Alternative observational designs to estimate the effectiveness of one dose of oral cholera vaccine in Lusaka, Zambia.

We conducted a matched case-control (MCC), test-negative case-control (TNCC) and case-cohort study in 2016 in Lusaka, Zambia, following a mass vaccination campaign. Confirmed cholera cases served as cases in all three study designs. In the TNCC, control-subjects were cases with negative cholera culture and polymerase chain reaction results. Matched controls by age and sex were selected among neighbours of the confirmed cases in the MCC study. For the case-cohort study, we recruited a cohort of randomly selected individuals living in areas considered at-risk of cholera. We recruited 211 suspected cases (66 confirmed cholera cases and 145 non-cholera diarrhoea cases), 1055 matched controls and a cohort of 921. Adjusted vaccine effectiveness of one dose of oral cholera vaccine (OCV) was 88.9% (95% confidence interval (CI) 42.7-97.8) in the MCC study, 80.2% (95% CI: 16.9-95.3) in the TNCC design and 89.4% (95% CI: 64.6-96.9) in the case-cohort study. Three study designs confirmed the short-term effectiveness of single dose OCV. Major healthcare-seeking behaviour bias did not appear to affect our estimates. Most of the protection among vaccinated individuals could be attributed to the direct effect of the vaccine.

Risk factors for cholera transmission in Haiti during inter-peak periods: insights to improve current control strategies from two case-control studies.

Two community-based density case-control studies were performed to assess risk factors for cholera transmission during inter-peak periods of the ongoing epidemic in two Haitian urban settings, Gonaives and Carrefour. The strongest associations were: close contact with cholera patients (sharing latrines, visiting cholera patients, helping someone with diarrhoea), eating food from street vendors and washing dishes with untreated water. Protective factors were: drinking chlorinated water, receiving prevention messages via television, church or training sessions, and high household socioeconomic level. These findings suggest that, in addition to contaminated water, factors related to direct and indirect inter-human contact play an important role in cholera transmission during inter-peak periods. In order to reduce cholera transmission in Haiti intensive preventive measures such as hygiene promotion and awareness campaigns should be implemented during inter-peak lulls, when prevention activities are typically scaled back.

Viral Load in Spanish HIV patients: trends since the introduction of HAART.

The aim of this study is to describe trends in the percentage of samples with undetectable HIV viral load in Spain after the implementation of HAART. A descriptive observational study of HIV-VL measurements carried out in the microbiology department of the Hospital Clínico Universitario de Valladolid (HCUV) was conducted over a 9-year period (1996-2004). Regarding the trend over the study period, the 30-39 years age group accounted for most of the samples, although the percentage decreased from 65.5% to 59.6% over the study period. In contrast, the 40-49 years group increased from 9.1% to 14.5%. The preponderance of men, with percentages above 70%, was observed during the whole period. Although the purpose of this treatment is to maintain undetectable viral loads, since 1999 more than 60% of nonfirst samples had detectable levels. Based on the results of the VL trend among HIV/AIDS patients observed in this study, a large number of patients maintain elevated detectable VL years after HAART was implemented. Although different factors may be the cause of this and should be delimited in future studies, the phenomenon observed demonstrates the usefulness of monitoring VL and analyzing its time trend to gain further knowledge about the therapeutic results and care of HIV patients as a whole, also serving as the basis for corrective measures.

Is Rotavirus contributing to an increase of diarrhoea in a region of Spain?

Diarrhoeal illnesses are the most frequent of notifiable diseases in Aragon. Physicians notify diarrhoea cases with presumed infectious origin on a weekly basis. Following an increase in 2005-2006, we aimed to identify the responsible organism(s) in order to inform control measures. We described seasonality of diarrhoea notifications for 1998-2004 and 2005-2006. We calculated correlations between diarrhoea notifications and enteric pathogens diagnosed in two Aragonese laboratories, and applied linear regression using coefficients of determination (r2). In 2005-2006 the winter peak of diarrhoea notifications increased from 2494 to 3357 weekly cases (34.6%) and the peak in Rotavirus diagnoses from 15 to 39 weekly cases. The correlation of diarrhoea notifications with Rotavirus was 0.05 in 1998-2004 and 0.42 in 2005-2006. The model for 1998-2004 included Salmonella enterica, Giardia lamblia and Clostridium difficile (r2=0.08) and for 2005-2006 Rotavirus and Astrovirus (r2=0.24). Our results suggest that Rotavirus contributed to the increase of diarrhoea notifications. We recommend determining the disease burden of Rotavirus in order to guide vaccination policies.

Trend and seasonality of tuberculosis in Spain, 1996-2004.

This study aimed to analyse the trend and seasonality of tuberculosis (TB) in Spain over the past decade. Weekly TB incidence was calculated using data from the National Surveillance Network for the period 1996-2004. Secular trends and seasonal components were estimated using time-series analysis (least-squares method and Fourier transformation). A decline in incidence was observed, from 23.4 cases per 100,000 population in 1997 to 15.1 in 2004, and an annual cycle peaking in June was detected. Time-series analyses are necessary for detecting changes in the epidemiological pattern of TB in Spain, and it should be the first step towards the development of a predictive model.

[Evaluation of the appropriateness of stays in a third level hospital]. / Evaluación de la adecuación de las estancias en un hospital de tercer nivel.

BACKGROUND: Appropriateness Evaluation Protocol (AEP) has proved to be a useful tool for reviewing the utilisation of hospital resources. The aim of this article is to determine the proportion of inappropriate admissions and stays, as well as their causes, in patients hospitalised in the Hospital Clínico Universitario de Valladolid (HCUV). MATERIAL AND METHODS: A retrospective, analytical, observational, cohort study. The period of study was one year (2004). A sample of 1,630 admissions was gathered. Case definition, variables of interest and the model of data gathering were carried out in accordance with the AEP. The principal variables were analysed by means of a basal analysis and the possible relations between them. RESULTS: Fifty-four percent of the admissions showed at least one day of inappropriate stay, with the global rate of inappropriateness being 34.17%. Amongst the causes responsible for inappropriateness, 68.9% of admissions showed at least one criterion falling under the responsibility of the doctor or the hospital, and 51.3% were due to delays in the development of study or treatment. CONCLUSIONS: The utilisation of methods of identification of inappropriate use such as AEP show applications both in planning and in hospital management, by making it possible to identify hospital problems causing delays, principally problems of an organisational type, making it possible to develop interventions aimed at reducing inappropriate use.