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close this bookHIV in Pregnancy: A Review (UNAIDS, 1999, 67 p.)
close this folderSECTION A : HIV IN PREGNANCY
close this folderSusceptibility of women to HIV infection
View the document(introduction...)
View the documentBiological factors
View the documentSocio-cultural factors

Biological factors

The rate of transmission of HIV from male to female is two to three times higher than that from female to male27,28. The Langerhans' cells of the cervix may provide a portal of entry for HIV and it has been suggested that some HIV serotypes may have higher affinity for these, and therefore to be more efficient in heterosexual transmission29.

Vulval and vaginal inflammation or ulceration may facilitate entry of the virus. Sexually transmitted infections (STI) are common in many African countries, where HIV prevalence is also high30,31,32. Inadequately treated or "silent" chlamydial and other sexually transmitted infections may act as co-factors for HIV infection and transmission33,34,35,36,37,38. Syphilis rates as high as 30% have been described in antenatal women39,40 and 4.2% of women in a population based study in the United Republic of Tanzania reported a history of genital ulceration41, which has been well established as a co-factor for HIV acquisition42,43,44. In Zimbabwe, women reporting a history of genital ulceration and pelvic inflammatory disease were six times more likely to be HIV-positive45. Improved STI treatment in a randomized controlled trial in the United Republic of Tanzania was shown to reduce the rate of new HIV infections46. Other non-sexually transmitted cervical lesions, such as schistosomiasis, may also facilitate HIV infection47. Although the evidence is still inconclusive, associations between oral and injectable contraceptive use and increased HIV risk have been reported48,49.