Evaluating a neonatal intensive care unit MRSA surveillance programme using agent-based network modelling.

BACKGROUND: Surveillance for meticillin-resistant Staphylococcus aureus (MRSA) in neonatal intensive care units (NICUs) is a commonplace infection prevention strategy, yet the optimal frequency with which to monitor the unit is unknown. AIM: To compare various surveillance frequencies using simulation modelling. METHODS: One hundred NICU networks of 52 infants were simulated over a six-month period to assess MRSA transmission. Unit-wide surveillance occurred every N weeks where N={1,2,3,4}, and was compared with the current NICU policy of dynamic surveillance (i.e. weekly when at least one positive screen, otherwise every three weeks). For each surveillance period, colonized infants received a decolonization regimen (56% effective) and were moved to isolation rooms, if available. FINDINGS: As the surveillance frequency increased, the mean number of MRSA-colonized infants decreased, from a high of 2.9 (four-weekly monitoring) to a low of 0.6 (weekly monitoring) detected per episode. The mean duration of colonization decreased from 307 h (four-weekly monitoring) to 61 h (weekly monitoring). Meanwhile, the availability of isolation rooms followed an inverse relationship: as surveillance frequency increased, the availability of isolation rooms decreased (61% isolation success rate for four-weekly monitoring vs 49% success rate for weekly monitoring). The dynamic policy performed similar to a biweekly programme. CONCLUSIONS: An effective MRSA surveillance programme needs to balance resource availability with potential for harm due to longer colonization periods and opportunity for development of invasive disease. While more frequent monitoring led to greater use of a decolonization regimen, it also reduced the likelihood of isolation rooms being available.

Factors associated with recent HIV testing among men who have sex with men in New York City.

Understanding factors associated with recent HIV testing among men who have sex with men (MSM) is important for designing interventions to increase testing rates and link cases to care. A cross-sectional study of MSM was conducted in NYC in 2011 using venue-based sampling. Associations between HIV testing in the past 12 months and relevant variables were examined through the estimation of prevalence ratios (PR) and 95 % confidence intervals (CI). Of 448 participants, 107 (23.9 %) had not been tested in the past 12 months. Factors independently associated with not testing in the previous 12 months were: lack of a visit to a healthcare provider in the past 12 months (aPR: 2.5; 95 % CI: 1.9, 3.2); age ≥30 (adjusted PR: 1.9; 95 % CI: 1.4, 2.7); not having completed a bachelor's degree (aPR: 1.6; 95 % CI: 1.0, 2.4); and non-gay sexual identity (aPR: 1.4; 95 % CI: 1.0, 1.8); such MSM may be less aware of the need for frequent HIV testing.

Herpes simplex virus type 2 associated with HIV infection among New York heterosexuals living in high-risk areas.

Herpes simplex virus type 2 (HSV-2) has been shown to increase the risk of sexual human immunodeficiency virus (HIV) transmission. A matched case-control design was used to examine the association between HSV-2 and HIV infection among heterosexuals in 'high-risk areas' (HRAs) in New York City (NYC). We identified NYC HRAs using HIV surveillance data on heterosexual-related adult HIV diagnoses and USA census data on household poverty. Heterosexuals who were socially or geographically linked to an HRA were recruited using respondent-driven sampling. HIV prevalence was 8.6% and HSV-2 prevalence was 80.1%. Only 6% of HIV-positives knew they were infected. HIV-positive cases were matched to HIV-negative controls on gender, race/ethnicity and age, and tested for antibody to HSV-2. In a multivariate model, HIV infection was associated with HSV-2 infection (adjusted odds ratio [AOR] = 3.5, 95% confidence interval 1.1-11.7) and non-HSV-related sexually transmitted infection diagnosis in the previous year (AOR = 2.6, 1.1-6.2). Effective approaches to HIV risk reduction for individuals with HSV-2 remain uncertain, and these are urgently needed in high-risk communities where multiple social, behavioural and biological factors that facilitate HIV infection coexist.