I was, I'd never liked to kind of go any place without doing some field work and one of the things that really got... I was interested about was insect transmission. You know, I'd worked in the tropics a lot, or some, and the importance of the viruses, that is viruses... are the viruses that are carried by mosquitoes or by insects. I was always fascinated by that because that's a strange, you know, very terrible method of transmission. So we... so I, in Senegal I was collecting mosquitoes. I had, you know, the... the medical entomologist from the Commonwealth of Pennsylvania came and trained me in using mosquito traps. It's kind of...

[Q] It must have been unpleasant.

It, well, turns out it was and he actually, that was William Wills who subsequently came to work for us and so I, he gave me a bunch of, he loaned me a bunch of traps. It was kind of complicated because to collect mosquitoes, you... you have this trap, you know, it has a little fan that when the mosquitoes get into the trap they... the current of air prevents them from exiting and then you have a small incandescent light, you know, searchlight... light bulb, a small one, and then also you usually use CO₂, dry ice, because many mosquitoes are attracted to CO₂ that... put out by humans, mammals. So I collected all these things and then I decided when I had a kind of cheap method of transport to get around Uganda and so I went on a... a game park tour. So, they... they put you on, on a van and they took you all over the country sort of thing, you know, to see about half... four or five game parks. So we'd get into these usually tented camps and everybody else was having dinner and I'd rush off and hang my traps. Well, we were in a game park and they didn't... it was not a good idea to be out at night, you know, without some guide or gun or something and there were a lot of... we were right near the, some of the places right near the Nile, you know, where the hippopotamus are kind of really... so I used to, you know... you know, wait until—and the batteries only lasted about 10-11 hours and the, you know, it's dark for a long time in the tropics, so I had to put them out there just before it got dark. So I'd sort of rush out just at twilight, you know, hang it next to some, you know, places where there were people and then run back, then I'd have a kind of a sleepless night and as soon as it was the crack of dawn I'd go out and look for hippopotamuses and then rush off and bring the trap in, and we found a lot of mosquitoes and...

[Q] Did you ever find a hippopotamus?

Oh yeah, I saw plenty of hippopotamus, and some of them close. I mean you... you can or at least I could, I did have a guide sometimes and he... he assured me they were close. They come out at night to... to eat and then go back to the river in the morning. So... but the important thing about that Uganda meeting was that there were several people reported this, in effect confirmed, the connection that... that Bruce Smith and I had inferred from our study. I came back and said, ‘That's what we're working on now, hepatitis B and primary cancer of the liver’, and we focused on that for a long time.

I also had a rather unfortunate run-in with the police there also. It, well, not so unfortunate, but we were there just as Idi Amin came into power. His predecessor, Milton Obode was off at a meeting I think in the United States and while he was there — Amin was in the military — he took over but it wasn't recognized at that time, how savage his administration was. But at one point I was in a village kind of just walking around. I wasn't doing anything, I was just looking there and I had a camera and I passed a police station and a policeman came out and told me to come in, a plain-clothes policeman, and he said, ‘What are you doing with that camera?’ I said, ‘Well, you know, I'm just taking pictures around here’. He said, ‘Did you take a picture of this police station?’ I said, ‘No, no’. I said, ‘Well look, take the camera, take the film’. Well, I was, you know, he took it and he let me go but it was, they were very unusually for, you know, African people are usually pretty friendly, you know, pretty welcoming, these guys were... were hostile. When I got back home, I... it was all over the newspapers, a couple of newspaper reporters—from Philadelphia by the way—had been murdered; right, not exactly the town I was in but... but nearby. But in any case at the time... but...

[Q] What was the connection with the police station not wanting pictures taken?

I think just the high level of suspicion. You know, they were... they were defensive. You know, afraid people were going to... because there was a lot of commotion when we were there; quite a few people were killed. But any case, from the point of view of the hepatitis, that charged us to move ahead with the... with the association with cancer of the liver. Well, we... we got very involved in that. Much of our work in Senegal was directed to that; the Senegal work came after that Uganda meeting and I... and then a lot of other people, of course, became involved and it was in time appreciated that a... that a great deal of primary cancer of the liver was due to hepatitis B.