New SIV strains found among monkeys and chimps in Africa
In the jungle habitat in East Africa, a chimpanzee plays with its troop in the trees, carrying a potential threat to mankind – another virus which might cause human immunodeficiency. The chimp carries a strain of the SIVcpz virus that has not yet jumped from the animal world to humans as several other simian viruses have, leading to the worldwide AIDS epidemic. But as man invades the habitat of the animals and continues to hunt, prepare and eat the animals in the bushmeat marketplace, the risk of another AIDS-like outbreak exists.
That is the prediction of researchers who used molecular techniques to investigate the borderline world of the African bushmeat trade. At the Eighth Annual Retrovirus Conference in Chicago, a French team reported that they had identified 13 different species of monkeys in West Africa that harbored SIVcpz, the virus that is closely related to HIV.
17 percent infected
Dr. Eric Delacorte, of the University of Montpelier, France, took blood samples from various monkey species that were sold as bushmeat as well as blood from animals kept as pets. Laboratory analyses of the viruses in those animals showed that about 17% of the specimens harbored SIVcpz strains – including four strains not seen before.
`‘These data document for the first time that humans are continuously exposed to an unprecedented variety of SIVs through the consumption of bushmeat,’’ Delacorte said.
Mario Santiago, a researcher at the University of Alabama-Birmingham, said that many experts believe that HIV jumped from animals to man a number of times in the past – as evidenced by different strains of the AIDS virus that have been identified in Africa, and now have spread around the world.
Santiago and his colleagues tracked a troop of chimps in East Africa, collecting urine and fecal samples from several chimpanzee families before isolating SIVcpz strains in those animals. Although endangered and legally protected, the chimpanzees are also hunted for food by some African communities.
Continuing threat of infection
Santiago said the findings of his study and those of Delacorte's suggest ‘‘that cross-species transmissions between men and animals are still going on.’’ Scientists theorize that the virus infected humans either through cuts in preparing the meat or bites or scratches from pets.
`‘Although the circumstances, frequencies and routes of zoonotic [animal to human] transmission of primate lentiviruses remain to be determined,’’ Delacorte said, ‘‘surveillance programs using specific tests for the various SIVs may be warranted.’'
A pharmacist on your belt
For patients taking antiretroviral therapy, keeping on the proper schedule can be a daunting task – especially for the many patients who suffer from HIV-related mental impairment. The answer, researchers suggest, might be to carry your pharmacist along with you.
In a pilot program, patients carried a standard tape recorder-sized device on their belts that could alert them to when it was time to take medicines and to answer some questions about their therapies. ‘‘Jerry’’ the pharmacist – a disembodied voice in the Walkman-sized box – was found to be effective in getting patients to adhere to therapy, even if those patients have cognitive defects.
`‘Cognitive problems – especially memory difficulties – affect as many as 30% of patients with HIV’', said Dr. Adriana Andrade, a senior clinical pharmacologist at Johns Hopkins University, Baltimore.
`‘Complex treatment of HIV infection with combinations of drugs are difficult for any patient to comply with,’’ Andrade said in her presentation at the retrovirus conference, ‘‘but it is even more difficult for people who are already having problems with memory and concentration.’'
That's where Jerry comes in. The experimental voice box equipped with flashing lights that tell a patient when to take medication was given to 22 patients with cognitive functioning problems due to HIV infection. Another 21 patients were given standard antiretroviral education information. Both groups took their medication using a system which monitored when they took the pills.
After 6 months, 83% of the standard education group was complying with their medical regime compared with 90% of those using Jerry, officially known as a Disease Management Assistance System.
`‘We wondered if the inner city patients listening to Jerry would heed him,’’ said investigator Dr. Shivaun Celano, a research associate and study coordinator at the Johns Hopkins University School of Medicine's division of general internal medicine.
A question of tone
Celano, who manages the outpatient pharmacy for the Moore (HIV/AIDS) Clinic and is co-chair of the patient education committee for the AIDS service at Johns Hopkins Hospital, said that Jerry's voice sounded like a white, educated male. ‘‘Our clients are mainly from inner cities and we were concerned that some of the patients might be turned off by Jerry's voice,’’ Celano said. ‘‘Some patients mentioned that,’’ said Andrade, ‘‘and we are working to change the voice characteristics. Other patients suggested that a women's voice might be more effective.’'
Although the treatment appeared to be a success, Andrade suggested that a different voice might have bumped the compliance rate even higher. The patients who had access to Jerry, Andrade said, appeared to increase their compliance as the program progressed, climbing from 74% compliance at the 4 week mark to finish at 99% after 24 weeks – averaging 90%. In contrast, the group that was given just education on taking medication, started at 84% compliance and declined over time so that by the end of the study, in week 24, about 69% of patients were adherent. That equaled an 83% overall adherence rate.
`‘This system is great,’’ said Dr. David Ostrow, professor of psychiatry and behavioral neurosciences and director of addiction medicine at Loyola University Chicago, Maywood, Ill. He said he was particularly impressed that the study found patients using the device had better control of circulating virus than other patients after 6 months.
Potential for wider use
Dr Ostrow said that the devices would benefit any patient on a complex medical regime. ‘‘Everybody has problems with these regimens,’’ he said. He said that few similar trials show improvement over the length of time of Andrade's study.
The device beeps and prompts patients when and how to take their medications, some of which have to be taken with meals or at certain times during the day. Andrade said the devices can also be used to test psychomotor skills of patients, allowing doctors to detect signs of improvement or deterioration of mental skills.
CDC aims to identify the unknown infected
Although the level of HIV infection in the USA appears to have reached a plateau, officials at the Centers for Disease Control and Prevention (CDC) are preparing to spend $300 million on a program to identify people infected with the virus.
`‘We believe this program can break the back of the epidemic in the US,’’ said Dr. Rob Janssen, director of the Division of HIV Prevention at the Centers for Disease Control and Prevention (CDC) National Center for HIV, STD and TB Prevention.
`‘About 40 000 new HIV infections occur each year and the goal of the new program is aimed at reducing that infection rate by half. We will be highly targeting HIV testing in neighborhoods, mainly in inner cities, where HIV prevalence is high’’ Janssen said. He noted that recent studies show that as many as two-thirds of high-risk individuals are not aware of their HIV status.
Protect their partners
`Some people will ask, ‘‘What good does it do to know if you are HIV positive or not?’’ But studies have demonstrated that if a person knows he or she is HIV positive then that person will take steps to protect their partners’ Janssen said. ‘‘However, some infected individuals are having problems maintaining safe behavior over the long haul.’'
The program, called SAFE (Serostatus Approach to Fighting the HIV Epidemic) will initially focus on expanding voluntary counseling and testing programs in an attempt to reach all people living with HIV infection, including the estimated 275 000 Americans who are infected, but don't yet know it.
For example, in one presentation at the meeting, CDC epidemiologist Linda Valleroy, found that in a six-city sample of young gay men, aged 23–29 who continued to engage in unprotected sexual acts, only 91 of the 293 men had ever been tested for their HIV status.