Blocking transmission

A Cambridge University engineer has helped to develop a novel method for preventing HIV transmission from mother to child.

Stephen Gerrard, a Cambridge University chemical engineering graduate and an Engineers Without Borders UK volunteer, contributed to the development of a modified nipple shield which is capable of disinfecting breast milk as it passes through it.

He now plans to continue work on the design as he takes up an MPhil at the university this year.

The device is the result of work at the International Design Development Summit (IDDS), a unique conference held at MIT last August. The Summit brings together engineers and field workers, both amateur and professional, to work on research projects aimed at developing prototype designs.

Gerrard, together with a team of five others, was assigned the task of creating a practical design for heating milk to deactivate the virus, following on from work being carried out by a research group at Berkeley, California.

He said: 'We quickly established the concern that this may be too lengthy for many women in developing countries so they might not have the time for it.'

Accordingly, his team began looking at other methods besides heat treatment that are being tested. They came across several potential compounds that could deactivate HIV in breast milk.

Gerrard added: 'Research has shown that copper and copper compounds can work, but another approach, carried out by a group at Drexel University seemed more promising. Their research has focused on a compound called Sodium Dodecyl Sulphate (SDS), which can kill the HIV virus quickly and in fairly non-toxic concentrations.'

The new design adds a layer of non-woven material, such as cotton wool, soaked in SDS to a conventional shield, typically used to make breast feeding easier. The layer allows the virus to be deactivated without having to go through heat treatment.

Their project could also have benefits beyond prevention of HIV. Gerrard said: 'We were concerned that using our nipple shield could be stigmatising, since it would identify a mother as HIV infected. We're considering marketing it as a way to deliver medicines or micronutrient supplements to aid breast feeding. For example, they can also be used for iron or iodine deficiency.'

Given that the modification is simple, as well as cost-effective - it requires only that the cotton wool is replaced on a daily basis - the team's idea could provide a quick way to improve medicine delivery to babies. The invention provides a low-cost alternative to the use of syrups, for example, which are expensive and usually require refrigeration.

The group is now looking for a lab to test the efficacy of their design and establish that the majority of the virus is deactivated on its passage through the layer. It has also made preliminary contact with the Institute for Pediatric Innovation in Boston, and is searching for a pharmaceutical company that will be interested in the invention.

Other members of the team include Tombo Banda, a mechanical engineer from Imperial College, Geoff Galgon of the California Institute of Technology, Ryan Hubbard, a systems engineer from Olin College, Elizabeth Kneen, a mechanical engineer from Olin College and David Sokal, an experienced physician and public health specialist from Family Health International (FHI).