Human papillomavirus is a necessary cause of invasive cervical cancer worldwide

A recent report that 93 per cent of invasive cervical cancers worldwide contain human papillomavirus (HPV) may be an underestimate, due to sample inadequacy or integration events affecting the HPV L1 gene, which is the target of the polymerase chain reaction (PCR)-based test which was used. The formerly HPV-negative cases from this study have therefore been reanalyzed for HPV serum antibodies and HPV DNA. Serology for HPV 16 VLPs, E6, and E7 antibodies was performed on 49 of the 66 cases which were HPV-negative and a sample of 48 of the 866 cases which were HPV-positive in the original study. Moreover, 55 of the 66 formerly HPV-negative biopsies were also reanalyzed by a sandwich procedure in which the outer sections in a series of sections are used for histological review, while the inner sections are assayed by three different HPV PCR assays targeting different open reading frames (ORFs). No significant difference was found in serology for HPV 16 proteins between the cases that were originally HPV PCR-negative and -positive. Type-specific E7 PCR for 14 high-risk HPV types detected HPV DNA in 38 (69 per cent) of the 55 originally HPV-negative and amplifiable specimens. The HPV types detected were 16, 18, 31, 33, 39, 45, 52, and 58. Two (4 per cent) additional cases were only HPV DNA-positive by E1 and/or L1 consensus PCR. Histological analysis of the 55 specimens revealed that 21 were qualitatively inadequate. Only two of the 34 adequate samples were HPV-negative on all PCR tests, as against 13 of the 21 that were inadequate ( p< 0.001). Combining the data from this and the previous study and excluding inadequate specimens, the worldwide HPV prevalence in cervical carcinomas is 99.7 per cent. The presence of HPV in virtually all cervical cancers implies the highest worldwide attributable fraction so far reported for a specific cause of any major human cancer. The extreme rarity of HPV-negative cancers reinforces the rationale for HPV testing in addition to, or even instead of, cervical cytology in routine cervical screening.

IDF Diabetes Atlas: Global, regional and country-level diabetes prevalence estimates for 2021 and projections for 2045

AIMS

To provide global, regional, and country-level estimates of diabetes prevalence and health expenditures for 2021 and projections for 2045.

METHODS

A total of 219 data sources meeting pre-established quality criteria reporting research conducted between 2005 and 2020 and representing 215 countries and territories were identified. For countries without data meeting quality criteria, estimates were extrapolated from countries with similar economies, ethnicity, geography and language. Logistic regression was used to generate smoothed age-specific diabetes prevalence estimates. Diabetes-related health expenditures were estimated using an attributable fraction method. The 2021 diabetes prevalence estimates were applied to population estimates for 2045 to project future prevalence.

RESULTS

The global diabetes prevalence in 20-79 year olds in 2021 was estimated to be 10.5% (536.6 million people), rising to 12.2% (783.2 million) in 2045. Diabetes prevalence was similar in men and women and was highest in those aged 75-79 years. Prevalence (in 2021) was estimated to be higher in urban (12.1%) than rural (8.3%) areas, and in high-income (11.1%) compared to low-income countries (5.5%). The greatest relative increase in the prevalence of diabetes between 2021 and 2045 is expected to occur in middle-income countries (21.1%) compared to high- (12.2%) and low-income (11.9%) countries. Global diabetes-related health expenditures were estimated at 966 billion USD in 2021, and are projected to reach 1,054 billion USD by 2045.

CONCLUSIONS

Just over half a billion people are living with diabetes worldwide which means that over 10.5% of the world's adult population now have this condition.

IDF Diabetes Atlas: Global estimates of diabetes prevalence for 2017 and projections for 2045

INTRODUCTION

Since the year 2000, IDF has been measuring the prevalence of diabetes nationally, regionally and globally.

AIM

To produce estimates of the global burden of diabetes and its impact for 2017 and projections for 2045.

