Changing Epidemiology (changing + epidemiology)

Distribution by Scientific Domains


Selected Abstracts


Changing epidemiology of Helicobacter pylori in Asia

JOURNAL OF DIGESTIVE DISEASES, Issue 4 2008
Huck J TAN
As in developed societies, the prevalence of Helicobacter pylori has declined rapidly in Asia. This has been shown in both seroprevalence-based and endoscopy-based studies. While the decline in the incidence of gastric cancer has now been observed, a decrease in peptic ulcer disease has not been so clearly evident. This apparent paradox can be explained by an increase in non- H. pylori associated ulcers , such as those related to non-steroidal anti-inflammatory drugs or idiopathic ulcers. The increase of gastroesophageal reflux disease in Asia has been widely observed and commented on and its relationship to the decline in H. pylori speculated upon. However there have been few conclusive studies from Asia on this subject. While the improved diagnosis and elimination of H. pylori has contributed to its decline, a more basic change involving large segments of the Asian population must be responsible. An improvement in hygiene and living conditions that results from more affluent Asian societies is thought to be a possible cause. [source]


Changing epidemiology of invasive pneumococcal disease following increased coverage with the heptavalent conjugate vaccine in Navarre, Spain

CLINICAL MICROBIOLOGY AND INFECTION, Issue 11 2009
M. Guevara
Abstract The present study evaluated changes in the incidence of invasive pneumococcal disease (IPD) and the pattern of serotypes isolated in Navarre, Spain, after the introduction and increased coverage of the heptavalent pneumococcal conjugate vaccine (PCV7). All cases with isolation of pneumococcus from normally sterile bodily fluids were included. The incidence of IPD in children and adults was compared for the periods 2001,2002 and 2006,2007. By the end of 2002, only 11% of children aged <5 years had received any dose of PCV7, whereas, beginning in 2007, the proportion exceeded 50%. Among the cases of IPD aged <5 years, the percentage of those vaccinated increased from 7% during 2001,2002 to 53% during 2006,2007 (p <0.001). The incidence of IPD from PCV7-serotypes decreased by 85% in children <5 years (p <0.001), by 45% in the population aged 5,64 years (p 0.10) and by 68% in those ,65 years (p 0.004). By contrast, the incidence of IPD from non-PCV7 serotypes increased by 40% overall (p 0.006). The incidence of IPD from all serotypes did not change significantly in children <5 years (from 83 to 72 per 100 000) or in the total population (from 15.8 to 16.3 per 100 000). The percentage of cases as a result of serotypes 7 and 19A increased significantly in both children and adults. No significant changes were seen in the clinical forms of IPD. The pattern of serotypes causing IPD has changed, in both children and adults, following the increased coverage of PCV7, although the incidence has been reduced only slightly. [source]


Varicella susceptibility and vaccine use among young adults enlisting in the United States Navy,,

JOURNAL OF MEDICAL VIROLOGY, Issue S1 2003
Margaret A.K. Ryan
Abstract Primary varicella infection, or chicken pox, is a threat to all young adults who join the United States (U.S.) military if they fail to develop immunity prior to enlistment. Historically, outbreaks of chicken pox have caused marked morbidity and impaired military readiness. In December 1996, the U.S. Navy began performing serologic testing for varicella among all new recruits, and vaccinating those found to be sero-negative. We evaluated results of the screening program in its first 4 years, and used multivariable logistic regression modeling to describe factors associated with varicella susceptibility. Cases of chicken pox were tracked among all military services before and after program implementation. More than 190,000 young adults enlisted in the U.S. Navy between 1997 and 2000. Recruits originated from all 50 states and several foreign countries; 84% were male, and their average age was 19 years. Seven percent were found to be susceptible (sero-negative) to varicella. In multivariable modeling, race/ethnicity was associated with susceptibility, but age, gender, and home state were not. The overall incidence of chicken pox in the Navy was reduced by more than 80% after initiation of the screening-vaccination program. A successful varicella screening-vaccination program has been implemented in the U.S. Navy. Results of serologic screening undertaken on this large number of young adults may be useful in tracking the changing epidemiology of varicella in the general population in the post-vaccine era. J. Med. Virol. 70:S15,S19, 2003. © 2003 Wiley-Liss, Inc. [source]


Mycobacterium ulcerans infection diagnosed by polymerase chain reaction

JOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 3 2002
FM Russell
Abstract: Mycobacterium ulcerans infection is the third most important mycobacterial infection world-wide affecting immunocompetent individuals and causes chronic progressive skin ulcers. It has been described in many different regions world-wide. The diagnosis of M. ulcerans infection is often delayed because the diagnosis is difficult to make when new cases appear outside known endemic areas. However, molecular methods are now available to diagnose and distinguish M. ulcerans from other mycobacteria, allowing rapid diagnosis. Presented here is the case of a previously well girl from Townsville, Queensland, with extensive M. ulcerans infection involving the elbow joint, triceps tendon and underlying bone. Rapid diagnosis by polymerase chain reaction confirmed M. ulcerans infection. This is the first known case of M. ulcerans infection from Townsville in over 25 years, highlighting the changing epidemiology of this disease. [source]


Has the time come to control hepatitis A globally?

