This is the VOA Special English Development Report.
Two new discoveries could offer easier ways to identify infectious diseases in developing countries.
The first involves sheep. Researchers have found that hair sheep are a good source of blood for use in tests to diagnose infectious diseases in people.
In developed countries, microbiologists do these tests with blood from wool sheep or horses. But for developing countries, that costs too much. So tests often use human blood instead.
Ellen Yeh from the Stanford University School of Medicine in California was one of the authors of the study. She explains the problems with using human blood:
First of all, there is a risk of HIV or other infectious disease from handling human blood. The other big problem with using human blood for making what are called blood agar plates is that they are not accurate. The results may be wrong.
The study found that blood from hair sheep is an excellent substitute. It produced the same results as tests using wool sheep and horses. Also, hair sheep require less care than wool sheep. They could better handle hot, dry climates because they do not have a lot of wool.
It also means they do not need to be sheared.
Doctor Yeh says having to shear the sheep for wool is very costly and labor intensive. Another advantage of hair sheep is that they are more resistant to parasites, so they are less at risk of infection.
The scientists also tested an easier, cheaper way to prepare and process the blood. They found this new method effective. The blood can be collected directly into bags, much like with human donors.
The study appeared in July in the online journal PLoS One, from the Public Library of Science.
The same journal also published a report in July on an experimental device called the CellScope. The CellScope is a cell phone microscope. Engineers at the University of California, Berkeley, developed it.
They attached small microscope lenses to a holder fitted to a mobile phone. The phone's camera was able to take color images of malaria parasites and tuberculosis bacteria in blood and sputum. The team used a special dye and special lighting to make the images bright.
The pictures could also be sent wirelessly to distant experts for diagnosis.
Dan Fletcher heads the team that developed the CellScope. He notes that many poor areas of the world have few hospitals, yet have mobile phone networks that are
And that's the VOA Special English Development Report, available online at voaspecialenglish.com.