Paediatrics: Prevention of neonatal infection

Prevention of neonatal infection

General measures

•   Good hand washing with antiseptic solutions and use of gloves.

•   Avoidance of overcrowding.

•   Low nurse to patient ratio.

•   Nurse cohorting.

•   Patient isolation and barrier nursing.

•   Minimal handling.

•   Rational antibiotic use.

•   Minimize indwelling vascular access.

Group B streptococcal disease

The best approach to minimize early onset sepsis due to Group B strepto-coccal infection is uncertain because there have not been trials that permit the overall risks and benefits of intrapartum antibiotic prophylaxis (IAP) to be judged. IAP reduces the number of newborns with positive blood cultures, but with a very low disease incidence and a very high rate of ma-ternal GBS colonization (around 25%) a very large number of women must be treated to prevent a case if bacteriological screening programs are implemented. Routine bacteriological screening of pregnant women is not presently recommended in the UK. Current practice follows a risk factor based approach. The incidence of early-onset GBS disease in term infants without antenatal risk factors in the UK is 0.2cases/1000 births.

The Royal College of Obstetrics and Gynaecology¹ recommend that intrapartum IV penicillin (or clindamycin) should be offered to women with a previous baby with neonatal GBS disease. Other risk factors that should prompt consideration of IAP are:

•   intrapartum fever >38*C;

•   preterm (<37/40);

•   PROM >18hr;

•   GBS maternal carriage detected on low vaginal swab culture or GBS bacteriuria.

Management of the newborn is not well evidenced. Any ill newborn infants should have cultures taken and be treated with broad spectrum antibiot-ics that are effective against Group B streptococcus and other common neonatal pathogens.

Well infants exposed to the above risk factors should be evaluated clini-cally and observed. Because more than 90% of cases of early onset GBS disease present in the first 12–24hr after birth. Infants who remain well after this time are not at increased risk of disease in comparison with infants without risk factors. There is no need to send investigations on infants who are not ill. If there are multiple risk factors, or a previous child has been affected by Group B streptococcal sepsis many would consider blood culture and starting antibiotics appropriate.

Hepatitis B

Usually contracted at birth. Routine antenatal screening detects maternal carrier state (hepatitis B (HBsAg) +ve). Transmission risk 710% if mother is a low-risk carrier, (i.e. anti-HBe +ve). To reduce vertical transmission give hepatitis B vaccine to infant within 24hr of birth. Also give specific hepatitis B immunoglobulin 200IU IM if mother is a high-risk carrier, (i.e. mother HBeAg +ve, or, anti-HBe –ve, or, antibody/antigen status unknown), since the untreated transmission risk is 90%. In both groups, subsequent hepati-tis B vaccine is required at 1, 2, and 12mths (UK schedule).

Human immunodeficiency virus (HIV)

Vertical transmission rate 715–25%. Risk markedly reduced by:

• Maternal antiretroviral drug therapy to minimize viral load during third trimester and labour and then postnatal treatment of baby for 6wks.

• Elective lower segment Cesarean section (LSCS).

• Avoidance of breastfeeding (in developed world).

Infants are usually asymptomatic at birth. Test at birth and 3 and 6mths for:

• HIV viral PCR;

• P24 antigen;

• specific IgA.

Infection is very unlikely if all negative at 6mths and baby well.

Herpes simplex

85% of neonatal HSV is contracted at birth from active maternal genital le-sions. Elective LSCS reduces transmission if mother has active genital her-pes. Treat infant with prophylactic IV aciclovir if born by vaginal delivery and there is primary maternal herpes (transmission risk of 50% compared with 3% in secondary herpes). To prevent infection from carers with cold sores, the lesions should be covered with a mask and the sores treated with topical aciclovir.

Herpes zoster

Perinatal infection can cause severe disseminated disease with high mortal-ity (30%) if:

• Maternal rash occurs in the period between 7 days antenatally and 7 days postnatally;

• A LBW infant (<1mth old) has contact with varicella and whose mother is non-immune (i.e. check maternal antibody status if unsure).

Prevention 

Oral aciclovir and specific zoster immunoglobulin (ZIG) 100mg IM given soon after delivery.