The HIV epidemic in Italy

The implementation of surveillance systems for HIV and of large cohort studies have allowed for the construction of models that more accurately describe the HIV epidemic. This review focuses on changes in the epidemiological pattern, and the effect of changes in behaviour and of antiretroviral therapy.     

COVID-19 epidemic control approach in Italy

正1. Diffusion of pathogens and globalization The diffusion of health risks in a globalized world is characterized by an exponential increase of transmission opportunities requiring more important and extensive control and prevention measures against possible impact on public health and agro-zootechnics production. Various keywords in this global situation are: diffusion     

Phylogenetic analysis of rubella virus isolated during a period of epidemic transmission in Italy, 1991-1997

To study the molecular epidemiology of rubella virus during endemic transmission, phylogenetic analysis of the nucleotide sequence of the E1 gene was done with 31 isolates collected in northern Italy during 1991-1997, a period spanning 3 epidemics. The viruses segregated into distinct genotypic strains. Cocirculation of genotypic strains was detected; however, each epidemic was associated with specific strains, and strain displacement occurred concomitantly with each epidemic. Although most of the viruses from Italy belonged to rubella genotype I and many were related to viruses isolated concurrently in other European countries, 3 viruses belonged to rubella genotype II, which previously had been isolated only in Asia. Thus, intercontinental importation of viruses also occurred.     

The impact of the HIV epidemic on tuberculosis control programmes in developing countries.

Worldwide, approximately 1.7 billion persons are infected with M. tuberculosis, and 5 million with HIV. In developing countries, a strong association exists between the 2 pathogens, with 14-30% of AIDS patients having tuberculosis (TB), and 12-60% of TB patients HIV-seropositive (HIV+). TB is one of the most frequent opportunistic infection in AIDS, and is a common way for AIDS to present. Evidence suggests that most TB cases in HIV+ patients are due to the endogenous reactivation of past TB infection instead of from new exogenous infection. Particular cause for concern exists in developing countries where approximately 1/2 of the population aged 20-40 years is infected with TB. While 10% of HIV-individuals may develop TB over their lifetimes, HIV+ individuals are at far greater risk of developing the disease. The paper discusses diagnosis, chemoprophylaxis, and treatment of TB. To help stymie major increases in TB patients as HIV spreads across populations with high prevalence of TB, the authors recommend offering HIV testing and counseling to all patients, including TB in the differential diagnoses of all pulmonary diseases in HIV+ patients, offering BCG vaccination to every nonsymptomatic AIDS newborn in countries with high levels of TB infection, routinely obtaining mycobacterial stains and cultures on specimens from HIV+ patients with respiratory symptoms, making clinicians aware of the many false negative tuberculin tests and atypical radiographic patterns in advanced HIV infection, offering 12 months of isoniazid chemoprophylaxis to those HIV+, treating HIV patients with TB with isoniazid, rifampicin, and 1 or 2 of pyrazinamide, ethambutol, or streptomycin during the 1st 2 months, and making health workers aware of infection risks from doing tuberculin tests and injecting streptomycin.     

Risk factors for the sexual transmission of genital herpes.

OBJECTIVE: To determine the risk of sexual transmission of genital herpes simplex virus (HSV) in heterosexual couples. DESIGN: Prospective study of couples who were participants in a clinical trial. Each source partner had symptomatic, recurrent genital HSV, and each susceptible partner was without serologic or clinical evidence of genital herpes. Couples were followed for a median of 334 days. SETTING: Two university-based research clinics. PATIENTS: One hundred forty-four heterosexual couples were studied out of an initial enrollment of 214 couples. MAIN OUTCOME MEASURES: Development of culture-proven HSV infection or type-specific antibodies in the susceptible partner. MAIN RESULTS: Transmission occurred in 14 (9.7%) couples, including 11 (16.9%) of 65 couples with male and 3 (3.8%) of 79 with female source partners (P = 0.05). The annual rate of acquisition was higher (31.8%) in susceptible female partners who lacked antibodies to either HSV type 1 or 2 at entry compared with females with HSV type 1 antibodies at entry (9.1%). Couples avoiding transmission of HSV reported fewer days with genital lesions in source partners. Detailed histories were available at the time of transmission in 13 couples. In nine couples, transmission occurred when the source partner was reported to be asymptomatic and in four, it resulted from sexual contact at the time of prodrome (1 case) or within hours before lesions were first noticed by the source partner (3 cases). CONCLUSIONS: Despite clear recognition of genital herpes in source partners, there was substantial risk for transmission; in 70% of patients, transmission appeared to result from sexual contact during periods of asymptomatic viral shedding. The risk for acquisition of HSV was higher in women than men, and previous HSV type 1 infection appeared to reduce the risk for acquisition of HSV type 2 infection among women.     

The sexual behaviour of bisexual men in relation to HIV transmission.

