Dear Editor,

In an editor's note to our previous letter on the safety of condoms you asked for details of the British Medical Journal. My colleague who also signed the letter has that information, but she has left the country and will get the reference to me soon. We certainly owe it to the public. I apologise for the omission.

Apart from that, there are two issues raised in the exchange. One is the 100 per cent safety of condoms claimed in the editorial on Ms Edghill's interview.

The editorial agreed with the message of the anti aids activist as not being different from that of others: "that in order to prevent HIV infection persons abstain, use a condom, or be faithful to one partner". It disagreed with the Aids activist's personal conviction, "Abstinence is number one prevention. Condoms are not 100 per cent safe."

To the implied warning, your editorial responded, "So which is it?". The truth is that condoms used consistently and correctly prevent the transmission of HIV 100 per cent."

Let me repeat that your questioning of our source for the percentage of reliability of condoms is your public duty and we will respect it . We omitted it only because my colleague was about to travel and had secured her information. We owe it to the public and ourselves.

Speaking personally, I do not find the statement you question unreasonable. What I find puzzling is your repeating from the WHO website what it calls an apparent misunderstanding of the difference between "lack of evidence of effectiveness" and a "lack of effectiveness". How can "effectiveness" be claimed without "evidence of effectiveness"?

I myself personally wish to believe that condoms used consistently and correctly are effective against HIV infection, but reject the idea of 100 percent effectiveness. All manufactured goods vary in quality. Condoms do too.

In this very vital concern, has any official source like the Bureau of Standards put out guidelines on the buying or selection of condoms?

An HIV infected friend told me a story of how what he called "junkies" take condoms out of garbage, dust off the packages and sell them to houses of traffic.

At one stage users were told how condoms should be stored, to ensure a higher degree of safety. I trust that the hotlines and telephone services give this information out. A website I visited recently before assisting in our letter warned condom users to look for the words "for disease protection." Is this a requirement in some places?

The full reliance on condoms without "evidence of effectiveness" reminds me of the head teacher who sent the upper school males across a river to gather sticks. The school inspector arrived, noticed their absence and when told about their errand was concerned about their safety when the tide rose. The head teacher said he was not worried, as he had found the average height of the students sent. The average height was above the height of the high tide!

Abstinence offers the highest degree of safety from sexual infection. The rate of infection has not come down without a change in attitude and behaviour. Condoms cut the risk of infection. They do not remove it.

When we hear that young people are postponing sex, doing long preparation before jumping to that climax, then the rate of infection should fall at a satisfactory rate.