Archive for the ‘virus’ Category

The Ebola-Reston virus scare in the Philippines

March 2, 2009

Ebola Hemorrhagic Fever

There was panic and alarm when Ebola virus first emerged as a fatal bleeding disease in Congo (Zaire) in 1978. Similar outbreaks in neighboring countries in Africa occured. Transmitted mainly by body fluids, the acute infection (aka Ebola hemorrhagic fever, EHF) of the Filoviridae family of RNA viruses presented like a typical viral infection— fever, headache, joint and muscle pain, sore throat, and weakness after an incubation of 2 to 21 days. Some manifested with a skin rash, conjunctival injection, diarrhea, vomiting, stomach pain, internal and external bleeding.

There were those who survived and spontaneously recovered, but many with severe infections showed signs of hemorrhage, fluid loss, shock, and eventual death. EHF is feared because it is highly transmissible and carries a high mortality rate.

Reported cases of EHF have been zoonotic infections (animal borne.) A potential agent of bioterrorism, Ebola can present as a nosocomial infection, a disease contracted in hospitals and medical facilities during an outbreak. The exact origin, location, and natural habitat (known as the “natural reservoir”) of Ebola virus aren’t fully known. This makes containment of the infection difficult.

The first 4 of the 5 subtypes of Ebola is known to cause disease in humans: Ebola-Zaire, Ebola-Sudan, Ebola-Ivory Coast and Ebola-Bundibugyo. The virulence and lethality of these viral strains are suggested by World Health Organizations’s (WHO) containment recommendations below. EHF has no known vaccine nor specific cure.

WHO’s containment of Ebola

•Suspected cases should be isolated from other patients and strict barrier nursing techniques implemented.
•Tracing and following up people who may have been exposed to Ebola through close contact with patients are essential.
•All hospital staff should be briefed on the nature of the disease and its transmission routes. Particular emphasis should be placed on ensuring that invasive procedures such as the placing of intravenous lines and the handling of blood, secretions, catheters and suction devices are carried out under strict barrier nursing conditions (biohazard.) Hospital staff should have individual gowns, gloves, masks and goggles. Non-disposable protective equipment must not be reused unless they have been properly disinfected.
•Infection may also spread through contact with the soiled clothing or bed linens from a patient with Ebola. Disinfection is therefore required before handling these items.
•Communities affected by Ebola should make efforts to ensure that the population is well informed, both about the nature of the disease itself and about necessary outbreak containment measures, including burial of the deceased. People who have died from Ebola should be promptly and safely buried. — World Health Organization (WHO)

WHO’s therapy and treatment of Ebola

• Severe cases require intensive supportive care, as patients are frequently dehydrated and in need of intravenous fluids or oral rehydration with solutions containing electrolytes.
• No specific treatment or vaccine is yet available for Ebola haemorrhagic fever. Several potential vaccines are being tested but it could be several years before any is available. A new drug therapy has shown some promise in laboratory studies and is currently being evaluated. But this too will take several years.
• Experimental studies using hyper-immune sera on animals have shown no protection against the disease. —World Health Organization (WHO)

Ebola Reston virus in the Philippines

“In 1989, Reston, an Ebola virus subtype, was isolated in quarantined laboratory cynomolgus monkeys (Macacca fascicularis) in Reston, Virginia, USA. From 1989 to 1996, several outbreaks caused by the Ebola Reston subtype occurred in monkeys imported from the Philippines to the USA (Reston in Virginia, Alice in Texas and Pennsylvania) and to Italy. Investigations traced the source of all Ebola Reston outbreaks to one export facility near Manila in the Philippines, but the mode of contamination of this facility was not determined. Several monkeys died, and at least four people were infected, although none of them suffered clinical illness.”—World Health Organization (WHO)

The Ebola-Reston (ERV,) the fifth subtype of the virus was first found in Philippine monkeys. It has caused disease in primates, but not in humans. Mainly because this that local health authorities seem to be “in control” over the simmering Ebola outbreak that has infected pigs in Pandi, Bulacan.

To make sure the ERV doesn’t spread to the general population, the Philippine government in coordination with the World Health Organization (WHO) is on the process of slaughtering 6,000 infected pigs. So far no person has been reported to have fallen ill of the disease, but there are 6 farm workers and butchers who turned positive for Ebola antibodies. This is surely a cause of concern.

In spite the Department of Health’s (DOH) effort to contain the disease, nobody knows the extent ERV has spread in the country at this time. It is unclear which other animal species harbor the disease agent and need isolation or killing. Philippine health authorities can only speak of what they know—that a number of pigs and some individuals were proven to be positive for antibodies— which means they encountered the virus without suffering signs of illness.

With the potential to mutate and acquire virulence, Ebola-Reston can be transmitted to susceptible hosts and become infective to more animals and humans. Though ERV doesn’t cause disease in healthy individuals, it’s unclear what happens if the virus infects people with weak immunity or those sick of debilitating illnesses. That’s why to avoid epidemics, isolation or euthanasia of infected animals (like in the Avian Flu infection) are high in the list of priorities.

Awareness of the disease is enhanced through step-up public health education. Cleanliness is important. There is heightened watch over the sale of “double-dead” meat that may carry the disease agent. As a precaution, testing for ERV is expanded and export of porcine meat to other countries has been halted.

The strategies to combat ERV is complex and tedious. Despite DOH’s monitoring and vigilance, medical workers have to deal with the challenges of a serious health threat whose outcome is just starting to unravel. The danger of Ebola doesn’t only rest on the Philippines, but on the entire world as well. It’s a global effort that this disease is nipped on the bud. (Photo Credit: [][][][][]/ /KeeAun)=0=