Epidemiology of epilepsy--recent achievements and future

Epilepsy is a very common neurological disease. Reliable epidemiological data are of great importance for understanding the etiology and risk factors for its development. It is necessary to use standardized methodology for the results from epilepsy studies in different geographical regions to be comparable. Most of the epidemiological studies of epilepsy find an incidence rate of 20-70/100,000 per year (range 11-134/100,000). The state of the problem in Bulgaria and other countries of Eastern Europe is not adequately studied. It is considered that the figures are higher in the developing countries. Incidence is higher in men than in women and varies considerably with age--it is high in childhood, decreases in young people and rises again in the elderly. Only approximately 30% of the newly-registered cases can be assigned to one of the diagnostic categories. The studies identify an etiological factor in only about one third of all cases. The most commonly reported etiological factors are: cerebro-vascular disease, tumors, alcohol, head injuries, congenital factors and neuroinfections. Most of the developed countries report prevalence of active epilepsy in the range of 4-8/1000. The prevalence rates in Latin America and some African states are especially high. In Bulgaria by means of the system of regional psychoneurological dispensaries about 30,000 epilepsy patients are registered, but it may be assumed that their real number is over 60,000. Contemporary views on the prognosis of this disease are favorable--more than 70% of the diseased reach long-term remission. Different prognostic factors predicting the final outcome of epilepsy patients are described. Epilepsy patients exhibit more than 2 times higher mortality rate than the expected rate for the corresponding population. It is necessary to conduct additional projects, based on the available standardized methodology for epidemiological monitoring of epilepsy in different geographical regions, including Bulgaria.     

Epidemiology of cataract��a major cause of preventable blindness

Cataract, or opacity of the lens of the eye, is the most common easily correctable cause of blindness in the world. However, little is known of its prevalence and incidence in different regions, particularly in developing countries, or of the relative importance of the various risk factors. This article describes the available knowledge on the epidemiology of cataract in both developing and industrialized countries, and reviews the methods used to obtain these data. The various predisposing factors, such as diabetes, exposure to radiation, and abnormalities of metabolism, along with the possible mechanisms of cataract formation, are also discussed.     

Ensuring Appropriate Care in Epilepsy

Epilepsy is an important health problem throughout the world. In order to best manage epilepsy within a population, its epidemiological profile should be established. Epidemiological studies have shown that epilepsy is a very common, chronic condition that particularly affects the young and those in developing countries. Although the reported rates vary widely, the annual incidence rate of epilepsy is estimated to be approximately 40 to 70 per 100 000 population, and the prevalence is estimated to be approximately 4 to 10 per 1000 population.It can also be demonstrated that epilepsy represents a significant economic burden on health services and society as a whole. The average annual cost of epilepsy may be as high as $US 14 500 (1995 values) per patient. Indirect costs, such as lost productivity, account for a large percentage of this cost. However, there are significant methodological limitations to the cost of illness studies that have been performed to date, and thus the true cost of epilepsy remains to be unequivocally established. Furthermore, it is not clear how changing economic status of countries, the aging of the population and advances in technology will affect the costs of epilepsy in the future.The priority given to managing epilepsy is often too low and identifying the economic cost of epilepsy and on whom this cost falls is an essential part of raising the awareness of this significant public health problem.Many important issues regarding the epidemiology and economics of epilepsy remain unexplored. For example, the relationship between socioeconomic status and epilepsy and the reasons for the changing demographic and secular trends are unknown. The relationship between the clinical type of epilepsy experienced, seizure frequency, seizure severity and cost of illness has not yet been clearly established.     

