Seroepidemiological study of Epstein-Barr virus infection in Bangladesh

Using blood donors and solid organ transplant donors and recipients to estimate the seroprevalence of cytomegalovirus and Epstein-Barr virus in Canada: A cross-sectional study

BACKGROUND

Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections are common, causing significant morbidity in pregnancy (congenital CMV) and transplant recipients (CMV, EBV). Canadian prevalence data are needed to model disease burden and develop strategies for future vaccines. We estimated prevalence using screening data from blood donors and solid organ transplant (SOT) donors and recipients.

METHODS

We retrospectively analyzed CMV and EBV serology from Alberta SOT donors (n = 3,016) and recipients (n = 4,614) (1984-2013) and Canadian Blood Services blood donors (n = 1,253,350) (2005-2014), studying associations with age, sex, organ, year, and geographic region.

RESULTS

CMV seroprevalence rises gradually with age. By age 70, CMV seropositivity ranged from 67% (blood donors) to 73% (SOT recipients). Significant proportions of women of child-bearing age were CMV-seronegative (organ donors, 44%; SOT recipients, 43%; blood donors, 61%). Blood donor CMV seroprevalence decreased from 48% in Western Canada to 30% in Eastern Canada. Women were more likely to be CMV-seropositive (ORs = 1.58, 1.45, and 1.11 for organ donors, SOT recipients, and blood donors, respectively) and EBV-seropositive (ORs = 1.87 and 1.46 for organ donors and SOT recipients, respectively). EBV prevalence rises rapidly, and by age 17-29 years, 81% of SOT recipients and 90% of organ donors were seropositive.

CONCLUSIONS

Canada has relatively low and perhaps decreasing age-specific EBV and CMV prevalence, making Canadians vulnerable to primary infection-associated morbidity and suggesting benefit from future vaccines. Collection and analysis of routine serology screening data are useful for observing trends.

Seroprevalence of Anti-EBV IgG among Various Age Groups from Khon Kaen Province, Thailand

Epstein-Barr virus (EBV) is an extremely common herpesvirus that may cause asymptomatic infection or various diseases, including infectious mononucleosis, certain lymphoproliferative diseases and several types of neoplasms. Vaccine development is an important strategy to reduce the burden of EBV-associated diseases and the timing of vaccinations should be before primary infection occurs. In the past, more than 90% of Thai children were infected with EBV in early childhood. Now, due to the improved healthcare system in Thailand, we aim to determine current prevalence of EBV infection among people in different age groups. A total of 538 sera were collected from residents of Khon Kaen province in northeastern Thailand for detecting anti-EBV IgG. Sera of infants under 2-years-old were also tested for anti-EBV IgM and EBV-DNA. The prevalence of anti-EBV IgG was 47.1% (95% CI: 23.3-70.8) in infants aged 0-6 months, 34.9% (95% CI: 23.1-46.7) in those aged 6-24 months, 87.9% (95% CI: 79.5-96.3) in children aged 3-5 years and then maintained at above 95% through adulthood. These seropositivity rates among Thai children remain similar to those found in a previous study conducted 20 years ago. Thai children are still exposed to EBV from an early age. Therefore, a prophylactic vaccine should be given within the first two years of life.

Estimation of Cancer Burden Attributable to Infection in Asia

BACKGROUND

Some infectious agents have been shown to be human carcinogens. The current study focused on estimation of cancer burden attributable to infection in different regions of Asia.

METHODS

By systematically reviewing previous studies of the infection prevalence data of 13 countries in Asia and relative risks of specific cancers, we calculated the population attributable fraction of carcinogenic infections. Using data from GLOBOCAN 2012, the overall country-specific and gender-specific number of new cancer cases and deaths resulting from infection were estimated.

RESULTS

Across 13 principal Asian countries, the average prevalence and range was 6.6% (0.5% in Japanese women to 15.0% in Vietnamese men) for hepatitis B virus (HBV), 2.6% (0.3% in Iran to 5.1% in Saudi Arabia) for hepatitis C virus (HCV), 7.9% (2.8% in Pakistan to 17.7% in China) for human papillomavirus (HPV), and 61.8% (12.8% in Indonesia to 91.7% in Bangladesh) for Helicobacter pylori (HP). The estimated total number of cancer cases and deaths caused by infection in these 13 countries were 1 212 026 (19.6% of all new cancer cases) and 908 549 (22.0% of all deaths from cancer). The fractions of cancer incidence attributable to infection were 19.7% and 19.5% in men and women, respectively. The percentages of cancer deaths attributable to infection were 21.9% and 22.1% in men and women, respectively. Among the main infectious agents, HP was responsible for 31.5% of infection-related cancer cases and 32.8% of infection-related cancer deaths, followed by HBV (28.6% of new cases and 23.8% of deaths), HPV (22.0% of new cases and 27.3% of deaths), and HCV (12.2% of new cases and 10.6% of deaths).

