THE SHATTERING RETURN OF MEASLES

Measles, once considered a relatively mild ‘childhood infection’, is frequently relegated to historical accounts or the recollections of older generations. This might lead to the misconception that measles is no longer a concern today. However, the reality is quite different: in 2019, the world witnessed the largest outbreak of measles in decades.

Measles is a severe illness, highly contagious, and transmitted through airborne droplets. It ranks among the most infectious diseases in the world, with an infected person capable of spreading it to nine of ten individuals they encounter. And in the past, locating a child who hadn't experienced measles was quite challenging. The disease is dangerous both in terms of its direct impact—2019 statistics indicate over 200,000 fatalities—and its potential consequences. Measles can result in severe complications affecting the eyes, potentially causing blindness, as well as ear infections, intense diarrhea, and even encephalitis. Currently, it is one of the primary causes of child mortality in developing nations.

Why, in that case, hasn't humanity discovered an effective means to combat this disease? Moreover, why, toward the end of the twentieth century, was measles regarded as under control to the point where it seemed unnecessary to take it seriously, only to witness its resurgence at the beginning of the twenty-first century?

Measles has been recorded in human communities at least as far back as the sixth century BCE. The establishment and proliferation of large cities was likely a crucial factor in the spread of this disease as the mass gathering of people facilitated the continuous transmission of the infection.

Humanity is familiar with numerous infectious diseases, many of which often share similar symptoms. The primary symptoms of measles include a high fever, a cough, a runny nose, and rashes. However, this clinical presentation is also characteristic of many other diseases. Thus, a medical professional’s first challenge is to ‘recognize the face’ of the disease.

The initial description of measles is attributed to the Treatise on Smallpox and Measles by the Persian physician Abu Bakr Muhammad ibn Zakariya al-Razi (865–925). He became famous outside his homeland, and Razi's (the Latinized form of his name) works were translated and studied in universities in European countries. Al-Razi considered measles a variety of smallpox, albeit with several important distinctions.

‘The appearance of smallpox is preceded by persistent fever, back pain, itching in the nose, and restless sleep. Next, the patient experiences pain through their body, swelling of the face that quickly alternates between swollen and normal appearances, a feverish flush, and an intense redness in both cheeks. Subsequently, they also experience a reddening of the eyes, a feeling of heaviness in the entire body, an intense restlessness which manifests in involuntary yawning, throat and chest pain, a slight shortness of breath, cough, dryness in the mouth, thick saliva, a hoarse voice, a headache, heaviness in the head, restlessness, apathy, nausea, melancholic mood (restlessness, nausea, and a melancholic mood are more prevalent in measles rather than smallpox; pain in the back characterizes smallpox rather than measles), overall body heat, feverish redness, shining and reddening of the eyes, and intense redness of the gums.’

The treatise by al-Razi only marks the beginning of a centuries-long endeavor to study and combat measles. It should be noted that his definitions remain somewhat imprecise: while nausea is more characteristic of measles and back pain of smallpox, the latter is also quite probable for measles. This was an initial attempt to identify and differentiate a common illness from others. Al-Razi described the clinical symptoms of both diseases and provided recommendations for treatment. He advised bed rest, cold water baths (avoiding steam baths), undergoing bloodletting, and adhering to a specific diet, which included avoiding sweets, particularly dates and honey, while considering vegetables and lemon juice as beneficial.

These prescriptions, however, turned out to be ineffective. Doctors persisted in ‘chasing shadows’, relying on symptomatic treatment. One thing was clear: measles was an infectious disease, and the primary goal for medical professionals was to isolate the infected individuals to prevent its further spread. It was also clear that such isolation was often impractical, especially in urban settings and particularly among large, impoverished families. Nevertheless, in pre-industrial societies, high child mortality was often viewed and accepted philosophically, being compensated as it was by high birth rates.

In 1670, a significant measles epidemic struck London. During this period, the renowned English physician Thomas Sydenham (1624–89) was working on the treatise Medical Observations Concerning the History and Cure of Acute Diseases, documenting observations on epidemics in London from 1661 to 1675. Sydenham provided a comprehensive description of the clinical presentation of measles, emphasizing the differences between measles and scarlet fever.

The illness started with a feeling of general malaise and fever. This was followed by a papular rash starting behind the ears, descending down the neck and chest and eventually covering the entire body. The rash persisted for several days, gradually fading and disappearing. Sydenham emphasized that both measles and scarlet fever most often afflicted children under the age of five. These two diseases, alongside diphtheria, remained the primary causes of child mortality at the time. However, they were also dangerous for adults for at least two reasons.