Maternal immunisation in developing countries

Maternal immunisation could help to prevent the 2-3 million neonatal and early infant deaths that occur in the developing world each year. Determining the causes of neonatal and early infant deaths in developing countries is difficult as most occur at home. However, it is likely that at least half are due to infections, several of which might be prevented by maternal immunisation. Even in poor countries with few health facilities, a high percentage of pregnant women attend an antenatal clinic at least once during pregnancy. Thus, an effective delivery system for maternal immunisation already exists and, because of the success of maternal tetanus immunisation, this approach to the prevention of serious illness or death in young infants is widely accepted by the general population. However, the high prevalence of HIV and malaria found in pregnant women in some parts of the developing world, especially sub-Saharan Africa, could have an effect on the efficacy of maternal immunisation as both of these infections adversely affect placental function. Nevertheless, the potential of maternal immunisation to prevent early infant deaths in developing countries needs to be fully explored. The incidence of pneumococcal infections is high in many developing countries and about 25% of these infections occur at an age before protection could be anticipated following vaccination with a pneumococcal conjugate vaccine in infancy. Thus, a strong case can be made for a trial of the effectiveness of maternal immunisation with a pneumococcal vaccine in preventing serious illness or death in young infants in developing countries.     

Epidemiological research on dementia in developing countries

As the world population is ageing, dementia becomes an important public health problem, particularly in developing countries. Epidemiological research in these settings is scarce and present additional methodological difficulties, mainly regarding the socio-cultural adequacy of instruments used to identify cases of dementia. As a result of these concerns the 10/66 Dementia Research Group was founded to fill this gap. This is an international network of investigators, mostly from developing countries, and the group's name was based on the paradox that less than 10% of the population-based studies on dementia are directed to 2/3 or more cases of people with dementia living in developing countries. The aim of the paper is to update data in the literature regarding the differences in dementia prevalence and incidence seen in developed and developing countries.     

STD control in less developed countries: the time is now

This discussion of sexually transmitted diseases (STDs) in less developed countries covers incidence/prevalence, antimicrobial resistance, sequelae, future trends, and new opportunities for STD control -- technological changes, health service changes, and social and political changes. For most countries, current, population-based information on STD is lacking, yet STDs appear to be common problems in nearly all countries. The prevalence of gonococcal infection in non-STD clinic populations has been as high as 5-20%, and incidence estimates made in a few settings have ranged from 3-10% per annum. These observations may overrepresent the STD problem, yet they have been identified in countries in Asia, Africa, and the Americas. The prevalence of reactive serological tests for syphilis among antenatal clinic attendees has been as high as 10-15% in some countries of Africa and the Western Pacific. Chancroid infection is extremely common in many of the developing countries of Asia, Africa, and the Americas. Penicillinase-producing "N. gonorrhoeae" (PPNG) infections are a dramatic example of the emergence and worldwide dissemination of resistant gonococci since 1976. At this time PPNG isolates constitute over 10% of all gonococcal infections in nearly all southeast Asian and Africa settings where this problem has been explored. PPNG cause more than 50% of gonococcal infections in some settings. As a result of increasing PPNG prevalence, penicillin, previously the standard therapy for gonorrhea, has been replaced by alternative agents in many settings. A variety of antimicrobial agents are effective for PPNG infections, but these are too expensive or unavailable in many developing countries. Sequelae of STD produce enormous direct and indirect costs. Acute pelvic inflammatory disease (PID) caused by gonorrhea, chlamydia, and other STD agents is common throughout the world. In developing countries ectopic pregnancy is a common surgical emergency. Improved diagnostic tests, new approaches to treatment of STD, and development of vaccines provide opportunities for better STD control, as have changes in health care delivery. The promotion of the primary health care concept, a shift in emphasis of the international family planning programs, as well as a focus on support systems of health programs all are crucial to STD efforts, and their improvement enhances STD control possibilities. Also, greater discussion of the STD health problems has led to more serious consideration of these diseases and their control.     

Clinical management of acute respiratory infections in children: a WHO Memorandum

To reduce the massive mortality from acute respiratory infections which now occurs in children under 5 years of age in developing countries, the improvement and upgrading of clinical management, particularly by primary health care workers, seems to be the strategy of choice. This Memorandum draws attention to the need for more information on both the etiological agents and the environmental factors involved, in order to provide a scientific basis for approaches to control.     

