Transient lymphopenia and neutropenia: pediatric influenza A/H1N1 infection in a primary hospital in Israel.

BACKGROUND: Pandemic influenza A/H1N1 carries a relatively high morbidity, particularly in young people. Early identification would enable prompt initiation of therapy, thereby improving outcomes. OBJECTIVE: To describe the epidemiological, clinical and laboratory characteristics of children admitted to hospital with the clinical diagnosis of influenza with reference to pandemic influenza A/H1N1. METHODS: We conducted a prospective study of all children aged 16 years or less admitted to the pediatric department with the clinical diagnosis of influenza-like illness from July to October 2009. The presence of A/H1N1 virus was confirmed using real-time reverse transcriptase polymerase chain reaction (RT-PCR) analysis of nasopharyngeal secretions. Positive cases were compared with negative cases concerning epidemiological data, risk factors, clinical presentation and laboratory parameters, with emphasis on changes in the differential blood count. RESULTS: Of the 106 study patients, 53 were positive to influenza A/H1N1 and 53 were negative. In both groups nearly all patients had fever at presentation and approximately two-thirds had both fever and cough. All patients had a mild clinical course, no patient needed to be admitted to the intensive care unit and no mortalities were recorded. Hyperactive airway disease was more common in the A/H1N1-positive group. Pneumonia occurred in 30% of children in both groups. Laboratory findings included early lymphopenia and later neutropenia in theA/H1N1-infected patients. CONCLUSIONS: Leukopenia consisting of lymphopenia and later neutropenia was common in patients with A/H1N1 infection but was not correlated with disease severity or clinical course, which were similar in both groups. However, reduced leukocyte count can be used as an additional criterion for diagnosing A/H1N1 infection until RT-PCR results are available.

[Tuberculosis in a pair of twins--the use of molecular biology methods for the detection of the source of infection].

Tuberculosis is still one of the most prevalent infectious diseases worldwide with a high annual morbidity and mortality rate. Its mode of spread necessitates prompt investigation to identify those with active disease, possible carriers and as many contacts as possible. This article describes a pair of twins with endobronchial tuberculosis following close contact with a family relative who had active disease. Mycobacterium tuberculosis was isolated from the family relative and the two children. Laboratory diagnosis of the mycobacterial strain and epidemiologic follow-up were performed using a molecular biology tool, the restriction fragment length polymorphism method. Treatment was successful due to the close cooperation between the medical staff of the hospitals, the community clinics and the Center for Diagnosis and Treatment of Tuberculosis. Treatment was administered by the directly observed therapy (DOT) method recommended by the World Health Organization. This article describes the clinical course and treatment of the patients and reviews the new molecular biology methods currently being used for the diagnosis of tuberculosis and their important clinical applications.