JOURNAL OF VIRAL HEPATITIS, Issue 2008
Matching prevention to the changing epidemiology
Summary., For the first time a global meeting on hepatitis A virus (HAV) infection as vaccine preventable disease was organized at the end of 2007. More than 200 experts from 46 countries gathered to investigate the changing global HAV epidemiology reflecting the increasing numbers of persons at risk for severe clinical disease and mortality from HAV infection. The benefits of childhood and adult hepatitis A (HepA) vaccination strategies and the data needed by individual countries and international health organizations to assess current HepA prevention strategies were discussed. New approaches in preventing HAV infection including universal HepA vaccination were considered. This introductory paper summarizes the major findings of the meeting and describes the changing epidemiology of HAV infections and the impact of HepA vaccination strategies in various countries. Implementation of HepA vaccination strategies should take into account the level of endemicity, the level of the socio-economic development and sanitation, and the risk of outbreaks. A stepwise strategy for introduction of HepA universal immunisation of children was recommended. This strategy should be based on accurate surveillance of cases and qualitative documentation of outbreaks and their control, secure political support on the basis of high-quality results, and comprehensive cost-effectiveness studies. The recognition of the need for increased global attention towards HepA prevention is an important outcome of this meeting. [source]


Utilization rates, complications and costs of percutaneous liver biopsy: a population-based study including 4275 biopsies

LIVER INTERNATIONAL, Issue 5 2008
Robert P. Myers
Abstract Background: Liver biopsy is an important tool in the management of patients with liver disease. Because biopsy practices may be changing, we studied patterns of use in a large Canadian Health Region. We aimed to describe trends in biopsy utilization and the incidence and costs of complications from a population-based perspective. Methods: Administrative databases were used to identify percutaneous liver biopsies performed between 1994 and 2002. Significant complications were identified by reviewing medical records of patients hospitalized within 7 days of a biopsy and those with a diagnostic code indicative of a procedural complication. Analyses of biopsy rates employed Poisson regression. Results: Between 1994 and 2002, 3627 patients had 4275 liver biopsies (median 1 per patient; range 1,12). Radiologists performed the majority (90%), particularly during the latter years (1994 vs. 2002: 73 vs. 98%; P<0.0001). The overall annual biopsy rate was 54.8 per 100 000 population with a 41% (95% CI 23,61%) increase between 1994 and 2002. Annual increases were greatest in males and patients 30,59 years. Thirty-two patients (0.75%) had significant biopsy-related complications (1994,1997 vs. 1998,2002: 1.28 vs. 0.44%; P=0.003). Pain requiring admission (0.51%) and bleeding (0.35%) were most common. Six patients (0.14%) died; all had malignancies. The median direct cost of a hospitalization for complications was $4579 (range $1164,29 641). Conclusions: Liver biopsy rates are increasing likely owing to the changing epidemiology and management of common liver diseases. The similarity of the complication rate in our population-based study with estimates from specialized centres supports the safety of this important procedure. [source]


Vaccines and the changing epidemiology of autism

CHILD: CARE, HEALTH AND DEVELOPMENT, Issue 5 2006
B. Taylor
Abstract Background The epidemiology of autism has been rather confusing, with very variable published prevalence figures and no clear incidence data. The cause of autism is unclear; vaccines have been incriminated. Methods Literature review and interpretation. Results The recorded prevalence of autism has increased considerably in recent years. This reflects greater recognition, with changes in diagnostic practice associated with more trained diagnosticians; broadening of diagnostic criteria to include a spectrum of disorder; a greater willingness by parents and educationalists to accept the label (in part because of entitlement to services); and better recording systems, among other factors. The cause(s) of autism remains unclear. There is a strong genetic component which, along with prenatally determined neuro-anatomical/biochemical changes, makes any post-natal ,cause' unlikely. Conclusions There has (probably) been no real increase in the incidence of autism. There is no scientific evidence that the measles, mumps and rubella (MMR) vaccine or the mercury preservative used in some vaccines plays any part in the aetiology or triggering of autism, even in a subgroup of children with the condition. [source]