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At least 829 records · Page 46Linked to original sources
PubMed2005

[Study on the molecular epidemiology of people infected with human immunodeficiency virus-1 in Shandong province].

OBJECTIVE: To study the distribution of human immunodeficiency virus-1 (HIV-1) strains subtypes in Shandong province and to study their source in order to predict the epidemic trend. METHODS: Epidemiological investigation was made and 93 DNA fragments of HIV-1 env, gag, tat gene were amplified by nested polymerase chain reaction from people infected with HIV-1, in 2002 - 2003. Their C2-V3, P17/P24, 1st exon of tat and adjacent region were sequenced. RESULTS: Sequence analysis showed that there were 7 HIV-1 strains or circulating recombinant forms (CRFs), B' (n = 71), CRF01-AE (n = 9), CRF07-BC (n = 3), CRF08-BC (n = 3), B (n = 2), C (n = 2), CRF02-AG (n = 2). B' strains was the predominant which, covered 10 cities and 4 kinds of population including blood donors, blood receivers, spouses of the infected people and clients of the sex workers. CRF07-BC, CRF08-BC strains were identified in 5 cities, mainly from injecting drug users. CRF01-AE and other strains were found distributed in developed cities, among sex workers. CONCLUSION: There were many kinds of subtypes and CRFs of HIV and their genomes which generated obvious variation in Shandong province, suggesting that they might facilitate the spread of the disease in Shandong province.

Adolescent↗
PubMed2002

Structure of epidemiological studies on genetic susceptibility to environmental toxicants.

Metabolic genes code for enzymes that are involved in conjugation and detoxification of environmental toxicants. Polymorphisms in these genes result in individual differences in susceptibility to carcinogens and therefore in differences in cancer risk. The most common study design used in the area of genetic susceptibility is the case-control study, because of both economic and logistic constraints. Since metabolic gene polymorphisms are germ line mutations that are present before the onset of the disease, this study design is applicable, and the assessment of the polymorphism can be performed after diagnosis. Since the polymorphism interacts with the exposure through type 2 gene-environment interaction, and in the absence of exposure the polymorphism alone has no effect on the risk of disease, the measurement of the relevant exposure is mandatory. Relevant exposures can be measured according to the classical epidemiological methods, or by means of specific biomarkers, and therefore biases and confounders have to be taken into account in both design and analysis of the study, like in classic epidemiologic studies.

Carcinogens↗
PubMed1992

Astroviruses and caliciviruses: emerging enteric pathogens.

Acute, infectious gastroenteritis is an extremely common disease that contributes significantly to morbidity and mortality worldwide. In the United States, it is the second most frequent illness encountered in families. While this illness generally runs a self-limited course, it may be temporarily incapacitating and impact substantially on numbers of days lost from work or school. At present, 30-40% of infectious gastroenteritis cases in the United States are attributable to viral agents, while 20-30% are due to bacteria and parasites. These estimates are almost certainly low, since the cause of gastroenteritis is not discernible in approximately 40% of the cases, and gastroenteritis may be caused by viruses or other pathogens that cannot be identified at this time. Rotavirus and enteric adenovirus are two of the most prevalent and well-studied of the viral agents and have been reviewed extensively elsewhere. This review focuses on two broad groups of small round structured viruses (SRSV), astroviruses and caliciviruses (classic, Norwalk, and Norwalk-like). Although recognized in association with acute, nonbacterial gastroenteritis since the early 1970s, the study of these viruses has been hampered by the relatively low levels of viral shedding in feces, difficulty in propagating the virus in cell or organ culture, and the lack of widely available, well-standardized reagents for their detection. In spite of these obstacles, much has been learned about these viruses using standard virologic (electron microscopy, biophysical characterization, immunoassays) and epidemiologic methods. More recently, substantial progress has been made in studying astroviruses and caliciviruses at the molecular level. Molecular techniques are now being used as diagnostic aids to characterize the epidemiology of these agents in greater detail.

Animals↗
PubMed2004

[Prevalence of hemorrhagic fever with renal syndrome virus in domestic pigs: an epidemiological investigation in Shandong province].

