John Hockenberry: The tip of the spear of trust, or at least government information on issues like this is Tom Skinner, spokesperson for the Centers of Disease Control, who began our program yesterday. He joins us once again. Tom, thanks for being here with us.

Tom Skinner: My pleasure.

John Hockenberry: How much trust do you think people have in the CDC as you get ready for another day of, I suspect, pretty hectic evaluating of information coming in from all sides?

Tom Skinner: Well I hope to have a lot of trust in what we're saying. It's very important that they be informed. You know, the best antidote for fear really is information, and so we really do want people to be informed about what's going on and know that there really are steps that they can take to protect themselves and others.

John Hockenberry: Now I don't want to put you on the spot too much here, Tom. I know you're on your way into the office, but can I run down some numbers with you? We've got 152 deaths, all of them in Mexico and none of them anywhere else. Does that surprise you at all?

Tom Skinner: You know, this is an evolving situation, and I think that the longer this goes on we're going to learn more about cases in the United States, and thankfully all of the cases in our country have recovered. We haven't had any deaths, but we're still talking about a relatively small number of cases and so, we would expect to see some more cases here, more severe cases and possibly some deaths. But we still want people to know that there really are steps they can take to protect themselves, and to take those steps to protect themselves and others and to limit the impact this has on public health.

John Hockenberry: Exactly 24 hours ago we were looking at 20 cases in the United States. It more than doubled. We've got 50 confirmed cases. Would you expect that to double again today, or is this going to settle down?

Tom Skinner: We should know by later this morning how many cases we're seeing. We do expect more from possibly some more states, but we'll have more information later this morning.

John Hockenberry: We've got a cluster in New York at one New York City school, 28 cases. Any sign of clusters, or are these individual instances as far as you can tell?

Tom Skinner: They're both. We do have some clusters going on, but they're primarily sporadic cases coming in from various states as our surveillance, our enhanced surveillance picks up these cases.

John Hockenberry: Alright, Tom Skinner, thanks so much. Spokesperson for the Centers for Disease Control. We wish you good luck today and we'll speak with you tomorrow if possible.

Tom Skinner: Ok, thank you.

John Hockenberry: Tom Skinner, spokesperson for the Centers for Disease Control. Now from Mexico City, Ioan Grillo joins us, he's Mexico correspondent for Time Magazine and was talking yesterday about how significantly gripped Mexico City was by the announcements coming out of the government. A lot of public events were cancelled yesterday. What's it look like this morning, Ioan?

Ioan Grillo: It's more of the same picture, more and more. I mean, we've had the schools shut down across Mexico City for three or four days, now they've shut down the schools in the entire country. So every school and university across all of Mexico has been given a holiday. And then, you were talking about trust, there's still the issue of trust here. People are worried and tense and suspicious, but some are also suspicious about their own government and wondering if their government is handling this crisis well, or if it's making some wrong moves. There's been some interesting information about the origins of the flu and the way the government handled that. Don't know if you've seen that information?

John Hockenberry: Let me know. We do know that it began, at least the suspicion is that it began at an agricultural center where there was a fairly large scale production of pigs, right?

Ioan Grillo: That's correct. I mean, originally they were talking about, just a couple of days ago, about the first case being a woman on April 12 who died of this virus in the southern state of Oaxaca, but then yesterday at a news conference, the health secretary conceded that that wasn't the first case. They'd actually found as early as February there was a flu outbreak in the eastern gulf of Mexico state of Vera Cruz, and they'd confirmed from a sample from a 4-year-old boy who suffered from influenza in, or shall I say near a pig farm, that he had the swine flu virus. Now the health minister was asked and again the issue of trust comes up here, they asked him why wasn't there more done by the government back then, and his answer was well, this is a new virus, a new phenomenon in the world and we really didn't know it was happening.

John Hockenberry: Wow, well that's interesting and will definitely affect the way people proceed in following government instructions about closing events and maintaining limited contact if they expect to contain things, and of course the World Health Organization says that we're past the point of containment. Ioan Grillo, thanks so much for being with us.

Ioan Grillo: Thank you.