METHODS

A systematic literature review was conducted to identify published studies on the prevalence of diabetes, impaired glucose tolerance and hyperglycaemia in pregnancy in the period from 1990 to 2016. The highest quality studies on diabetes prevalence were selected for each country. A logistic regression model was used to generate age-specific prevalence estimates or each country. Estimates for countries without data were extrapolated from similar countries.

RESULTS

It was estimated that in 2017 there are 451 million (age 18-99 years) people with diabetes worldwide. These figures were expected to increase to 693 million) by 2045. It was estimated that almost half of all people (49.7%) living with diabetes are undiagnosed. Moreover, there was an estimated 374 million people with impaired glucose tolerance (IGT) and it was projected that almost 21.3 million live births to women were affected by some form of hyperglycaemia in pregnancy. In 2017, approximately 5 million deaths worldwide were attributable to diabetes in the 20-99 years age range. The global healthcare expenditure on people with diabetes was estimated to be USD 850 billion in 2017.

CONCLUSION

The new estimates of diabetes prevalence, deaths attributable to diabetes and healthcare expenditure due to diabetes present a large social, financial and health system burden across the world.

Prevalence of comorbidities and its effects in patients infected with SARS-CoV-2: a systematic review and meta-analysis

BACKGROUND

An outbreak of coronavirus disease 2019 (COVID-19) occurred in Wuhan, China; the epidemic is more widespread than initially estimated, with cases now confirmed in multiple countries.

AIMS

The aim of this meta-analysis was to assess the prevalence of comorbidities in the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infected patients and the risk of underlying diseases in severe patients compared to non-severe patients.

METHODS

A literature search was conducted using the databases PubMed, EMBASE, and Web of Science through February 25, 2020. Odds ratios (ORs) and 95% confidence intervals (CIs) were pooled using random-effects models.

RESULTS

Seven studies were included in the meta-analysis, including 1 576 infected patients. The results showed the most prevalent clinical symptom was fever (91.3%, 95% CI: 86-97%), followed by cough (67.7%, 95% CI: 59-76%), fatigue (51.0%, 95% CI: 34-68%) and dyspnea (30.4%, 95% CI: 21-40%). The most prevalent comorbidities were hypertension (21.1%, 95% CI: 13.0-27.2%) and diabetes (9.7%, 95% CI: 7.2-12.2%), followed by cardiovascular disease (8.4%, 95% CI: 3.8-13.8%) and respiratory system disease (1.5%, 95% CI: 0.9-2.1%). When compared between severe and non-severe patients, the pooled OR of hypertension, respiratory system disease, and cardiovascular disease were 2.36 (95% CI: 1.46-3.83), 2.46 (95% CI: 1.76-3.44) and 3.42 (95% CI: 1.88-6.22) respectively.

CONCLUSION

We assessed the prevalence of comorbidities in the COVID-19 patients and found that underlying disease, including hypertension, respiratory system disease and cardiovascular disease, may be risk factors for severe patients compared with non-severe patients.

IDF Diabetes Atlas: Global estimates for the prevalence of diabetes for 2015 and 2040

AIM

To produce current estimates of the national, regional and global impact of diabetes for 2015 and 2040.

METHODS

A systematic literature review was conducted to identify data sources on the prevalence of diabetes from studies conducted in the period from 1990 to 2015. An analytic hierarchy process was used to select the most appropriate studies for each country, and estimates for countries without data were modelled using extrapolation from similar countries that had available data. A logistic regression model was used to generate smoothed age-specific estimates, which were applied to UN population estimates.

RESULTS

540 data sources were reviewed, of which 196 sources from 111 countries were selected. In 2015 it was estimated that there were 415 million (uncertainty interval: 340-536 million) people with diabetes aged 20-79years, 5.0 million deaths attributable to diabetes, and the total global health expenditure due to diabetes was estimated at 673 billion US dollars. Three quarters (75%) of those with diabetes were living in low- and middle-income countries. The number of people with diabetes aged 20-79years was predicted to rise to 642 million (uncertainty interval: 521-829 million) by 2040.

