Stabilization of HIV incidence in women of reproductive age in southern Mozambique.

INTRODUCTION: The collection of incidence data on HIV infection is necessary to evaluate the status and dynamics of the epidemic and the effectiveness of intervention strategies. However, this is usually difficult in low-income countries. METHODS: Five yearly point HIV prevalence estimations (in 1999, 2003, 2004, 2005 and 2008) were obtained for women between 15 and 45 years of age participating in three studies carried out for other purposes at the Antenatal Clinic (ANC) in Manhiça, Mozambique. HIV incidence was estimated between prevalence points using a previously validated methodology. Two methods were used, one based on mortality rates for three HIV epidemic scenarios, and the other based on survival information after infection. The pattern over time was captured by fitting a log-regression model. RESULTS: The prevalence of HIV infection ranged from 12% in 1999 to 49% in 2008. The HIV incidence increased from approximately 3.5 cases per 100 person-years in 2001 to 14 per 100 person-years in 2004, with stabilization thereafter to levels of around 12 cases per 100 person-years. The incidence estimates were comparable for the two methods used. CONCLUSION: These findings indicate an increase in the prevalence and incidence of HIV infection among women of reproductive age over the 9 years of the analysis, with a plateau in the incidence of infection since 2005. However, the very high figures for both prevalence and incidence highlight the importance of the continuation of the prevention and treatment programmes that already exist, and suggest that implementation of preventive measures is needed in this area.

Distribution of hepatitis E virus infection and its prevalence in pigs on commercial farms in Spain.

A survey to detect antibodies against hepatitis E virus (HEV) was undertaken on 41 Spanish pig farms using an indirect enzyme-linked immunosorbent assay (ELISA). Forty of the farms (97.6%) were positive for anti-HEV IgG antibodies, while 34/41 (82.9%) had IgM positive animals. The highest proportion of IgG positive pigs comprised the adult sows (45/74, 60.8%; P=0.01), followed by young piglets aged 3-6 weeks (79/218, 36.2%). IgM positive pigs were more frequently found to be those animals > or = 12 weeks of age (P<0.001). In a second part of the study, the age distribution of the infection on one HEV infected farm was studied by combining the ELISA test with reverse transcription polymerase chain reaction (RT-PCR). On this farm, viraemia was mostly detected in animals aged 8-12 weeks and faecal shedding of HEV was detected in pigs of the same age. All HEV sequences corresponded to genotype 3. The study confirmed that HEV is spread in pigs in Spain and is probably endemic in many farms.

Association of hepatitis E virus (HEV) and postweaning multisystemic wasting syndrome (PMWS) with lesions of hepatitis in pigs.

The aim of the study was to determine the presence of swine hepatitis E virus (HEV) RNA and antibodies in postweaning multisystemic wasting syndrome-affected (n=114) and non-affected (n=46) pigs and the possible association with hepatitis lesions. Forty-four pigs were RT-PCR positive (28.2%); 25 of them were PMWS cases, while 19 were non-PMWS pigs. In both groups, HEV RT-PCR results were associated with hepatitis (OR=5.61 for PMWS-affected pigs and OR=5.17 for non-PMWS affected pigs; p=0.01). No interaction was detected in a logistic regression between PMWS occurrence and HEV infection for the development of hepatitis lesions. Seropositivity to HEV was more likely to occur in pigs with hepatitis (51.9%) compared to pigs without hepatitis (36.1%; p=0.03). Significant differences in optical densities were notices comparing the lesional stage of pigs (p=0.009). While pigs with slight or moderate hepatitis were seropositive, pigs with more severe lesions were seronegative to HEV. These results indicate that swine HEV infection can be a significant contributor to the development of moderate hepatitis in pigs regardless of the PMWS status.