Reintroduction failure after negative peanut challenges in children.

BACKGROUND: A negative double-blind placebo-controlled food challenge (DBPCFC) should normally be followed by reintroduction of the food. However, reintroduction fails in a subset of children. The observed reintroduction problems could be due to refusal of the food that long has been avoided, to other behavioural/psychological factors or to false negative DBPCFC outcome. This study analyses the frequency, causes and risk factors for reintroduction failure in children after negative peanut DBPCFC. METHODS: A retrospective study of children with a negative DBPCFC for peanut was performed. During follow-up after DBPCFC, parents were systematically interviewed about the current diet, symptoms and problems during reintroduction, and reactions to peanut after the reintroduction period. Successful reintroduction was defined as eating peanut or products containing peanut as ingredient on a regular basis. RESULTS: Follow-up data were obtained in 103 children with a negative peanut challenge. In 70 (68%) children, reintroduction was successful (54 children tolerated peanut, 16 children tolerated peanut as ingredient). Reintroduction failed in 33 (32%) children. Food refusal (45%) and peanut-related symptoms (33%) were the most reported reasons. Risk factors for reintroduction failure were an elimination diet for more than three other foods (p = 0.019), a long elimination diet for peanut (p = 0.048) and peanut-related symptoms at home (p = 0.002). CONCLUSION: Reintroduction failure is a common problem in children after negative peanut challenge. To guide reintroduction and identify potential peanut-related symptoms at home, careful follow-up after negative DBPCFC is advised. When symptoms occur or persist, food challenge outcome needs to be reconsidered.

[Pre-exposure prophylaxis for the prevention of sexual HIV transmission; new preventative strategy using tenofovir/emtricitabine]. / Pre-expositieprofylaxe van seksuele hiv-transmissie; nieuwe preventiestrategie met tenofovir/emtricitabine.

The Netherlands has approximately 20,000 registered HIV-infected patients. The current HIV prevention policy consisting of condom use and active HIV testing does not effectively mitigate the HIV epidemic in all risk groups. In July of 2012, tenofovir/emtricitabine (TDF/FTC) was approved by the American Food and Drug Administration (FDA) for pre-exposure prophylaxis (PrEP) for long-term use in persons who exhibit frequent risky and unsafe sexual behaviour. With once-daily use and good therapy compliance, TDF/FTC has proved to be effective as PrEP, and few side effects are reported. Drawbacks in the use of TDF/FTC as PrEP are the potential risk of viral resistance and reduced condom use, the relatively high cost and the intensive counselling required. In special cases, long-term PrEP could enhance the current Dutch preventive policy. Further research is needed into the practical feasibility and protective efficacy of the ad hoc use of TDF/FTC as PrEP before a high-risk contact occurs.