CONCLUSION

Diabetes prevalence, deaths attributable to diabetes, and health expenditure due to diabetes continue to rise across the globe with important social, financial and health system implications.

The global burden of hip and knee osteoarthritis: estimates from the global burden of disease 2010 study

OBJECTIVE

To estimate the global burden of hip and knee osteoarthritis (OA) as part of the Global Burden of Disease 2010 study and to explore how the burden of hip and knee OA compares with other conditions.

METHODS

Systematic reviews were conducted to source age-specific and sex-specific epidemiological data for hip and knee OA prevalence, incidence and mortality risk. The prevalence and incidence of symptomatic, radiographic and self-reported hip or knee OA were included. Three levels of severity were defined to derive disability weights (DWs) and severity distribution (proportion with mild, moderate and severe OA). The prevalence by country and region was multiplied by the severity distribution and the appropriate disability weight to calculate years of life lived with disability (YLDs). As there are no deaths directly attributed to OA, YLDs equate disability-adjusted life years (DALYs).

RESULTS

Globally, of the 291 conditions, hip and knee OA was ranked as the 11th highest contributor to global disability and 38th highest in DALYs. The global age-standardised prevalence of knee OA was 3.8% (95% uncertainty interval (UI) 3.6% to 4.1%) and hip OA was 0.85% (95% UI 0.74% to 1.02%), with no discernible change from 1990 to 2010. Prevalence was higher in females than males. YLDs for hip and knee OA increased from 10.5 million in 1990 (0.42% of total DALYs) to 17.1 million in 2010 (0.69% of total DALYs).

CONCLUSIONS

Hip and knee OA is one of the leading causes of global disability. Methodological issues within this study make it highly likely that the real burden of OA has been underestimated. With the aging and increasing obesity of the world's population, health professions need to prepare for a large increase in the demand for health services to treat hip and knee OA.

The global burden of low back pain: estimates from the Global Burden of Disease 2010 study

OBJECTIVE

To estimate the global burden of low back pain (LBP).

METHODS

LBP was defined as pain in the area on the posterior aspect of the body from the lower margin of the twelfth ribs to the lower glutaeal folds with or without pain referred into one or both lower limbs that lasts for at least one day. Systematic reviews were performed of the prevalence, incidence, remission, duration, and mortality risk of LBP. Four levels of severity were identified for LBP with and without leg pain, each with their own disability weights. The disability weights were applied to prevalence values to derive the overall disability of LBP expressed as years lived with disability (YLDs). As there is no mortality from LBP, YLDs are the same as disability-adjusted life years (DALYs).

RESULTS

Out of all 291 conditions studied in the Global Burden of Disease 2010 Study, LBP ranked highest in terms of disability (YLDs), and sixth in terms of overall burden (DALYs). The global point prevalence of LBP was 9.4% (95% CI 9.0 to 9.8). DALYs increased from 58.2 million (M) (95% CI 39.9M to 78.1M) in 1990 to 83.0M (95% CI 56.6M to 111.9M) in 2010. Prevalence and burden increased with age.

CONCLUSIONS

LBP causes more global disability than any other condition. With the ageing population, there is an urgent need for further research to better understand LBP across different settings.

Natural history of cervicovaginal papillomavirus infection in young women

BACKGROUND

Genital human papillomavirus (HPV) infection is highly prevalent in sexually active young women. However, precise risk factors for HPV infection and its incidence and duration are not well known.

METHODS

We followed 608 college women at six-month intervals for three years. At each visit, we collected information about lifestyle and sexual behavior and obtained cervicovaginal-lavage samples for the detection of HPV DNA by polymerase chain reaction and Southern blot hybridization. Pap smears were obtained annually.

