Back to the big city for our final preparation before we set up base in Moyamba for good. We need somewhere to stay on our return and have asked the Norwegians if we can camp with them while they build the base camp.

They have erected large eight-person tents, but there's only sufficient room for their forward party, and they still need to build basic facilities for the new guests. We have left them hammering and sawing in the fine Scandinavian Ikea style.

The latest UN Emergency Ebola Response ‘sitrep’ for Sierra Leone is out. 6,535 cases and 1,367 deaths. I don't understand why the mortality is so low - some recording bias or case ascertainment, I suspect.

In health care workers the numbers are 136 and 105 - 77% mortality, which is much more in keeping with what we would expect, and the case ascertainment and reporting will be more accurate. Only 53% of Ebola cases are being isolated, and 60% having safe burials within 24 hours, so much work to do. The target for Ebola Treatment beds is 1,500, with only 500 in operation.

The country now needs 200,000 Personal Protection Equipment suits every month to cope with clinical demand. For us the debate rages over goggles or visors. We have all been trained with visors and have been told that the goggles are terrible to wear - fogging up in the heat within minutes and dangerously reducing vision.

However, MSF are entrenched in their view that hoods and goggles are the safest and we appear to have stepped unwittingly into a religious crusade with dogma and evangelicalism in place of reason and dialogue.

I email Professor Nigel Silman at Porton Down who helped develop our PPE and he reassures me that there is no evidence that either method is safer. We will keep the visor faith for now.

A new arrival in the office today with Julio, our watsan (water and sanitation) expert. He will take the lead for the safe decontamination of any potential sources of infection leaving the red zone.

New rules in the MDM office are quickly established to reinforce that hygiene begins at home. He tells us we need separate water bottles to pour our water, which seems a particularly paranoid approach - drinking out of the same bottle I understand, but having to write our names on each water bottle for pouring?

He views the world through a particular microbe-covered lens, but that is exactly the sort of obsessional perspective we need at the moment.

Without any sense of irony, he demonstrates the safest method to take and light a cigarette to minimise contact and protect health. We go over the Ebola Centre plans to identify potential breaches in the armour, and list changes that may be required.

We gatecrash the WHO Ebola briefing, which seems preoccupied with the design of a data collection form for a national audit. One and half hours into a very slow meeting I text Chris, who is sitting opposite, with a request to kill me quickly.

The highlight is a drop-in visit from Mike Ryan, who is the director of the WHO’s alert and response operations and has been involved in an impressive 19 out of the last 20 Ebola epidemics.

I ask him why this one is so bad. The answer is simple - we were late. He describes how viruses like influenza spread in waves affecting everybody, whereas Ebola spreads in a more sinister fashion, travelling undetected along channels until it finds a weak point, a burial or a poorly run health centre, and then it explodes. Health care workers are the mine canaries, their deaths providing the critical warning for an epidemic.

Mike is concerned about some of the Ebola Centres becoming ‘amplification’ centres - where misdiagnosed cases mix with Ebola patients and then go home to carry on transmission.

Also that we need to balance the approach to looking after patients across the spectrum of community centres and holding units and not just on Ebola Treatment Centres - if we get it wrong upstream we will end up seeing patients at death's door and having to undertake high-risk interventional procedures that are risky to the clinicians and mostly futile for the patient.

If we get it right then we will be able to manage them simply and safely. I will have to go and explore the community centres and holding centres, though I am nervous about exposure in these low-protection areas, so will have to be cautious.

Being in the red zone, fully kitted out and fully trained is probably the safest place to be in this epidemic. It is the less rigorously controlled community settings where danger lurks.

The informal discussions after the meeting are the most useful and we get some invaluable tips for what we will need - which guidelines to use, mentoring for the staff when we open, reassurance about the clinical side (‘It’s actually pretty boring from a medical perspective - just one disease’).

Also insight into Kerrytown over which clouds appear to have gathered. One lesson from this ETC is that they opened their doors to everyone on the first day and were quickly overrun. We need to adopt a measured approach and manage community expectations as we take our first tentative steps.

MORE BLOG POSTS FROM PROFESSOR JOHN WRIGHT