HIV has been isolated from semen, cervical secretions,lymphocytes, cell-free plasma, cerebrospinal fluid, tears, saliva,urine, and breast milk. This does not mean, however, that thesefluids all transmit infection since the concentration of virus inthem varies considerably. Particularly infectious are semen,blood, and possibly cervical secretions. The commonest mode oftransmission of the virus throughout the world is by sexualintercourse. Whether this is anal or vaginal is unimportant.Other methods of transmission are through the receipt ofinfected blood or blood products, donated organs, and semen.Transmission also occurs through the sharing or reuse ofcontaminated needles by injecting drug users or for therapeuticprocedures, and from mother to child. Transmission frommother to child occurs in utero and also possibly at birth. Finally,the virus is transmitted through breast milk.The virus is not spread by casual or social contact. Healthcare workers can, however, be infected through needlestickinjuries, and skin and mucosal exposure to infected blood orbody fluids. Prospective studies in health care workers sufferingpercutaneous exposure to a known HIV seropositive patientindicate a transmission rate of 0.32%. As of December 1999there have been 96 reported cases of documentedseroconversion after occupational exposure in such workers.
The precautions and risks for such groups are covered indetail in chapter 15. Finally, there is no evidence that the virusis spread by mosquitoes, lice, bed bugs, in swimming pools, orby sharing cups, eating and cooking utensils, toilets, and airspace with an infected individual. Hence, HIV infection andAIDS are not contagious.
The precautions and risks for such groups are covered indetail in chapter 15. Finally, there is no evidence that the virusis spread by mosquitoes, lice, bed bugs, in swimming pools, orby sharing cups, eating and cooking utensils, toilets, and airspace with an infected individual. Hence, HIV infection andAIDS are not contagious.