RESULTS

The cumulative 36-month incidence of HPV infection was 43 percent (95 percent confidence interval, 36 to 49 percent). An increased risk of HPV infection was significantly associated with younger age, Hispanic ethnicity, black race, an increased number of vaginal-sex partners, high frequencies of vaginal sex and alcohol consumption, anal sex, and certain characteristics of partners (regular partners having an increased number of lifetime partners and not being in school). The median duration of new infections was 8 months (95 percent confidence interval, 7 to 10 months). The persistence of HPV for > or =6 months was related to older age, types of HPV associated with cervical cancer, and infection with multiple types of HPV but not with smoking. The risk of an abnormal Pap smear increased with persistent HPV infection, particularly with high-risk types (relative risk, 37.2; 95 percent confidence interval, 14.6 to 94.8).

CONCLUSIONS

The incidence of HPV infection in sexually active young college women is high. The short duration of most HPV infections in these women suggests that the associated cervical dysplasia should be managed conservatively.

Epidemiology of Prostate Cancer

Prostate cancer is the second most frequent cancer diagnosis made in men and the fifth leading cause of death worldwide. Prostate cancer may be asymptomatic at the early stage and often has an indolent course that may require only active surveillance. Based on GLOBOCAN 2018 estimates, 1,276,106 new cases of prostate cancer were reported worldwide in 2018, with higher prevalence in the developed countries. Differences in the incidence rates worldwide reflect differences in the use of diagnostic testing. Prostate cancer incidence and mortality rates are strongly related to the age with the highest incidence being seen in elderly men (> 65 years of age). African-American men have the highest incidence rates and more aggressive type of prostate cancer compared to White men. There is no evidence yet on how to prevent prostate cancer; however, it is possible to lower the risk by limiting high-fat foods, increasing the intake of vegetables and fruits and performing more exercise. Screening is highly recommended at age 45 for men with familial history and African-American men. Up-to-date statistics on prostate cancer occurrence and outcomes along with a better understanding of the etiology and causative risk factors are essential for the primary prevention of this disease.

Epidemiology of Pancreatic Cancer: Global Trends, Etiology and Risk Factors

Pancreatic cancer is the seventh leading cause of cancer-related deaths worldwide. However, its toll is higher in more developed countries. Reasons for vast differences in mortality rates of pancreatic cancer are not completely clear yet, but it may be due to lack of appropriate diagnosis, treatment and cataloging of cancer cases. Because patients seldom exhibit symptoms until an advanced stage of the disease, pancreatic cancer remains one of the most lethal malignant neoplasms that caused 432,242 new deaths in 2018 (GLOBOCAN 2018 estimates). Globally, 458,918 new cases of pancreatic cancer have been reported in 2018, and 355,317 new cases are estimated to occur until 2040. Despite advancements in the detection and management of pancreatic cancer, the 5-year survival rate still stands at 9% only. To date, the causes of pancreatic carcinoma are still insufficiently known, although certain risk factors have been identified, such as tobacco smoking, diabetes mellitus, obesity, dietary factors, alcohol abuse, age, ethnicity, family history and genetic factors, Helicobacter pylori infection, non-O blood group and chronic pancreatitis. In general population, screening of large groups is not considered useful to detect the disease at its early stage, although newer techniques and the screening of tightly targeted groups (especially of those with family history), are being evaluated. Primary prevention is considered of utmost importance. Up-to-date statistics on pancreatic cancer occurrence and outcome along with a better understanding of the etiology and identifying the causative risk factors are essential for the primary prevention of this disease.

