Community genetics and community medicine

In the decades to come, molecular genetic insights and techniques will have great influence on prevention and health care. Health care providers should anticipate important new developments rather than just wait and see. For community doctors, who can impossibly oversee all relevant developments in sufficient detail, close communication with the community and clinical genetic specialists is necessary to keep pace with progress. With regard to genetic counselling and reproductive medicine, working agreements between primary care and specialist centres are important. General communication about hereditary issues can be dealt with by well informed GPs, with appropriate computerized decision support, but in order to address specific risks and disorders consultation at a clinical genetic centre is preferred. In clinical medicine, much work is being done on DNA-based 'dia-prognosis' and more targeted interventions. Estimations of when such innovations will really have an impact range from 2005 to beyond 2020, and there are still many uncertainties, especially regarding common multifactorial disorders. Community-based genetic epidemiology has become a basic science in understanding the human genome. Clinical epidemiological methodology can contribute a lot to the quality of molecular clinico-genetic studies. Long-term follow-up to evaluate predictions and interventions needs more attention, and can easily be integrated into primary care medicine. In view of the ambition to develop more tailormade interventions, research methodology will be challenged regarding n = 1 studies. With respect to counselling and clinical practice, many ethical issues, relevant for community medicine, have to be considered in the domains of both reproductive medicine and clinical practice. Doctors, patients and society, traditionally battling to reduce diagnostic and prognostic uncertainties, must now learn to cope with approaching certainties. As for all new technologies, cost-effectiveness is an important topic for genetics. Increased cost-effectiveness because of better targeted interventions may be counterbalanced by the price of the new technologies and an expanding indicated population. In view of current developments, community practitioners must integrate community genetics into their daily routine, and critically anticipate possibly relevant innovations. More efforts in genetic risk assessment and communication are necessary in undergraduate and postgraduate training. A multidisciplinary approach is needed, in collaboration with primary care-oriented genetic specialists. Efforts to educate the public and (potential) patients should start at an early age, and must focus on what (future) health care users need for a balanced appraisal of genetic information and for optimal decision making in health promotion and health care.     

Community genetics: a new discipline and its application in Brazil

Community genetics is a new discipline which aims to provide genetic services to the community as a whole. As a science, community genetics encompasses all research needed to develop and evaluate its application. There is no question that the development of community genetics is necessary in Brazil. The implementation of such programs in our country, especially for hemoglobinopathies, has been recommended by the World Health Organization and other international organizations. Apart from the need for and appeal of community genetics programs, some aspects require serious review. This article discusses various cultural, social, psychological, and economic factors that can make genetic screening an invasion of individual privacy.     

Consumption of toothpaste and associated factors in a Brazilian population group

This cross-sectional study evaluated the consumption of fluoridated dentifrice and associated factors in Passo Fundo, Rio Grande do Sul State, Brazil. A total of 688 households were selected. A structured questionnaire was answered by the mother to obtain demographics, habits, and toothpaste consumption. Household toothpaste consumption was considered low when a tube lasted > 1 month and high when < 1 month. Logistic regression models were applied to evaluate the association between consumption and independent variables. 61.2% of households showed high toothpaste consumption. In the multivariate model, mother's age > 50 years (OR = 1.62; 95%CI: 1.02-2.61), mother's brushing frequency (OR = 2.53; 95%CI: 1.53-4.16), number of people brushing (OR = 5.69; 95%CI: 3.68-8.81), and cosmetic features in choice of the dentifrice (OR = 1.64; 95%CI: 1.03-2.61) showed the highest odds of high toothpaste consumption.     

Community engagement with genetics: public perceptions and expectations about genetics research

Background

Knowledge of molecular biology and genomics continues to expand rapidly, promising numerous opportunities for improving health. However, a key aspect of the success of genomic medicine is related to public understanding and acceptance.

Design

Using community consultations and an online survey, we explored public attitudes and expectations about genomics research.

Results

Thirty‐three members of the general public in Newfoundland, Canada, took part in the community sessions, while 1024 Atlantic Canadians completed the online survey. Overall, many participants noted they lacked knowledge about genetics and associated research and took the opportunity to ask numerous questions throughout sessions. Participants were largely hopeful about genomics research in its capacity to improve health, not only for current residents, but also for future generations. However, they did not accept such research uncritically, and a variety of complex issues and questions arose during the community consultations and were reflected in survey responses.

Discussion

With the proliferation of biobanks and the rapid pace of discoveries in genomics research, public support will be crucial to realize health improvements. If researchers can engage the public in regular, transparent dialogue, this two‐way communication could allow greater understanding of the research process and the design of efficient and effective genetic health services, informed by the public that will use them.     

The aging process in the Brazilian population: a demographic approach

Contrary to common sense, the population aging process is due to the decline in fertility rather than mortality. The aging process began around the end of the 19th century in a number of Western European countries, expanded to the rest of the so-called First World over the past century, and reached several Third World countries afterwards, including Brazil over the last decades. In the Brazilian case, a sharp and widespread fertility decline began by the end of the 1960s, and an accelerated population aging process can thus be expected. This process will necessarily be faster and with deeper structural changes, demographically speaking, than in First World countries, for two reasons: the fertility decline in Brazil was faster, and it took place in a population with a younger age structure.     