OBJECTIVE: To investigate the epidemiological significance of hemorrhagic fever with renal syndrome virus (HFRSV) infection in domestic pigs in Shandong province, and study the role of domestic pigs in the prevalence of HFRS. METHODS: Epidemiological investigation was performed in 4 cities of Shandong province. Reversed passive hemagglutination assay (RPHA), reversed passive hemagglutination inhibition (RPHI), HPR-SPA, immunofluorescent antibody (IFA), and reverse transcriptional PCR (RT-PCR) were used to detect antigen and antibody of HFRSV. RESULTS: HFRSV antigen and antibody were detected in the heart, liver, lung, spleen, kidney, blood, urine, and stool of domestic pigs as well as in the sewage of the pigpen facilities. The positivity rate of HFRSV antigen ranged from 3.33% to 5.00% in the organ of pigs, and HFRSV positivity rate in the blood, urine, stool, and sewage was 3.67%, 7.04%, 2.51%, and 5.56%, respectively, with a total serum antibody positivity rate of 1.96%. The virus was isolated from the HFRSV antigen-positive samples, and could infect many organs after artificial infection of the pigs. HFRSV antigen can be detected in suckling rat brain and histopathological examination suggested transient pathological changes in such organs as the liver, lung and kidney. HFRSV may proliferate in pigs and was discharged through multiple routes. CONCLUSION: Domestic pigs can be the host of HFRSV for the viral transmission.

Animals↗
PubMed1988

The epidemiology and public health significance of Rett syndrome.

Current data indicate that Rett syndrome is an important contributor to the total burden of idiopathic mental retardation. Studies from Sweden suggest that among girls the prevalence of Rett syndrome may be twice the prevalence of phenylketonuria. Successful epidemiologic studies of idiopathic mental retardation syndromes will require both large sample sizes and homogeneous populations. Because Rett syndrome is a relatively homogeneous and common syndrome of idiopathic mental retardation, epidemiologic methods may be more productive in the study of Rett syndrome than in other syndromes of mental retardation that are less clinically homogeneous. The approaches used in studying Rett syndrome epidemiologically may later be useful in the study of other syndromes of idiopathic mental retardation.

Ammonia↗
PubMed1979

Behavioural aspects of the control of parasitic diseases.

Human behaviour has been largely neglected in research on the parasitic diseases, in part because of the long-standing separation of the behavioural disciplines from the physical and biomedical sciences. Some of the reasons for the persistence of this "intellectual discontinuity" are discussed. The paper is principally concerned with the prospects for greater use of the methods and orientations of the behavioural sciences in parasitic disease research and control programmes. Behavioural research tends to fall into two categories employing, on the one hand, survey research and epidemiological methods and, on the other, participant observation and interviewing in depth. These approaches are shown to be complementary-equally useful and necessary. Various categories of health-related behaviour and kinds of research objective are reviewed in the following sections. Special attention is given to psychosocial cost-benefit studies, to analyses of control sectors, and to the formulation of a control philosophy. Finally, some specific behavioural research needs are discussed for some of the parasitic diseases of priority in the UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases-schistosomiasis, filariasis, American and African trypanosomiases, and malaria.

Attitude to Health↗
PubMedDate not supplied

[The prevalence of ischemic heart disease and the risk factors for its occurrence in an organized population of a large city].

Using standard epidemiological methods, an organized population of men and women aged 20-59 (20%-representative sample, with the population size being 1,511) was examined. An outline has been done of the epidemiologic situation with respect to risk factors and different forms of IHD in an industrial body of workers, which allowed a contribution to be assessed of hypercholesterinemia, hypertriglyceridemia, hypoalphacholesterinemia, smoking habits, excessive body mass, hypodynamia, to the development of cardiovascular abnormalities.

Adult↗
PubMed1986

Epidemiological studies of anticancer drug carcinogenicity.

In recent years, epidemiological methods have been used increasingly to study the carcinogenicity of drugs used in the chemotherapy of cancer. Such studies are useful to clinicians in identifying therapeutic agents with particular long-term risk to patients. They can also provide information on the dose- and time-related risks of cancer in one of the few human populations intentionally exposed to known levels of carcinogens. Aspects of epidemiological studies of second cancer risk are described, including sources of cases, study design, statistical methods, and possible biases. Results from a cohort study of second cancers following ovarian cancer, testicular cancer and Hodgkin's disease and from a case-control study of leukaemia following Hodgkin's disease are also given.

Antineoplastic Agents↗
PubMed2005

Hereditary angioedema due to C1 inhibitor deficiency: patient registry and approach to the prevalence in Spain.