John Hockenberry: Joining us now is Dr. Michael Edmonds, an epidemiologist at Virginia Commonwealth University. Let's begin, Doctor, right there. The World Health Organization says we're beyond containment, the Mexican government concedes this has been going on since February, what does that say to you as an epidemiologist?

Dr. Michael Edmonds: Well it sounds as though the outbreak continues to grow, and I think we just have to continue to educate the public about what things they may do to protect themselves.

John Hockenberry: And in the United States we're talking about trust and in Mexico we're talking about trust and the United States actually wondering if our listeners can tell us what they think about what the U.S. is doing. How do you rate the responses of the government so far?

Dr. Michael Edmonds: Well I think it's been quite good, I think they've tried to get information out to the public, and doing it in a way in which they give information but not create alarm. I think they've done a pretty good job of that.

John Hockenberry: Now, if this actually began in February, what's the chance that the virus we're dealing with now is actually a mutated virus from the one that was responsible for the first outbreaks back in February.

Dr. Michael Edmonds: Well, that's possible. I think one of the things that we know about influenza is that over time it continues to change. It can change in small ways that we call shift or drift if it's larger in terms of the changes that it makes. And because it's ever changing, it's always a virus in which we seem to be chasing it.

John Hockenberry: What does that mean exactly?

Dr. Michael Edmonds: Well, for example, even from year to year we're never certain about which strains may be circulating to the greatest degree in the community, and that's why you'll see in some years the strains in the influenza vaccine don't match the strains that are circulating within the community, and in fact we don't get a good response to the vaccine.

John Hockenberry: Well, Dr. Richard Besser, who's acting Director of the Centers for Disease Control addressed that point directly in a news conference yesterday afternoon. Take a listen to this.

Dr. Richard Besser: [on tape]: It's hard to know what the course of an outbreak is going to look like until you're much further into it. Another thing that's important to note is that we're nearing the end of flu season, and often in outbreaks of influenza you'll see a decline in the number of cases because of the flu season, and we can't rest too comfortably on that because sometimes those come back again in the fall when flu season comes back.

John Hockenberry: So Dr. Edmonds, is the season and the weather working against the proliferation of this virus, but that it is likely to remain dormant until next fall?

Dr. Michael Edmonds: Well that's typically what happens, as we move into spring you start to see fewer cases of the flu, and as you probably know, the flu seasons are opposite in the opposite hemispheres, so this time of the year in the northern hemisphere we would tend to see flu cases go away.

John Hockenberry: Now, no one has explained to me why there would be 152 deaths in Mexico and no deaths anywhere else. Is that possible?

Dr. Michael Edmonds: Well, it's happened so yes it's possible, but --

John Hockenberry: Well, let me just say, actually, do we really know that? In others words, is this a reporting issue, is this a reporting error, are there other deaths out there we might not know about or is it actually conceivable that there would be only deaths in one location?

Dr. Michael Edmonds: Well I think the answer to that is that there's probably some to both things of what you said. We probably don't know of all the deaths, we probably don't know of all the cases even, but I think there probably is a kernel of truth in the fact that there was a much higher mortality rate in Mexico than we've seen in the United States to this point, but that could change.

John Hockenberry: Back in the 70s we had a Swine flu scare and the government urged people to get vaccines and it didn't turn out very well. Is there any lesson from the period in the 70s?

Dr. Michael Edmonds: I think the lesson about this particular virus, influenza, is that it's always unpredictable.

John Hockenberry: But does that mean that you should get a shot, that if there is an anti-viral therapy that you should proceed aggressively against that, or you should just hope for the best?

Dr. Michael Edmonds: No, I think flu shots are really valuable and people should avail themselves of them.

John Hockenberry: And what's the time frame on the development of a vaccine? We're sort of at the initial stages now, and the current seasonal flu virus isn't going to help us.

Dr. Michael Edmonds: I think that at the earliest it would be months.

John Hockenberry: Months. Dr. Michael Edmonds, epidemiologist at Virginia Commonwealth University, thanks for helping us out with that.

Dr. Michael Edmonds: Thank you.