Epidemiology of Parkinson's disease

Parkinson's disease (PD) affects 1-2 per 1000 of the population at any time. PD prevalence is increasing with age and PD affects 1% of the population above 60 years. The main neuropathological finding is α-synuclein-containing Lewy bodies and loss of dopaminergic neurons in the substantia nigra, manifesting as reduced facilitation of voluntary movements. With progression of PD, Lewy body pathology spreads to neocortical and cortical regions. PD is regarded as a movement disorder with three cardinal signs: tremor, rigidity and bradykinesia. A recent revision of the diagnostic criteria excludes postural instability as a fourth hallmark and defines supportive criteria, absolute exclusion criteria and red flags. Non-motor symptoms in PD have gained increasing attention and both motor and non-motor signs are now included among the supportive criteria. The cause of PD is unknown in most cases. Genetic risk factors have been identified, including monogenetic causes that are rare in unselected populations. Some genetic factor can be identified in 5-10% of the patients. Several environmental factors are associated with increased risk of PD. Autopsy studies show that the clinical diagnosis of PD is not confirmed at autopsy in a significant proportion of patients. Revised diagnostic criteria are expected to improve the clinician´s accuracy in diagnosing PD. Increasing knowledge on genetic and environmental risk factors of PD will probably elucidate the cause of this disease within the near future.

Non-alcoholic fatty liver disease - A global public health perspective

As the epidemics of obesity and type 2 diabetes mellitus increase worldwide, the prevalence of non-alcoholic fatty liver disease (NAFLD) is increasing proportionately. The subtype of NAFLD which can be characterised as non-alcoholic steatohepatitis (NASH) is a potentially progressive liver disease that can lead to cirrhosis, hepatocellular carcinoma, liver transplantation, and death. NAFLD is also associated with extrahepatic manifestations such as chronic kidney disease, cardiovascular disease and sleep apnoea. NAFLD and NASH carry a large economic burden and create poor health-related quality of life. Despite this important burden, we are only beginning to understand its mechanisms of pathogenesis and the contribution of environmental and genetic factors to the risk of developing a progressive course of disease. Research is underway to identify appropriate non-invasive diagnostic methods and effective treatments. Although the risk of liver-related mortality is increased in patients with NAFLD and liver fibrosis stages F3 or F4, the leading cause of death is cardiovascular disease. Given the rapidly growing global burden of NAFLD and NASH, efforts must continue to find accurate non-invasive diagnostic and prognostic biomarkers, to develop effective treatments for individuals with advanced NASH and prevention methods for individuals at high risk of NAFLD and progressive liver disease.

Global epidemiology and genotype distribution of the hepatitis C virus infection

The treatment of chronic hepatitis C virus (HCV) infection has the potential to change significantly over the next few years as therapeutic regimens are rapidly evolving. However, the burden of chronic infection has not been quantified at the global level using the most recent data. Updated estimates of HCV prevalence, viremia and genotypes are critical for developing strategies to manage or eliminate HCV infection. To achieve this, a comprehensive literature search was conducted for anti-HCV prevalence, viraemic prevalence and genotypes for all countries. Studies were included based on how well they could be extrapolated to the general population, sample size and the age of the study. Available country estimates were used to develop regional and global estimates. Eighty-seven countries reported anti-HCV prevalence, while HCV viraemic rates were available for fifty-four countries. Total global viraemic HCV infections were estimated at 80 (64-103) million infections. Genotype distribution was available for ninety-eight countries. Globally, genotype 1 (G1) was the most common (46%), followed by G3 (22%), G2 (13%), and G4 (13%). In conclusion, the total number of HCV infections reported here are lower than previous estimates. The exclusion of data from earlier studies conducted at the peak of the HCV epidemic, along with adjustments for reduced prevalence among children, are likely contributors. The results highlight the need for more robust surveillance studies to quantify the HCV disease burden more accurately.

Global colorectal cancer burden in 2020 and projections to 2040

As the third most common malignancy and the second most deadly cancer, colorectal cancer (CRC) induces estimated 1.9 million incidence cases and 0.9 million deaths worldwide in 2020. The incidence of CRC is higher in highly developed countries, and it is increasing in middle- and low-income countries due to westernization. Moreover, a rising incidence of early-onset CRC is also emerging. The large number of CRC cases poses a growing global public health challenge. Raising awareness of CRC is important to promote healthy lifestyle choices, novel strategies for CRC management, and implementation of global screening programs, which are critical to reducing CRC morbidity and mortality in the future. CRC is a heterogeneous disease, and its subtype affiliation influences prognosis and therapeutic response. An accurate CRC subtype classification system is of great significance for basic research and clinical outcome. Here, we present the global epidemiology of CRC in 2020 and projections for 2040, review the major CRC subtypes to better understand CRC molecular basis, and summarize current risk factors, prevention, and screening strategies for CRC.

