The nature of Ebola

While we are all focused on malaria reduction with the national efforts to fumigate nearly all houses in Kigali City to reduce the spread of malaria, the World Health Organisation (WHO) issued a statement confirming the latest Ebola outbreak in the Democratic Republic of Congo, which we have lost sight of its pressing threats.

Tuesday, September 25, 2007

While we are all focused on malaria reduction with the national efforts to fumigate nearly all houses in Kigali City to reduce the spread of malaria, the World Health Organisation (WHO) issued a statement confirming the latest Ebola outbreak in the Democratic Republic of Congo, which we have lost sight of its pressing threats.

Ebola is an acute infectious and hemorrhagic viral fever which first appeared in 1972 in the then Zaire, but it was not identified until later cases appeared in 1976.

Of most recent there have been reports that Ebola has re-appeared in the DRC and efforts to curb the infection is underway.

However the possibility to cross to neighbouring countries including ours remains a main concern. Ebola have got many subtypes of which Ebola Zaire is the most dangerous and contagious probably than all other forms.

The disease may kill nearly 90% of all infected persons in a very short period; in fact Ebola comes like waves from the jungle.” In other words, it is like a tide and comes in, kills and goes out thus ending the outbreak.

It is well known that the virus has a wide geographic distribution in which monkeys are a significant factor--not as a reservoir, but possibly as a host species to an as-yet unknown arthropod vector.  

Studies have shown that 10% of all African monkeys tested carry Ebola antibodies, meaning that they have been in contact with the virus at one time or another. 

However, because the virus is as pathogenic (able to cause diseases) in nonhuman primates as it is in humans, it is highly unlikely that monkeys themselves are a reservoir.  

It is speculated that persistent mammalian infection may help maintain the virus in nature, but that the natural reservoir is more likely to be a long-lived arthropod associated with the monkeys.

Secondary spread of the disease is via contact with infected persons or contact with blood, secretions, or excretions of infected persons.  

Infection via contact during the incubation period is rare but nosocomial (hospital aquired infection) transmission is extremely dangerous.  

In all epidemics, nosocomial transmission, via contaminated syringes or needles, has been found to be responsible for a significant number of deaths.

Ebola viruses can persist in injection equipment, multidose medicine vials, or in dried material, also it continue to be shed in the patient’s semen or other body fluids for 3 or 4 months after symptoms has disappeared.  

The exact mechanism of how Ebola viruses invade the body is unknown but all that is known is that it involves the heart, blood vessels, stomach, intestine, liver, lymphoid organs, and kidneys, causing haemorrhaging and in many cases, organ failure thus leading to sudden deaths.

Sudden onset of fever and malaise, with extreme prostration and weight loss, other subsequent symptoms include: sore throat, chest pain, abdominal pain, skin rash, and diarrhoea.

The patient’s blood fails to clot, and patients may begin to bleed from needle/injection sites as well as into the skin and stomach, intestines, and other internal organs. Excessive effusions from internal organs occur, followed by pulmonary interstitial edema and renal dysfunction.

Some patients become jaundiced.  About 15% of patients experience hiccups when infected with Ebola Zaire; 38% develop bleeding.  Within 7 to 10 days, patients who will survive begin to recover.  

Recovery can take 5 weeks or more, and is marked by prostration, weight loss, and amnesia for the period of acute illness.

Patients who are at greatest risk of dying experience generalized or extensive haemorrhage into the skin, mucous membranes, and internal organs, including the cavities of the stomach and intestines.  

Swelling of the spleen, lymph nodes, kidneys, and brain occurs. In addition, there is usually evidence of interstitial pneumonia and sometimes of pancreatitis and inflammation in the eyes.  

By the end of the first week of acute symptoms, the patient can bleed freely from the eyes, ears, and nose. Patients begin to vomit a black "sludge” of blood and disintegrated internal organs.  

Capillary leakage results in vascular collapse. Patients experience coma and convulsions, followed by respiratory distress, and finally death.

Health workers must have the capability to perform diagnostic tests and be ready to employ practical viral hemorrhagic fever isolation precautions, or barrier nursing techniques.

These techniques include the wearing of protective clothing, such as masks, gloves, gowns, and goggles; the use of infection-control measures, including complete equipment sterilization; and the isolation of Ebola patients from contact with unprotected persons.

The aim of all these techniques is to avoid any person’s contact with the blood or secretions of any patient. If a patient with Ebola dies, it is equally important that direct contact with the body of the deceased patient be prevented.

The writer is an Anesthesist at facyal Hospital