West Nile virus population genetics and evolution

West Nile virus (WNV) (Flaviviridae: Flavivirus) is transmitted from mosquitoes to birds, but can cause fatal encephalitis in infected humans. Since its introduction into North America in New York in 1999, it has spread throughout the western hemisphere. Multiple outbreaks have also occurred in Europe over the last 20 years. This review highlights recent efforts to understand how host pressures impact viral population genetics, genotypic and phenotypic changes which have occurred in the WNV genome as it adapts to this novel environment, and molecular epidemiology of WNV worldwide. Future research directions are also discussed.     

MBL2 gene polymorphisms and susceptibility to tuberculosis in a northeastern Brazilian population

The innate immune system represents the first line of host defense against pathogens. Genetics factors regulating the immune responses play a role in the susceptibility to infectious diseases, such as tuberculosis (TB). We analyzed MBL2 promoter and exon 1 functional single nucleotide polymorphisms (SNPs) in a group of 155 TB patients and 148 healthy controls in order to evaluate their influence on the onset of infection and TB development. There was no association between MBL2 −550 HL promoter polymorphisms and susceptibility to develop TB, but heterozygous −221 Y/X genotype was significantly more frequent in pulmonary TB patients than controls. Moreover, MBL2 exon 1 O allele, was significantly associated with susceptibility to TB development in general (p = 0.023, OR = 1.61, 95% CI 1.05–2.49) and pulmonary TB (p = 0.0008, OR = 2.16, 95% CI 1.35–3.46); C allele at codon 57, as well as A/C genotype, were significantly more frequent in TB patients than in controls. Our results indicate that MBL2 polymorphisms, especially at codon 57, could be considered as risk factors for TB development.     

Elevated blood lead levels in a riverside population in the Brazilian Amazon

Lead (Pb) is recognized as one of the most toxic metals. Sources of Pb exposure have been widely documented in North America, and the removal of Pb additives from gasoline was reflected in a dramatic lowering of blood Pb concentration. In Latin America, the removal of Pb from gasoline resulted in decreased exposure, but Pb levels in many areas remain high due to occupational and environmental sources of exposure. While many of the Pb sources have been identified (mining, industries, battery recycling, lead-based paint, ceramics), new ones occasionally crop up. Here we report on blood Pb (B-Pb) levels in remote riverside communities of the Brazilian Amazon. Blood Pb (B-Pb) levels were determined in 448 persons from 12 villages of the Lower Tapajós River Basin, Pará, Brazil. Socio-demographic and dietary information, as well as occupational, residential and medical history was collected using an interview-administered questionnaire. B-Pb, measured by ICP-MS, showed elevated concentrations. Mean B-Pb was 13.1 μg/dL±8.5, median B-Pb was 11.2 μg/dL and ranged from 0.59 to 48.3 μg/dL. Men had higher B-Pb compared to women (median: 15.3 μg/dL vs 7.9 μg/dL respectively). B-Pb increased with age for women, while it decreased for men. For both genders, B-Pb decreased with education. There were significant differences between villages. Exploratory analyses, using linear partition models, showed that for men B-Pb was lower among those who were involved in cattle-raising, and higher among those who hunted, farmed and fished. The distribution profile of B-Pb directed us towards artisanal transformation of manioc to flour (farinha), which requires heating in a large metal pan, with stirring primarily done by young men. In the village with the highest B-Pb, analysis of Pb concentrations (dry weight) of manioc (prior to transformation) and farinha (following transformation) from 6 houses showed a tenfold increase in Pb concentration (mean: 0.017±0.016 to 0.19±0.10 μg/g). This was confirmed in one of these villages where we sampled manioc paste (just before roasting) and the roasted farinha (0.05 μg/g vs 0.20 μg/g). While there may be other sources (ammunition, sinkers for fishing nets), the high concentrations in farinha, a dietary staple, assuredly makes an important contribution. Further action needs to reduce Pb sources in this region.     

Bat population genetics and Lyssavirus presence in Great Britain

Most lyssaviruses appear to have bat species as reservoir hosts. In Europe, of around 800 reported cases in bats, most were of European bat lyssavirus type 1 (EBLV-1) in Eptesicus serotinus (where the bat species was identified). About 20 cases of EBLV-2 were recorded, and these were in Myotis daubentonii and M. dasycneme. Through a passive surveillance scheme, Britain reports about one case a year of EBLV-2, but no cases of the more prevalent EBLV-1. An analysis of E. serotinus and M. daubentonii bat genetics in Britain reveals more structure in the former population than in the latter. Here we briefly review these differences, ask if this correlates with dispersal and movement patterns and use the results to suggest an hypothesis that EBLV-2 is more common than EBLV-1 in the UK, as genetic data suggest greater movement and regular immigration from Europe of M. daubentonii. We further suggest that this genetic approach is useful to anticipate the spread of exotic diseases in bats in any region of the world.     

