[Influenza vaccination in the elderly: effectiveness not in doubt]

In a recent review the effectiveness of influenza vaccination in the elderly was brought into question. Selection bias, which would occurr if healthy people were more likely to be vaccinated than their infirm peers, and the use of non-specific outcomes, such as death from all causes, were considered to have contributed to the effectiveness of the vaccine as to morbidity and mortality being overestimated. However, a recent study has shown that even when potential bias and residual confounding were addressed, influenza vaccination was associated with a significant reduction in the risk of influenza-related morbidity and mortality among community-dwelling elderly persons. Direct estimates of influenza-related morbidity were hampered by delayed and insufficiently sensitive diagnostics. Excess studies, however, comparing morbidity and mortality during periods with and without influenza predominance, present reliable indirect estimates in favour of vaccination. While the vaccination rate of high-risk subjects in The Netherlands is traditionally high, the age limit for influenza vaccination was lowered from 65 to 60 in 2008, taking into account influenza-related morbidity and mortality in healthy people aged 60 to 65 years and the undisputed effectiveness of vaccination against influenza.

[Less ventilator-associated pneumonia after oral decontamination with chlorhexidine; a randomised trial]

OBJECTIVE

To determine the effect of oral decontamination with either chlorhexidine (CHX, 2%) or the combination chlorhexidine-colistin (CHX-COL, 2%-2%) on the frequency and the time to onset of ventilator-associated pneumonia in Intensive Care patients.

DESIGN

Double blind, placebo-controlled, multicentre, randomised trial.

METHODS

Consecutive ICU patients needing at least 48 h of mechanical ventilation were enrolled in a randomized trial with 3 arms: CHX, CHX-COL, and placebo (PLAC). The trial medication was administered in the oral cavity every 6 h. Oropharyngeal swabs were obtained daily and analysed quantitatively for Gram-positive and Gram-negative microorganisms. Endotracheal colonisation was monitored twice weekly. Ventilator-associated pneumonia was diagnosed on the basis of a combination of clinical, radiological and microbiological criteria.

RESULTS

Of 385 patients included, 130 received PLAC, 127 CHX and 128 CHX-COL. Baseline characteristics in the three groups were comparable. The daily risk of ventilator-associated pneumonia was reduced in both treatment groups compared to PLAC: 65% (HR= 0.352; 95% CI: 0.160-0.791; p = 0.012) for CHX and 55% (HR= 0.454; 95%/ CI: 0.224-0.925; p = 0.030) for CHX-COL. CHX-COL provided a significant reduction in oropharyngeal colonisation with both Gram-negative and Gram-positive microorganisms, whereas CHX significantly affected only colonisation with Gram-positive microorganisms. There were no differences in the duration of mechanical ventilation, ICU-stay or ICU-survival.

CONCLUSION

Oral decontamination of the oropharyngeal cavity with chlorhexidine or the combination chlorhexidine-colistin reduced the incidence and the time to onset ofventilator-associated pneumonia.

Attitude of Dutch hospital personnel towards influenza vaccination

In 2007, the Dutch Health Council recommended influenza vaccination of all institutional healthcare workers (HCWs). In this questionnaire study largely based on the health belief model we assessed the attitude and intentions of hospital personnel towards such vaccination. We sent out 220 questionnaires to medical personnel and nurses of departments of the University Medical Center Utrecht, The Netherlands. Only one-third of the 112 responders (response rate of 51%) reported a positive intention to comply with the national recommendation. Factors associated with a positive intention were the awareness of a HCW's responsibility not to harm patients, the belief to have a high risk of influenza infection and confidence in vaccine efficacy. Physicians were more likely than nurses and other staff to have a positive intention. Education is needed to convince hospital personnel about influenza vaccination.

No intention to comply with influenza and pneumococcal vaccination: behavioural determinants among smokers and non-smokers

OBJECTIVE

Smoking increases the risk for influenza and pneumococcal disease, but vaccination uptake is lower among smokers than non-smokers. We therefore aimed to determine reasons for not complying with vaccination among smokers and non-smokers.

