Carmen Varela

Emergence of new norovirus variants on spring cruise ships and prediction of winter epidemics.

In June 2006, reported outbreaks of norovirus on cruise ships suddenly increased; 43 outbreaks occurred on 13 vessels. All outbreaks investigated manifested person-to-person transmission. Detection of a point source was impossible because of limited investigation of initial outbreaks and data sharing. The most probable explanation for these outbreaks is increased norovirus activity in the community, which coincided with the emergence of 2 new GGII.4 variant strains in Europe and the Pacific. As in 2002, a new GGII.4 variant detected in the spring and summer corresponded with high norovirus activity in the subsequent winter. Because outbreaks on cruise ships are likely to occur when new variants circulate, an active reporting system could function as an early warning system. Internationally accepted guidelines are needed for reporting, investigating, and controlling norovirus illness on cruise ships in Europe.

An outbreak of Campylobacter jejuni enteritis in a school of Madrid, Spain

An outbreak of gastroenteritis caused by Campylobacter infection was identified in May 2003 in a school in Madrid, Spain. Eighty one cases were identified in a total of 253 people studied. A retrospective cohort study showed that a custard made with ultra high temperature (UHT) milk was associated with illness (RR: 3.15; 95% CI: 1.25-7.93). The custard was probably contaminated with Campylobacter jejuni from a raw chicken prepared a day previously in the same kitchen. Our recommendations were to periodically remind the schools authorities how to act if an outbreak should be suspected, to include the monitoring of a food handlers working day in each environmental investigation in order to detect any risk behaviour; to implement microbiological analysis from the surfaces and utensils of the collective kitchens and improve the sanitary education of food handlers.

Non-imported malaria in non-endemic countries: a review of cases in Spain

Spain declared the elimination of malaria in 1964. In non-endemic areas, the overwhelming majority of malaria cases are acquired abroad, and locally acquired infections are rare events. In Spain, malaria is a statutorily notifiable disease. During these fifty years more than ten thousand malaria cases have been reported, and about 0.8% of them did not have a history of recent travel. In this report, it was carried out a review of the ways in which malaria can be transmitted in non-endemic areas and a short description of the Spanish cases, aggregated by their transmission mechanisms. Four cases contracted malaria by mosquito bites; there were two autochthonous cases and two of “airport malaria”. The other 28 cases were: congenital malaria cases, transfusion-transmitted malaria, post-transplant cases, nosocomial transmission and cases in intravenous drug users. In addition, in 1971 there was an outbreak of 54 cases due to exposure to blood or blood products. So, while malaria usually is an imported disease in non-endemic areas, it should not be excluded in the differential diagnosis of persons who have fever of unknown origin, regardless of their travel history.

Epidemiología descriptiva de meningitis no meningocócicas bacterianas de la provincia de Zaragoza (1999-2004): evaluación de su sistema de vigilancia

Objetivos: Describir las meningitis no meningococicas bacterianas (MnMB) y evaluar el Sistema de Vigilancia Epidemiologica (SVE) en la provincia de Zaragoza entre 1999 y 2004. Metodos: Se utilizo el registro de enfermedades de declaracion obligatoria (EDO) y el conjunto minimo basico de datos (CMBD). Se evaluo el SVE utilizando criterios de los Centers for Disease Control and Prevention, estimando la exhaustividad mediante captura-recaptura. Resultados: Se notificaron 111 casos de MnMB (62,2% en hombres). La edad media fue de 40,7 anos. La mayor proporcion de casos (16,5%) fue en ninos menores de 2 anos. La forma clinica en el 81,1% de los casos fue la meningitis; el 70,3% fue diagnosticada por cultivo. Aparecieron Streptococcus en el 54% de los casos (el 82% por S. pneumoniae), enterobacterias en el 5,4%, Lysteria y Staphylococcus en el 4,5%, Pseudomona aeruginosa en el 1,8%, y Haemophilus influenzae en el 0,9%. La incidencia por 100.000 habitantes fue entre 1,6 en 2004 y 2,6 en 2001. La letalidad fue del 7,3%. La exhaustividad del sistema EDO fue maxima en el ano 2001 (del 84,4%). La exhaustividad conjunta con CMBD fue superior al 85% y la oportunidad fue de 2 dias. La aceptabilidad del sistema fue buena, ya que el 75% de las variables estaban cumplimentadas en el 97% de las encuestas. Conclusiones: Se destaca la relevancia de la evaluacion del SVE en funcion de sus resultados. Las MnMB debidas a S. pneumoniae representan un grupo significativo y su letalidad es elevada. La exhaustividad del SVE en Zaragoza supera el 80%, al considerar EDO y CMBD. La incorporacion del CMBD en la vigilancia facilitaria una aproximacion a la incidencia real de algunas EDO.

