GENEVA: Hantavirus, being linked to deaths on a cruise ship in the Atlantic Ocean, circulates in rodents and can be deadly when transmitted to humans.
Dutch cruise operator Oceanwide Expeditions confirmed Monday it was dealing with "a serious medical situation" on board the MV Hondius, travelling from Argentina to Cape Verde.
Hantaviruses can cause respiratory and cardiac distress, as well as hemorrhagic fevers.
There are no vaccines or specific medications to combat hantaviruses — meaning treatment consists solely of attempting to relieve the symptoms.
The virus
Each hantavirus is associated with a specific rodent reservoir species, in which it can cause long-term infection without apparent illness.
Only a few hantavirus species are known to cause human disease.
The virus is named after the Hantan River in South Korea, where more than 3,000 troops fell seriously ill after becoming infected with it during the 1950-1953 Korean War, Switzerland's FOPH health ministry says.
Transmission
Transmission of hantaviruses to humans occurs from contact with contaminated urine, droppings or saliva of infected wild rodents, such as mice or rats. More rarely, infection may occur through bites.
The French National Public Health Agency says human infection generally occurs through inhaling contaminated dust and aerosols.
The only way to minimize the risk of infection is to avoid contact with rodents and their secretions and excretions.
Andes virus, found in South America, is the only known hantavirus for which limited human‑to‑human transmission has been documented, and only then linked to "close and prolonged contact", says the World Health Organization.
The WHO's epidemic preparedness chief, Maria Van Kerkhove, said Monday that based on previous outbreaks, "the overall risk to the public is low."
Diagnosis
The WHO says early diagnosis "can be challenging" as the symptoms resemble several other respiratory illnesses, such as Covid-19.
Suspected cases can be confirmed through various laboratory tests, according to the WHO, including through "the presence of hantavirus-specific IgM antibodies."
Van Kerkhove said the WHO was working to understand the source of exposure through epidemiological investigations, along with contact tracing and lab tests.
Symptoms
"In the Americas, infection has been known to lead to hantavirus cardiopulmonary syndrome (HCPS), a rapidly progressive condition affecting the lungs and heart, while in Europe and Asia hantaviruses has been known to hemorrhagic fever with renal syndrome (HFRS), which primarily affects the kidneys and blood vessels," says the WHO.
Different health authorities give varying time periods between exposure and symptoms starting to appear.
According to the US Centers for Disease Control and Prevention (CDC), in the Americas, symptoms usually start to show one to eight weeks after contact, while HFRS symptoms usually develop within one to two weeks.
Early symptoms typically include fever, headache, muscle aches, abdominal pain, nausea or vomiting.
In HCPS, the disease may progress rapidly to cough, shortness of breath, accumulation of fluid in the lungs and shock, says the WHO, while with HFRS, later stages may include low blood pressure, bleeding disorders and kidney failure.
Case numbers, fatality rate
Worldwide, it is estimated that from 10,000 to over 100,000 infections occur each year, with the largest burden in Asia and Europe, says the WHO.
HFRS accounts for many thousands of cases annually in East Asia, particularly in China and South Korea.
The case fatality rate is between less than one percent to 15% in Asia and Europe, the WHO says.
Despite the much lower incidence, HCPS has a case fatality rate commonly between 20% and 40%, says the WHO, making it a disease of major public health concern.
.jpg)
.jpg)
.jpg)
.jpg)
.jpg)