CONCLUSIONS

Approximately one quarter of all cancer cases and deaths were infection-associated in Asia, which could be effectively prevented if appropriate long-term controls of infectious agents were applied.

A large-scale seroprevalence of Epstein-Barr virus in Taiwan

Background

Epstein-Barr virus (EBV) causes a variety of clinical manifestations from asymptomatic infection to acute infectious mononucleosis in human. Moreover, the EBV infection is associated with malignancies. The large-scale EBV seroepidemiology across all age groups has been lacking in Taiwan.

Methods

A total of 1411 serum samples were tested to examine the seroprevalence of EBV in 2007. The samples were collected during an island-wide seroepidemiological survey of vaccine preventable diseases in Taiwan. The enzyme-linked immunosorbent assay was performed to detect anti-EBV viral capsid IgG in sera. Demographic and personal health data were obtained by questionnaires.

Results

The overall weighted seropositive rate of EBV was 88.5% (95% CI, 86.7%–90.1%). The seropositive rate of EBV reached 52.8% (95% CI, 44.0%–61.6%) in children aged 2 years, rapidly rose to 88.7% (95% CI, 79.0%–95.1%) in those aged 5–7 years and 93.0% (95%CI, 83.0%-98.1%) for those aged 14–16 years. Age and higher educational level were associated with the increased EBV seropositive rate.

Conclusion

In Taiwan, people had the EBV infection early in life. Children under 7 years should be the primary target popution of public health measures in the future.

The epidemiology of infectious mononucleosis in Northern Scotland: a decreasing incidence and winter peak

Background

Infection with Epstein-Barr virus (EBV) is almost ubiquitous in humans and generally occurs at two ages: infantile, which is usually asymptomatic and associated with poorer socioeconomic conditions, and adolescent, which causes infectious mononucleosis (IM) in ~25% cases. The determinants of whether the infection causes IM remain uncertain. We aimed to evaluate seasonality and temporal trends in IM.

Methods

Data from all Monospot tests, used as a marker for IM, were collected from the Grampian population over 16 years.

Results

Positive Monospot test results peaked at 17 years in females and 19 in males. Females had 16% more diagnoses, although 55% more tests. IM was ~38% more common in winter than summer. The annual rate of positive tests decreased progressively over the study period, from 174/100 000 (95% CI 171–178) in 1997 to 67/100 000 (95% CI 65–69) in 2012.

Conclusions

IM appears to be decreasing in incidence, which may be caused by changing environmental influences on immune systems. One such factor may be exposure to sunlight.

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Funding The Medical Research Council and NHS Grampian-MS endowments.

Cancer control in Bangladesh

Cancer is predicted to be an increasingly important cause of morbidity and mortality in Bangladesh in the next few decades. The estimated incidence of 12.7 million new cancer cases will rise to 21.4 million by 2030. More than two-thirds of the total expenditure on health is through out-of-pocket payments. According to the Bangladesh Bureau of Statistics, cancer is the sixth leading cause of death. International Agency for Research on Cancer has estimated cancer-related death rates in Bangladesh to be 7.5% in 2005 and 13% in 2030. The two leading causes are in males are lung and oral cancer and in females are breast cancer and cervical cancer. Bangladesh is now in severe shortage of radiation therapy machines, hospital bed, trained oncologists, medical radiation physicists and technologists. Bangladesh having different cancers associated with smoking and smokeless tobacco use, Human papilloma virus infection, Hepatitis B and C infection, Helicobacter Pylori infection, arsenic contaminated groundwater, availability of chemical carcinogens mainly formalin treated fruits, fish and vegetables at open market, tannery waste contaminated with chromium (which is used for poultry feed and fish feed preparation). A World Health Organization study revealed the annual cost of illnesses in Bangladesh attributable to tobacco usage is US$ 500 million and the total annual benefit from the tobacco sector is US$ 305 million as tax revenue. Bangladesh has developed a National Cancer Control Strategy and Action Plan with the aim of delivering a universal, quality-based and timely service. Cancer prevention through tobacco control, health promotion and vaccination program, cancer early detection program for oral cavity, breast and cervix has initiated. Cancer detection and diagnostic facilities will be made available at medical colleges and district- hospitals and establish a referral chain. National capacity development, more cancer research will allow Bangladesh to deal effectively and efficiently with the cancer problems through evidence-based decision making.