COLUMN. The outbreak of measles currently underway in Gothenburg is the largest in five years, with at least 27 cases. Henry Sjövall, columnist for Akademiliv (Academy Life), provides historical background on measles and reminds us of why it’s so important that there is adequate vaccination coverage in the population against the “The Little Misery.”
When I hear the word measles, I think about tennis and Tolkien. I probably have to explain that. When I was going to England for a language course abroad in 1970, I caught a “cold,” went to the doctor and got a green light to travel. My host family had arranged for tickets to a Wimbledon match between the Roger Federer of that day, Rod Laver, and an opponent who was considerably weaker on paper, Roger Taylor. Laver was the obvious favorite. I remember coughing throughout the match; Taylor had a sensational upset. In the evening came the measles outbreak. The family doctor who was summoned made the diagnosis and recommended “bed rest.” The host family felt sorry for me, of course, and the oldest son came in with a big book titled Lord of the Rings. “This is a good read; will keep you busy for a while.” When I came home, I was the only person who had heard of this book, a variation on secondary sickness gain.
Varför allt detta ståhej?
Now before Christmas, when the current measles outbreak in Gothenburg came, I remembered that story and wondered rather timorously, what’s all the fuss about? After all, it wasn’t so bad lying in bed for a week and reading Tolkien … Besides, don’t we now have essentially a vaccinated population?! Why this fear?
I’m a history buff and picked up three books on the cultural history of epidemics: Plagues and Peoples; Guns, Germs and Steel; and Deadly Companions. Began to understand the crucial role epidemics have played in human history and became more and more interested. Got to learn that some special circumstances are necessary for a virus to cause problems for the population as a whole. If its goal is to spread, there should not be immediate mortality. It’s also wise for the symptoms to be manageable, preferably the kind that promote proliferation, such as head colds or stomach problems, and ideally for a rather long time. And when the virus makes the jump to the next individual, it should be welcomed by the new host. It’s possible to put a number to that, the so-called R-factor, which essentially reflects the number infected by a primary case in a susceptible population. The R-factor for measles is 15, which is very high (compare this with smallpox, which has an R-factor between 3 and 11, or tuberculosis, where the R-factor is between 4 and 5). There are studies confirming that measles is extremely contagious – among other things, that a single import case can infect an entire island and spread the disease to virtually everyone.
What the virus dislikes most is when people are sparsely distributed over large areas, especially if the people do not have a fixed dwelling, because then the virus has nowhere to go when the confounded immune system makes short work of it. One way to handle that is to “spend the night” with someone else, such as livestock or pets, and bide your time. Then the virus can sometimes return by learning new tricks and jumping back to people.
How then has the measles virus handled those rules of the game throughout history? The hunter-gatherer period was a real inconvenience. There weren’t many people then, and they moved around all the time. There were then similar viruses in cattle and dogs as a reservoir, known as rinderpest and canine distemper respectively, and it is believed that these viruses underwent some type of transformation and began infecting humans in one of our earliest civilizations, ancient Mesopotamia, in approximately 2500 BC. The virus is found again now and then in the history books. The so-called “plague” that afflicted Athens during the Peloponnesian War and forced Athenians to surrender may have been measles. The disease also appears to have reached China along with smallpox, most recently in 600 BC, perhaps via a chain of infection along the Silk Road (there was no maritime traffic there then).
Of course, people mulled over what they could do to prevent the disease, and the first person to make a distinction between smallpox and measles was a Persian physician by the name of Rhazes in the 10th century. He called measles “hasbah,” which roughly translates as “bad blood,” and believed that the disease was more dangerous than smallpox. In the Middle Ages it acquired its modern name, morbilli, a diminutive of morbus, disease. The English term measles is similarly a linguistic diminutive of the Latin word miser, thus “the little misery.” There is debate over what the great misery was. The principal line of inquiry is smallpox, but others propose – leprosy! None of this philosophizing seems to have appreciably thwarted the virus. It proceeded calmly to circulate in the population and took the lives of a large number of people, especially poor infants. It is said that parents who discovered that their child had contracted measles already began to regard the child as dead!
A linguistic diminutive of the Latin word miser, thus “the little misery.”
