1 cases of suspected transient HIV infection among 1,562 infants exposed to HIV in the birth process. (The others did not become infected.) The cases came from five large multi-center trials across the country. In all 43 cases, blood tests had originally shown evidence of HIV infection on one or more occasions, but later tests did not find evidence of HIV-1.

The researchers re-analyzed the infant specimens that had tested positive for HIV-1 and the mothers' specimens. They performed tests to study the genetic code in the babies' and mothers' specimens, to determine whether the virus in the baby's specimen was related to the mother's virus. "The test results in the case where both the mother and baby were positive and later showed no evidence of infection showed that none of their five specimens with HIV-1 had viruses that were related," said Frenkel. "These viruses looked genetically different enough that they did not come from the same source. Also, one of the viruses was a known strain used in laboratories."

In 20 of the other 41 cases, the researchers could not find the envelope gene -- the outside coating of the virus used to evaluate the relatedness of the genes -- which suggested that the patients' specimens had become contaminated with HIV-1 in the laboratory.

In another six cases, they found there was a mix-up in the specimens, since the infant's human gene markers did not match the gene markers found in two or more of the same infant's other virus-negative specimens.

Where they did find envelope virus in the infant specimen, they analyzed the gene sequence of the envelope virus and compared it with that of the mother. In 17 cases, they showed that the envelope virus in the child's specimen was not related to the envelope virus in the mother.

"Our hypothesis was that transient infection could occur," Frenkel said. "By using a rigorous genetic standard in examining all the supposed cases we could find fr
'"/>

Contact: Laurie McHale
lmchale@u.washington.edu
(206) 543-3620
University of Washington
14-May-1998

Page: 1 2 3
Related biology news :

1. Researchers determine genetic cause of Timothy syndrome
2. Researchers find color sensitive atomic switch in bacteria
3. Researchers identify protein promoting vascular tumor growth
4. Researchers devise potent new tools to curb ivory poaching
5. Researchers create nanotubes that change colors, form nanocarpet and kill bacteria
6. Researchers ID chlorophyll-regulating gene
7. Researchers develop fast track way to discover how cells are regulated
8. Researchers identify distinctive signature for metastatic prostate cancer
9. Researchers report new gene test for isolated cleft lip and palate
10. Researchers discover why mutant gene causes colon cancer
11. Researchers identify the genomes controlling elements