The epidemiology of pertussis in Germany: past and present

<p>Abstract</p> <p>Background</p> <p>Current and past pertussis epidemiology in the two parts of Germany is compared in the context of different histories of vaccination recommendations and coverage to better understand patterns of disease transmission.</p> <p>Methods</p> <p>Available regional pertussis surveillance and vaccination coverage data, supplemented by a literature search for published surveys as well as official national hospital and mortality statistics, were analyzed in the context of respective vaccination recommendations from 1964 onwards.</p> <p>Results</p> <p>Routine childhood pertussis vaccination was recommended in the German Democratic Republic (GDR) from 1964 and in former West German states (FWG) from 1969, but withdrawn from 1974–1991 in FWG. Pertussis incidence declined to <1 case/100.000 inhabitants in GDR prior to reunification in 1991, while in FWG, where pertussis was not notifiable after 1961, incidence was estimated at 160–180 cases/100.000 inhabitants in the 1970s-1980s. Despite recommendations for universal childhood immunization in 1991, vaccination coverage decreased in former East German States (FEG) and increased only slowly in FWG. After introduction of acellular pertussis vaccines in 1995, vaccination coverage increased markedly among younger children, but remains low in adolescents, especially in FWG, despite introduction of a booster vaccination for 9–17 year olds in 2000. Reported pertussis incidence increased in FEG to 39.3 cases/100.000 inhabitants in 2007, with the proportion of adults increasing from 20% in 1995 to 68% in 2007. From 2004–2007, incidence was highest among 5–14 year-old children, with a high proportion fully vaccinated according to official recommendations, which did not include a preschool booster until 2006. Hospital discharge statistics revealed a ~2-fold higher pertussis morbidity among infants in FWG than FEG.</p> <p>Conclusion</p> <p>The shift in pertussis morbidity to older age groups observed in FEG is similar to reports from other countries with longstanding vaccination programs and suggests that additional booster vaccination may be necessary beyond adolescence. The high proportion of fully vaccinated cases in older children in FEG suggests waning immunity 5–10 years after primary immunisation in infancy. The higher incidence of pertussis hospitalisations in infants suggests a stronger force of infection in FWG than FEG. Nationwide pertussis reporting is required for better evaluation of transmission patterns and vaccination policy in both parts of Germany.</p

Flow microenvironment of two marine peritrich ciliates with ectobiotic chemoautotrophic bacteria

The flow microenvironment of 2 marine peritrich ciliates, Vorticella sp. and Zoothamnium niveum, with ectobiotic sulfur bacteria was studied with frame-by-frame analyses of video sequences and a microsensor for fluid velocity. Both species populate the chemocline above H2Sreleasing mangrove peat. Vorticella sp. moves the surrounding seawater up to a horizontal and vertical distance of at least 400 μm with a maximum flow velocity of 18 mm s–1 close to its peristomial edge. The feather-shaped colonies of Z. niveum generate a unidirectional flow of seawater passing the colony perpendicular to the stalk; the convex side of the feather faces upstream. The flow velocity increased exponentially towards the colony, up to 11 mm s–1 at a distance of 100 μm. Contraction of the stalk forces the zooids of Vorticella sp. and Z. niveum towards the substrate at a high velocity of 71 and 520 mm s–1, respectively. During contraction of Vorticella sp., only little seawater is dragged along towards the surface to which the ciliates are attached whereas the contraction of Z. niveum resulted in a clear increase in the velocity of the seawater both surrounding the colony and above the substrate. Extension of the species proceeds 700 to 1000 times more slowly than contraction, and the surrounding seawater sticks to the cells and therefore is dragged along. The measurements given here support our earlier data indicating the importance of the feeding current for the bacteria-ciliate association, i.e. the cilia beat drives H2S- and O2-containing seawater toward the zooid at high velocity and thus, supports the growth of the ectobiotic sulfide-oxidizing bacteria. Rapid movement, shrinkage (Vorticella sp.) and bunching (Z. niveum) of the zooids during stalk contraction apparently cause sufficient shear stress to abrade ectobiotic bacteria that, once suspended, could enter the feeding currents

Kosten-Nutzen-Anlayse der Malariaprophylaxe bei Keniareisenden mit Mefloquin

With an increasing movement towards cost saving in the health sector, preventive medicine must also be judged according to its economic viability. The fact that prevention can autofinance itself is suggested by the results of a cost/benefit analysis of chemoprophylaxis of Falciparum malaria with Mefloquin among travellers in Kenya. Out of the whole group of travellers analysed by means of an interview-based test (Malpro-Study), the costs in the case of both Switzerland and the Federal German Republic were lower for those people who had undergone Mefloquin-prophylaxis than for those who had not. In this way the prophylaxis not only compensates the required outlay but also results in an overall benefit in macroeconomic terms. Therefore economically based opposition to the prophylaxis of malaria with Mefloquin for short stays in high-risk countries is not justified