First, in adulthood, measles tended to be significantly more severe, often leading to complications and fatal outcomes. Second, measles proved to be extremely dangerous for geographically isolated communities where it appeared for the first time or after a prolonged hiatus. Such communities were devastated by the epidemic. Historians are aware that the era of the Great Geographical Discoveries changed the epidemic situation in both the Old and New Worlds. The conquest became not only a meeting of different cultures but also an inadvertent exchange of microorganisms, and thus the Europeans introduced smallpox and measles to the American continent. The indigenous people were powerless not only against the firearms of the conquistadors but also against their new diseases. Since both diseases appeared in America for the first time, they manifested in a very severe form, causing mass fatalities.

In 1846, a resident of one of the Faroe Islands contracted measles from an acquaintance from Denmark. Prior to this, the island had not recorded a single case of measles for over fifty years. The epidemic spread rapidly. The island had about 8,000 inhabitants, of whom 6,000 contracted measles. Notably, the adults also fell ill. The mortality rate turned out to be relatively low, but the rapid spread of the disease was a mystery for doctors.

Danish physician Peter Ludvig Panum arrived on the archipelago and conducted a significant epidemiological study titled ‘Observations Made During the Measles Epidemic on the Faroe Islands in 1846’. He concluded that the cause of the spread of measles was related to economic activities. The island's residents were engaged in fishing, a collective action where several fishermen would go to sea, and the fishing vessel—a small, cramped space—made it easy for one person to infect others. The deceptive aspect of measles lies in the fact that symptoms only appear several days after infection: a person may be sick without knowing it and continue to interact with others. After a significant portion of the population had contracted measles, a collective immunity developed on the island, and outbreaks of this disease did not recur for a long time.

In the second half of the nineteenth century, the world learned about the tragedy of the Fiji Islands. Similar to the Faroe Islands, the epidemic started with a single imported case. The ruler of Fiji, Takombau, decided to place the country under the protection of the British Empire and made an official visit to the British Residency in Sydney, Australia. At that time, there was a measles outbreak in Sydney, which the authorities did not pay sufficient attention to. Protocol required the ruler and his entourage to participate in mass events. As a result, Takombau's son contracted measles. When the first symptoms appeared, the ship's doctor attempted to isolate him, but as we know, a person becomes contagious before the onset of fever and rash. When the ship returned to Fiji, the captain did not raise the quarantine flag as required by the rules at the time. The police garrison organized the customary grand reception for the royal family.

As a result, the entire police force of the island (147 people) contracted measles. Within four months, the entire archipelago was engulfed by the epidemic. Entire villages perished, and there was no one to care for the sick. A judge residing on Lau Island wrote:

As the epidemic coincided with the establishment of the British protectorate, the residents of the island suspected the English of witchcraft and refused to seek treatment from their doctors. Suffering from high fever, the sick plunged into cold streams, leading to pneumonia, and drank untreated water, resulting in intestinal infections. Almost the entire population of the island fell ill, and a quarter perished.

In the nineteenth and the first half of the twentieth century, there were no breakthroughs in the fight against measles. Both children and adults throughout the Old World continued to suffer from measles, scarlet fever, diphtheria, and other infections. In the meanwhile, doctors persisted in researching and refining the clinical description of measles. In 1896, American pediatrician Henry Koplik wrote that measles was characterized by bright red spots in the mouth with white or bluish-white centers resembling sand grains. Currently, pediatricians recognize these spots, known as Koplik's spots, as a crucial diagnostic indicator.

The founder of Russian pediatrics Professor Nil Fyodorovich Filatov (1847–1902) emphasized that measles should not be considered a mild illness that usually passes without consequences:

Measles is often accompanied by photophobia, and thus the pediatric guidelines of the nineteenth century recommended keeping patients in rooms with partially closed shutters or curtains. It was believed that light was harmful to sick children and worsened their condition. The rest of the treatment had a symptomatic nature, with the primary action during a measles outbreak being to place the sick on bed rest and enforce strict isolation.

However, even N.F. Filatov himself could not ignore the fact that preventive measures were always delayed during measles—the sick child felt well for several days. In some cases, attempts were made to take healthy children to relatives or acquaintances, but this did not always help and often contributed to the spread of the disease.

Moreover, measures to isolate sick children were not taken by everyone. In large peasant families, there was often no such opportunity. Sometimes, in villages, if there was an outbreak of measles, mothers intentionally kept all the children together, placing them in the same bed so that everyone would get sick at once. This shortened the overall duration of the illness.

In the second half of the nineteenth century, many countries already had specialized children's hospitals, which primarily admitted children with infectious diseases. The main goal of these places was not as much treating the children as isolating them and preventing the spread of the disease. In 1876, the St. Vladimir Children's Hospital was opened in Moscow and was considered an exemplary institution. The hospital's most notable feature was its pavilion system that enabled the separation of children. This consisted of various pavilions, including the main building, typhoid barracks, and pavilions for measles, scarlet fever, smallpox, diphtheria, syphilis, and outpatients. However, most cases of measles were still treated at home.