BACKGROUND: Hereditary angioedema (HAE) is a rare disease caused by C1 inhibitor mutations. Although more than 100 mutations have been described, epidemiologic data are lacking; therefore, we developed a Spanish HAE patient registry. OBJECTIVE: To study the prevalence of HAE and the current state of diagnosis and treatment of this disease in Spain. METHODS: Epidemiologic data were obtained by direct contact with physicians who treat patients with HAE and with patients themselves. Diagnosis was evaluated by measuring C1 inhibitor levels and function, and most families also underwent genetic studies. RESULTS: We registered 444 patients (minimal prevalence, 1.09 per 100,000 inhabitants), many of whom are asymptomatic (never having symptoms) (n = 61, 13.7%). Most symptomatic patients (62.9%) receive long-term prophylaxis with attenuated androgens (80.9%) and antifibrinolytic agents (22.8%), alone or in combination, but no patients are receiving long-term prophylaxis with C1 inhibitor. There is a long delay in diagnosis (mean, 13.1 years). Nine patients underwent a tracheotomy as a consequence of a laryngeal attack, and 30 families recalled a total of 38 relatives who died of HAE, which underlines the severity of the illness. CONCLUSIONS: The detected minimal prevalence of HAE in Spain is 1.09 per 100,000 inhabitants. Because this is a rare disease and some patients may be misdiagnosed, this prevalence could be higher.

Adult↗
PubMedDate not supplied

Molecular epidemiology of TB: challenging dogmas and asking new questions.

Traditional epidemiological methods provide insight into the dynamics of diseases such as tuberculosis. These traditional techniques have limitations and rely on a number of assumptions. The application of molecular techniques to the study of epidemiology has allowed us to gain new insights into the biology of the organism Mycobacterium tuberculosis and the dynamics of the disease. We have been enabled to push the limits of understanding of the epidemiology of this disease, allowing us to challenge the old clinical dogmas, ask new questions, design new strategies, and measure the efficacy of such new interventions to combat this age-old scourge. Among the dogmas challenged are that infection outside the home is commonplace, so-called relapse cases may in fact be largely reinfection, and active transmission may be more common than previously thought and reactivation disease relatively uncommon. These findings alone demand urgent attention and the design of optimal intervention strategies to reduce the burden of disease.

Humans↗
PubMed1990

Teaching nutrition to medical students: a community-based problem-solving approach.

This paper presents a community-based problem-solving educational programme which aims at teaching medical and other health science students the importance of nutrition and its application. Through community surveys students assess the nutritional status of children under five using different anthropometric methods. They understand the cultural beliefs and customs related to food fads and the reasons for them. They also acquire the skill to educate the community using the information gathered. They use epidemiological methods such as case control study to find associations between malnutrition and other causative factors. Feedback from students has been positive and evaluation of students' knowledge before and after the programme has shown significant improvement.

Community Medicine↗
PubMed1993

[Investigational methods in Lyme disease].

After the first clinical case of Lyme disease had been recorded in Belgrade in 1987 a multi-level research of the disease was undertaken in our country. The research was organized on the team basis and was systematized. Ever since the beginning epidemiological method has been applied. Professional approach was provided by guidelines, while methods and research stages have been provided and further developed during seminars and symposiums dealing with lyme disease. Research team was comprised of experts from Institute of Public Health of Belgrade, Institute for Preventive Medicine of the Medical Military Academy and clinicians--specialists in the relevant areas. The team gathered its own precious experience in Lyme borreliosis, the disease with precisely defined features and well-described manifestations and characteristics. This work describes methodology applied in the research of Lyme disease in our country.

Animals↗
PubMedDate not supplied

On the biological effects of cosmic rays: epidemiological studies.

Determining the biological effects of cosmic rays and other natural ionizing radiations, could possibly help us in shedding light on the more general problem of low-dose ionizing-radiation effects. In this work we provide a survey of the most recent studies available on epidemiological methods: we discuss the main difficulties in using these methods, as well as the discrepancies in their results.

Animals↗
PubMed1994

Energy adjustment methods for nutritional epidemiology: the effect of categorization.

The authors discuss the interpretation of four alternative energy adjustment methods (Residual, Standard, Partition, and Nutrient Density) that have been proposed for the analysis of nutritional epidemiology studies. These methods have so far been compared under circumstances where intake of the nutrient of interest is measured as a continuous variable. Because it is common practice to categorize nutrient intakes in the analysis, the authors investigate the effect of such categorization on the interpretation of results from the four methods with the use of computer simulations and statistical theory. They consider four cases: where the nutrient intake is either divided into quartiles or ordered so as to investigate trend over the quartile groups, combined with using an adjusting variable that is either continuous or categorized. The results show: 1) the Residual, Standard, and Partition methods are no longer equivalent as they are in the continuous case; 2) compared with the Standard method, the Residual method appears to be more powerful for detecting trends in relative odds, is more robust to residual confounding when the adjustment variable is categorized, and provides more meaningful odds ratios; and 3) the Residual and Nutrient Density methods give closely similar results.

