34 research outputs found
Suche nach hochenergetischen Neutrinos kosmichen Ursprungs mit dem Baikal-Neutrinoteleskop
Suche nach hochenergetischen Neutrinos kosmischen Ursprungs mit dem Baikal-Neutrinoteleskop
The Baikal Neutrino Telescope was projected for the detection of high energy cosmic neutrinos. The main purpose of the present work was to develop an effective algorithm for the reconstruction of muon-neutrino tracks in the Baikal detector. (MSA)Available from TIB Hannover: RR 4482(95-02) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman
Assessment of exposure to Vibrio in shellfish consumed in Abidjan, CĂ´te d'Ivoire
The consumption of shellfish contaminated with Vibrio spp. is a cause of serious food borne diseases
(FBD) and a concern in Abidjan where shellfish are mostly purchased on informal markets. This study
assessed the risk of exposure to Vibrio spp. via the consumption of shellfish in Abidjan using stochastic
modelling. Parameters were derived from 3 studies: Vibrio spp. prevalence in shellfish (n=322) at markets,
household survey (n=120) and focus group discussions (n=8) on consumers’ practices. Both non-parametric
bootstrapping and parametric distributions were used to represent uncertainty. The model was implemented
in ModelRisk, using Monte Carlo simulation with 5,000 iterations. The incidence rate of consumption of
shellfish contaminated by Vibrio spp. at the time of purchase was 5 per person year [90% CI=2.7; 7.3].
The prevalence of Vibrio spp. in shrimp and crab were 10.5% and 6.9%, respectively. The main parameter
influencing the exposure was Vibrio spp. prevalence in crab, followed by the daily rate of consumption of
shellfish. Shellfish consumption was daily for 11.7% of households, occasional for 45.8% and rare for 42.5%.
Hazard and risk characterization are ongoing to estimate the risk of FBD associated with the consumption
of contaminated shellfish. Results from the household survey showed that 7.5% of respondents reported
symptoms of food poisoning. Shellfish are consumed boiled (96.7%) or fried (3.3%); reported cooking times
varied from 5-15 min (6.8%) to more than an hour (64.2%). Although shellfish cooking practices seem to
limit the risk of FBD, findings from focus group discussions suggest cross-contamination of vegetables and
other food items consumed raw might happen
Risk for Vibrio and Paragonimus infections linked to shellfish consumption in Côte d’Ivoire
Background: Due to their living environment, shellfish can be contaminated with
infectious agents such as Vibrio and Paragonimus which cause Vibrio infection and
paragonimiasis, two neglected tropical diseases. The symptoms of paragonimiasis and
tuberculosis (TB) are similar, differential diagnosis is therefore necessary for appropriate
patient treatment. The objective of this study was to determine whether paragonimiasis
and Vibrio infections occur in the south of Côte d’Ivoire, and investigate transmission
factors so as to better assess the risk to consumers. Methods: Two cross-sectional
surveys were carried out in 2009 and 2010 in 332 patients attending two tuberculosis
centres of Abidjan and in 269 schoolchildren of two primary schools in Dabou. Sputum
and stools samples were analysed to identify Paragonimus and intestinal parasite
eggs. A questionnaire on food consumption habits was administered to patients and
schoolchildren. A third survey on the consumption of crustaceans was conducted on
120 randomly selected households in Abidjan. Also, 594 shellfish were purchased from
markets in Abidjan and Dabou and 272 were examined for Paragonimus and 322 for
Vibrio species. Results: The prevalence of trematode metacercariae in shellfish was
11.8%. The prevalence of Vibrio was 7.8 %. Twenty five Vibrio strains were isolated
and their average concentration was 6.26 Log UFC per gram of shellfish. No human
case of paragonimiasis was diagnosed in attendants of TB centres and schoolchildren.
Among 278 patients in TB centres, 62 had TB, with a higher prevalence amongst males
(28.8% vs. 13.9% in females, p = 0.003).The result of 216 patients with negative results
to TB diagnostic tests calls for more in-depth studies to elucidate the aetiology of their
chronic cough. In the school survey, the prevalence of helminths and intestinal protozoa
was 22.3% and 48.8%, respectively. Boys had significantly higher levels of infection.