METHOD

In 2005 a self-administered questionnaire was sent to a random sample of Dutch patients (n=4,000) assessing medical, social and behavioural determinants. Independent factors associated with not complying with influenza and pneumococcal vaccination among smokers and non-smokers were assessed by multivariate logistic regression analysis.

RESULTS

In all, 1,725 of 4,000 patients returned the questionnaire (response rate: 43%), 426 (25%) were smokers. Among smokers self-reported flu vaccine uptake was 42% and among non-smokers 52% among both only 0,2% received both vaccines. Most important predictors of not complying in smokers and non-smokers were patient's beliefs not to be susceptible to disease (odds ratio (OR) 4.0, 95% confidence interval (CI): 2.0, 8.0 and OR 2.8, CI: 2.0, 3.9), finding it difficult to go to the GP for vaccination (OR 2.5, CI: 1.3, 4.8 and OR 1.8, CI: 1.3, 2.6) and being against vaccination (OR 2.4 CI: 1.3, 4.4 and OR 1.8, CI: 1.3, 2.6), respectively.

CONCLUSION

There are no substantial differences in determinants associated with not complying with influenza and pneumococcal vaccination between smokers and non-smokers but there is a trend towards stronger associations in smokers.

Influenza- and respiratory syncytial virus-associated mortality and hospitalisations

The aim of the current study was to estimate influenza- and respiratory syncytial virus (RSV)-associated mortality and hospitalisations, especially the influenza-associated burden among low-risk individuals < or =65 yrs old, not yet recommended for influenza vaccination in many European countries. Retrospectively during 1997-2003, Dutch national all-cause mortality and hospital discharge figures and virus surveillance data were used to estimate annual average influenza- and RSV-associated excess mortality and hospitalisation using rate difference methods. Influenza virus active periods were significantly associated with excess mortality among 50-64-yr-olds and the elderly, but not in younger age categories. Influenza-associated hospitalisation was highest and about equal for 0-1-yr-olds and the elderly, and also significant for low-risk adults. Hospitalisation among children was mostly due to respiratory conditions, and among adults cardiovascular complications were frequent. RSV-active periods were associated with excess mortality and hospitalisation among the elderly. The highest RSV-related excess hospitalisation was found in 0-1-yr-olds. Influenza-associated mortality was demonstrated in 50-64-yr-olds. Among low-risk individuals < or =65 yrs of age, influenza-associated hospitalisation rates were highest for 0-4-yr-olds, but also significant for 5-64-yr-olds. These data may further support extension of recommendations for influenza vaccination to include younger low-risk persons. The respiratory syncytial virus-associated burden was highest for young children but also substantial for the elderly.

A prediction rule for elderly primary-care patients with lower respiratory tract infections

Prognostic scores for lower respiratory tract infections (LRTI) have been mainly derived in a hospital setting. The current authors have developed and validated a prediction rule for the prognosis of acute LRTI in elderly primary-care patients. Data including demographics, medication use, healthcare use and comorbid conditions from 3,166 episodes of patients aged > or =65 yrs visiting the general practitioner (GP) with LRTI were collected. Multiple logistic regression analysis was used to construct a predictive model. The main outcome measure was 30-day hospitalisation or death. The Second Dutch Survey of GPs was used for validation. The following were independent predictors of 30-day hospitalisation or death: increasing age; previous hospitalisation; heart failure; diabetes; use of oral glucocorticoids; previous use of antibiotics; a diagnosis of pneumonia; and exacerbation of chronic obstructive pulmonary disease. A prediction rule based on these variables showed that the outcome increased directly with increasing scores: 3, 10 and 31% for scores of <2 points, 3-6 and > or =7 points, respectively. Corresponding figures for the validation cohort were 3, 11 and 26%, respectively. This simple prediction rule can help the primary-care physician to differentiate between high- and low-risk patients. As a possible consequence, low-risk patients may be suitable for home treatment, whereas high-risk patients might be monitored more closely in a homecare or hospital setting. Future studies should assess whether information on signs and symptoms can further improve this prediction rule.