The risk of pathogenic intestinal parasite infections in Kisii Municipality,Kenya

Background  

Intestinal parasitic infections are among the most common infections worldwide. Various epidemiological studies indicate that the prevalence of intestinal parasites is high especially in developing countries, although in many of these, the environmental risk factors have not been clearly elucidated. The objective of this study was to determine the risk of pathogenic intestinal parasites infections in Kisii Municipality.     

Surgical-site infections at Kilimanjaro Christian Medical Center

A five-month prospective survey of surgical-site infections (SSI) was conducted in the department of general surgery at Kilimanjaro Christian Medical Center, Tanzania. SSI were classified according to Centers for Disease Control and Prevention (CDC) criteria and identified by bedside surveillance and post-discharge follow-up. This study showed that 77 (19.4%) of the patients developed SSI. Twenty-eight (36.4%) of these infections were apparent only after discharge from hospital. Eighty-seven percent of those who developed SSI had received antibiotic prophylaxis. Significant risk factors for developing SSI during hospital stay were: operations classified as contaminated or dirty, operations lasting for more than 50 min and the length of preoperative stay. The only significant risk factor for those who developed SSI after discharge was having undergone a clean-contaminated operation. Staphylococcus aureus was the most frequently isolated micro-organism followed by Escherichia coli and Klebsiella spp., most of which were multi-resistant. An exception was S. aureus where 54.5% of the isolates were fully susceptible. The incidence of SSI and the prevalence of antibiotic resistance in this teaching and tertiary care hospital are high. The risk factors were similar to those reported from countries with more resources. The findings suggest that infection prevention measures, particularly antibiotic prophylaxis, should be re-evaluated.     

Dengue virus infection in Africa

Reported incidence of dengue has increased worldwide in recent decades, but little is known about its incidence in Africa. During 1960-2010, a total of 22 countries in Africa reported sporadic cases or outbreaks of dengue; 12 other countries in Africa reported dengue only in travelers. The presence of disease and high prevalence of antibody to dengue virus in limited serologic surveys suggest endemic dengue virus infection in all or many parts of Africa. Dengue is likely underrecognized and underreported in Africa because of low awareness by health care providers, other prevalent febrile illnesses, and lack of diagnostic testing and systematic surveillance. Other hypotheses to explain low reported numbers of cases include cross-protection from other endemic flavivirus infections, genetic host factors protecting against infection or disease, and low vector competence and transmission efficiency. Population-based studies of febrile illness are needed to determine the epidemiology and true incidence of dengue in Africa.     

Device-associated nosocomial infection rates in intensive care units of Argentina.

BACKGROUND: Nosocomial infections are an important public health problem in many developing countries, particularly in the intensive care unit (ICU) setting. No previous data are available on the incidence of device-associated nosocomial infections in different types of ICUs in Argentina. METHODS: We performed a prospective nosocomial infection surveillance study during the first year of an infection control program in six Argentinean ICUs. Nosocomial infections were identified using the Centers for Disease Control and Prevention National Nosocomial Infections Surveillance System definitions, and site-specific nosocomial infection rates were calculated. RESULTS: The rate of catheter-associated bloodstream infections in medical-surgical ICUs was 30.3 per 1,000 device-days; it was 14.2 per 1,000 device-days in coronary care units (CCUs). The rate of ventilator-associated pneumonia in medical-surgical ICUs was 46.3 per 1,000 device-days; it was 45.5 per 1,000 device-days in CCUs. The rate of symptomatic catheter-associated urinary tract infections in medical-surgical ICUs was 18.5 per 1,000 device-days; it was 12.1 per 1,000 device-days in CCUs. CONCLUSION: The high rate of nosocomial infections in Argentinean ICUs found during our surveillance suggests that ongoing targeted surveillance and implementation of proven infection control strategies is needed in developing countries such as Argentina.     

Can tuberculosis be controlled?