Bisphenol A and human health: a review of the literature

There is growing evidence that bisphenol A (BPA) may adversely affect humans. BPA is an endocrine disruptor that has been shown to be harmful in laboratory animal studies. Until recently, there were relatively few epidemiological studies examining the relationship between BPA and health effects in humans. However, in the last year, the number of these studies has more than doubled. A comprehensive literature search found 91 studies linking BPA to human health; 53 published within the last year. This review outlines this body of literature, showing associations between BPA exposure and adverse perinatal, childhood, and adult health outcomes, including reproductive and developmental effects, metabolic disease, and other health effects. These studies encompass both prenatal and postnatal exposures, and include several study designs and population types. While it is difficult to make causal links with epidemiological studies, the growing human literature correlating environmental BPA exposure to adverse effects in humans, along with laboratory studies in many species including primates, provides increasing support that environmental BPA exposure can be harmful to humans, especially in regards to behavioral and other effects in children.

Update on the epidemiology of gastro-oesophageal reflux disease: a systematic review

OBJECTIVE

To update the findings of the 2005 systematic review of population-based studies assessing the epidemiology of gastro-oesophageal reflux disease (GERD).

DESIGN

PubMed and Embase were screened for new references using the original search strings. Studies were required to be population-based, to include ≥ 200 individuals, to have response rates ≥ 50% and recall periods <12 months. GERD was defined as heartburn and/or regurgitation on at least 1 day a week, or according to the Montreal definition, or diagnosed by a clinician. Temporal and geographic trends in disease prevalence were examined using a Poisson regression model.

RESULTS

16 studies of GERD epidemiology published since the original review were found to be suitable for inclusion (15 reporting prevalence and one reporting incidence), and were added to the 13 prevalence and two incidence studies found previously. The range of GERD prevalence estimates was 18.1%-27.8% in North America, 8.8%-25.9% in Europe, 2.5%-7.8% in East Asia, 8.7%-33.1% in the Middle East, 11.6% in Australia and 23.0% in South America. Incidence per 1000 person-years was approximately 5 in the overall UK and US populations, and 0.84 in paediatric patients aged 1-17 years in the UK. Evidence suggests an increase in GERD prevalence since 1995 (p<0.0001), particularly in North America and East Asia.

CONCLUSIONS

GERD is prevalent worldwide, and disease burden may be increasing. Prevalence estimates show considerable geographic variation, but only East Asia shows estimates consistently lower than 10%.

Epidemiology and Management of Hepatocellular Carcinoma

The major risk factors for hepatocellular carcinoma (HCC) in contemporary clinical practice are becoming increasingly related to sustained virological response after hepatitis C, suppressed hepatitis B virus during treatment, and alcoholic and nonalcoholic fatty liver disease. We review the emerging data on the risk and determinants of HCC in these conditions and the implications of HCC surveillance. However, from a public health perspective, active hepatitis C and B continue to drive most of the global burden of HCC. In United States, the age-adjusted incidence rates of HCC in Hispanics have surpassed those of HCC in Asians. Prognosis in HCC is complex because of the competing risk imposed by underlying cirrhosis and presence of malignancy. In addition to tumor burden, liver function and performance status; additional parameters including tumor biopsy, serum markers, and subclassification of current staging systems; and taking into account patterns of tumor progression may improve patient selection for therapy. Advancements in the treatment of HCC have included identification of patients who are most likely to derive a clinically significant benefit from the available therapeutic options. Additionally, the combination strategies of locoregional therapies and/or systemic therapy are being investigated.