Application of guidelines on preoperative antibiotic prophylaxis in León, Nicaragua

BACKGROUND

To determine adherence to the guideline for preoperative antibiotic use in Nicaragua.

METHODS

An observational study in the University Hospital of León, Nicaragua. All surgical patients in the departments of general surgery, orthopaedics, gynaecology and obstetrics, and paediatrics during a four-week period were included. Patients with infections prior to surgery were excluded. Main outcome measures were the proportion of patients that received appropriate preoperative antibiotics based on wound classification, suspected pathogens, administered antibiotics (type and dose), therapy duration and timing according to the local protocol.

RESULTS

In the study, 297 patients received a total of 395 antibiotics with 2595 doses for a total of 1087 days. Only 68% of patients received antibiotic prophylaxis for indications mentioned in the protocol. Antibiotics were given without indication or as treatment in 23%. In 9% of the cases no preoperative antibiotic therapy was given (no indication for 6%, but indicated for 3%). Of the 201 patients with an indication for prophylaxis, 25% received more antibiotic therapies than indicated. Antibiotic choice was discordant with the protocol in 69%, dose in 20%, and both the moment of administration and duration in 78%. Overall adherence was achieved in 7% of patients. Complete protocol violations were observed in 12%. The 243 patients in the prophylaxis group received 1707 doses, 83% of which were administered unnecessarily.

CONCLUSION

Protocol violations are frequent in preoperative antibiotic prophylaxis in Nicaragua leading to considerable overprescription. Educational strategies to reinforce protocolised antibiotic use are essential for reducing costs and antibiotic resistance rates.

Modelling the health-economic impact of the next influenza pandemic in The Netherlands

To optimally develop or adjust national contingency plans to respond to the next influenza pandemic, we developed a decision type model and estimated the total health burden and direct medical costs during the next possible influenza pandemic in the Netherlands on the basis of health care burden during a regular epidemic. Using an arithmetic decision tree-type model we took into account population characteristics, varying influenza attack rates, health care consumption according to the Dutch health care model and all-cause mortality. Actual direct medical cost estimates were based on the Dutch guidelines for pharmaco-economic evaluation. In the base-case scenario with no preventive measure available and an average influenza attack rate of 30%, 4,958,188 influenza infections, 1,552,687 GP consultations, 83,515 hospitalizations and 173,396 deaths will take place in The Netherlands. The burden is highest in adults aged 20 to 64 years. If minimizing the total mortality and sustaining highest net economic returns is the objective, this group needs to be targeted in interventions.

Prognostic factors for early clinical failure in patients with severe community-acquired pneumonia

For patients with community-acquired pneumonia (CAP), clinical response during the first days of treatment is predictive of clinical outcome. As risk assessments can improve the efficiency of pneumonia management, a prospective cohort study to assess clinical, biochemical and microbiological predictors of early clinical failure was conducted in patients with severe CAP (pneumonia severity index score of >90 or according to the American Thoracic Society definition). Failure was assessed at day 3 and was defined as death, a need for mechanical ventilation, respiratory rate >25/min, PaO2 <55 mm Hg, oxygen saturation <90%, haemodynamic instability, temperature >38 degrees C or confusion. Of 260 patients, 80 (31%) had early clinical failure, associated mainly with a respiratory rate >25/minute (n = 34), oxygen saturation <90% (n = 28) and confusion (n = 20). In multivariate logistic regression analysis, failure was associated independently with altered mental state (OR 3.19, 95% CI 1.75-5.80), arterial PaH <7.35 mm Hg (OR 4.29, 95% CI 1.53-12.05) and PaO2 <60 mm Hg (OR 1.75, 95% CI 0.97-3.15). A history of heart failure was associated inversely with clinical failure (OR 0.30, 95% CI 0.10-0.96). Patients who failed to respond had a higher 28-day mortality rate and a longer hospital stay. It was concluded that routine clinical and biochemical information can be used to predict early clinical failure in patients with severe CAP.

