Working frantically, Osterholm`s staff had definitely linked the first four patients by 8 p.m. on that fateful Friday. The amoxicillins carried different brand names but had been made by the same manufacturer and repackaged as ”house brands” by various drug chains. That`s when Osterholm called Mitchell Cohen, who heads the Centers for Disease Control branch that deals with gastrointestinal diseases. He`d called Cohen at home only once before–on the toxic shock case.
The Tylenol poisonings were vivid in Osterholm`s memory. So-called
”copycats” had tampered with over-the-counter eyedrops and other drugs. What if some lunatic working for a drug company had contaminated an entire batch of amoxicillin? Osterholm had a potential disaster on his hands.
”It couldn`t wait until Monday. In the interim 500 more people could have taken that antibiotic,” Osterholm says. As a precaution, Osterholm ordered all amoxicillins from the involved drug lots pulled off pharmacy shelves.
But before that order could take effect there was another victim. This patient–a young man–also had taken an antibiotic within 48 hours of the onset of the Salmonella, but he had not taken amoxicillin. He had taken penicillin, and he was just as sick as the others.
The phone lines between Atlanta and Minneapolis stayed busy through the night, and by early Saturday Cohen dispatched help to the beleaguered Minnesota Department of Health in the form of Scott Holmberg, an intense 33- year-old epidemiologist with a lopsided smile and an Italian organ- grinder`s mustache. Holmberg hadn`t started out to be a medical detective. In fact, he had been an English major at Harvard College before journeying to Somalia for the Peace Corps. There, he was a witness to one of the most remarkable milestones in medical history, the eradication of smallpox.
That event had turned Holmberg to the field of medicine and public health, and he returned to the United States to cram all of the pre-med he`d missed into one year at Boston College. He went on to Columbia University`s College of Physicians and Surgeons and then interned in the same hospital he`d been born in–in Providence, R.I.–before coming to the CDC.
Holmberg was on the first flight to Minneapolis Sunday. Osterholm met his colleague`s plane. On the way into Minneapolis they hashed over the facts. There were now 10 victims of S. newport.
The drug-contamination hypothesis had been shot down as the number of victims climbed, but there was still concern about some link with antibiotics, and one very frightening development. ”By this time we had some patients who had not taken an antibiotic, and they weren`t as ill,” Holmberg says.
That meant this particular S. newport was a ”superbug.” More correctly, it causes a ”super infection” because it is resistant to antibiotics. Giving an antibiotic to someone infected with an antibiotic-resistant strain of Salmonella is like ”throwing gasoline on a fire,” Holmberg says. The antibiotic can knock out the competing bacteria in a person`s intestines–even the beneficial bacteria which are normally in the system, such as Escherichia coli–allowing the resistant strain to flourish.
The fatality rate for such super infections is more than 20 times that for an ordinary Salmonella.
Without delay, the epidemiologists launched their search for the source of the deadly bacteria.
”First we phoned the people who were sick. Then we phoned a comparision group: people who`d had Salmonella in 1982. People who`d been taking antibiotics but did not have Salmonella. People who`d been taking antibiotics and had gotten diarrhea, but not Salmonella. We looked at people who had other kinds of Salmonella. We checked diarrhea rates. We literally called scores of people,” Holmberg recalls, with a rueful laugh. ”It may sound funny, but if you tell someone why you want to know about the diarrhea they had two years ago they`ll usually tell you.”
The results: It appeared the victims had eaten some food items in common
–eggs, poultry, hamburger, peanut butter, white bread. ”But they weren`t in any way different in what they ate than you or me,” Holmberg says. ”At a point like that, one thing you can do is go out and visit people.”
The first stop on Holmberg and Osterholm`s list was a tidy split level home in Maple Grove, a suburb northwest of Minneapolis.
Its owners, Pat and Bob Moore, put two sets of kids together when they married six years ago. ”That put us on the average American budget–steak once a month if you can afford it. If you can`t, eat a lot of hamburger,” Bob Moore says.
Monday Jan. 20, 1983, Pat Moore saw her doctor for what she describes as a cold. He prescribed amoxicillin. Wednesday the family attended a junior high school basketball game and she began to feel really ill. ”I was getting so warm. I went to the restroom and got sick to my stomach. Then I could hardly stand up.”
Thursday morning she was worse. ”I`ve never ever been this sick before. I gave birth to two children, and it was nothing like this,” she recalls. For the next eight days her temperature hovered near 105 degrees. Her husband finally stopped coming to the hospital because he couldn`t bear to see her as sick as she was (she would lose 22 pounds in the space of 10 days), and because he began feeling rotten himself. He took some of his wife`s antibiotic for his ”cold.”
The next night, Pat Moore recalls telling her husband she just wanted to die. There were injections to quell the pain and intravenous fluids to stave off dehydration, but she wasn`t getting any better. About 2 a.m. Bob Moore began to understand why his tough, usually stoic wife felt so defeated. It, whatever it was, hit him.
Pat Moore was hospitalized eight days; her husband, five. When they were discharged, before they allowed their children to come home from their grandparents, ”We sanitized the whole house–Spic & Span from top to bottom,” Pat says. ”Nobody could tell us what it was that had made us sick, so we threw a lot of groceries out–eggs, cheese, milk–and washed out the refrigerator with really hot water and disinfectant. I mean we used like Pine Sol! Lysol!”
Holmberg called to arrange a visit. ”He asked if we minded if he snooped around a bit,” Moore recalls. ”We really started laughing–there was really nothing left to look at.”
For Holmberg, the clue was right there–he just couldn`t see it at the time. ”These were friendly, intelligent, nice, normal people who as far as I could tell had absolutely nothing different about them compared to everyone else. It was the same story at the other homes I went to–nice, normal, intelligent people who had good personal habits and nothing unusual at all about what they ate or did.
”It sounds strange to say I was frustrated at meeting such normal Americans, but it really makes our job easier when we find something unusual about patients that allows us to link them together and find out what`s making them sick. In our job, normality is a stumbling block.”
But by now there was another frustrating and fascinating piece of information. The team was certain the S. newport cluster had a common source. Researchers have a new tool which ”fingerprints” the offending bug. The technique, developed at the Harvard Medical School, enables investigators to look at the bacteria`s plasmid DNA. These S. newports were more identical than peas in a pod–they were absolute clones.
But where had they come from?
It was a question the epidemiologists could not answer. No hypothesis fit all the facts. Holmberg, with Osterholm and his staff, spent two more weeks going around in circles before deciding they had come to a dead end.
Osterholm admits dead ends are common for epidemiologists, more common than they like to acknowledge. ”We get clusters that come through all the time. We try to trace them back–usually unsuccessfully. Salmonella happens all the time and we miss on it. When you hit, it`s usually serendipity.”
Serendipity was in the cards this time.
