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Last fall Hong Kong recorded the first known human infection with a rat Hepatitis E virus (see ECDC CDTR Notice) in an elderly immunosuppressed individual who had recently received a liver transplant.
The announcement from HKU reads, in part:
HKU discovers that rat hepatitis E virus can cause hepatitis in humans
28 Sep 2018
Rat hepatitis E virus (rat HEV) was first discovered in 2010 and circulates in house rats (Rattus rattus) and sewer rats (Rattus norvegicus). It is very distantly related to human hepatitis E virus variants. Human infection by rat HEV has never been documented previously. A study led by Professor Yuen Kwok-Yung, Henry Fok Professor in Infectious Diseases, Chair Professor of Infectious Diseases, and Dr Siddharth Sridhar, Clinical Assistant Professor at the Department of Microbiology of Li Ka Shing Faculty of Medicine, The University of Hong Kong (HKU) has discovered for the first time that rat HEV can infect humans.
Findings of the study
While investigating the impact of hepatitis E infection among immunocompromised transplant recipients in Hong Kong, the researchers identified a 56-year-old man who was taking immunosuppressive drugs after deceased-donor liver transplantation. He presented with persistently abnormal liver function tests indicating dysfunction of the liver graft. Rat HEV was identified in several of his clinical samples including stool, blood, and liver tissue. Complete genome sequencing of the virus isolate showed that it was closely related to a rat HEV strain previously identified in Vietnam.
Epidemiological investigation could not find any evidence of rat HEV infection in the organ donor or blood product donors excluding these individuals as sources of infection. However, evidence of rodent infestation was noted in the patient’s housing estate. Rat HEV could not be detected in rodent fecal samples collected from the housing estate, but screening of archived rodent samples from the patient’s residential district shows that rat HEV circulates in rats in Hong Kong. The patient was given oral ribavirin, an effective antiviral for chronic hepatitis E infections, and the infection has been cured. His liver function has returned to normal.(Continue . . . )
Retrospective testing uncovered a 2nd case, involving a 70-year old woman in November of last year (cite), and since then three more cases have been announced by Hong Kong's CHP.
In a letter to doctors last month, the CHP wrote:
Since November 2018, the Public Health Laboratory Services BranchToday, the CHP announces a 6th human infection.
(PHLSB) of CHP has enhanced the surveillance of both human and rat HEV. In May 2019, PHLSB detected three additional cases of human rat HEV infection involving three men aged 67, 74 and 81 years respectively.
All three cases had major underlying illnesses (one with metastatic carcinoma, and two had renal transplants and were on immunosuppressants) and presented with liver function derangement without other obvious symptoms of acute hepatitis
HP investigates case of human infection of rat Hepatitis E virus
The Centre for Health Protection (CHP) of the Department of Health is today (June 28) investigating a case of human infection of rat Hepatitis E virus (HEV) and urged members of the public to be vigilant against hepatitis E infection and to strictly observe good personal, food and environmental hygiene.
The case involves a 73-year-old man with underlying illnesses, who had presented with liver function derangement earlier this month. He has been in a stable condition all along and no hospitalisation is required. His blood sample tested positive for rat HEV upon laboratory testing.
The CHP's epidemiological investigations revealed that the patient resided in Wong Tai Sin. He could neither recall having direct contact with rodents or their excreta, nor had noticed rodents in his residence. He had no travel history during the incubation period.
"Based on the available epidemiological information, the source and the route of infection could not be determined. The CHP's investigation is ongoing," a spokesman for the CHP said.
"The CHP has already informed the Pest Control Advisory Section of the Food and Environmental Hygiene Department about the case to carry out rodent control measures and survey as appropriate," the spokesman added.
The exact mode of transmission of rat HEV to humans is unknown at the moment. Possible routes of transmission include ingestion of food or water contaminated by rodents or their excreta, exposure to environments or objects contaminated by rodents or their excreta and direct contact with rodents or their excreta. The usual HEV causing human infection is transmitted mainly through the faecal-oral route.
(Continue . . . )
Earlier this year a case was reported in Canada, detected in a person with recent travel history to Africa (see Rat hepatitis E may be ‘under-recognized’ cause of hepatitis infection), but it remains unknown how widespread transmission really is.
Hong Kong has a notorious`rat problem', and following last month's announcement of 3 additional Rat Hepatitis E cases, HK's Food and Health Bureau announced a massive cleanup campaign.On June 20th, they issued their first progress report:
Government reviews territory-wide cleansing and anti-rodent work (with photos)
The interdepartmental Pest Control Steering Committee met today (June 20) to review the enhanced anti-rodent work carried out by various government departments since the cleaning campaign over the territory commenced on May 20 and set priorities for the work ahead.
The Government has provided an additional funding of $91 million this financial year to various departments for enhancing pest control work. During today's meeting, various departments discussed the extra resources required for the relevant work. The Government had earlier expressed that full support would be given to department’s pest prevention and control work.
Various departments briefed the meeting on the progress of territory-wide cleaning work in all 18 districts. They include:
- District Offices (DO) of the Home Affairs Department (HAD) have assisted different departments on reporting the cleaning and anti-rodent work carried out in each district as well as the liaison with stakeholders in the community to raise public awareness of rodent prevention and control.
Whether human infections with rat hepatitis E are a recent phenomenon, or have simply been under-recognized, is less than clear. Now that it is on our radar, however, we should get a clearer picture of its true incidence and impact.- Among the some 180 public rental housing estates in the territory, the Housing Authority (HA) has examined the rodent-proofing structure installed in 133 estates. The HA will repair and arrange the reinforcement of the existing structure as well as install additional structure immediately if needed with a view to eliminating activities of rodents and their harbourage points. The HA has also enhanced the cleaning work in all public rental housing estates and strengthened enforcement action under the Marking Scheme.(Continue . . . )