Aetiology and resistance patterns of community-acquired pneumonia in León, Nicaragua

We conducted a prevalence study to gain greater insight into the aetiology, bacterial resistance and risk factors for community-acquired pneumonia (CAP) in the region of León, Nicaragua. During the period from July 2002 to January 2005, all consecutive patients with signs and symptoms suggestive of CAP were included in the study. Sputum samples, paired serum samples and urinary samples were collected for the detection of respiratory pathogens. The most frequently identified pathogens were Streptococcus pneumoniae (17%), followed by Staphylococcus aureus (5%), Chlamydia pneumoniae (5%) and Mycoplasma pneumoniae (4%). Pseudomonas aeruginosa was cultured from 5% of patients. No pathogens were identified in 55%. All tested S. pneumoniae were sensitive to erythromycin and penicillin. In contrast, resistance of S. aureus to penicillin and erythromycin was high.

Statin treatment and reduced risk of pneumonia in patients with diabetes

BACKGROUND

Recent prognostic studies have shown that previous treatment with statins is associated with a better outcome in patients admitted to hospital with pneumonia. Because of an increased risk of pneumonia in patients with diabetes, we assessed the effects of statin use on the occurrence of pneumonia in adult diabetic patients.

METHODS

All patients with a diagnosis of diabetes (types 1 and 2) enlisted in the UK General Practice Research Database between 1 June 1987 and 21 January 2001 were included. A case-control study was performed with cases defined as patients with a first recorded diagnosis of pneumonia. For each case up to four controls were matched by age, sex, practice, and index date. Patients were classified as current users when the index date was between the start and end date of statin treatment. Conditional multiple logistic regression analysis was used to estimate the strength of the association between statin treatment and the occurrence of pneumonia.

RESULTS

Statins were used in 1.1% of 4719 cases and in 2.1% of 15 322 matched controls (crude odds ratio (OR) 0.51, 95% CI 0.37 to 0.68). After adjusting for potential confounders, treatment with statins was associated with a significant reduction in the risk of pneumonia (adjusted OR 0.49, 95% CI 0.35 to 0.69). The association was consistent among relevant subgroups (cardiovascular diseases, pulmonary diseases) and independent of the use of other prescription drugs.

CONCLUSIONS

The use of statins is associated with a considerable reduction in the risk of pneumonia in diabetic patients. In addition to lowering the risk of cardiovascular disease, statins may be useful in preventing respiratory infections.

Incidence of GP-diagnosed respiratory tract infections according to age, gender and high-risk co-morbidity: the Second Dutch National Survey of General Practice

BACKGROUND

Figures on GP-diagnosed respiratory tract infections (RTI) are outdated because of demographic changes and increase in co-morbid conditions, respiratory vaccination programmes and change in illness behaviour.

OBJECTIVE

To determine the incidence of RTI in patients presenting to the GP according to age, gender and common high-risk co-morbidity in primary care.

METHODS

In the Second Dutch National Survey of General Practice 90 computerized general practices with 358,008 patients recorded all consecutive patient contact by use of the ICPC coding system in a year. Incidences were calculated using the mid-year population in the denominator and RTI episodes as the nominator.

RESULTS

In all, 4.2% of the patient population were diagnosed with RTI with an incidence rate of 144 per 1000 person-years. Upper RTI were more common in children of 0-4 years than in other year-cohorts [392 versus 80 per 1000; relative risk 4.9, 95% confidence interval (95% CI) 4.8-5.0]. An U-shape association was observed between age and lower RTI (78 and 70 per 1000 in children and persons aged 75 years or over, respectively, versus 23 per 1000 in other age-categories). Females had slightly higher incidence rates of URTI (relative risk 1.4, 95% CI 1.35-1.45) and similar rates for LRTI. Patients with chronic medical conditions as pulmonary and cardiac disease, and diabetes.