Global burden of heart failure: a comprehensive and updated review of epidemiology

Heart Failure (HF) is a multi-faceted and life-threatening syndrome characterized by significant morbidity and mortality, poor functional capacity and quality of life, and high costs. HF affects more than 64 million people worldwide. Therefore, attempts to decrease its social and economic burden have become a major global public health priority. While the incidence of HF has stabilized and seems to be declining in industrialized countries, the prevalence is increasing due to the ageing of the population, improved treatment of and survival with ischaemic heart disease, and the availability of effective evidence-based therapies prolonging life in patients with HF. There are geographical variations in HF epidemiology. There is substantial lack of data from developing countries, where HF exhibits different features compared with that observed in the Western world. In this review, we provide a contemporary overview on the global burden of HF, providing updated estimates on prevalence, incidence, outcomes, and costs worldwide.

Global Burden of 5 Major Types of Gastrointestinal Cancer

BACKGROUND & AIMS

There were an estimated 4.8 million new cases of gastrointestinal (GI) cancers and 3.4 million related deaths, worldwide, in 2018. GI cancers account for 26% of the global cancer incidence and 35% of all cancer-related deaths. We investigated the global burden from the 5 major GI cancers, as well as geographic and temporal trends in cancer-specific incidence and mortality.

METHODS

Data on primary cancers of the esophagus, stomach, colorectum, liver, and pancreas were extracted from the GLOBOCAN database for the year 2018, as well as from the Cancer Incidence in 5 Continents series, and the World Health Organization mortality database from 1960 onward. Age-standardized incidence and mortality rates were calculated by sex, country, and level of human development.

RESULTS

We observed geographic and temporal variations in incidence and mortality for all 5 types of GI cancers. Esophageal, gastric, and liver cancers were more common in Asia than in other parts of the world, and the burden from colorectal and pancreatic cancers was highest in Europe and North America. There was a uniform decrease in gastric cancer incidence, but an increasing incidence of colorectal cancer in formerly low-incidence regions during the studied time period. We found slight increases in incidence of liver and pancreatic cancer in some high-income regions.

CONCLUSIONS

Although the incidence of some GI cancer types has decreased, this group of malignancies continues to pose major challenges to public health. Primary and secondary prevention measures are important for controlling these malignancies-most importantly reducing consumption of tobacco and alcohol, obesity control, immunizing populations against hepatitis B virus infection, and screening for colorectal cancer.

Epidemiology of heart failure

The heart failure syndrome has first been described as an emerging epidemic about 25 years ago. Today, because of a growing and ageing population, the total number of heart failure patients still continues to rise. However, the case mix of heart failure seems to be evolving. Incidence has stabilized and may even be decreasing in some populations, but alarming opposite trends have been observed in the relatively young, possibly related to an increase in obesity. In addition, a clear transition towards heart failure with a preserved ejection fraction has occurred. Although this transition is partially artificial, due to improved recognition of heart failure as a disorder affecting the entire left ventricular ejection fraction spectrum, links can be made with the growing burden of obesity‐related diseases and with the ageing of the population. Similarly, evidence suggests that the number of patients with heart failure may be on the rise in low‐income countries struggling under the double burden of communicable diseases and conditions associated with a Western‐type lifestyle. These findings, together with the observation that the mortality rate of heart failure is declining less rapidly than previously, indicate we have not reached the end of the epidemic yet. In this review, the evolving epidemiology of heart failure is put into perspective, to discern major trends and project future directions.

Epidemiology of Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) accounts for about 90% of the 456,000 incident esophageal cancers each year. Regions of high incidence include Eastern to Central Asia, along the Rift Valley in East Africa, and into South Africa. There are many causes of ESCC, which vary among regions. Early studies in France associated smoking cigarettes and heavy alcohol consumption with high rates of ESCC, but these factors cannot explain the high incidence in other regions. We discuss other risk factors for ESCC, including polycyclic aromatic hydrocarbons from a variety of sources, high-temperature foods, diet, and oral health and the microbiome-all require further research. A growing list of defined genomic regions affects susceptibility, but large genome-wide association studies have been conducted with ethnic Chinese subjects only; more studies are called for in the rest of Asia and Africa. ESCC has been understudied, but growing infrastructure in more high-incidence countries will allow rapid progress in our understanding.

