This 41:32 minute Discovery Channel documentary describes outbreaks of an emerging disease and the team of scientists who travel around the world to investigate the transmission of the Nipah virus. Students see how the steps of epidemiological investigations play out in the real world, find out how teams of scientists work through problems, and understand the worldwide efforts that solve disease outbreaks.
- At the beginning of the video, Dr. John Epstein from the Consortium for Conservation Medicine at the Wildlife Trust, comments that “we have seen more emerging disease in the past decade than we saw in the previous 80-90 years. We have to think of the whole world as a single place now”. Why does Dr. Epstein say that?
Because we are more globally connected now and disease can get around the world quickly before it can be contained.
- In what country is Dr. Epstein at the beginning of the video? What disease is he studying? What is the mortality rate (death rate) for this disease?
He is in Bangladesh, studying the Nipah virus. It has a 70% mortality rate.
- The Nipah virus was found in fruit-eating bats. What was so alarming about the outbreak in the video?
The virus was first found in bats and jumped to human infections. Then, it was found out that the virus could be transmitted from human to human and that is an even worse situation.
- What is a “super spreader” and how did this affect the outbreak in Bangladesh?
A super spreader is a person who contracts the disease and then spreads it to many people. The super spreader in the Nipah outbreak in Bangladesh was a revered religious leader in the village. Everyone came to see him when he got sick and took care of him. They all got the infection.
- The outbreak of 1998 in Malaysia was traced to large pigs farms that were nearby the rain forests with fruit trees. The bats contaminated the fruit with Nipah-containing saliva and the pigs got sick. The more pigs present, the greater the chance of the virus mutating, and the greater the chances the virus will “jump” to different species. Why didn’t the virus “jump” to people in Malaysia as it did in Bangladesh?
Because officials killed millions of pigs to keep the virus contained.
- Describe what Dr. Epstein does to try to identify the specific transmission method of the Nipah virus in the Bangladesh village.
Dr. Epstein and his team go out at night and set up nets to catch bats; they are looking for bats with live Nipah virus. The bats have a large range, but somehow, the virus keeps spilling over to humans in this village. Dr. Epstein wants to find out why it is occurring in this village and not in the nearby village. He catches bats, tests the bats’ saliva and urine for live Nipah virus, paints their toenails red so he knows not to catch them again, and releases them.
- Dr. Epstein says bats are amazing animals. They are responsible for pollinating about one-half of the rain forest. They also carry disease, but it is not the wildlife causing the disease. The bats have been there for a long time and only recently have been carriers of disease. What changed?
The way people change the environment and the way people interact with the environment has changed and has suddenly allowed a disease that was only in bats to become a human disease.
- The video describes the SARS (Severe Acute Respiratory Syndrome) outbreak that started in China in 2002. How did a super-spreader infect so many people?
The SARS outbreak started in China and was later tracked to a large open wildlife food market. A professor fleeing the outbreak in China took an airplane to Hong Kong and stopped at a hotel. Twenty percent of the passengers on the plane were infected and many more were infected in Hong Kong. In just days, over 400 people were infected and 43 had died. Efforts by the World Health Organization, the U.S. Centers for Disease Control and Prevention (CDC) stopped the outbreak before it reached pandemic proportions, but not before it appeared in several other countries, including Canada.
- What did Dr. Epstein find out was causing the Nipah outbreak in the Bangladesh village?
Both the villagers and the bats like date palm tree sap and many local farmers earned extra money by harvesting data palm juice. They attached clay pots to trees, cut into the trees, and let the sap from the trees flow into the pot. People drink the fresh sap.
Bats also like to drink the sap and farmers would often see the bats in their trees. The bats drink directly from the pots and contaminate the sap with Nipah virus in their saliva. People then drink the Nipah-contaminated sap and become infected.
If this were true, more infections would occur in the fall and winter when the sap runs and harvesting occurs. This was the case which was confirmed when the scientists took infrared images at night showing bats drinking from the pots.
- Dr. Steven Luby, “point man” for the CDC in Bangladesh, heads the Bangladesh Disease Unit. Why is Dr. Luby so concerned about a new strain of the avian flu?
He is concerned because this new strain has the potential for even more devastating effects than the Nipah virus. Fifty percent of people infected with the new strain have died. Bangladesh’s population is so dense and highly populated that the killing disease could spread quickly.
- How did they solve the problem of the bats contaminating the sap pots?
Villagers made mats out of native materials to keep the bats from eating from the pots.