DISCUSSION

A small proportion of the patient population present themselves to the GP with a RTI. RTI are more common among children, elderly persons and patients with pulmonary and cardiac disease, and diabetes of the ICPC coding system.

Do recommended high-risk adults benefit from a first influenza vaccination?

It is unknown whether a first influenza vaccination protects high-risk adults from severe morbidity and mortality during influenza epidemics. As part of the PRISMA nested case-control study, we aimed to evaluate the effectiveness of first-time and repeat influenza vaccinations in adult persons recommended for vaccination aged between 18 and 64 years during the 1999-2000 influenza A epidemic. After adjustments, 69% of hospitalizations for acute respiratory or cardiovascular disease or death were prevented in first-time vaccinees (95% percent confidence interval [95% CI]: 8-90%). The corresponding figure in persons who were vaccinated before was 85% (95% CI: 36-96%). Adult persons with high-risk medical conditions can substantially benefit from a first and repeat influenza vaccination prior to an epidemic.

[Increased risk of infection in patients with diabetes mellitus type 1 or 2]

OBJECTIVE

To determine the risk of common infections in patients with diabetes mellitus type 1 (DM1) or type 2 (DM2).

DESIGN

Prospective controlled study.

METHODS

In a 12-month prospective cohort study as part of the Second Dutch National Survey of General Practice, 705 adult DM1 and 6,712 DM2 patients were compared with 18,911 control patients who had hypertension without diabetes. Outcome measures were medically-attended episodes of infections of the respiratory tract, urinary tract, skin and mucous membranes. Multivariate and multinomial logistic regression analysis was applied to determine independent risks of infections and their recurrence in patients with diabetes compared to controls.

RESULTS

Upper respiratory-tract infections were as common in diabetes patients as in controls. Diabetes patients had a higher risk of lower respiratory-tract infections (DM2: odds ratio (OR): 1.30; 95% CI: 1.11-1.52), urinary-tract infections (DM1: OR: 1.56; 95% CI: 1.13-2.15; DM2: OR: 1.21; 95% CI: 1.07-1.38), bacterial skin or mucous-membrane infections (DM1: OR: 1.48; 95% CI: 1.01-2.15; DM2: OR: 1.32; 95% CI: 1.13-1.55) and mycotic skin or mucous-membrane infections (DM2: OR: 1.41; 95% CI: 1.24-1.61). The risk of recurrence of these common infections was seen to be increased.

CONCLUSIONS

Patients with type-1 and type-2 diabetes are at increased risk of lower respiratory-tract infections, urinary-tract infections and skin or mucous-membrane infections.

Rationale and design of the prevention of respiratory infections and management in children (PRIMAKid) study: a randomized controlled trial on the effectiveness and costs of combined influenza and pneumococcal vaccination in pre-school children with recurrent respiratory tract infections

Health and economic burden of recurrent respiratory tract infections (RTIs) in early childhood is considerable. A systematic review of licensed influenza and pneumococcal vaccines showed substantial efficacy in children, but the health-economic impact of such vaccines among pre-school children with recurrent RTIs is unknown. We therefore, designed a double-blind randomized controlled trial to determine the effectiveness and costs of a combined influenza and pneumococcal vaccination program among a primary care based cohort of children with recurrent episodes of RTI aged between 18 and 72 months. We will enroll 690 children over three consecutive years (2003--2005) who will be randomly allocated to receive vaccinations against influenza and pneumococcal disease, influenza alone or hepatitis B in a similar schedule. Follow up by parental diaries, tympanic temperature measurements, questionnaires and interviews is planned until May 2006. Primary outcome is number of febrile RTIs. Other outcomes include duration and severity of RTI episodes, medical consumption, safety and costs.

