neonatal care. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins. ISBN 9781608317776; Access provided by the University of Pittsburgh
{{cite book}}: CS1 maint: postscript (link) - ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab Sinha, Sunil (2012). Essential neonatal medicine. Chichester, West Sussex: John Wiley & Sons. ISBN 9780470670408; Access provided by the University of Pittsburgh
{{cite book}}: CS1 maint: postscript (link) - ^ https://www.gpnotebook.co.uk/simplepage.cfm?ID=-328531926 ;subscription required
- ^ Mayhall, C (2012). Hospital epidemiology and infection control. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins. ISBN 9781608313006; Access provided by the University of Pittsburgh
{{cite book}}: CS1 maint: postscript (link) - ^ https://www.gov.uk/guidance/infectious-diseases-in-pregnancy-screening-programme-overview
- ^ Ohlsson, Arne; Shah, Vibhuti S; Stade, Brenda C; Ohlsson, Arne (2014). "Vaginal chlorhexidine during labour to prevent early-onset neonatal group B streptococcal infection". doi:10.1002/14651858.CD003520.pub3.
{{cite journal}}: Cite journal requires|journal=(help) - ^ https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/482642/hpr4315_ntntlscrng.pdf