South African scientists’ extraordinarily fast and accurate diagnosis of the rare hantavirus cases in the recent outbreak deserves credit, and did the country proud, notes MedicalBrief.
Professor Lucille Blumberg of the National Institute for Communicable Diseases described the work by the NICD and and other health authorities in pinning down the unusual virus as a superb team effort, which was also commended by government and Health Minister Aaron Motsoaledi.
This week, after possible exposure, a South African passenger tested negative for the virus, but authorities are now monitoring nearly 100 close contacts linked to the deadly outbreak aboard the luxury cruise liner MV Hondius, reports Daily Maverick.
There have been 11 total reported cases so far, nine of them confirmed.
Three people on the cruise died, including an elderly Dutch couple whom officials believe were the first exposed to the virus while visiting South America.
While no South Africans were on board, several passengers later travelled on flights with South Africans, and medical personnel in this country had treated two infected patients.
The National Health Department confirmed on Monday that a Western Cape resident who had shown flu-like symptoms after possible exposure on a flight from St Helena Island to Johannesburg had tested negative for the Andes virus, or a hantavirus infection.
But the department has now increased the number of close contacts that need monitoring from 62 to 97.
Cases so far
AP reports that a French passenger testedpositive for the virus after evacuation from the ship on Sunday.
The Dutch couple who died were probably exposed to the virus during a bird-watching excursion in Argentina, suspects the WHO. They had boarded the MV Hondius, carrying 147 passengers, on 1 April, and the husband died on board on 11 April.
At that stage, the ship’s medical team was unable to test for the virus, so he is considered a probable case.
On 24 April, the ship docked at St Helena for his body to be repatriated to The Netherlands. His wife went ashore at Saint Helena. She deteriorated on a flight to Johannesburg on 25 April and died on 26 April in a Johannesburg hospital. The Andes virus is transmissible in the later stages of the disease, with the onset of symptoms.
When the NICD tested a blood sample, she was confirmed positive for a hantavirus infection, with the scientists later narrowing down it down to the Andes virus.
South African authorities then began contact tracing to ensure that passengers on the flight to Johannesburg who were in contact with the woman were not infected. Four were traced to the Western Cape. One showed flu-like symptoms and was tested, but this test came back negative on Monday.
A British man, currently in ICU in Johannesburg, developed symptoms on 24 April and was medically evacuated from Ascension Island on 27 April. He too tested positive.
The French passenger admitted to a Paris hospital has a severe form of the disease that has caused life-threatening lung and heart problems, Dr Xavier Lescure, an infectious disease specialist, told AP.
She is on a life-support device, with Lescure calling it “the final stage of supportive care”.
Also confirmed to be infected was a Spanish passenger who tested positive after being evacuated from the ship, with that country’s Health Ministry saying on Tuesday that the passenger was in quarantine at a Madrid military hospital.
Other linked cases
A woman who had flu-like symptoms and was later diagnosed with pneumonia died on the ship on 28 April. A post-mortem sample was sent to The Netherlands with the evacuated patients, where it was confirmed she too had been infected by the Andes virus.
The ship’s doctor then fell ill on 30 April. He tested positive for the Andes virus on 6 May, was medically evacuated to The Netherlands, and is in a stable condition.
A guide on the ship reported symptoms on 27 April. After his blood sample tested positive, he was medically evacuated to The Netherlands and is in a stable condition.
A passenger who left the cruise in St Helena and flew home to Switzerland through South Africa and Qatar has meanwhile tested positive for the Andes virus. He is in isolation in a Swiss hospital.
A flight attendant who had contact with the Dutch tourist who died in Johannesburg was feared to have the Andes virus, but her test returned a negative result.
Authorities are awaiting the test results for another passenger, a Briton, who left the cruise liner in Tristan da Cunha on 14 April and then fell ill. He is in a stable condition.
Blumberg said that the incubation period for hantaviruses was around six weeks, so those who had contact with the woman who died will have to be monitored continuously until this period expires.
The WHO said that confirmed and suspected cases have been reported only among the cruise ship’s passengers or crew.
“There is no sign we are seeing the start of a larger outbreak,” said Tedros Adhanom Ghebreyesus, WHO director general. “But the situation could change, and given the long incubation period of the virus, it’s possible we might see more cases in the coming weeks.”
The BBC reports that Maria van Kerkhove, an infectious disease epidemiologist at the WHO, said it was not the same situation as six years ago with Covid-19, because hantavirus spreads through “close, intimate contact”.
“This is not the start of a pandemic,” she said.
SA scientists hunt and ID
Just as with Covid-19, South African scientists again did the country proud by working fast and efficiently to discover the cause of death and illness on the stricken cruise ship.
It had begun with an email that arrived late on 1 May, for Blumberg of the NICD from a concerned colleague.
The message was from a UK infectious disease specialist and led to Blumberg’s team finding the rare virus as the cause of the outbreak within 24 hours.
“It was – if I say it myself – amazing, a team effort,” she said. “They have done extremely well.”
Within 24 hours after receiving the email, the team managed to confirm a hantavirus infection in the British patient who had been evacuated to South Africa for treatment on 27 April, and who is still in a Sandton hospital.
By Wednesday, 6 May, it was identified as the Andes virus – the only strain of hantavirus that can be transmitted between humans.
Blumberg said the email from her UK colleague had said there was concern about an outbreak on a ship.
