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The Red Sea zooplankton distribution pattern is characterized by a decreasing gradient in species numbers from the south to north while biomass and abundance of small-sized copepods decrease from the epipelagic zone of the southern Red Sea to the central-northern area. In the northern Red Sea, the seasonal abundance of the total zooplankton standing crop showed two peaks. The highest peak was observed in autumn with a maximum of 4990 ind/m3 in November, while the small peak was recorded during late spring-early summer, attaining a maximum (4300 ind/m3) in July. The diversity of oceanic zooplankton species in the Red Sea is relatively poor compared to other tropical seas and the number of oceanic species decreases with depth and toward the Gulfs of Suez and Aqaba. Species composition and abundance of demersal zooplankton differed considerably between the reef substrates. The highest mean density of zooplankton emerged from the living coral area (daily average: 4983 ind/m2), while the lowest mean density emerged from sand substrates (daily average: 938 ind/m2). The total number of demersal zooplankton that emerged from the coral patch was significantly higher than from sand or rubble areas. The emerged zooplankton was significantly higher in night-hours (2251 ind/m2) than in day-hours (286 ind/m2) over any substrate in the studied areas. Seasonally, the demersal zooplankton increased during summer with the maximum averages of 493 ind/m2 and 3813 ind/m2 during day and night, respectively. The minimum abundance of demersal zooplankton was recorded during autumn with the lowest values in October. Copepods were the most abundant group of all catches, accounting for 58.7% of the total demersal zooplankton abundance. The presence of copepod larval stages (nauplii and copepodites) all the year round indicated the continuous reproduction of copepods throughout the year. A total of 34 zooplankton species could be identified from the emergence trap fixed on different substrates (i.e., living corals, rubble and sand).

Tuberculosis infection represents a global health problem and a great risk to health care workers. The detection and treatment of latent tuberculosis infection is a key strategy in the control of tuberculosis. The aim of this study was to estimate the usefulness of QuantiFERON-TB Gold In-Tube test which is an interferon-gamma release assay for the detection of latent tuberculosis infection, in a group of Egyptian Health Care Workers in comparison to the tuberculin skin test. A total of 100 Health Care Workers were enrolled. Subjects diagnosed as latent tuberculosis infection by tuberculin were 88% as compared to 36% by quantiferon. Higher tuberculin positive results were associated with direct contact to tuberculosis patients and job categories as physicians and nurses, while higher quantiferon positive results were associated with longer duration of employment and absence of BCG vaccination. The overall agreement between the two tests was poor (k=0.109). The negative discordant results (quantiferon negative/tuberculin positive) were 53% and were found among both contacts and non contact group, which could reflect high number of false positive tuberculin skin test. These data suggest that using IFN-γ method to screen new entrant health care workers for latent tuberculosis infection in our population could be more helpful because it is more specific for detecting latent tuberculosis infection compared to tuberculin skin test. Key words: Tuberculin, gamma-interferon, health care, latent infection.