By the beginning of the twentieth century, doctors had adopted a different approach from al-Razi or Thomas Sydenham. Now, the most effective tactic against infection was recognized as vaccination rather than isolation. This was evident in the case of smallpox, which has been successfully eradicated globally, and rabies, for which the vaccine remains the only possible treatment to this day. Medical professionals globally engaged in the development of vaccines to prevent epidemics, including measles. Before mass vaccination against measles began in the 1960s, it caused around 2.6 million deaths annually.

To effectively combat measles, it was necessary to identify the pathogen causing it. In 1911, American scientists John Anderson and Joseph Goldberger conducted experiments involving the experimental infection of healthy monkeys with filtered blood from infected individuals. Using this approach, they proved the viral nature of the measles pathogen.

However, the experiments on animals were inconclusive. Subsequently, microbiologist John Franklin Enders (1897–1985), a Nobel Prize laureate for his research on the poliovirus (1954), took the next significant step. Working with T. Weller, he isolated the measles virus from an eleven-year-old boy, David Edmonston, and began working on a measles vaccine. Clinical trials commenced in 1960 and were reportedly conducted on ‘1,500 mentally retarded children in New York and 4,500 children in Nigeria’.

Of course, contemporary medical ethics do not permit such experiments. Conducting clinical trials requires the informed, voluntary consent of the patient or their legal representative. However, in the mid-twentieth century, such cases of involuntary experimentation occurred, and the vaccine was deemed safe, allowing research to continue. Unfortunately, Enders’ work did not lead to success; his vaccine proved to be ineffective and provided immunity only for a short period. A more successful vaccine was developed in 1963 by American virologist Maurice Ralph Hilleman, who also created the trivalent MMR—measles, mumps, rubella—vaccine.

Research toward creating a measles vaccine was also conducted in the Soviet Union. In the 1960s, at the Leningrad Pasteur Institute of Epidemiology and Microbiology, a group of scientists led by A.A. Smorodintsev succeeded in creating the ‘Leningrad-16’ strain and developed a measles vaccine based on it. The new vaccine was included in the vaccination schedule in the Union of Soviet Socialist Republics (USSR) in 1967, resulting in a 650-fold decrease in measles cases.

As measles vaccination became a widespread practice, doctors encountered a strange phenomenon. In areas where children were mass vaccinated, child mortality decreased to such an extent that it could not be explained only by the victory over measles. Nowadays, scientists lean toward the theory that measles significantly suppresses immunity, making a person who has had it more prone to other infections. Thus, by protecting the body from measles through vaccination, we are also protecting the immune system against other pathogens.

The global resurgence of measles cases in recent years can be attributed to a simple fact: a growing number of parents are choosing not to vaccinate their children. Although herd immunity persisted for some time—the number of vaccinated children significantly outnumbered the unvaccinated—the effectiveness of vaccination is subject to the law of large numbers. As the count of vaccinated individuals diminishes, the risk of disease resurgence increases.

Arguments from anti-vaxxers often revolve around two primary concepts: the perceived harm of vaccines and religious prohibitions. It is indeed true that at the onset of the ‘vaccine era’ in the late eighteenth and nineteenth centuries, vaccines were not as safe as they are today. Those administering vaccines lacked an understanding of disinfection, leading to the possibility of contracting another disease during the process of vaccination. However, contemporary science has learned its lessons from past experiences, resulting in significantly safer vaccines. For instance, the Soviet strain utilized in producing the measles vaccine is named ‘Leningrad-16’, indicating that a safe and effective substance was developed after fifteen not-so-successful attempts.

Regarding religious objections to vaccination, it is important to note that no major world religion opposes medical assistance or intervention. Since all the major world religions emerged well before the advent of vaccines, there is no prohibition on vaccination in the Torah, Bible, or Koran. One of the main principles of vaccination is to protect not only the individual receiving the vaccine but also others from potential infection, complications, and death. For instance, Muslim pilgrims embarking on the Hajj to Mecca must provide a certificate of vaccination against meningococcal infection, diphtheria, and Covid-19. During the Covid-19 pandemic, Pope Francis received the coronavirus vaccine. The Russian Orthodox Church, while emphasizing that the Almighty has granted humans the freedom to make their own decisions, condemned anti-vaccination propaganda.

The extensive history of measles and the continuous efforts to address it underscore the importance of not underestimating the threat posed by seemingly conquered diseases as they can reemerge. Despite the significant success achieved by the world's top doctors in combating childhood diseases, there is a risk of reverting to a point where infectious diseases once again become a leading cause of child mortality. Taking preventive measures now can help avert this potential regression; it’s still not too late.