Increased risk of early virological failure in non-European HIV-1-infected patients in a Dutch cohort on highly active antiretroviral therapy

OBJECTIVE

To compare early and late responses to highly active antiretroviral therapy (HAART) in European and non-European HIV-1 infected patients in a Dutch cohort.

METHODS

We retrospectively analysed the response to HAART of 216 previously treatment-naive HIV-1-infected patients using the University Medical Centre Utrecht HIV database. African (n=51), Asian (n=7), and Central/South American (n=6) patients were classified as non-European, and others as European (n=152). Early failure was defined as a viral load that remained above 400 HIV-1 RNA copies/mL after 6 months of treatment with HAART. Late-phase failure was determined in patients who were successfully treated in the early phase and was defined as two consecutive viral load measurements above 400 copies/mL, a new AIDS-defining event or death.

RESULTS

In the early phase, four of 152 (2.6%) European and eight of 64 (12.5%) non-European patients failed HAART. A significant increased risk of virological failure in the early phase of treatment was observed for non-Europeans as compared to Europeans (odds ratio 4.6; 95% confidence interval 1.1-20.2). Low serum drug levels in the absence of resistant virus were often seen at the time of early failure. No difference in late-phase failure was observed between the two groups (adjusted hazard ratio 0.6; 95% confidence interval 0.3-1.2).

CONCLUSIONS

Non-European patients had a 4.6 times higher risk of virological failure than their European counterparts in the first 6 months of treatment with HAART. This failure seemed to be associated with low serum drug levels at the time of failure. However, if HAART was successful in the early phase, response rates in the late phase were similar for Europeans and non-Europeans.

Prognostic factors for serious morbidity and mortality from community-acquired lower respiratory tract infections among the elderly in primary care

BACKGROUND

Uncertainty about the prognosis of lower respiratory tract infections (LRTI) hinders optimal management in primary care.

OBJECTIVE

We determined prognostic factors for a severe complicated course of LRTI among elderly patients in primary care.

METHODS

In a retrospective clinical database study we examined 455 patients with a first LRTI episode; 226 with physician-diagnosed acute bronchitis or lung exacerbations and 229 with pneumonia. Multivariate logistic regression analysis was used to assess independent associations of the potential predictors with the endpoint.

RESULTS

Occurrence of the combined endpoint 30-day home-treated complications from LRTI (4.4%) or hospitalisation (4.6%), or all-cause mortality (5.3%) was 14.3%. In a logistic regression model, increasing age [odds ratio (OR) 1.04; 95% confidence interval (95% CI) 1.00-1.08], male sex (OR 3.12; 95% CI 1.66-5.87), heart failure (OR 5.14; 95% CI 2.33-11.34), stroke or dementia (OR 3.36; 95% CI 1.18-9.58), use of antidepressants or benzodiazepines (OR 1.89; 95% CI 1.02-3.52) and a diagnosis of pneumonia (OR 4.24; 95% CI 2.17-8.28) were independent predictors.

CONCLUSION

GPs need to be aware of readily available prognostic factors that can be used in primary care to complement physical examination and laboratory data in LRTI to guide preventive and therapeutic management decisions.

Negative attitude of highly educated parents and health care workers towards future vaccinations in the Dutch childhood vaccination program

BACKGROUND

It is unknown whether further expansion of the Dutch childhood vaccination program with other vaccines will be accepted and whom should be targeted in educational strategies.

AIM

To determine attitudes of parents towards possible future vaccinations for their children and the behavioural determinants associated with a negative attitude.

DESIGN

Questionnaire study.

METHODS

Parents of children aged between 3 months and 5 years of day-care centres were asked to fill out a questionnaire. Determinants of a negative attitude to comply with possible future vaccinations against example diseases such as pneumonia or influenza, hepatitis B, TBC, smallpox and SARS were assessed using polytomous logistic regression analysis.

