Abstract:
Background: Tanzania is among Sub-Saharan countries mostly affected by the HIV and AIDS pandemic, females
being more vulnerable than males. HIV infected women appear to have a higher rate of persistent infection by
high risk types of human papillomavirus (HPV) strongly associated with high-grade squamous intraepithelial lesions
(HSIL) and invasive cervical carcinoma. Furthermore, although HIV infection and cervical cancer are major public
health problems, the frequency and HIV/HPV association of cervical cancer and HSIL is not well documented in
Tanzania, thus limiting the development of preventive and therapeutic strategies.
Methods: A prospective unmatched, case-control study of HIV-seropositive, ≥ 18 years of age and consenting nonpregnant
patients attending the care and treatment center (CTC) at Muhimbili National Hoospital (MNH) as cases
was done between 2005 and 2006. HIV seronegative, non-pregnant and consenting women recruited from the
Cervical Cancer Screening unit (CCSU) at ORCI were used as controls while those who did not consent to study
participation and/or individuals under < 18 years were excluded. Pap smears were collected for routine
cytodiagnosis and P53 immunohistochemistry (IHC). Cervical lesions were classified according to the Modified
Bethesda System.
Results: A total of 170 participants from the two centers were recruited including 50 HIV-seronegative controls
were from the CCSU. Ages ranged from 20-66 years (mean 40.5 years) for cases and 20-69 years (mean 41.6 years)
for controls. The age group 36-45 years was the most affected by HIV (39.2%, n = 47). Cervicitis, squamous
intraepithelial lesions (SIL) and carcinoma constituted 28.3% (n = 34), 38.3% (n = 46) and 5.8% (n = 7) respectively
among cases, and 28% (n = 14), 34% (n = 17) and 2% (n = 1) for controls, although this was not statistically
significant (P-value = 0.61). IHC showed that p53 was not detectable in HPV + Pap smears and cell blocks
indicating possible degradation.
Conclusions: The frequency of SIL and carcinoma appeared to be higher among HIV-infected women on HAART
compared to seronegative controls and as expected increased with age. HIV seropositive patients appeared to
present earlier with SIL compared to those HIV seronegative suggesting a role of HIV in altering the natural history
of HPV infection and cervical lesions. The absence of p53 immunoreactivity in HPV + lesions is indicative of the
ability of HPV E6 proteins to interact with the tumor suppressor gene and pave way for viral-induced oncogenesis
in the studied Tanzanian women.
