Legionella found onboard the Bibby Stockholm is most deadly strain

New testing of water samples on the Bibby Stockholm has confirmed a potentially deadly strain of legionella onboard, the Guardian has learned.

The presence of legionella bacteria on the barge, which the Home Office has said can accommodate more than 500 asylum seekers, was initially detected by the testing of water samples on the first day people boarded on 7 August. It was publicly confirmed by the Home Office on 11 August and officials evacuated all 39 people onboard that day.

After the evacuation of the barge, its water system was flushed in the hope of eliminating the bacteria. New tests were carried out on 15 August and the Home Office hoped the results would show there was no longer legionella onboard so that asylum seekers could return.

The Home Office has not yet announced the results. However, freedom of information data from Dorset council shared with the Guardian has confirmed that the most deadly strain – Legionella pneumophila Serogroup 1 – has been found in a galley pot-wash hose outlet in tests conducted at 3.28pm on 15 August. According to the FoI response, this result was “unsatisfactory”.

An inspection of the barge’s pipework by Wessex Water identified problems which required repair. The Home Office said these repairs could be carried out while people were onboard.

The discovery of legionella on the Bibby Stockholm was an embarrassment to the government as the barge was a key part of its policy to end the use of hotel accommodation for asylum seekers. The Home Office had provided assurances that all relevant health and safety checks had been carried out prior to moving people onboard.

Peter English, a retired public health consultant, said that the results of the 15 August tests did not come as a surprise and that the strain of legionella identified was the most serious type.

“Remedial action needs to be taken. The system needs to be hyper-chlorinated,” he said. “That needs to be done for quite a long period. We wouldn’t expect the plumbing in a barge of the sort of age the Bibby Stockholm is to be very wonderful, particularly because it had been empty for some time.”

It is understood that two of the 39 asylum seekers who were briefly onboard have found accommodation with relatives, but the remaining 37 said they do not want to return to the barge due to what they have said are inhumane conditions.

The 39 sent a letter to the home secretary, Suella Braverman, documenting the poor conditions onboard and saying one person had attempted suicide.

One of the 39, now at a hotel, told the Guardian: “Nobody can really bear to return to the ship. In addition to the water, the risk of fire and the spread of disease in this small space is very high. In my opinion the Home Office has not done its research on this ship.”

A petition has been launched calling for the barge plan to be abandoned and for people to instead be accommodated in communities.

It is understood further water samples from the barge were taken on 24 August and the results of are expected to be announced shortly.