BACKGROUND: Tuberculosis (TB) is nearly 100% curable. However, the ability of medical and public health interventions to control TB, particularly in developing countries, is often doubted. METHODS: We reviewed data for the amenability of TB to control. We considered separately control of deaths, prevalence, rate of infection and incidence. RESULTS: Tuberculosis mortality can be reduced by more than 80% in less than 5 years. The prevalence of TB can be reduced by 30% or more annually; sustained annual decreases of 17% have been documented in a developing country. The TB infection rate can be reduced by 15% annually. In the absence of human immunodeficiency virus (HIV), TB incidence can be decreased by as much as 25% per year and up to 10% annually in developing countries. A high prevalence of untreated HIV infection in the adult population of a developing country will inevitably result in a significant increase in TB incidence despite optimal use of currently available technologies. CONCLUSIONS: Tuberculosis can be controlled if appropriate policies are followed, effective clinical and public health management is ensured, and there are committed and co-ordinated efforts from within and outside the health sector. However, in the context of a large epidemic of AIDS, TB incidence will inevitably increase. By 2001, less than 30% of global TB cases were reported to have received effective diagnosis, treatment and monitoring. Rapid expansion of effective TB control services is urgently required, both to avert the continued high burden of morbidity and mortality from TB and because of the HIV pandemic.     

The prevalence of epilepsy follows the distribution of onchocerciasis in a west Ugandan focus.

Epidemiological surveys indicate that the prevalence of epilepsy is higher in developing countries than in industrialized countries. Except for neurocystocercosis due to Taenia solium, little is known about possible underlying causes. This article reports the relationship between epilepsy and onchocerciasis in an Onchocerca volvulus endemic area in West Uganda. Individuals complaining of seizures were identified by means of a population census in 12 villages. Active epilepsy was confirmed in 61 of 4743 inhabitants (crude prevalence rate = 1.3%; age-standardized rate = 1.1%). Distribution of epilepsy in the study area was clustered, ranging from a prevalence of 0.2% to 3.4% in different villages. Age-specific prevalence was highest between 10 and 19 years, with a rate of 3.6% for the study are as a whole, and up to 10.0% in villages of high epilepsy prevalence. The prevalence of onchocerciasis in the 10-19-year-old age group was assessed by skin-snip biopsy and ranged from 15% to 85% in different villages. Epilepsy was significantly more frequent in the three villages with the highest levels of O. volvulus endemicity than in other villages (P < 0.0001). Serological testing for T. solium infection was positive in one and borderline in three of 53 epilepsy patients tested. The significant correlation between epilepsy and onchocerciasis did not change when these four patients were excluded from the analysis. These findings suggest a strong association between epilepsy and onchocerciasis in this area. This could have significant implications for the concept of morbidity due to O. volvulus.     

Childhood Overweight, Obesity, and the Metabolic Syndrome in Developing Countries

The incidence of chronic disease is escalating much more rapidlyin developing countries than in industrialized countries. Apotential emerging public health issue may be the increasingincidence of childhood obesity in developing countries and theresulting socioeconomic and public health burden faced by thesecountries in the near future. In a systematic review carriedout through an electronic search of the literature from 1950–2007,the author compared data from surveys on the prevalence of overweight,obesity, and the metabolic syndrome among children living indeveloping countries. The highest prevalence of childhood overweightwas found in Eastern Europe and the Middle East, whereas Indiaand Sri Lanka had the lowest prevalence. The few studies conductedin developing countries showed a considerably high prevalenceof the metabolic syndrome among youth. These findings providealarming data for health professionals and policy-makers aboutthe extent of these problems in developing countries, many ofwhich are still grappling with malnutrition and micronutrientdeficiencies. Time trends in childhood obesity and its metabolicconsequences, defined by uniform criteria, should be monitoredin developing countries in order to obtain useful insights forprimordial and primary prevention of the upcoming chronic diseaseepidemic in such communities. child • developing countries • metabolic syndrome X • obesity • overweight     

