Les Roberts – Freetown, Sierra Leone – November 12th, 2014
Day 39: The plural of anecdote is not data
This past week, I was assessing the completeness of the main case listing database (a sensitivity analysis) which involved going to villages and asking if there had been any suspected cases in the village during the month of October. In one village, there had been a woman and her two small children who had returned from Freetown just after the three day lockdown (September 28-30). She was originally from the town, was married to a man from the town, but had been living in Freetown for a while. When she returned, the village quarantined her in a store. It is against the law to allow a visitor to stay in your house in Bombali District. But she was from the village so they could not turn her away. Quarantine in a non-house building seemed like the right thing to do in this village that had reportedly never had an Ebola case and was officially closed to outsiders. I am sure they saw this as a humane compromise.
On day 18 of the quarantine, one of the 18 month-old children died in the morning and the other twin died in the evening. The village chief reported to us that they were Ebola cases. The bodies were swabbed before burial and one is listed as a positive swab in the official CDC VHF database (I am sure you are asking why one and not two….that is the sensitivity part, and I wonder the same thing). The mother supposedly was never sick? Was she an asymptomatic case? Hard to say. The kids could have been infected 19 days earlier (unlikely, but a theoretical possibility). The mother could have really been a case, was discharged and did not tell anyone and somehow infected the kids. Again, unlikely as the very limited fluid sampling I have heard about suggests the virus disappears from breast milk quickly, making it safe, while other fluids like sperm remain deadly for months (Therese McGinn has been saying variations of that same theme for years!). Whatever happened, it was a pretty odd case. As we drove back, a colleague told me one of the guards at a holding center in Makeni had developed fever, been tested, was positive, but never developed serious illness. The next day, another colleague told me of a family where a mother was ill, there were no open beds at treatment centers or holding centers so she was quarantined in the house with her two small children and her sister. The woman died; a week later a kid died, and then the other while the sister spent perhaps 30 days in a house caring for three people as they died, a house that was never disinfected, and she never fell ill. I have now heard perhaps a dozen stories like this. No one story is very convincing that it was an asymptomatic or mild infection. Taken together, the likelihood that this is not a disease like measles (where virtually everyone can get it) seems to be growing in lots of people’s minds. There are supposedly almost no villages where the attack rate has been more than 20 or 30%. These are often really humble villages where no children have shoes and feces flow like social media in New York. Lots of us are lamenting that there is so much work to do, that there is no time to learn the lessons that are passing before us (like drawing blood in these high attack villages to see if people who report never being sick have antibodies). Maybe next year, when the outbreak has passed…
Instead, tomorrow I am off with my Ministry Of Health mates to measure if quarantine causes or prevents infections within a home. We are planning to interview most of 100 homes… Finally, there will be something more than anecdotes linking quarantine and secondary household deaths. Either way (and I have no idea what we will find) a lot of people are going to be annoyed with the results. Ebola, the rift that keeps on rifting!