The next boom for the virus was the period in which the Portuguese and Spaniards began to colonize the world. The latter brought measles to South America with them, and there was a big market there – namely, a completely unprotected population that lived in communities with relatively unfavorable means of transportation. In other words, they were sufficiently tightly packed in communities up in the mountains, but with a sufficient intercourse with the environment to allow for the spreading of disease. Manna for the virus, of course! As expected, lots of casualties, and probably a large part of the blame for the collapse of the Inca Empire. The natives in South America wondered (justifiably) why only they became sick, and not the Spaniards themselves. And this became part of the myth of Spanish invincibility. The same pattern was also seen a few hundred years later, when measles reached native Americans in North America. How highly contagious the disease was became apparent when it managed to get to geographically delimited areas, such as semi-isolated island communities. A work titled “Observation made during the epidemic on measles on Faroe Islands in the year 1846” describes how the disease afflicted 6,100 of the 7,864 islanders, resulting, however, in a relatively modest 102 deaths. Measles did a better job in the Pacific region, accounting for 40,000 fatalities in a total population of 150,000 on Hawaii in 1848, for example!
Up until then, people had not made any significant attempt to mount a counterattack. But with Edward Jenner’s success with a vaccine against smallpox, scientists saw an opening and began the search for a vaccine against the Little Misery! In 1911 Andersson and Goldberger demonstrated that tissue from sick people could infect monkeys. In 1938 researchers succeeded in growing the virus in a tissue culture. In 1963 an attenuated (editor’s note: weakened) live vaccine was tried in the United States for the first time, with promising results. The virus now had good reason to be concerned. In 1974 the World Health Organization started its global immunization program, and in the 1980s came today’s viable two-dose vaccine that now is part of the basic immunization schedule in most countries. The results were particularly unfavorable for the virus (image) and no better for its old pal smallpox, which was completely wiped out! Fortunately for the virus, continual wars and famines have interfered with the vaccinations. It also turned out to be almost impossible to get a 100-percent vaccination rate in a population. The Mediterranean countries still seem to be a fairly safe home port, and with all the population movements in the wake of war, with persecution and with stays in filthy and crowded camps, there is fairly good potential for contagion. Sweden nowadays is very inhospitable for the measles virus. We’ve had viable two-step vaccination since the early 80s, and people who have received the two-step vaccine or who have had the disease are considered to be immune. Occasionally vaccinated people seem to actually be able to get sick again, but then with very mild symptoms and with low or no infectivity. People born in Sweden prior to 1960 have generally had the disease and thus constitute a closed market.
Globally, the Little Misery causes the death of approx 100 000 children annually.
Infants might offer a small opening for the virus. They receive some protection from their mother (if she has antibodies), but there can be a gap between the time that protection ends and the first injection is given at 18 months of age, an opening that is now going to be closed. Nevertheless, the group is an important market for the virus. Globally, the Little Misery, or its complications, is believed to kill about 100’000 children annually. As we know, the Great Misery, the smallpox virus, is not a factor anymore.
With this perspective, how do we then interpret the current hullabaloo around the outbreak in Gothenburg? It all started with an import case and a rapid waiting room contagion followed by a contagious person working with infants. Our world-renowned infectious diseases organization was activated instantly, and the University Hospital went into a state of readiness, roughly equivalent to a state of emergency in the community at large. We tried through the media to release accurate information about the expected course of events, with a limited number of secondary cases, and issued strong recommendations about getting vaccinated in case of the slightest doubt. In the internal medicine course we distributed a questionnaire in connection with the exam, and less than 10 percent were found to be lacking certain protection. We did the same for the supplementary program for foreign doctors, with about the same results. At this point students are not allowed in health care environments unless they have countersigned that they have been vaccinated. The same procedure applies on the health care side. The small number who cannot be vaccinated because of medical contraindications receive immunoglobulin if contagion is feared. And for children, the first vaccination is being moved up to 12 months of age.
The hope is that the Little Misery eventually will follow in the footsteps of the Great Misery until neither of them are an issue in the dark cemetery of epidemics!
Henrik Sjövall, Professor, Institue of Medicine
Thanks to Leif Dotevall, infectious diseases doctor, for fact-checking.