Households consumed shellfish boiled (96.7%) or fried (3.3%). Cooking times reported
by respondents were as follows: over an hour in 64.2% of households, 45 to 60 min
in 21.7% of cases, 5 to 15 min in 6.8% of households, and between 15 to 45 min in
the remaining cases. In addition, 11.7% of households consumed shellfish every day,
45.8% consumed them occasionally and 42.5% rarely. Seven point five percent (7.5%)
households had sometimes observed symptoms of food poisoning associated with
the consumption of shellfish as porridge. Information collected suggests that crosscontamination
of vegetables and other food purchased or prepared at the same time as
shellfish might happen. Trematode metacercariae, V. alginolyticus, V. parahaemolyticus
and V. cholerae were present in shellfish consumed regularly by humans. Summary:
Shellfish preparation practices seem to prevent infection in humans. Changes of
practices constitute a major risk factor for transmission. People should cook shellfish
well before consumption. They should avoid buying dead crabs. They should also avoid
mixing crab with vegetables and lettuce during transport from market and store them
separately in the refrigerator
Risk of vibrio transmission linked to the consumption of crustaceans in coastal towns of CĂ´te d'Ivoire
The purpose of this study was to assess the risk of Vibrio spp. transmission from crustaceans to humans in two coastal towns of Cote d'Ivoire. Bacteriologic analysis was performed on 322 crustacean samples obtained from six markets in Abidjan and one in Dabou. Suspected Vibrio colonies were identified by morphological, cultural, biochemical, and molecular tests and matrixassisted laser desorption ionization-time-of-flight mass spectrometry. PCR assays were used to further characterize Vibrio strains. A survey on consumption of crustaceans was conducted among 120 randomly selected households in Abidjan. Overall, Vibrio spp. were isolated from 7.8% of the crustacean samples studied, at levels as high as 6.3 log CFU/g. Of the Vibrio strains identified, 40% were V. alginolyticus, 36% were V. parahaemolyticus, and 24% were nontoxigenic V. cholerae; the latter two species can cause mild to severe forms of seafood-associated gastroenteritis. Among interviewed households, 11.7% reported daily consumption of crustaceans, confirming the high probability of exposure of human population to Vibrio spp., and 7.5% reported symptoms of food poisoning after consumption of crustaceans. The absence of genes encoding major virulence factors in the studied strains, i.e., cholera toxin (ctxA and ctxB) in V. cholerae and thermostable direct hemolysin (tdh) and thermostable direct hemolysin-related hemolysin (trh) in V. parahaemolyticus, does not exclude the possibility of exposure to pathogenic strains. However, human infections are not common because most households (96.7%) boil crustaceans, usually for at least 45 min (85.9% of households) before consumptio
Risk of <I>Vibrio</I> Transmission Linked to the Consumption of Crustaceans in Coastal Towns of CĂ´te d'Ivoire
The purpose of this study was to assess the risk of Vibrio spp. transmission from crustaceans to humans in two coastal towns of Cote d'Ivoire. Bacteriologic analysis was performed on 322 crustacean samples obtained from six markets in Abidjan and one in Dabou. Suspected Vibrio colonies were identified by morphological, cultural, biochemical, and molecular tests and matrixassisted laser desorption ionization-time-of-flight mass spectrometry. PCR assays were used to further characterize Vibrio strains. A survey on consumption of crustaceans was conducted among 120 randomly selected households in Abidjan. Overall, Vibrio spp. were isolated from 7.8% of the crustacean samples studied, at levels as high as 6.3 log CFU/g. Of the Vibrio strains identified, 40% were V. alginolyticus, 36% were V. parahaemolyticus, and 24% were nontoxigenic V. cholerae; the latter two species can cause mild to severe forms of seafood-associated gastroenteritis. Among interviewed households, 11.7% reported daily consumption of crustaceans, confirming the high probability of exposure of human population to Vibrio spp., and 7.5% reported symptoms of food poisoning after consumption of crustaceans. The absence of genes encoding major virulence factors in the studied strains, i.e., cholera toxin (ctxA and ctxB) in V. cholerae and thermostable direct hemolysin (tdh) and thermostable direct hemolysin-related hemolysin (trh) in V. parahaemolyticus, does not exclude the possibility of exposure to pathogenic strains. However, human infections are not common because most households (96.7%) boil crustaceans, usually for at least 45 min (85.9% of households) before consumptio