Effectiveness of mass oral cholera vaccination in Beira, Mozambique.

BACKGROUND: New-generation, orally administered cholera vaccines offer the promise of improved control of cholera in sub-Saharan Africa. However, the high prevalence of human immunodeficiency virus (HIV) infection in many cholera-affected African populations has raised doubts about the level of protection possible with vaccination. We evaluated a mass immunization program with recombinant cholera-toxin B subunit, killed whole-cell (rBS-WC) oral cholera vaccine in Beira, Mozambique, a city where the seroprevalence of HIV is 20 to 30 percent. METHODS: From December 2003 to January 2004, we undertook mass immunization of nonpregnant persons at least two years of age, using a two-dose regimen of rBS-WC vaccine in Esturro, Beira (population 21,818). We then assessed vaccine protection in a case-control study during an outbreak of El Tor Ogawa cholera in Beira between January and May 2004. To estimate the level of vaccine protection, antecedent rates of vaccination were compared between persons with culture-confirmed cholera severe enough to have prompted them to seek treatment and age- and sex-matched neighborhood controls without treated diarrhea. RESULTS: We assessed the effectiveness of the vaccine in 43 persons with cholera and 172 controls. Receipt of one or more doses of rBS-WC vaccine was associated with 78 percent protection (95 percent confidence interval, 39 to 92 percent; P=0.004). The vaccine was equally effective in children younger than five years of age and in older persons. A concurrently conducted case-control study designed to detect bias compared persons with treated, noncholeraic diarrhea and controls without diarrhea in the same population and found no protection associated with receipt of the rBS-WC vaccine. CONCLUSIONS: The rBS-WC vaccine was highly effective against clinically significant cholera in an urban sub-Saharan African population with a high prevalence of HIV infection

Brandaris 128: a rotating-mirror digital camera with 128 frames at 25 Mfps

For studying microbubbles in a medical ultrasound field (ultrasound frequency between 0.5 and 5 MHz) ultra high-speed imaging camera is required. The ultrasound typically lasts 3 - 20 cycles during which the response of the microbubbles can be highly non-linear. The frame rate of such a high-speed camera therefore should exceed 10 million frames per second (Mfps). The number of frames should be sufficient to record the whole process, therefore, more than 100 frames are desirable. In this manuscript we describe a digital ultra high-speed camera system which combines the superior flexibility and sensitivity of CCD detectors with the high number of frames available in rotating mirror cameras. In a standard run the "BRANDARIS 128" camera records a full sequence of 128 digital images at a frame rate of 25 Mfps