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New Influenza: Is Quarantine a Rational Measure?

Kazuhiko Machida
Professor, Faculty of Human Sciences, Waseda University

Since World War II, infectious diseases were becoming a thing of the past in developed countries due to the development of public health and medical care, and especially the success of antibacterial agents and vaccines. At the same time, however, type-A influenza, with its highly variable antigen, continues to take its toll - seasonal flu kills about 10 thousand people in Japan and 30 thousand in the United States every year, even when there is no epidemic - and professionals and authorities have always been concerned about the potential emergence of a new flu in the future. We thought that the avian flu might have been that new strain, but surprisingly enough, it turned out to be another new flu, swine flu, which was suddenly contracted from pigs in Mexico in April 2009.

"Phase 5" is not related to toxicity factors

The number of patients, initially limited to Mexico, amounted to 3009 (3) in the U.S., 2282 (56) in Mexico, 358 (1) in Canada, and 302 in other areas including 1 in Costa Rica, totaling 5951 (61), within just two weeks (as of 13:00 on May 13th, death tolls in parentheses). These statistics show a strange fact that Mexico is suffering an extraordinarily high number of deaths in proportion to the number of people infected there (conversely, other countries have suffered a relatively small number of deaths considering the huge social impact of the flu), which implies that this infectious disease is unexpectedly low in its case fatality ratio and less contagious than expected in developed countries.

Table: Comparison between the New Flu and Avian Flu
  Swine Flu Avian Flu
Source of human infection 2005: Only an individual in Wisconsin, U.S.A.
Spring 2009: Many in Mexico, later worldwide
1997: Hong Kong
2003 and after: Southeastern Asia to Europe
Antigen H1N1 H5N1
Similar past antigens Spanish flu (1918 -)
Soviet-type (1977 -)
Case fatality ratio Estimated 0.4%, but currently 5 among 3669 outside Mexico. Spanish flu: 2% (U.K. 0.3%, India 4%) 62.8% for avian-human infection as of Feb. 2009. One human-human infection patient in Indonesia, one in Cambodia, and one in China.

Moreover, given that only Mexico, which has fewer patients than the U.S., is suffering a disproportionately high number of deaths, it is also probable that many people there are actually affected by extremely slight or imperceptible new flu there. If an extremely fatal virus led to a new infectious disease such as the avian flu shown in the table, patients would always need to be quarantined, though even quarantine cannot guarantee prevention of a pandemic. However, it has been pointed out from the outset that this flu is less virulent, and I wonder if the quarantine-oriented measures currently taken worldwide are rational.

Generally speaking, Mexico City and its suburbs are turning into slums where many people cannot receive adequate medical care. In the U.S., 47 million people are uninsured, despite high medical expenses such as a first visit costing more than 10 thousand yen. Taking these facts into consideration, I doubt that Japan and other developed countries should panic as they are. The World Health Organization (WHO) raised the alert level from Phase 4 to 5 on April 28th and requested tighter medical inspection worldwide. However, WHO announced on May 11th that this alert level pertains only to the level of contagion and not toxicity factors. I do not think I am the only one who doubts if people around the world should remain under this prolonged anxiety in addition to the protracted global economic stagnation.

Regret for human rights violations forgotten

In Japan, the Infectious Disease Law was enacted in 1999 based on regret for the violation of human rights induced by the quarantine clause of the Infectious Disease Prevention Act, which had lasted for over a century. However, the retention and quarantine of patients that is currently being conducted as a response to the new flu seems to be a return to the past. In fact, observing the commotion caused by an outbreak of measles among university students last year in Japan, I thought that the countermeasures were excessive. Developed countries tend to overreact to acute infectious diseases, probably because human life is highly respected and responsible treatment and administration are relentlessly pursued when the cause has been found in those countries. As a specialist in preventive medicine and health, welfare and medical policy, I wonder if it is good under a limited budget to take measures solely focused on infectious diseases, considering the impact that such a narrow approach has on people's daily lives in general.

If such measures are necessary, they must be pursued responsibly with a focus on preventive medicine. For example, it is odd that people are not vaccinated against measles or any other childhood diseases in Japan, unlike other countries throughout the world. Flu death risk factors include arteriosclerosis and other cardiovascular-related diseases, diabetes, and respiratory diseases. Preventive measures against these adult-onset diseases are top priority in order to prevent them or stop their progression. (Without any of these risk factors, the mortality rate is 4 out of 100,000 in a population over the age of 45. With one of these risk factors, the rate increases to 157, and with two or more risk factors, it goes as high as 615.) Authorities should make efforts to improve the current situation, where tobacco is not regulated as strictly as in other developed countries, and where national budgets have been cut to the extent that people are no longer actively invited even to have local health checkups.

