Covid 19 Resources Center

Marburg

The Marburg virus disease outbreaks (as of 14th April) have reached 38 cases (15 confirmed) and claimed 11 lives (79% CFR of confirmed cases) in Equatorial Guinea along with 8 cases and 5 deaths in Tanzania (63% CFR).  This CFR is typical of past outbreaks, but the occurrence of two simultaneous epicentres is unusual.

Recently WHO advised 26 countries had implemented measures to impede the spread of the virus.   Note that the WHO statement on Marburg advises against travel or trade restrictions with Equatorial Guinea or Tanzania.  See recent updates:  https://www.who.int/emergencies/disease-outbreak-news/item/2023-DON451
https://www.who.int/emergencies/disease-outbreak-news/item/2023-DON459

Marburg

BlueDot recently published an analysis of the risk relating to Marburg virus disease.  Bearing in mind the mode of spread and the travel patterns for the area and beyond, they assess the outbreak as having high concern regionally (Tanzania and neighbouring countries) but low internationally.  Similarly, WHO’s risk assessment is of high risk domestically, moderate risk sub-regionally, and low risk globally.   The forecast highest frequency overseas destination from Tanzania is Dubai (at 18% of traffic), followed by DRC and Kenya (via land borders). 

We see that a number of Middle Eastern countries (including Oman, Kuwait, UAE, Bahrain, Qatar), Indonesia, and others have advised their citizens against non-essential travel to the countries reporting Marburg cases.  Given that the mode of spread requires close contact with people or animals who are symptomatic at the time, this travel advisory seems inappropriately cautious.  Other advised precautions are more reasonable, including avoidance of sick people, of bats and their caves/mines, and of contact with others’ body fluids. 

Marburg has now reached at least 34 cases (including 30 deaths) in Equatorial Guinea. 

Infectious Diseases and Outbreaks

MARBURG:

Tanzania confirmed an outbreak of Marburg virus disease on 23 March. Preliminary samples carried out following the deaths of at least five people yielded some positive tests for the viral hemorrhagic fever. So far, 7 symptomatic cases with 5 dead were reported in addition to 161 contacts being traced by authorities. (GPHiN)

Meanwhile in Equatorial Guinea, concern about potential spread has been raised as four cases have been detected in the port city of Bata (population 200,000).  Actual case numbers may well be higher. (WHO)

Fruit bats can transmit the virus to humans, and human-to-human transmission occurs through direct contact with bodily fluids, or contaminated surfaces and materials. The case-fatality rate of Marburg virus disease is high (up to 88%), and no approved vaccines or antiviral treatments exist.  However WHO is preparing to commence a phase 3 vaccination trial amongst close contacts of cases (typically 20-50 contacts per case.  (Airfinity, WHO).

The Vietnam Health Ministry announced a requirement for visitors arriving from countries with Marburg outbreaks to be monitored for three weeks while in-country.  (Airfinity)

Furthermore:   As of March 27, an unidentified disease has killed three people in three days in northeastern Burundi. Symptoms developed by patients suffering from this disease resemble those of Ebola virus disease or Marburg virus disease. According to the Minister of Health, the case in Muyinga tested negative for both Ebola virus and Marburg virus disease. (SOS Media Burundi)

Further infections with H5N1 avian influenza virus continue to be reported in various mammals, including marine mammals in US and UK. Although only a few isolated cases have occurred in humans (through contact with birds), the mammalian infections are being watched closely.

COVID-19 rates continue to be a mixed picture, rising recently in some areas while falling in other regions. Several countries have announced the end of pre-travel COVID-19 testing requirements for travellers from China, including USA, Canada, UK, Japan and Australia. Just over half of global sequences of SARS-CoV-2 are the XBB.1.5 subvariant, while XBB.1.9.1 and XBB.1.9.2 currently make up around 12%. There are some further subvariants (EG.1, XBB.1.16, and XBL) whose significance is not yet clear due to low prevalence so far.

Mpox update fronm WHO is available at https://www.who.int/publications/m/item/multi-country-outbreak-of-mpox--external-situation-report---17---2-march-2023 Since 16 February 2023, there have been just 323 new mpox cases (0.4% increase in total cases) and 11 new related deaths. The latest epidemiological data suggests the outbreak is heading towards an end in the European Region, and slowing down in the Region of the Americas where human-to-human transmission occurs.

Local sources reported another death from Nipah virus in Bangladesh, two weeks after a family member died.

Infectious Diseases

Note that norovirus infections are 66% higher in UK than usual for this time of year according to national surveillance data.  Always a risk of on-board infection.   Some notes on norovirus from “YLE-Your Local Epidemiologist” are here:

1. Norovirus is very infectious. On average, one infected person will infect 2-7 other people…it can live on surfaces for weeks. It’s spread through the fecal to oral route so transmission avenues include: 

• Direct contact.6 in 10 infections are through direct contact, like shaking hands or touching door handles, and then putting your hand in your mouth. 
• Indirectly, like through foods. An infected person can touch food with bare hands that have viral particles on them. You can ingest the food and then get sick.
• Aerosolized. If someone throws up in a toilet, for example, viral particles can become aerosoled after flushing. This isn’t the main route of transmission. 
  
  Three out of four norovirus outbreaks occur in nursing homes. Restaurants and schools follow. Cruise ship outbreaks usually make the news, but only account for 1% of outbreaks.

2. People only need a few viral particles to get sick. Once the virus enters the body, norovirus hijacks your cells and turns them into viral factories. It latches on, specifically, to cells in your gut causing less than wonderful symptoms. Before 2018, we didn’t know why norovirus chose the gut, but a new study found it’s because our gut is home to one rare type of cell (tuft cells). 

3. Third, this virus spreads pre-symptomatically and up to 2 weeks after symptoms resolve. In other words, you can spread it even if you don’t have symptoms. 

In Equatorial Guinea an haemorrhagic fever now confirmed to be Marburg virus has caused at least nine deaths.

Two suspected cases in neighbouring Cameroon proved in fact to be malaria (GPHiN).

Bangladesh has reported 11 cases of Nipah virus and eight associated deaths. This is the largest number of cases since 2015 when 15 cases were reported. The outbreak risk is considered high locally.

COVID-19 Cases and deaths continue falling in China; it is estimated that there are currently ~1.64 million cases per day, ~61% lower than the peak, and ~12,600 deaths per day, 64% lower than peak deaths.  The EU has announced the end to its recommendation for pre-departure testing of travellers from China (Airfinity).

COVID-19 cases are increasing across Europe as well as in North America, Russia, and Indonesia. 

In terms of variants, it is suggested that XBB.1.9.1 is one to watch, growing more rapidly than even XBB.1.5, and circulating widely in Southern Asia and Europe - but still a very low percentage of sequences globally.  (Airfinity).