Prof. Mohamed Mutocheluh: Marburg and Ebola viruses are siblings

prof mohamed mutocheluh marburg and ebola viruses are siblings
Marburg disease

Recently the word ‘virus’ has become a household name due to the advent of the Covid-19 pandemic.

In 1892 Dmitry Ivanovsky showed that filtered sap from a disease tobacco plant remained infectious to healthy tobacco plants despite having been filtered. Dmitri Ivanovsky was a Russian botanist, the co-discoverer of viruses and one of the founders of virology.

The other co-discoverer was Martinus Willem Beijerinck, a Dutch microbiologist and botanist. Beijerinck is credited with the discovery of viruses, which he called Contagium vivum fluidum and later used the word “virus”, which at that time had the broad meaning “sickening things”

On the 24th of July 2022 the Ghana Health Service reported three confirmed cases of the Marburg Virus Disease (MVD) following test results from the Noguchi Memorial Institute for Medical Research (NMIMR).

A Ghana Health Service press release indicated that all the three cases belong to one family i.e., a man, his wife and their child. The index case (the man), was 26 years old, got ill on the 22nd June 2022 and later bled from the nose and mouth, was admitted to a hospital in the Ashanti Region on the 26th of June 2022 and died 28 hours after admission.

His two-month-old son got ill and was admitted on 17th of July 2022 but died on the third day of admission. However, the wife a 24-year-old female survived and was admitted to a government-designated isolation centre on Tuesday 25th July 2022.

These sequences of events confirm the man as the index case who might have contracted the virus outside and came home to infect his wife and son. Also, the high death rate reported among these individuals epitomises Marburg as a deadly virus.

Currently, the phrase ‘Marburg virus’ is trending not only on social media but on national television and radio stations. Many Ghanaians are hearing of the Marburg virus for the first time and so have been calling for public education to be intensified as part of the prevention and control measures of the MVD.

Marburg and Ebola viruses are siblings belonging to the Filoviridae family. They are subtly distinct from each other but cause clinically similar diseases characterized by haemorrhagic fevers and capillary leakage with high mortality. Ebola virus infection is slightly more virulent (deadly) than Marburg virus infection.

Structurally, they are approximately the same size (~1900 nm long) and appear indistinguishably like Chinese characters under the electron microscope. Both viruses are classified as category A pathogens. Thus, requiring the highest biosafety level 4 containment facility to handle or work with.

Ebola virus is subdivided into five species i.e., Zaire Ebola virus, Sudan Ebola virus, Tai Forest Ebola virus, Bundibugyo Ebola virus and Reston Ebola virus.

Marburg virus, on the other hand, belongs to a single species called Marburg Marburgvirus, which include two distinct viruses, Marburg and Ravn viruses. Both Marburg and Ravn viruses are approximately 20% genetic divergence.

Most previous outbreaks of Marburg and Ebola infections have originated from sub-Saharan Africa. Past outbreaks have been sporadic; they have been contained partly because they have occurred in isolated areas.

Spread to other areas, when it occurs, has usually resulted from travelers returning from affected regions. However, in 1967, a small Marburg haemorrhagic fever outbreak occurred in Germany and Yugoslavia (now Serbia) among laboratory workers who had been exposed to tissues from imported African green monkeys. The virus was named after the city of Marburg, where majority of the 1967 epidemic were documented.

Transmissions of Marburg or Ebola among monkeys, bats and other wild animals is a natural process in the jungle and that sometimes leads to sporadic outbreaks of viral haemorrhagic fevers among the animals. Most index cases involve exposure to these wild animals as people go hunting, mining and farming. Marburg and Ebola outbreaks have been linked to consumption of meat (bush meat) from wild animals in affected areas; especially during the process of preparing infected wild animals.

In December 2013, a large Ebola virus outbreak began in rural Guinea (this was referred to as the West African Ebola virus outbreak) then spread to densely populated urban regions of Guinea and neighbouring Liberia and Sierra Leone. It involved thousands of people and had a case fatality or death rate of approximately 60%. Marburg and Ebola case fatality rate ranges from 20 to 90%.

Filoviruses are highly contagious. During an outbreak, transmission is mainly human-to-human, resulting from close contact with the blood, secretions, other body fluids, or organs of infected people. Burial ceremonies in which the body is washed and in which mourners have physical contact with the deceased have played an important role in transmission of infection.

Symptoms of Marburg and Ebola infections are difficult to distinguish and so a definitive diagnosis can only be made in the laboratory. After an incubation period of 2 to 21 days, fever, muscle aches and headache occur, often with abdominal pain, nausea, and upper respiratory symptoms (cough, chest pain, pharyngitis).

Photophobia (where bright lights hurt one’s eyes), jaundice, and lymphadenopathy (swelling of the bean-shaped glands found in the neck, armpits, chest, groin, and abdomen) also occur. Vomiting and diarrhea may soon follow. Confusion, stupor, and coma may occur, indicating central nervous system involvement.

Haemorrhagic symptoms begin within the first few days and may include uncontrolled bleeding within mucous membranes and orifices. Also, the patient may experience capillary leakage and excess fluid lost resulting in electrolytes imbalance, irregular heartbeat, etc. During the second week of symptoms, the patient may recover or develop multiple organ failure and die.

The same methods are used in the diagnosis of both Marburg and Ebola viruses. Blood and other bodily fluids are collected and transported to specialized high level containment category 4 laboratories. Detection of the viral proteins (antigens) and or genetic material (RNA) are performed.

Treatment of Marburg and Ebola viruses’ infections are largely supportive care i.e., maintenance of blood volume and electrolyte balance etc. Also, the preventive and control measures of both viruses are the same. To prevent spread, symptomatic patients with possible Ebola or Marburg viruses’ infection must be isolated in dedicated containment facilities. Standard intensive care units (ICUs) in public hospitals are not suitable. Special containment facilities provide for total control of fluid effluent and respiratory products.

As part of the response to the current Marburg virus outbreak, the Ghana Health Service tracked approximately 116 people who came into contact with the three MVD cases. They are currently doing well after having completed the compulsory 21-day quarantine and follow up formalities.

The author is convinced that Ghana is very well prepared to contain and stop the current Marburg virus outbreak owing to the significant lessons learnt during the last Ebola outbreak in West Africa and the current Covid-19 pandemic. Importantly, the Covid-19 safety protocols currently being observed by most Ghanaians will play a key role in containing the current Marburg virus outbreak.

Due to climate change, population explosion and environmental degradation the outbreak of deadly infectious agents will become the new normal.

With regards to the current outbreak, the Ghana government should:

(1) start Marburg and Ebola viruses’ surveillance among wild animals in the affected areas of the Ashanti region and neighbouring regions among others;

(2) resource the health care frontline workers in the affected regions with proper personal protective equipment (PPE) and beef up Marburg virus surveillance systems in the communities;

(3) step up public education on Marburg virus in order to curtail the spread of this deadly disease;

(4) supervise the burial of people who die of Marburg virus infection and

(5) prioritise scientific research investment.

Professor Mohamed Mutocheluh, PhD, Associate Professor in the Department of Clinical Microbiology

School of Medicine and Dentistry, KNUST.

Email: [email protected]

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