Everyone needs to take measures against adult-onset diseases

Nevertheless, we should protect ourselves against this new flu as much as we possibly can, since it is certainly possible that it will spread throughout many countries in the next few years. For this purpose, we should gargle and wash our hands - more thoroughly than usual, drying our hands and fingers well - wear a mask whenever possible and dispose of it after use if anyone around us is infected, because we always have potential to infect others even when we do not know if we ourselves are already infected. While some scientists in the U.S. and the U.K. are skeptical about the effectiveness of masks, I believe that they are certainly effective, given that flu is not airborne, but rather it is transmitted through spray (of course I am also doubtful about the necessity of masks in the case of less virulent strains such as this new flu, but I still maintain that they are required against avian flu). It is also important to have adequate rest and develop physical strength and resistance. In particular, all people need to take measures against adult-onset diseases, given the risk factors.

Anti-flu medicines and vaccines

Though this new flu can be treated in the same way as regular flu, no one currently knows what degree of social impact and damages would result if a new flu stemmed from avian flu. I just hope that giving priority to the provision of anti-flu medicines and vaccines against this new flu will not impede preparation for avian and normal flu - existing types of flu kill more than 10 thousand people every year in Japan alone. Amid concern for the emergence of resistant viruses, Japan consumes over 70% of all the anti-flu medicines in the world. If other countries also started using medicine this way, what remedies would remain available if a new strain of avian or swine flu actually becomes virulent? Anti-flu medicines should never be exhausted in case cytokine storms kill many young people, as in the case of Spanish flu or avian flu. Whereas many people rely on vaccines, they also have many problems. First, unlike live vaccines, it is hard to say whether flu vaccines are originally very effective. Second, because they use fertilized eggs, it is difficult to prioritize the strains to use. In addition, vaccines may have side effects: when a swine flu similar to this new flu was prevalent in the U.S. in 1976, a side effect of the vaccine caused an intractable nervous disease (Guillain-Barre Syndrome) in over 500 people and killed more than 30. In any case, medical care should not be relied on excessively for treatment against viral diseases. I believe that flu prevention and measures against adult-onset diseases, which are flu death risk factors, are the most fundamental and essential elements.

96 infected people found in Japan - fears are realized

As the Japanese version of this article was set to be published on May 18th, I decided to add information to it if anything special happened prior to that day. Domestic secondary infection was announced on May 16th, and the next day it was reported that the number of infected people suddenly increased to 96 in Kobe and Osaka, among whom only 4 had recently been abroad. This is the very characteristic of influenza. While both the public and private sectors in every European country are calmly taking crisis-management measures, Japan and China seem to have responded a little irrationally. Most measures currently being taken in Japan were initially developed for use against new flu emerging from avian flu or a virulent mutation of the present strain - quarantine should originally be a measure against extraordinarily fatal diseases such as those - and for this reason, a thorough review of the current measures will be useful in the future.

Kazuhiko Machida / Professor, Faculty of Human Sciences, Waseda University

Professor Machida finished the doctoral course of epidemiology in the Graduate School of Medicine at the University of Tokyo. He has been in his current position since 1988 after serving as Assistant Professor of Hygiene in the School of Medicine at Juntendo University; Senior Researcher in the Environmental Health Department at the National Institute for Environmental Studies; Associate Professor of Public and Health Medicine in the School of Medicine at Oita Medical University; and Visiting Professor at New York Medical College. Professor Machida specializes in seroepidemiology, preventive medicine, and health, welfare and medical policy.

Major publications
Infectious Diseases Creeping Up [Shinobi-yoru Kansensho] (Waseda University Press, Sep. 1999); The World of Infectious Diseases: Immunity, Health, and Environment, Second Edition [Kansensho Warudo: Men'eki-ryoku, Kenko, Kankyo, Dai 2 Han] (Waseda University Press, Jul. 2007); and Preventive Medicine and Public Health in the 21st Century [21-Seiki no Yobo-igaku, Koshu-eisei] (Kyorin Shoin Publishers, May 2008).