First Human Case of Rat Hepatitis E Infection Detected in Hong Kong 

A new report confirmed the first case of human infection of the rat variant of the hepatitis E virus. The case has been identified in Hong Kong and reported by one of the top universities in the country. The case was confirmed by the University of Hong Kong. The university warned the public about the discovery of the human infection of the rat hepatitis E virus. The transmission of the virus is now a major public health concern. Hepatitis E Virus in Rats Contracted by a HumanIn Hong Kong, a 56-year-old man has been hospitalized due to alarming, abnormal results from liver function tests. The patient recently received a new liver and as part of treatment and care, the doctors need to regularly check his liver function. When the clinicians investigated the abnormal test results, they detected the presence of hepatitis E virus found in rats in the system of the patient.

The researchers who conducted the study believe that the virus was contracted through food contaminated with rat droppings. They considered the contamination because of the rat infestation outside the residence of the patient. "This study conclusively proves for the first time in the world that rat HEV can infect humans to cause clinical infection," the university said, quoted Medical Xpress. The patient already received the appropriate treatment, ribavirin, and currently recovering from the disease. Zoonotic Hepatitis E VirusHepatitis E virus in rats is not closely related to the human HEV, not even a single variant, which signifies the major concern caused by the recent report. The common denominators of the HEV rat variant and HEV human variant are the clinical symptoms, such as a fever, jaundice, and stomach pain. HEV in rats is common in animal populations in different parts of the world, according to several studies:- In a 2012 study, researchers found the presence of the zoonotic HEV in wild Norway rats or Rattus norvegicus in Hamburg, Germany. The virus was detected with its usual genome organization, but had a high nucleotide and a more diverse amino acid sequence than normal. - In another 2012 study, scientists examined 446 wild rats in the United States and 35 of the animals were found with HEV RNA in their liver tissues.

The HEV RNA had been isolated and analyzed to determine genetic properties. Results showed that three isolates were all genotypes of zoonotic HEV. - In 2011, investigators published a study regarding the presence of zoonotic HEV in rats in Los Angeles, California. The genome sequence of the HEV identified in Germany has been found genetically similar to the isolated sample in Los Angeles, California. They tested the HEV obtained from the urban rats in California and found it incapable of infected rhesus monkeys, which suggested its very low potential to infect humans. - Another study in 2011 conducted a wider search of zoonotic HEV in different regions. They found the presence of hepevirus RNA in 85 out 3,869 bat species in five continents. Analysis of the genome sequence suggested high diversity compared to the human HEV. Hepeviridae is the family of viruses that include HEV. Human Hepatitis E VirusAccording to the World Health Organization, about 20 million of HEV infections occur around the world annually. While it can be found in every corner of the planet, the prevalence of the viral infection is higher in East and Southeast Asia. The most common source of HEV is drinking water contaminated with rat droppings. Hepatitis E virus, in general, is divided into four genotypes. The genotypes 1 and 2 are exclusive to humans, while genotypes 3 and 4 are specifically found in animals. "Genotype 3 and 4 viruses circulate in several animals (including pigs, wild boars, and deer) without causing any disease, and occasionally infect humans," wrote WHO.

When a person contracts the virus, they can develop either acute or chronic HEV infection. Acute HEV rarely occurs in healthy people but more common in pregnant women who contracted the virus. The acute infection can cause acute liver failure, premature death of the fetus, and early mortality of the patient. On the other hand, chronic HEV infection usually occurs in people who are taking immunosuppressant medications due to organ transplant. The WHO confirms that cases of chronic HEV in immunosuppressed patients are usually caused by HEV genotypes 3 or 4. Treatment of Hepatitis E InfectionAccording to the Centers for Disease Control and Prevention, there is no specific treatment for acute HEV infection. Patients normally recover on their own without requiring medical attention, but in case the symptoms worsen, clinicians can provide supported medications. For patients of chronic HEV, an antiviral medication called ribavirin is used to treat the hepatitis E virus. It is a broad-spectrum antiviral for DNA and RNA viruses, including hepatitis C and viral hemorrhagic fever. The CDC confirms that modification of the immunosuppressant drugs and the antiviral medication may be applied for chronic HEV infection.