Background. Previous case-control studies of neonatal tetanus (NNT) in
the North West Frontier Province of Pakistan indicated that clarified
butter (ghee) applied to the umbilical wound of newborns was a signif
icant risk factor for NNT. However, the mechanisms underlying the risk
remained undisclosed. Methods. A hospital-based case-control study wa
s undertaken to evaluate further ghee and other factors possibly assoc
iated with risk of NNT. Mothers of several recent ghee-associated case
s were visited in their homes, asked to simulate the procedures used i
n preparing the ghee, and samples of ghee were collected for culture.
Results. Topical application of ghee to the umbilical wound was again
shown to pose a significant risk for NNT. in-use contamination of ghee
was documented as mothers repeatedly heated and manipulated samples o
f ghee set aside in special containers for this purpose. Ghee was usua
lly applied to the umbilical wound of the baby several times each day
for the first few days of life. Mothers of cases were again confirmed
to be substantially more likely to report prior NNT cases than mothers
of controls. Conclusions. Educational interventions to reduce umbilic
al ghee use or to wash hands before each manipulation might reduce the
risk of NNT in babies exposed to ghee who are born to non-immunized m
others. Increased efforts to immunize women of childbearing age with t
etanus toroid are also needed, with special priority for mothers known
to have been associated with a previous NNT case. Topical antibiotics
should be further evaluated for protective effects in nonimmunized mo
thers.