Spread of Ebola virus disease based on the density of roads in West Africa

On March 23rd 2014 the World Health Organization announced that a new Ebola outbreak had appeared in West Africa involving three countries. The objective of this study was to show how a road density index (RDI) could be constructed and a study of its association with Ebola cases during the outbreak. The study was carried out at the district level across the affected countries. RDI was calculated by km2 of territory as a proxy for the mobility of the population. To calculate this index, the number of km of road constructed in each district was estimated and subsequently divided by the area of each district expressed in km2. The accumulated incidence of Ebola was calculated per district. A generalised linear model with a Poisson distribution was used. The RDI varied from 0.12 to 0.84 between the districts. An RDI increase of 0.01 indicates a 3% increase in Ebola infection risk (RR is 1.03; CI 1.03-1.04). The density of the road network can influence the increased incidence of Ebola cases in the affected zone. An exhaustive mapping of the area could help the relevant organisations to manage another outbreak in the future and it could help the distribution of resources in an emergency situation.

[Descriptive epidemiology of non-meningococcal bacterial meningitis in the province of Saragossa [Spain] from 1999 to 2004. Evaluation of the Epidemiological Surveillance System].

OBJECTIVES To describe non-meningococcal bacterial meningitis (nMM) and to evaluate the Epidemiological Surveillance System (ESS) in the province of Saragossa (Spain) between 1999 and 2004. METHODS Information was obtained from the register of diseases subject to mandatory reporting and the Minimum Basic Data Set (MBDS). The ESS was evaluated by using the Centers for Disease Control and Prevention (CDC) criteria and by estimating the completeness of the system through the capture-recapture technique. RESULTS 111 cases of nMM were notified (62.2% in males) and the mean age was 40.7 years. The largest proportion of cases (16.5%) occurred in children under 2 years of age. The clinical presentation was meningitis in 81.1%. Diagnosis was through bacterial culture in 70.3%. Streptococcus sp. was found in 54% (82% due to S. pneumoniae), enterobacteria in 5.4%, Listeria and Staphylococcus in 4.5%, Pseudomonas aeruginosa in 1.8%, and Haemophilus influenzae in 0.9%. The incidence rate per 100,000 inhabitants was 1.6 in 2004 and 2.6 in 2001. The case fatality was 7.3%. The completeness of the mandatory reporting system reached a peak in 2004 at 84.4%. The combined completeness of the MBDS and the mandatory reporting system was above 85% and timeliness of reporting was 2 days. The acceptability of the system was high since 75% of all variables were complete in 97% of the questionnaires. CONCLUSION We highlight the importance of evaluation of the ESS, based on its results. nMM due to S. pneumoniae represent an important group of diseases and their case fatality is high. The completeness of the ESS in Saragossa was over 80% when the mandatory reporting system and the MBDS were combined. Incorporating the MBDS into surveillance would facilitate the estimation of the real incidence of various diseases subject to mandatory reporting.

Brote de gastroenteritis en turistas: limitaciones de información y respuesta

Background: We present the results of different studies performed in the investigation of a gastroenteritis outbreak and we describe the difficulties and limitations encountered during its study. Methods: Several analytical studies were designed: one cohort study and one case-control study with different samples sizes. Results: Of the 189 trip participants, 43% answered the questionnaire. Forty-five cases were identified. The factors significantly associated with the disease were: dinner in one of the restaurants of the resort on December 11 in all analytical studies and the excursion to a nearby island in the cohort study. Discussion: The outbreak was confirmed however due to the low response rate and the problems encountered to interview the participants in the trip, it was not possible to identify the route of transmission.Background We present the results of different studies performed in the investigation of a gastroenteritis outbreak and we describe the difficulties and limitations encountered during its study.

Gastroenteritis outbreak in tourists: limitations of information and response.

BACKGROUND We present the results of different studies performed in the investigation of a gastroenteritis outbreak and we describe the difficulties and limitations encountered during its study. METHODS Several analytical studies were designed: one cohort study and one case-control study with different samples sizes. RESULTS Of the 189 trip participants, 43% answered the questionnaire. Forty-five cases were identified. The factors significantly associated with the disease were: dinner in one of the restaurants of the resort on December 11 in all analytical studies and the excursion to a nearby island in the cohort study. DISCUSSION The outbreak was confirmed however due to the low response rate and the problems encountered to interview the participants in the trip, it was not possible to identify the route of transmission.