The results suggest that HHV8 infection is widespread in Western Sicily. The high seroprevalence in individuals with high risk sexual activity point to the role of sexual behaviour in the transmission of the infection in adults, whereas the detection of antibodies in younger population (under 16 years old) is suggestive of a non-sexual route of transmission, probably occurring during childhood by close personal contact.

HHV-8 is widespread in the general population in Sicily since it was detected in PBMC and semen of heterosexual HIV-negative individuals and is not found only in high-risk groups. The viral load appears to be more elevated in a high-risk population and it may be ascribed to a viral reactivation. The higher incidence rates of KS in Sicily compared with northern Italy and other European countries might be related to the presence of HHV-8 in the general population.

To evaluate whether or not human herpesvirus 8 (HHV8) can be transmitted through a non-sexual route a serological survey was carried out in a group of 51 catholic nuns. The seroprevalence rate and the geometrical mean antibody titre to anti-latent HHV8 antigen were similar in nuns and in a group of 60 women, matched by age, in the general population (27 vs. 24%; 1028 vs. 1575, respectively). Moreover, by using nested polymerase chain reaction (PCR), HHV8 DNA sequences were detected in 7 of 16 (43.8%) saliva and peripheral blood mononuclear cells (PBMC) from patients with classical Kaposi's sarcoma (KS) and in 3 out of 7 (42%) AIDS-KS patients. None of 5 HIV positive persons who did not have KS tested positive for HHV8 DNA. HHV8 DNA sequences were also detected in 2 of 12 (17%) saliva and 1 PBMC sample out of 12 healthy HHV8 positive individuals (age range: 30-80 years old). This paper suggests that non-sexual transmission of HHV8 is operating in our geographical setting and saliva may be a potential source of HHV8 spreading in the general population.

To investigate a new insertion mutation in the protease (PR) gene of human immunodeficiency virus type 1 (HIV-1) in a patient extensively pretreated with antiretroviral drugs, genotypic analyses of plasma-derived viruses were performed by sequencing segments of 1302 nucleotides in the pol gene of HIV-1. Despite optimal compliance to highly active antiretroviral therapy (HAART) the patient showed poor virological success. Nucleotide sequences of retrospective available plasma samples exhibited a previously unknown 3-bp insertion mutation, corresponding to a leucine, between codons 31 and 32 of the PR gene. This kind of mutation appears to be very rare and it does not seem to be associated with any phenotypic resistance profile known so far. It should be noted that the insert mutation, once it appeared, did not revert to the wild-type variant, suggesting that it seems to correspond to a better fitness of the variant viruses.

SUMMARY Kaposi sarcoma (KS) may develop because of incompetent immune responses, both nonspecifically and specifically against the KS-associated herpes virus (KSHV). Peripheral blood mononuclear cells from 15 classic (non-AIDS) KS cases, 13 KSHV seropositives (without KS), and 15 KSHV-seronegative controls were tested for interferon-γ T-cell (Elispot) responses to KSHV-LANA, KSHV-K8.1, and CMV/EBV peptide pools. The forearm and thigh of each participant also was tested for delayed-type hypersensitivity (DTH) against common recall antigens. Groups were compared with Fisher exact test and multinomial logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI). KSHV Elispot response was detected in 10 (67%) classic KS cases, 11 (85%) KSHV seropositives (without KS), and 2 (13%) seronegative controls. All 4 cases with KSHV-LANA responses had current KS lesions, whereas 5 of 6 cases with KSHV-K8.1 responses had no lesions (P=0.048). No case responded to both LANA and K8.1. Compared to seronegative controls, risk for classic KS was inversely related to DTH in the thigh (OR 0.71, 95% CI 0.55–0.94, P=0.01), directly associated with DTH in the forearm (OR 1.35, 95% CI 1.02–1.80, P=0.04), and tended to be increased 5-fold per KSHV Elispot response (OR 5.13, 95% CI 0.86–30.77, P=0.07). Compared to KSHV seropositives (without KS), risk for classic KS, was reduced 5-fold (OR 0.20, CI 0.03–0.77, P=0.04) per KSHV response. CMV/EBV Elispot responses were irrelevant. Deficiency of both KSHV-specific and –nonspecific immunity is associated with classic KS. This may clarify why Kaposi sarcoma responds to immune reconstitution.