Gay Teen HIV Cases - Theresa Doesn't Know Her Maths

I stopped subscribing to the Straits Times a few years ago. It was only quite recently that I decided to start subscribing again (this time to the online version).

On 21 May, however, I was reminded of why I had stopped subscribing in the first place. Right on page one, the Straits Times published quite a stupid article by one Theresa Tan. Let's see why the article is stupid. Its title was:

"WORRYING INCREASE IN TEEN HIV CASES"

I therefore expected to see an article producing statistics to demonstrate a significant upward trend in teen HIV cases. Instead I saw this:

"THREE teenagers caught the Aids virus last year ... The increase is likely to be the biggest in a year since 1985, when the virus first hit Singapore. Before last year, official figures show only one teen at most tested positive for HIV."

You don't need a degree in mathematics to know that an increase from one to three doesn't show any kind of trend. Let's say that in a school last month, one student had the common cold. This month, three students had the common cold. Would you describe it as a "worrying increase" of 200% in common cold cases in school? Of course not. Duh.

If 100 teens in Singapore had HIV last year and this year 300 students had HIV, then you could fairly say that there is a "worrying increase". But if the number increased from one to three, and you describe this as a "worrying increase", then you are just not very convincing.

Let's see how else the ST article was stupid:

"Another worrying change is that the infected teens in the past two years were gay. Previously, the three teens infected between 2000 and 2002 were heterosexual, the Health Ministry told The Straits Times."

This comment is dumb for a variety of reasons. So far we have learned that:

1. From 2000 to 2002, 3 teens were infected. All were heterosexual.

2. From 2003 t0 2004, 4 teens (3 in 2004 plus 1 in 2003 ) were infected. All were gay.

Again the numbers are too small to draw any statistically meaningful conclusion. It is highly misleading for the article to suggest that over the past two years, a significant trend of HIV cases has emerged among gay teens. Mathematically, there is no such trend. To suggest that there is such a trend would be as absurd as saying:

"Good news! Statistics show that AIDS is no longer an issue for heterosexual teens! There has been a 100% decline in the past two years!"

... even though it is true that the number of new heterosexual teen HIV cases has fallen from three to zero over the past 2 years.

Perhaps more importantly, the writer here seems to be some inherent prejudice against gays. Why is it a "worrying change" that the recently-infected teens are now gay, not straight? If instead they had been heterosexual, would the writer have said:

"Three new cases of teens with HIV. But it's fine, nothing to worry about, they are heterosexual. When straight people get AIDS, it's not a cause for concern."

Surely not. After all these years, it is sad that so much ignorance still persists in the media about AIDS. The disease is a public health issue for MANY categories of people, Ms Theresa Tan. It concerns the ah pek having sex in a Batam brothel as much as any promiscuous teen in Singapore. Gay OR straight.