A map depicting the estimated number of adults and children living with HIV in sub-Saharan Africa in 2009, according to the 2010 Global Report by UNAIDS/WHO.
MEDIA GALLERY

ENGINEERING REDEFINED: COMPASSION

Compassion for people living with HIV and AIDS leads to better diagnosis.

Of the 33.4 million people in the world now coping with HIV, two-thirds live in sub-Saharan Africa. And more than 14 million children in the region, according to UNAIDS, have lost one or both parents to AIDS.

For Xuanhong Cheng, an assistant professor of materials science and engineering, one statistic stands out. More than 400,000 children each year are infected with HIV. The vast majority contract the virus through mother-to-child transmission, a phenomenon that occurs during pregnancy, labor, childbirth or breastfeeding. Preventing or decreasing the likelihood of mother-to-child transmission is a top priority of global health organizations.

HIV testing and diagnosis are critical to this effort. But in Kenya, for example, an estimated 83 percent of the people with HIV remain undiagnosed because of the lack of resources in hospitals and clinics. To help overcome the shortage of facilities and staff in outlying areas, as well as difficulties in transportation, health officials are seeking to develop point-of-care diagnostics that eliminate the need to send blood samples and other specimens to laboratories for analysis. The goal is twofold: to determine if a child is infected with HIV and to monitor the progress of the disease, thus helping a doctor decide what level or type of treatment is necessary.

Cheng is part of a research team that has developed a hand-held point-of-care diagnostic device that monitors the progression of HIV by measuring the concentration of lymphocytes—a type of white blood cell—that possess a CD4 receptor on their surface in a droplet of blood. This CD4-counting device that Cheng helped develop is now being made commercially by Daktari Diagnostics Inc.

To gain a better understanding of the conditions faced by African healthcare professionals, Cheng went on a weeklong fact-finding mission to Kenya, where there are several different grades of health facility ranging from major National Referral Hospitals to local healthcare centers and dispensaries. The larger and better-equipped hospitals are situated near urban centers. In rural areas, patients have access only to small healthcare centers, dispensaries and mobile clinics, many of which do not have a full-time resident doctor. Other challenges, such as a lack of equipment, ventilation and stable electricity have serious implications for use of the device.

Funding for healthcare systems in Kenya has not increased for several years, and hospitals are lucky if they have 60 percent of the required staff. Money for even the most basic of diagnostic testing is limited. All funding for point-of-care diagnostics would have to be obtained from outside charitable agencies.

Despite these challenges, says Cheng, the healthcare workers she met were dedicated, often working long hours. She says her visit made her even more determined to play a part in improving their level of healthcare. She is now working on a second hand-held point-of-care diagnostic device that will measure the concentration of HIV virus particles present in a blood sample.