article_snippet: But despite thorough investigations by multiple authorities the cause of the release and extent of the contamination are still unknown.
article_snippet: It is the latest in a series of significant accidents that have taken place across the country.
article_snippet: Human error is always the first explanation you should consider for a laboratory accident.
article_snippet: The first was discovered nearly three months ago in November and two have since died.
article_snippet: But one US Department of Agriculture (USDA) investigator was also hospitalised after blood tests showed
article_snippet: one US Department of Agriculture (USDA) investigator had antibodies indicating a current or prior exposure to A potentially deadly bacteria.
article_snippet: one US Department of Agriculture (USDA) investigator is now recovering.
article_snippet: Authorities are concerned that too few samples have been taken to decide whether livestock and domestic animals are at risk.
article_snippet: Only 39 soil samples were taken from the grounds - far less than the 100 recommended by previous research completed in Thailand.