Anaemia -- the scourge of the Third World

Maternal anemia is an important cause of maternal mortality and morbidity in developing countries. It is responsible for intrauterine growth retardation, pre-term labor, intrauterine death, and birth of very low-birth-weight infants who die soon after birth, leading to a high perinatal mortality. This article discusses the incidence and prevalence of maternal anemia in developing countries. According to reviews, the highest prevalence rates of maternal anemia in the reproductive age group and pregnant women are found in South Asia and sub-Saharan Africa. In these regions, it is estimated that two-thirds of pregnant women and one-half of the nonpregnant women are anemic. Causes of anemia cited in this article include malaria, which causes destruction of red blood cells; and iron deficiency, which hinders the immune system's ability to fight infection. In the successful management of anemia, reliable techniques for detection, assessing its severity and monitoring the response to appropriate treatment should be available. Moreover, programs such as the National Nutritional Anaemia Prophylaxis Programme, which comprehensively covered the promotion consumption of iron and folate supplements, are much needed.     

Exploring substance use normalization among adolescents: A multilevel study in 35 countries

The substance use normalization thesis predicts that adolescent substance users are less likely to report substance use risk factors in high than in low prevalence countries. This study tests whether national population-level alcohol, cigarette and cannabis prevalence rates moderate the strength of the relationship between individual level social and behavioral risk factors and individual level alcohol, cigarette and cannabis use. Data from 2009/2010 Health Behaviour in School-Aged Children Study (N = 68,045, age = 15) from 35 countries was analyzed using logistic Hierarchical Linear Modeling. As expected based on low cannabis prevalence rates in all countries studied, no evidence of normalization was found for recent cannabis use. Also in line with the normalization thesis, results show that for substance use that reaches above 40% in at least some of the countries studied (drunkenness, alcohol and cigarette use), adolescents who reported use are less likely to report social and behavioral risk factors in high prevalence countries than in low prevalence countries. However, support for the normalization thesis was only partial in that results show that in models where evidence for normalization was found, there are risk factors that predict substance use to an equal degree regardless of country level prevalence rates. The current research shows that the normalization thesis is a useful framework for understanding the contextual aspects of adolescent alcohol, tobacco, and cannabis use. The study has implications for drug prevention as it suggests that selective prevention efforts may be particularly useful in low prevalence countries where screening based on risk factors may usefully identify adolescents at most risk for developing drug use problems. This approach may be less useful in high prevalence countries where screening based on risk factors is less likely to satisfactorily identify those at risk for developing drug use problems.     

HIV, syphilis, and hepatitis B and C prevalence among patients with mental illness: a review of the literature

A limited number of studies worldwide have investigated the prevalence of HIV, syphilis, and hepatitis B and C infection among psychiatric patients. However, prevalence of these infections in the population with chronic mental illness has not been clearly established. Most of the published papers are from developed countries and have derived from relatively small and non-representative samples. We performed a systematic review of the published literature to identify studies on these infectious diseases within psychiatric populations in Brazil and other developing countries. Overall, prevalence rates varied from 0% to 29% for HIV; 1.6% to 66% for HBV; 0.4% to 38% for HCV; and 1.1% to 7.6% for syphilis. Several risk factors were identified and discussed, although sampling limitations restrict the generalization of study findings. This review highlights the lack of information on the prevalence of sexually transmitted diseases and their associated factors among persons with chronic mental illness and identifies gaps in the knowledge base in both developing and developed countries.     