The trouble was, she added, that the patient was elderly with comorbidities, and because a lot of people on the ship were ill with respiratory symptoms, finding the exact pathogen was always going to be a struggle.
What made this even more remarkable is that hantavirus is not endemic to SA and not a usual cause of respiratory infections.
“It is not a virus we see in this country,” she said. “And it’s not the usual cause of respiratory infection outbreaks on ships.”
She said that normally in an outbreak of this nature on a ship, legionella bacteria or a flu virus would be the suspect.
“As a country we have done extremely well. Within 24 hours we knew what we were dealing with and we had a large amount of information,” she added.
By the time the British tourist was evacuated by helicopter to Johannesburg, the 70-year-old Dutch passenger had already died (on 11 April), and medical staff on board were unable to ascertain the cause of death.
The man’s body remained on the vessel until 24 April, when the crew reached St Helena and arranged for his repatriation to The Netherlands. His widow had accompanied the body on a flight to OR Tambo International Airport from St Helena and was meant to take a connecting flight to The Netherlands.
Health Minister Aaron Motsoaledi said she was never meant to enter SA and only had a transit visa.
However, she collapsed after arriving at the Johannesburg airport on 27 April, and despite emergency medical treatment at a nearby hospital, she also died.
Blumberg explained the frightening progression of the disease caused by hantavirus. After a long incubation period, the later stages of the illness “happen very, very quickly”.
Motsoaledi said the widow was screened at the airport, but at that stage did not have a fever. The medical team treating her at a Kempton Park hospital did take a blood sample to send for testing, but after she died it was marked for destruction.
“At first we did not know about this patient,” Blumberg said. “She did not report illness (to the airline or the customs officials). We had nothing to alert that she may have something.”
But when the team found out about her, they rushed to the hospital and managed to save a blood count specimen, taken as a routine sample, from being destroyed.
“It was a stroke of luck,” Blumberg said.
Tests revealed that the widow, too, had hantavirus, and the sequencing team later identified that both she and the patient in ICU in Sandton were infected with the Andes strain.
“The pieces came together extremely quickly – it was quite remarkable to make that diagnosis,” Blumberg said. “It was a most unusual pathogen in a most unusual setting.”
Blumberg said although medical teams on cruise liners sometimes had rapid influenza and Covid-19 tests on board, they could not test for viruses like hantavirus. It was therefore not possible to make a diagnosis on board.
Blumberg said the team had immediately started contact tracing even before they were sure what they were dealing with, out of caution.
Airlink, the airline on which the widow flew, said there were 82 passengers and six crew onboard the flight.
“At the time, Airlink was unaware any passengers were unwell. On Sunday, 3 May, Airlink was notified by health authorities that the passenger from the ship, who had been on the previous week’s flight, had died after arriving in Johannesburg and that her death was thought to be attributable to hantavirus,” the airline said.
In accordance with health protocols, Airlink provided the department with the names, contact details and seating allocation of all passengers and crew from the flight so authorities could start contact tracing.
‘Not in our country’
Argentinian authorities have disputed the WHO’s conclusion that the elderly Dutch couple were first infected by the Andes virus in Ushuaia, a popular tourism destination.
Juan Petrina, director of Epidemiology and Environmental Health for the Tierra del Fuego province, said the species of rodent carrying the virus did not live in the area and that the hantavirus “zone” was about 1 500km north.
The couple apparently did a bird-watching tour that included a stop at a garbage dump where they may have been exposed to rodents carrying the infection.
Ivermectin rears its head, again
News24 reports that the outbreak has already triggered familiar false-cure claims that Ivermectin can treat, prevent, or cure a dangerous viral infection, with one social media post suggesting that “as hantavirus is an RNA virus, Ivermectin should work against it”, and a former US congresswoman quickly responding favourably to the claim.
But Dr Roger Seheult, a US-based critical care doctor, said he had found “no clinical trials of Ivermectin for hantavirus” and no clear in vitro evidence for hantaviruses either.
The WHO said that although ribavirin has shown some efficacy against hantavirus haemorrhagic fever with renal syndrome, it has not been effective for hantavirus cardiopulmonary syndrome and is not licensed for its treatment or prevention.
The assessment by the European Centre for Disease Control was similarly blunt. It said: “No effective antiviral treatment is available; supportive care is key for a better chance of survival.”
It recommended early medical evacuation, testing, isolation, appropriate protective equipment, and symptom monitoring, not Ivermectin.
Dutch hospital staff quarantined
Meanwhile, Reuters reports that 12 employees at a Dutch hospital where a passenger from the MV Hondius is being treated have to quarantine for six weeks after improperly handling bodily fluids, Radboud University Medical Centre said this week.
The “risk of infection is low”, the hospital said, but it was requiring the dozen employees to go into preventive quarantine as a “precaution”.
The hospital had received a passenger last week from one of the evacuation flights that landed in The Netherlands and the person has since tested positive for hantavirus.
Blood and urine from the patient should have been handled “according to a stricter procedure”, the hospital said.
Daily Maverick article – How an SA team of scientists hunted a rare hantavirus strain (Open access)
Cape Argus article – South Africa’s response to hantavirus outbreak lauded (Open access)
See more from MedicalBrief archives:
Hantavirus outbreak on cruise ship sparks alarm
UK draws up new disease-threat watch list