Sepsis occurs in newborns Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get Original Essay Septicemia is one of the most important infections responsible for 1.6 million deaths caused by neonatal infections in developing countries each year. Bacterial bloodstream infections (BSIs) can be classified based on the time of onset of the disease: early onset (EOS) which occurs within the first 3 days of life, and late onset (LOS) in which the infection tends to appear any time between the first 3 days of life, week and first month of life, depending on whether the baby was born full term or premature. With EOS, the acquisition of microorganisms occurs following a transplacental infection or colonization of the mother's genitourinary tract, resulting in vertical transmission of pathogenic bacteria from mother to baby before or during birth. The organisms most commonly associated with EOS are Group B Streptococcus (GBS), Escherichia coli (E. coli) – which is the second leading cause of EOS, accounting for 24% of all cases, of which 81% in premature infants – and as coagulase-negative Staphylococcus (CoNS) and Haemophilus influenzae. These organisms typically colonize the maternal genitourinary tract leading to contamination of the amniotic fluid, placenta, cervix, or vaginal canal. Contamination of amniotic fluid can occur before or during labor, meaning the baby can acquire the pathogen in utero or during birth. In late-onset sepsis, pathogens are acquired after birth, normally from nosocomial or community sources. There is some consideration as to when the period for late-onset sepsis begins, however generally the infection is considered late-onset when it occurs after 6 days of life. By LOS, 70% of infections were associated with Gram-positive organisms; Coagulase-negative staphylococci contributed in 48% of cases and Gram-negative bacteria (such as E. coli) in 18%. Invasive microorganisms from the environment can colonize the skin, respiratory tract, conjunctiva, gastrointestinal tract, and umbilicus of the newborn and can be acquired vertically or horizontally. Both the E. coli that staphylococci are important bacterial agents of sepsis; however, E. coli is a more important cause of EOS, while CoNS is a major cause of LOS. Escherichia coli (E. coli) is responsible for a substantial percentage of mortality in newborns and is part of one of the most diverse bacterial species. The complex antigenic structure and some virulence factors have been important in neonatal sepsis: the best described virulence factor is the K1 capsular antigen which is present in some strains and is closely linked to neonatal meningitis. This polysialic acid impairs the killing of opsonophagocytes, meaning that individuals infected with antigenic K1 strains have greater morbidity and mortality than those with other strains. The severity of the disease is associated with the quantity and persistence of K1 antigen in the cerebrospinal fluid.