World Health Organization global oral health strategies for oral health promotion and disease prevention in the twenty-first century

Despite great improvements in oral health in the past decades, oral disease remains a major public health problem worldwide. The burden of oral disease is particularly high among the disadvantaged population groups in both developing and developed countries. The pattern of oral disease reflects distinct risk profiles across countries that are related to living conditions, lifestyles, environmental factors, and the availability and accessibility of oral health services. In several developing countries, people at large do not benefit from preventive oral health programmes. It is expected that the incidence of dental caries will increase in the near future in many of these countries as a result of growing consumption of sugars and inadequate exposure to fluorides. With the rising use of tobacco in developing countries, the risk of periodontal disease, tooth loss and oral cancer may therefore increase. Several oral diseases are linked to non-communicable chronic diseases or conditions that share common risk factors, such as diabetes, obesity and cancer. Similarly, general diseases often have oral manifestations (e.g. diabetes or HIV/AIDS). Worldwide strengthening of public health programmes through implementation of effective oral disease prevention measures and health promotion is urgently needed, and use of common risk factors approaches should integrate oral health within national health programmes. The challenges to oral health improvement are particularly high in developing countries. The World Health Organization Global Oral Health Programme formulates policies and actions for the improvement of oral health, strategies that are fully integrated with chronic disease prevention and general health promotion. At the 60th World Health Assembly in 2007, the WHO Member States agreed on an action plan for oral health and integrated disease prevention, thereby confirming the approach of the Oral Health Programme. The policy forms the basis for future development of oral health programmes.     

The epidemiology and risk factors of chronic polyneuropathy

Polyneuropathy is a disabling condition of the peripheral nerves, characterized by symmetrical distal numbness and paresthesia, often accompanied with pain and weakness. Although the disease is often encountered in neurological clinics and is well known by physicians, incidence and prevalence rates are not well known. We searched EMBASE, Medline, Web-of-science, Cochrane, PubMed Publisher, and Google Scholar, for population-based studies investigating the prevalence of polyneuropathy and its risk factors. Out of 5119 papers, we identified 29 eligible studies, consisting of 11 door-to-door survey studies, 7 case–control studies and 11 cohort/database studies. Prevalence of polyneuropathy across these studies varies substantially. This can partly be explained by differences in assessment protocols and study populations. The overall prevalence of polyneuropathy in the general population seems around 1 % and rises to up to 7 % in the elderly. Polyneuropathy seemed more common in Western countries than in developing countries and there are indications that females are more often affected than males. Risk factor profiles differ across countries. In developing countries communicable diseases, like leprosy, are more common causes of neuropathy, whereas in Western countries especially diabetes, alcohol overconsumption, cytostatic drugs and cardiovascular disease are more commonly associated with polyneuropathy. In all studies a substantial proportion of polyneuropathy cases (20–30 %) remains idiopathic. Most of these studies have been performed over 15 years ago. More recent evidence suggests that the prevalence of polyneuropathy in the general population has increased over the years. Future research is necessary to confirm this increase in prevalence and to identify new and potentially modifiable risk factors.     

Transmission of hepatitis B, hepatitis C and human immunodeficiency viruses through unsafe injections in the developing world: model-based regional estimates

Thousands of millions of injections are delivered every year in developing countries, many of them unsafe, and the transmission of certain bloodborne pathogens via this route is thought to be a major public health problem. In this article we report global and regional estimates of the number of hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infections that may occur from unsafe injections in the developing world. The estimates were determined using quantitative data on unsafe injection practices, transmission efficiency and disease burden of HBV, HCV and HIV and the prevalence of injection use obtained from a review of the literature. A simple mass-action model was used consisting of a generalized linear equation with variables accounting for the prevalence of a pathogen in a population, susceptibility of a population, transmission efficiency of the pathogen, proportion of injections that are unsafe, and the number of injections received. The model was applied to world census data to generate conservative estimates of incidence of transmission of bloodborne pathogens that may be attributable to unsafe injections. The model suggests that approximately 8-16 million HBV, 2.3-4.7 million HCV and 80,000-160,000 HIV infections may result every year from unsafe injections. The estimated range for HBV infections is in accordance with several epidemiological studies that attributed at least 20% of all new HBV infections to unsafe injections in developing countries. Our results suggest that unsafe injections may lead to a high number of infections with bloodborne pathogens. A major initiative is therefore needed to improve injection safety and decrease injection overuse in many countries.