RESULTS

Of the 283 respondents, 123 (43%) reported a positive attitude towards all vaccinations, 129 (46%) reported to have a positive attitude to have their child vaccinated against some diseases and 31 (11%) had no intention to comply with any new vaccination. Determinants of a fully negative attitude were a high education of the parent (odds ratio [OR] 3.3, 95% confidence interval [95% CI]: 1.3-8.6), being a health care worker (OR 4.2, 95% CI: 1.4-12.6), absence of religion (OR 2.6, 95% CI: 1.0-6.7), perception of vaccine ineffectiveness (OR 6.9, 95% CI: 2.5-18.9) and the perception that vaccinations cause asthma or allergies (OR 82.4, 95% CI: 8.9-766.8).

CONCLUSION

Modifiable determinants for a negative attitude to comply with new vaccinations are mainly based on lack of specific knowledge. These barriers to vaccinations might be overcome by improving health education in the vaccination program, especially when targeted at educated parents and health care workers.

Increased risk of common infections in patients with type 1 and type 2 diabetes mellitus

BACKGROUND

Clinical data on the association of diabetes mellitus with common infections are virtually lacking, not conclusive, and often biased. We intended to determine the relative risks of common infections in patients with type 1 and type 2 diabetes mellitus (DM1 and DM2, respectively).

METHODS

In a 12-month prospective cohort study conducted as part of the Second Dutch National Survey of General Practice, we compared 705 adult patients who had DM1 and 6712 adult patients who had DM2 with 18,911 control patients who had hypertension without diabetes. Outcome measures were medically attended episodes of infection of the respiratory tract, urinary tract, and skin and mucous membranes. We applied multivariable and polytomous logistic regression analysis to determine independent risks of infections and their recurrences in patients with diabetes, compared with control patients.

RESULTS

Upper respiratory infections were equally common among patients with diabetes and control patients. Patients with diabetes had a greater risk of lower respiratory tract infection (for patients with DM1: adjusted odds ratio [AOR], 1.42 [95% confidence interval {CI}, 0.96-2.08]; for patients with DM2: AOR, 1.32 [95% CI, 1.13-1.53]), urinary tract infection (for patients with DM1: AOR, 1.96 [95% CI, 1.49-2.58]; for patients with DM2: AOR, 1.24 [95% CI, 1.10-1.39]), bacterial skin and mucous membrane infection (for patients with DM1: AOR, 1.59 [95% CI, 1.12-2.24]; for patients with DM2: AOR, 1.33 [95% CI, 1.15-1.54]), and mycotic skin and mucous membrane infection (for patients with DM1: AOR, 1.34 [95% CI, 0.97-1.84]; for patients with DM2: AOR, 1.44 [95% CI, 1.27-1.63]). Risks increased with recurrences of common infections.

CONCLUSIONS

Patients with DM1 and DM2 are at increased risk for lower respiratory tract infection, urinary tract infection, and skin and mucous membrane infection. Studies are warranted into management of such infections in patients with diabetes.

Vaccination of high-risk patients against influenza: impact on primary care contact rates during epidemics. Analysis of routinely collected data

A general practice (GP) based retrospective cohort study was conducted to assess the effects of influenza vaccination on the primary care contact rate during influenza epidemics. Given the rising workload of family physicians, particularly due to ageing of the population, it is very relevant to know to whether influenza vaccination of high-risk patients reduces the contact rate during epidemics. No effect of vaccination was found on the contact rate of GP during a mild epidemic period. During a 'normal' influenza epidemic, the workload was reduced through fewer contacts by patients with cardiovascular or diabetic diseases. Epidemic periods severe enough to show contact rate reduction occurred approximately every other year.

