Signs and symptoms of infection may include respiratory distress, temperature instability, irritability, poor feeding, failure to thrive, persistent crying and skin rashes.

Risk factors include previous maternal infection, preterm delivery (< 37 weeks gestation) and premature rupture of membranes (breakage of the amniotic sac) which substantially increases the risk of neonatal sepsis by allowing passage for bacteria to enter the womb prior to the birth of the infant.

Instead of relying solely on culturing techniques, pathogen identification has improved substantially with advancing technology; however, neonate mortality reduction has not kept pace.

[5] Signs and symptoms of infection include respiratory distress, temperature instability, irritability, failure to thrive, and skin rashes.

[citation needed] Early-onset sepsis (EOS), defined as onset of symptoms within 72 hours of life, is generally caused by transmission of pathogens from the female genitourinary system to the fetus.

[citation needed] Late-onset sepsis (LOS), defined as onset of symptoms after 72 hours of life, is generally caused by transmission of pathogens from the environment after delivery.

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.

If the bacteria is found in the maternal GI / GU tract, mothers will receive IV antibiotic (usually penicillin or ampicillin).

[8] Escherichia coli is an encapsulated gram-negative bacilli that may cause neonatal infections due to its high prevalence in the GI and GU tracts of pregnant patients.

Typically, all neonates (regardless of symptoms or risk factors) receive erythromycin ointment applied to both eyes after delivery[10] Listeria monocytogenes is a gram-positive bacilli that can cause infection acquired from tainted food and present in the mother.

The mother acquires infection from ingesting food that contains animal products such as hot dogs, unpasteurized milk, delicatessen meats, and cheese.

[13][citation needed] Human immunodeficiency virus (HIV) infection can occur during delivery of the neonate, in utero through mother-to-child transmission or postnatally by way of breastfeeding.

Common symptoms include failure to thrive, recurrent infections such as pneumonia, intermittent diarrhea, swollen lymph nodes and oral thrush.

Common symptoms include rash, microcephaly (small head), low birth weight, jaundice, thrombocytopenia, seizures and retinitis.

Long-term complications of congenital CMV infections may include sensorineural hearing loss, developmental delay, and seizures.

Congenital infection can lead to fetal growth restriction and CNS abnormalities, including microcephaly, ventriculomegaly and intracranial calcifications.

[20] Other viral infections, such as respiratory syncytial virus (RSV), metapneumovirus (hMPV), rhinovirus, parainfluenza (PIV), and human coronavirus in the neonatal period are associated with recurrent wheezing in later childhood.

Other signs and symptoms may appear after the neonatal period and include: chorioretinitis development later in life, intracranial calcification hydrocephalus or central nervous system abnormalities.

Additionally, preterm neonates require longer hospital admissions, including the placement of invasive devices that increase risk of infection.

[36] Infected sepsis in an infant can be identified by culturing the blood and spinal fluid and if suspected, intravenous antibiotics are usually started.

[30] To reduce neonatal infection, screening of pregnant women for HIV, hepatitis B, and syphilis, is available in the UK and the United States.

[37][38] Treatment with a vaginal antibiotic wash prior to birth does not prevent infection with group B streptococcus bacteria (GBS).

[51] In general, in an unvaccinated individual, the viral hepatitis family causes liver damage due to a cell-mediated response via cytotoxic lymphocytes.

[30] Women with a history of genital herpes, can be treated with antiviral drugs to prevent symptomatic lesions and viral shedding that could infect the infant at birth.

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.

[31] In the UK, the proportions of pregnant women who are newly screened positive for hepatitis B, syphilis, and HIV have remained constant since 2010 at about 0.4%, 0.14% and 0.15%, respectively.

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.

Obstetrical and maternal complications are not typically the cause of these late onset infections; they are usually acquired by the infant in the hospital neonatal intensive care unit.

Research also continues into the role and protective effect of gut, skin and other human microbiomes and the colonization during the neonatal period.

[31] The result of some research has been the identification of diagnostic tools and procedures that could identify mothers with group B streptococcus infection in resource-poor regions.