HIV/AIDS Newsroom: September 6, 2000
Marginal Structural Models to Estimate the Causal Effect of Zidovudine on the Survival of HIV-Positive Men
Epidemiology 09/00 Vol. 11, No. 5, P. 561; Hernan, Miguel Angel; Brumback, Babette; Robins, James M. Between 1984 and 1991, the Multicenter AIDS Cohort Study enrolled more than 5,600 gay and bisexual men who had no prior AIDS-defining illness from four major metropolitan areas. The study focused on the 2,178 men who attended at least one visit between visits 5 and 21 while infected and who were not taking antiretroviral drugs when the research began. The cohort of HIV-positive men was given zidovudine for treatment during the study. The researchers used a marginal structural Cox proportional hazards model to assess survival and the effects of zidovudine on the subjects. Standard statistical methods, they note, "are not appropriate when there exists time-dependent confounding by variables, such as CD4 count, that are affected by previous exposure." After the follow-up, for which the median duration was 69 months, 1,296 men had started zidovudine and 750 had died. The researchers determined that the crude mortality rate ratio for zidovudine was 3.6, indicating the presence of confounding. The mortality rate ratio for zidovudine was 0.7, after controlling for baseline CD4 count and other factors using standard methods.
Dr. Anne De Groot, a professor at Brown University, is on a mission to prevent the spread of HIV and tuberculosis (TB). Her start-up firm EpiVax uses computer technology to look through genetic material to create a vaccine. Her goal is not personal wealth, but to help fight disease. Each year, 1.9 million people die from TB and 2.3 million die from AIDS, according to the World Health Organization. Using a grant from the Rhode Island Center for Cellular Medicine, De Groot hopes to come up with a vaccine faster using computerized algorithms. EpiVax has contracts with companies that use her algorithms, and De Groot applies for grants continuously. EpiVax and the TB/HIV Research Lab at Brown, which De Groot heads, recently formed a nonprofit partnership to provide an AIDS vaccine at "little or no cost," and the researchers hope to have a vaccine in clinical tests within five years.
Women in developing countries are at a much greater risk of dying from improper medical care during pregnancy and delivery than women in industrialized nations, according to a report from the International Federation of Gynecology and Obstetrics (FIGO). The report shows that women in developing nations receive poor healthcare, as women's sexuality contains a stigma, along with poverty and lack of education to create little access to preventive care. In Africa, for example, women are much more likely than men to contract HIV, and prostitution and cultural norms that make sexual decision making for most women difficult only increase that risk, noted the World Bank's Anne Tinker, who contributed to the report. Dr. Shirish Sheth, FIGO's new president, said that women's health has improved in a few places, but the changes are slow to come.
The director general of the World Health Organization (WHO), Gro Harlem Brundtland, said Tuesday that with continued growth in the base number of infections, India is increasingly vulnerable to HIV. "Although India and the South Asian region are not hit to the same extent as African countries, the curse is unfolding and millions of people are at risk," Brundtland said, emphasizing the need to use condoms. Over 3.5 million Indians have been infected with HIV, according to official Indian statistics. India's Health Minister C.P. Thakur said the government is taking preventive measures. Thakur also noted that a reduction in drug prices for AIDS would help a program to prevent vertical HIV transmission.
The World Health Organization (WHO) and South Asian Association for Regional Cooperation (SAARC) have signed an agreement to promote collaboration on such health issues as malaria, tuberculosis, and AIDS. The signing of the five-year agreement was set to coincide with the 18th meeting of health ministers from the WHO's South-East Asia Region (SEAR). The agreement outlines an understanding for the countries to fight health problems and promote research. Noting that 16 percent of the world's HIV infections are in SEAR, the regional countries asked the WHO to work the World Trade Organization and the pharmaceutical industry to try to further lower the prices of antiretroviral treatments.
South Africa's deputy foreign minister praised Thailand on Tuesday for its success in stemming the spread of HIV. Aziz Pahad, in Thailand to boost trade and investment relations between the two nations, noted that Thailand's achievements could be used as the basis for similar HIV prevention efforts in his country. The two nations reportedly also discussed exchanging health officials as part of the effort. According to the World Health Organization and other groups, there are an estimated 1,600 to 1,700 new HIV infections in South Africa every day.
According to a report in the Johannesburg Star newspaper, about 20 percent of South Africa's registered nurses are HIV-positive. The paper quoted Dr. Annette van der Merwe of the Hospital Association of South Africa, who also told participants at a medical conference on Monday that over 50 percent of first-year nursing students at a nursing school in Guateng province have HIV. Another participant, Eileen Brannigan of the Netcare hospital group, said the healthcare industry was being significantly affected by AIDS. "We are sitting with nurses who are dying now and the student are even worse off," she said.
Kenyan health official Dr. Fred Owino recently said that counseling and training prostitutes has helped fight HIV in Kisumu municipality. "Through counseling and training, we have noticed that most sex workers no longer charge more money for unprotected sex. They now insist that you either use a condom or you [leave]," Dr. Owino said. Dr. Owino made the comments at the graduation of 50 Trainers of Trainers at a five-day training and counseling course run by a local nongovernmental organization, the Muhoroni AIDS Awareness and Counseling Services. The group is working to increase AIDS awareness among the region's factory workers, many of whom do not work near their spouses. This article was provided by U.S. Centers for Disease Control and Prevention. It is a part of the publication CDC HIV/Hepatitis/STD/TB Prevention News Update. |
|