Sarah Carter - confusion reigns

On 12th March, 2011, I wrote about the tragic death in Chiang Mai of Sarah Carter.

Originally, her death was blamed on consumption of toxic seaweed.  At the time, I suggested that this was a highly suspect conclusion, based on the symptoms and the circumstances.

A short while later, it was claimed that Sarah and her two friends had been infected by an ECHO virus.  The symptoms matched.

However, more information came to light - a Thai tourist guide had died in the next room in the same hotel and a week earlier, two other tourists had died in a room one floor below. 

The New Zealand TV3 channel discovered that a total of seven tourists had died in Chiang Mai in similar circumstances.  Sara Hill, an investigative reporter for TV3, went to Chiang Mai and made a programme screened here a couple of weeks ago.

In an interview with Sarah Carter's friend, Sara Hill discovered that none of the three girls had eaten seaweed and had eaten two different meals.  They all developed sore stomachs and vomiting and were hospitalised.  According to a Thai cardiologist, Sara Carter suffered very low blood pressure, dehydration and low blood flow to the kidneys, with ultimate kidney failure.

The reporter managed to obtain swab samples from the room occupied by Sarah and returned them to New Zealand for testing.  Traces of chlorpyrifos, an organo-phosphorus insecticide used in corn and cotton farming, were found in the swabs.  Dow Chemical Company voluntarily withdrew the registration of chlorpyriphos for domestic use in 2001.  Mr. Ron McDowell, a UN scientist, hypothesised that Sarah had been exposed to chlorpyrifos as a result of over-zealous spraying of the hotel room to control bed bugs by a pest control operator.  McDowell claimed that the symptoms and pathology all fitted with chlorpyrifos poisoning.

However, the swabs were taken three months after the room was occupied by Sarah, so spraying could have occurred at any time during those three months. The report form was shown in the programme.  The level in Sarah's room was given as <0.1 microgram/sample, which probably means "below the limit of detection".  A sample from an air conditioner was 0.24 micrograms/sample, but the film of the sample being taken suggested that the area swabbed was uncontrolled.

The half life of chlorpyrifos in the human body is about one day, so, although it is absorbed quickly, it also disappears from the body quickly.  Thus tests at the hospital may not have shown its presence in Sarah's body.

I'm not convinced that we are much further forward.  The Thai authorities were not being particularly cooperative with the TV3 investigation and recently refuted the chlorpyrifos theory.  Three toxicologists in New Zealand have issued a statement criticising the programme and the conclusions drawn by the experts consulted by Sarah Hill.


It looks as though seaweed is off the hook and food poisoning seems a bit unlikely, as the three girls ate different meals, but suffered similar symptoms not commonly seen in microbial food poisoning.  Food contamination is not completely ruled out, as several meals could have been contaminated with a chemical.

I don't know if we will ever know the true story