Protective effects of topical antimicrobials against neonatal tetanus

Abstract

Background: Case-control studies previously conducted in Pakistan suggested that topical antimicrobials might provide protection against neonatal tetanus (NNT) when applied to the umbilical cord wound during the first several days of life. The present case-control study, the largest such study yet reported, was undertaken in Punjab Province, Pakistan and afforded further opportunities to evaluate such effects.

Methods: A population-based, matched, case-control study was undertaken to assess topical antimicrobials and other factors related to NNT risk in rural parts of Punjab Province.

Results: Continuous use of antimicrobial agents (antibiotics and antiseptics) at delivery and during the first few days after delivery was highly protective in univariate testing (matched odds ratio 0.2 [95% confidence interval: 0.11-0.64], P = 0.003), and remained significantly protective when other delivery and cord care practices were controlled. In contrast, applying nothing to the wound was risky compared with antimicrobial exposures. Hand washing and delivery by a trained birth attendant appeared protective. Application of animal dung or ash to the umbilical wound was hazardous. Similarly, predelivery cutaneous or intravaginal exposure of mothers to ghee (clarified butter) and delivery on a surface prepared with dried cow dung were risky, with significant interaction noted between them. Mortality and NNT were far more likely among previous births to mothers of cases.

Conclusions: Topical antimicrobials offer a new, effective and inexpensive means to prevent NNT, and could usefully complement maternal immunization with tetanus toxoid in controlling the disease. Special prevention efforts should be directed towards mothers of NNT cases.

PIP: A population-based case-control study in Pakistan's Punjab province evaluated the capability of topical application of antimicrobials to the umbilical cord wound in the first days of life to prevent neonatal tetanus infection. A 1990 cluster survey of 23,670 live births occurring in rural areas of Punjab Province in the preceding year identified 229 neonatal tetanus deaths. Overall, neonatal tetanus accounted for 64% of all neonatal deaths. The 18 cases where circumcision had occurred before tetanus onset were excluded, leaving 211 cases and 211 matched controls who survived the neonatal period for analysis. The greatest protection against neonatal tetanus (odds ratio, 0.27) was found when antimicrobial substances were used continuously. Hand washing and delivery by a trained birth attendant were also protective against neonatal tetanus, while maternal exposure to ghee and delivery on a surface prepared with dried cow dung increased the risk. The risk of neonatal tetanus was increased more than 2-fold (odds ratio, 2.5) for infants with dry cord care compared with those who had non-hazardous substances, including antimicrobials, applied. Efforts to protect the umbilical wound are especially important in villages where animals and animal dung exist in close proximity to living areas. The routine application of topical antimicrobials to the umbilical cord is recommended at all deliveries to complement maternal immunization with tetanus toxoid. The most promising agents for use in developing countries appear to be nitrofurazone, bacitracin, and povidone-iodine ointments.