[The increase in pneumonia-related morbidity and mortality among adults in the Netherlands and possible explanations for it]

As seen in several national registration systems, the morbidity and mortality due to pneumonia-related disease has increased in the Netherlands in the past 10 years. It is unlikely that the observed increase in mortality due to pneumonia is purely the result of the registration system used or misclassification. An increase in the elderly population is the most likely, albeit only partial, explanation. An increase in underlying diseases such as chronic obstructive pulmonary disease and diabetes mellitus is also a possible explanation. Increased antibiotic resistance, inadequate treatment or a shift in the spectrum of micro-organisms causing pneumonia are less likely explanations. Reducing the morbidity and mortality due to pneumonia demands an integrated approach aimed at elderly patients or patients with co-existing disease and executed by specialists in the fields of geriatrics, internal medicine, pulmonary disease and infectious diseases.

A nested case-control study of influenza vaccination was a cost-effective alternative to a full cohort analysis

OBJECTIVE

In the absence of trial results that are applicable to the target population, nested case-control studies might be an alternative to full-cohort analysis. We compared relative and absolute estimates of associations in an influenza vaccine study using both designs.

STUDY DESIGN AND SETTING

Data from elderly persons enrolled during six consecutive influenza seasons were used (147,551 person-periods). The endpoints "hospitalization for pneumonia or influenza" (P&I) or "death" were used combined and separately to define three types of cases. Controls for the case-control samples were randomly selected from the remainder of the total cohort at different ratios (1:1 to 1:4). Logistic regression analysis was used to assess adjusted vaccine effectiveness (VE). Sampling fractions were used to determine the number needed to treat to prevent one outcome. Receiver-operator-curve analysis was conducted to estimate the area under the curve (AUC) as a measure of discriminative capacity of the prognostic model.

RESULTS

In all, 978 P and I hospitalizations and 1,339 deaths were observed. The adjusted estimates of relative estimates (VE, AUC) and their corresponding 95% confidence intervals were virtually the same using both study designs, notably when the case-control ratio was high (1:4).

CONCLUSION

A nested case-control design can provide valid and precise estimates of associations and is a cost-effective alternative for full-cohort analysis.

Resistance of uropathogens in symptomatic urinary tract infections in León, Nicaragua

Management of urinary tract infections (UTI) in Central America and especially Nicaragua, is complicated by the lack of knowledge about the antibiotic resistance of uropathogens. We conducted a prevalence study to gain more insight into the aetiology, bacterial resistance and risk factors for symptomatic UTI in the region of León, Nicaragua. In 2002, all consecutive patients with UTI symptoms and pyuria >/=10 WBC/hpf were admitted to the study. Positive cultures from midstream urine specimens were defined as >/=10(5) cfu/ml of a single uropathogen. Susceptibility tests were performed with disc diffusion tests using the Kirby-Bauer method and broth microdilution using National Committee for Clinical Laboratory Standards criteria both in León and a reference laboratory in Utrecht. A positive culture was present in 62 of 208 study subjects (30%). Escherichia coli (56%), Klebsiella spp. (18%) and Enterobacter spp. (11%) were the most frequent pathogens isolated. Presence of cystocele, incontinence and increasing age were risk factors for bacterial UTI. E. coli was least resistant to ceftriaxone, amikacin and nitrofurantoin (>90% susceptible). We observed high resistance rates in E. coli to amoxicillin (82%, MIC(90) 128 mg/l), trimethoprim-sulphamethoxazole (TMP-SMX) (64%, MIC(90) 32 mg/l), cephalothin (58%, MIC(90), 32 mg/l), ciprofloxacin (30%; MIC(90), 32 mg/l), amoxicillin/clavulanate (21%, MIC(90) 8 mg/l) and gentamicin (12%, MIC(90) 2 mg/l). Our results suggests that community acquired uropathogens in Nicaragua are highly resistant to many antimicrobial agents. The use of amoxicillin, trimethoprim-sulphamethoxazole and cephalothin against uropathogens needs to be reconsidered. High quinolone resistance rates among E. coli in Nicaragua gives cause for great concern.