Age-specific seroprevalence to an immunodominant Cryptosporidium sporozoite antigen in a Brazilian population

The seroepidemiology of Cryptosporidium infection was investigated in a representative sample of a normal population in the State of Sao Paulo, Brazil using a recombinant form of the immunodominant 27-kDa sporozoite antigen. IgG seropositivity was low in infants following loss of maternal antibody but quickly increased to approximately 60% by 5 years, then 80% by the age of 10 years, after which prevalence remained constant. The broad range of antibody concentrations is consistent with previous reports that the IgG response to C. parvum is short-lived. There is also evidence that average antibody concentrations increase with age. Results suggest that the recombinant antigen may be a more sensitive method of measuring seroprevalence than the native antigen in Western blot. Although cross-sectional studies can provide an insight into the epidemiology of C. parvum in normal populations, further studies investigating the dynamics of the humoral immune responses to Cryptosporidium and the use of serology in epidemiological studies are required.     

Dental pain as the reason for visiting a dentist in a Brazilian adult population

OBJECTIVE: The occurrence of orofacial pain and chronic pain are frequent subjects for study today, but few studies have been made on dental pain in Brazil. The objective of the study was to assess the prevalence of dental pain and the associated factors as the reason for visiting a dentist among adults. METHODS: A cross-sectional study was carried out among 860 workers aged 18-58 years at a cooperative located in the State of Santa Catarina, in 1999. The clinical examinations and interviews were carried out by dentists who had received prior guidance. Complaints of dental pain as the reason for the last visit to a dentist were analyzed as the dependent variable, in relation to the socioeconomic and demographic conditions, access to dental services, shift pattern and caries (via the DMFT index), as the independent variables. Non-conditional multiple logistic regression analysis was utilized. RESULTS: The prevalence of dental pain as the reason for the last visit to a dentist was 18.7% (CI 95%: 15.9-20.1) and the mean DMFT index (decayed, missing and filled teeth) was 20.2 (CI 95%: 19.7-20.7), with 54% represented by the 'missing' component. The following were independently associated with the presence of dental pain: schooling of less than or equal to eight years (OR=1.9; CI 95%: 1.1-3.1); four to fifteen teeth lost due to caries (OR=2.6; CI 95%: 1.4-4.9); 16 to 32 teeth lost due to caries (OR=2.5; CI 95%: 1.1-5.8); and not having visited the company's dental service (OR=2.8; CI 95%: 1.6-5.1). CONCLUSIONS: Dental pain reflects the severity of the dental caries, expressed by the 'missing' component of the DMFT and non-usage of the company's dental services. These factors are determined by social conditions and represented by the schooling level.     

Knowledge about contraceptives in a population 15 years or older in a southern Brazilian city

In Brazil, prevalence of contraceptive use is high, but incorrect and inappropriate use is frequent, suggesting limited knowledge about methods. This study thus evaluated the knowledge about the most widely used contraceptive methods, measured through a score (0-10) and related factors. A population-based cross-sectional study was performed, with 3,542 subjects ages 15 or older, residing in the urban area of Pelotas, Rio Grande do Sul State. The mean overall knowledge score was 4.65 (sd = 2.07): 5.02 (sd = 2.10) for women and 4.18 (sd = 1.92) for men. Lower age, higher schooling, a report of unwanted pregnancy, and any lifetime use of contraceptive methods (exclusive or combined) were associated with higher knowledge scores among men, while for women, the determinants of higher knowledge were higher age, living with a partner, higher schooling, higher socioeconomic status, not reporting a religion, and any lifetime use of contraceptive methods (exclusive or combined). Despite high prevalence of any lifetime contraceptive use (75.3%), knowledge is still limited about the most widely used methods, as well as about the menstrual cycle and fertile period.     

Temporal trends in gonococcal population genetics in a high prevalence urban community.

Molecular evolutionary studies can provide insights into the spread of infectious diseases and inform infection control measures. We performed a population genetic analysis of gonococcal isolates obtained over a 15-year interval in Baltimore, MD, where gonorrhea is highly prevalent. Categorical analysis of genetic differentiation revealed temporal structuring of the gonococcal population. The use of a new method to determine the historical demography of Neisseria gonorrhoeae from sequence data showed a strong correlation with trends in the number of reported cases of N. gonorrhoeae. The historical trends may also reflect the influence of social and demographic factors and the impact of antimicrobial resistance on the molecular epidemiology of gonorrhea in Baltimore over the past 2 decades. The strong correlation between the population genetic inferences over the last 20 years and the demographic data collected over the same time period demonstrates the utility of these approaches for the accurate inference of complex population dynamics using multilocus sequence data. The real time application of population genetic analysis can provide sentinel data on gonococcal prevalence, antibiotic resistance patterns and changing epidemiology of gonococcal infections.