The Rodent and The Medicus: The Good, the Bad and the Ugly
by Vasudeva Iyer, MD
The recent outbreak of hantavirus in the Dutch cruise ship MV Hondius has triggered public debate on health safety, security, pandemics and vaccines. It also brought painful memories of the COVID-19 pandemic and the public anxiety that ensued. It was a great relief when the World Health Organization( WHO) recently announced that the hantavirus outbreak was over. I was fascinated with the process of medical sleuthing involved in the identification of the origin and transmission of the rodent-spread disease. During a fleeting moment of flight of ideas, I was forced to ponder over the role that rodents play in the broad field of medical science.
Let us first consider the“ the bad and the ugly” roles of rodents in causing / spreading diseases. The list of rodent-transmitted zoonoses has been steadily expanding over the years and according to one estimate stands at 70. 1 Historically, the term rodent in the public health context immediately brings attention to the plague which is caused by Yersinia pestis, named after Alexander Yersin. He was a protégé of Louis Pasteur, who in 1894 isolated the bacterium causing bubonic plague. Transmission of the bacteria from rodents occurs by flea bite.
The second recorded pandemic of plague named“ Black Death” occurred during the period 1334-1353 causing tens of millions to die. With the availability of antibiotics and prudent public health measures, the disease is under control although it is still endemic in countries like Madagascar, Democratic Republic of Congo and Peru. In the U. S., on average seven cases of bubonic plague are reported per year, mostly from New Mexico and Arizona. Transmission mostly occurs through bites by fleas living on infected rodents; direct contact through handling sick or dead rodents without protective gear is another cause. Pets that interact with rodents or their fleas can also be a source for human transmission.
Let us explore the more recent episode of the rodent-transmitted disease, the outbreak of the viral disease caused by the hantavirus that brought this topic into the limelight. The hantavirus was named after Hantan River in South Korea where the first strain of this virus was isolated in 1978. The Korean strain, spread by striped field mice, causes Hemorrhagic Fever with Renal Syndrome( HFRS). Another strain found in South Korea is the Seoul virus, spread by brown rats, causing a milder form of the disease. Yet another strain of the virus“ Sin Nombre” has been identified as the cause of a mysterious respiratory
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