Epidemiology, causes, clinical manifestation and diagnosis, prevention and control of coronavirus disease (COVID-19) during the early outbreak period: a scoping review

BACKGROUND

The coronavirus disease (COVID-19) has been identified as the cause of an outbreak of respiratory illness in Wuhan, Hubei Province, China beginning in December 2019. As of 31 January 2020, this epidemic had spread to 19 countries with 11 791 confirmed cases, including 213 deaths. The World Health Organization has declared it a Public Health Emergency of International Concern.

METHODS

A scoping review was conducted following the methodological framework suggested by Arksey and O'Malley. In this scoping review, 65 research articles published before 31 January 2020 were analyzed and discussed to better understand the epidemiology, causes, clinical diagnosis, prevention and control of this virus. The research domains, dates of publication, journal language, authors' affiliations, and methodological characteristics were included in the analysis. All the findings and statements in this review regarding the outbreak are based on published information as listed in the references.

RESULTS

Most of the publications were written using the English language (89.2%). The largest proportion of published articles were related to causes (38.5%) and a majority (67.7%) were published by Chinese scholars. Research articles initially focused on causes, but over time there was an increase of the articles related to prevention and control. Studies thus far have shown that the virus' origination is in connection to a seafood market in Wuhan, but specific animal associations have not been confirmed. Reported symptoms include fever, cough, fatigue, pneumonia, headache, diarrhea, hemoptysis, and dyspnea. Preventive measures such as masks, hand hygiene practices, avoidance of public contact, case detection, contact tracing, and quarantines have been discussed as ways to reduce transmission. To date, no specific antiviral treatment has proven effective; hence, infected people primarily rely on symptomatic treatment and supportive care.

CONCLUSIONS

There has been a rapid surge in research in response to the outbreak of COVID-19. During this early period, published research primarily explored the epidemiology, causes, clinical manifestation and diagnosis, as well as prevention and control of the novel coronavirus. Although these studies are relevant to control the current public emergency, more high-quality research is needed to provide valid and reliable ways to manage this kind of public health emergency in both the short- and long-term.

Neuropathic pain in the general population: a systematic review of epidemiological studies

Most patients with neuropathic pain symptoms present and are managed in primary care, with only a minority being referred for specialist clinical assessment and diagnoses. Previous reviews have focused mainly on specific neuropathic pain conditions based in specialist settings. This is the first systematic review of epidemiological studies of neuropathic pain in the general population. Electronic databases were searched from January 1966 to December 2012, and studies were included where the main focus was on neuropathic pain prevalence and/or incidence, either as part of a specific neuropathic pain-related condition or as a global entity in the general population. We excluded studies in which data were extracted from pain or other specialist clinics or focusing on specific population subgroups. Twenty-one articles were identified and underwent quality assessment and data extraction. Included studies differed in 3 main ways: method of data retrieval, case ascertainment tool used, and presentation of prevalence/incidence rates. This heterogeneity precluded any meta-analysis. We categorised comparable incidence and prevalence rates into 2 main subgroups: (1) chronic pain with neuropathic characteristics (range 3-17%), and (2) neuropathic pain associated with a specific condition, including postherpetic neuralgia (3.9-42.0/100,000 person-years [PY]), trigeminal neuralgia (12.6-28.9/100,000 PY), painful diabetic peripheral neuropathy (15.3-72.3/100,000 PY), glossopharyngeal neuralgia (0.2-0.4/100,000 PY). These differences highlight the importance of a standardised approach for identifying neuropathic pain in future epidemiological studies. A best estimate of population prevalence of pain with neuropathic characteristics is likely to lie between 6.9% and 10%.