Relatively little is known about the behaviour of bisexual men which may help in assessing their role in HIV transmission. A sample of 60 behaviourally bisexual men were asked about their sexual behaviour with male and female partners and their perceptions of risk of HIV infection. Only a minority of men engaged in unprotected anal sex with their male partners while two thirds had unprotected vaginal sex with their female partners. This asymmetrical pattern of sexual behaviour reflects a differential perception of risk of HIV infection with male and female partners. A quarter of the men had unprotected penetrative sex with both male and female partners in the previous year. The pattern of risk behaviour varied amongst men living in gay, heterosexual or bisexual contexts.     

Bacterial vaginosis in lesbians: evidence for lack of sexual transmission.

The effect of non-heterosexual factors on the vaginal flora has been studied. Ninety-one lesbians attending a specialist genitourinary medicine service for lesbians were studied. Bacterial vaginosis (BV) was diagnosed in 51.6% of them. While most of the women had previously had a male sexual partner, the presence of BV was not associated with a male sexual partner in the previous 12 months. A detailed analysis of lesbian sexual practices in the group did not relate BV to any sexual practice which would have the propensity to pass vaginal secretions from one to the other.     

The Chikungunya epidemic in Italy and its repercussion on the blood system

Background

The Chikungunya virus (CHIKV) is transmitted by Aedes mosquitoes and recently caused a massive epidemic on La Réunion Island, in the Indian Ocean. Between July and September 2007 it caused the first autochthonous epidemic outbreak in Europe, in the Region of Emilia-Romagna in the north-east of Italy.

Materials and Methods

After the first reports of an unusually high number of patients with a febrile illness of unknown origin in two contiguous villages, an outbreak investigation was carried out to identify the primary source of infection, the modes of transmission and the dynamics of the epidemic. An active surveillance system was also implemented. Laboratory diagnosis was performed through serology and polymerase chain reaction (PCR) analysis. Blood donation was discontinued in the areas involved from September to October 2007 and specific precautionary blood safety and self-sufficiency measures were adopted by the regional health and blood authorities and the National Blood Centre. An estimate method to early assess the risk of viraemic blood donations by asymptomatic donors was developed, as a tool for "pragmatic" risk assessment and management, aiming at providing a reliable order of magnitude of the mean risk of CHIKV transmission through blood transfusion.

Results

Two hundred and seventeen cases of CHIKV infection were identified between 4^th July and 28^th September. The disease was fairly mild in most of the cases. The precautionary measures adopted in the blood system caused a considerable reduction of the collection of blood components and of the delivery of plasma to the pharmaceutical industry for contract manufacturing. The estimated risk of CHIKV transmission through blood transfusion peaked in the third week of August.

Conclusion

A CHIKV epidemic poses considerable problems for public health authorities, who not only need good routine programmes of vector control and epidemiological surveillance but also local and national emergency plans to sustain the blood supply, so as to promptly deal with the potentially severe effects of an epidemic outbreak, especially when affected areas locally require a significant blood inventory and at the same time represent a critical resource for other areas depending on external supplies of blood components.     

Epidemiological,clinical and virological characteristics of four cases of monkeypox support transmission through sexual contact,Italy, May 2022

Since May 2022, an outbreak of monkeypox has been ongoing in non-endemic countries. We report four cases in Italy in young adult men reporting condomless sexual intercourse. The patients are in good clinical condition with no need for specific antiviral drugs. Biological samples from seminal fluid were positive for monkeypox viral DNA. For many other viruses found in semen there is no evidence of sexual transmission. The possibility of sexual transmission of monkeypox virus needs to be investigated.     

Recent trends in the HIV epidemic among injecting drug users in Northern Italy, 1993-1999.

OBJECTIVE: To monitor and describe the time trends of the HIV epidemic among intravenous drug users (IDU) attending drug dependence treatment centres (DDTC) in Northern Italy. DESIGN: A cohort of all seronegative IDU attending DDTC in Lombardy between 1993 and 1999; all had been tested for HIV at least twice. Periodic sample interview surveys were done to assess risk behaviours. METHODS: The incidence rates of HIV infection were calculated using the person-year (PY) method and expressed as the number of cases per 1000 PY at risk. Background HIV prevalence was calculated by dividing the number of positive cases by the total number of IDU tested at all DDTC in Lombardy. RESULTS: Between 1993 and 1999, 135 seroconversions occurred in 7945 subjects followed for 19 671 PY, yielding an incidence rate of 6.9/1000 PY. Ninety seroconversions occurred among the 6563 males and 45 seroconversions among 1382 females (incidence rates 5.5 and 14.0, respectively). Among the males, the incidence of HIV was 4.5 in those aged less than 25 years and 5.8 in those aged 25 years or more. Among the females, the corresponding figures were 21.1 and 10.3. HIV prevalence decreased over time, and it was higher among females. Sexual behaviours at risk were more common among females. CONCLUSIONS: The incidence of HIV infection among IDU in Northern Italy was stable between 1993 and 1999. The higher incidence and prevalence among females and the different prevalence of risk behaviours between genders suggest an increasing role of heterosexual transmission.