Infective endocarditis (IE) results from bacterial or fungal infection and is associated with significant morbidity and mortality. Several known risk factors exist for endocarditis, and 90% of pediatric cases have an underlying structural or congenital heart disease or prosthetic heart valve. Literature on IE in previously healthy children is relatively sparse, and the pathogenesis and underlying risk factors remain mostly unknown. Our patient was a 3-year-old male with a unique presentation of IE. His lack of structural and congenital risk factors for endocarditis prompted further workup, and labs were consistent with insufficient immunoglobulin, suggesting a primary immunodeficiency (PAD). PAD presents as heightened susceptibility to infections, commonly seen as recurrent pneumonia, meningitis, septic arthritis, and otitis media. Pediatric patients commonly have infections, yet as many as in 1 in 2000 patients have PAD. Our case emphasizes the potential need for further investigation into PAD in a young patient with no known risk factors who develops an uncommon infection such as IE.

Research on the influence of different architectural styles and ventilation systems on mite allergen levels is crucial to decrease mite allergen exposures in houses. The purpose of this study was to examine the seasonal changes in mite allergen (Der 1) levels on the floors and mattresses of houses with different architectural styles and ventilation systems. METHODS: Thirty-one families, without considering the families' histories of allergies, participated in this study. Written consent was obtained from all the families. All 31 families lived in Hamamatsu-city, Japan. Dust samples were monthly collected from the floors of the living rooms and mattresses in the bedrooms from March 2019 to February 2020. Mite allergen Der 1 (Der f 1 and Der p 1) levels were measured using sandwich ELISA. The air temperature and relative humidity in each house were measured using hygrothermography. RESULTS: Ten families lived in detached houses with balanced ventilation (group A), 10 families lived in detached houses with exhaustonly ventilation (group B), and 11 families lived in concrete apartment buildings with exhaust-only ventilation (group C). All groups showed significant seasonal changes in mean monthly temperature and relative humidity. Group A showed significantly lower mean monthly relative humidity than other groups. Group A showed significantly lower levels of Der 1 in mattress dust than other groups. CONCLUSIONS: Different architectural styles and ventilation systems may have some influence on mite allergen levels and could possibly be modified to decrease mite allergen exposure in houses.

Millions of illnesses, hospitalizations, and deaths are prevented by vaccination worldwide. This discussion examines vaccine safety concerns from the past several decades of immunization research. Both immunologic and non-immunologic side effects are reviewed, and clarification is provided regarding some highly-publicized myths regarding vaccine safety.

A seven year follow-up of immune parameters is reported for a patient with chronic immune thrombocytopenic purpura (ITP) pre and post human immunodeficiency virus (HIV) seroconversion. Therapies such as intravenous IgG, prednisone, vincristine, or Ciclosporin A had no clear-cut beneficial effect on platelet counts. A long-term normalization of platelet counts was achieved by splenectomy. At splenectomy the patient was seropositive for HIV, most likely transmitted by blood products received half a year prior to laparatomy. Mean plasma levels of the second component of complement, C2, were half of the normal values prior to and within the lowest normal range post HIV seroconversion. Nevertheless, the T cell-dependent B cell response to HIV, which is dependent on the activation of C3 via the classical pathway of complement, was normal: Western blot analysis of total IgG and of IgG subclass responses to individual HIV antigens proved to be unimpaired.

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