Bias↗
PubMed1995

Current Epidemiology and Treatment of Tsutsugamushi Disease in Japan.

Background: The classical manifestation of tsutsugamushi disease was attributable to Leptotrombidium akamushi; the peak incidence occurred in August. Now, for reasons unknown, the disease has peak incidences in May and November, the new vectors being L. pallidum and L. scutellare, respectively. Methods: Epidemiologic data on tsutsugamushi disease occurring in Japan over a period of 44 years (1950-1993) are analyzed. Results: The number of cases gradually declined from 116 in 1950 to three in 1969. The number increased again to 941 in 1990. The disease is endemic in almost all parts of Japan, but it exhibits different rates of morbidity. Miyazaki and Kagoshima, which are prefectures in the southern part of the country; Chiba and Kanagawa, which are near Tokyo; and Akita and Niigata in the northern part of Japan are highly endemic. Three quarters of patients are between 50 and 70 years of age, range <4 to >80 years. Conclusions: Prognosis is good when treatment with tetracycline or doxycycline in a traditional dose is given for 10-14 days. Administration should be as early as possible. Preventive medication is not considered necessary.

Journal Article↗
PubMed2006

Estimation of the cost of Taenia solium cysticercosis in Eastern Cape Province, South Africa.

OBJECTIVES: To provide a comprehensive estimate of the societal costs of Taenia solium cysticercosis for the Eastern Cape Province (ECP), South Africa, as an objective measure of its impact in this endemic area. METHODS: Epidemiological data on the prevalence of epilepsy, proportion of epilepsy cases due to neurocysticercosis (NCC) and consequences of cysticercosis were gathered from published and unpublished sources. Economical data were mostly obtained from governmental sources. Three methods were used for estimating productivity losses. Monte Carlo sampling was used to represent the uncertainty of the estimates with 95% Credible Intervals (95% CI). The estimation is for 1 year using a societal approach. All costs are reported in 2004 US Dollars. RESULTS: Overall, there were an estimated 34 662 (95% CI: 17 167-54 068) NCC-associated cases of epilepsy in ECP in 2004. The overall monetary burden (in million of US Dollars) was estimated to vary from US Dollars 18.6 (95% CI: US Dollars 9.0-32.9) to US Dollars 34.2 (95% CI: US Dollars 12.8-70.0) depending on the method used to estimate productivity losses. The agricultural sector contributed an average of Dollars 5.0 million. The prevalence of epilepsy, proportion of productivity reduction and the proportion of epilepsy cases attributable to NCC had the largest impact on the overall estimates. CONCLUSION: This preliminary estimate suggests that T. solium cysticercosis results in considerable monetary costs to a region that is already economically constrained. Because this infection is preventable, these results could guide stakeholders in deciding where to invest scarce health and agricultural resources in their countries.

Agriculture↗
PubMed2005

Defining the timing of respiratory syncytial virus (RSV) outbreaks: an epidemiological study.

BACKGROUND: Seasonal RSV infections occur every year and affect particularly children under six months of age. Passive immunoprophylaxis with monoclonal antibody Palivizumab is recommended in the period with high risk of RSV infection. This study aims to define the period for the southern part of Germany (Stuttgart area). METHODS: Epidemiological analysis of the RSV situation in southern Germany from 1996 to 2004 and comparison of results with literature was made. The respiratory tract specimens were sent in for the detection of RSV mainly by paediatric clinics. Detection of RSV was carried out mainly by real-time RT-PCR or by ELISA "Pathfinder". RSV outbreaks were depicted as an absolute number and as a percentage of RSV diagnoses in a month. Onsets, offsets, peaks, duration and severity of RSV seasons were defined and analysed. RESULTS: An early season with strong RSV activity (early-high phase) was followed by a weaker late season (late-low phase) in a regular biennial rhythm. However, onsets, offsets and durations of outbreaks varied significantly from year to year. RSV epidemics in southern Germany were found to oscillate in an antiphase with RSV epidemics in Finland and Sweden. CONCLUSION: The long-term regular biennial rhythm allows predicting whether the next outbreak will be late or early and whether RSV activity will be strong or weak. Not foreseeable, however, is the precise time of increase and decrease of RSV activity. Moreover, the regular seasonal pattern may be disrupted by irregular outbreaks. Thus, activity of RSV has to be monitored every year to define the period with high risk of infection.

Child↗