Seroepidemiology of Epstein-Barr virus infections in a developing country

Malignancy and viral infections in Sub-Saharan Africa: A review

The burden of malignancy related to viral infection is increasing in Sub-Saharan Africa (SSA). In 2018, approximately 2 million new cancer cases worldwide were attributable to infection. Prevention or treatment of these infections could reduce cancer cases by 23% in less developed regions and about 7% in developed regions. Contemporaneous increases in longevity and changes in lifestyle have contributed to the cancer burden in SSA. African hospitals are reporting more cases of cancer related to infection (e.g., cervical cancer in women and stomach and liver cancer in men). SSA populations also have elevated underlying prevalence of viral infections compared to other regions. Of 10 infectious agents identified as carcinogenic by the International Agency for Research on Cancer, six are viruses: hepatitis B and C viruses (HBV and HCV, respectively), Epstein-Barr virus (EBV), high-risk types of human papillomavirus (HPV), Human T-cell lymphotropic virus type 1 (HTLV-1), and Kaposi's sarcoma herpesvirus (KSHV, also known as human herpesvirus type 8, HHV-8). Human immunodeficiency virus type 1 (HIV) also facilitates oncogenesis. EBV is associated with lymphomas and nasopharyngeal carcinoma; HBV and HCV are associated with hepatocellular carcinoma; KSHV causes Kaposi's sarcoma; HTLV-1 causes T-cell leukemia and lymphoma; HPV causes carcinoma of the oropharynx and anogenital squamous cell cancer. HIV-1, for which SSA has the greatest global burden, has been linked to increasing risk of malignancy through immunologic dysregulation and clonal hematopoiesis. Public health approaches to prevent infection, such as vaccination, safer injection techniques, screening of blood products, antimicrobial treatments and safer sexual practices could reduce the burden of cancer in Africa. In SSA, inequalities in access to cancer screening and treatment are exacerbated by the perception of cancer as taboo. National level cancer registries, new screening strategies for detection of viral infection and public health messaging should be prioritized in SSA's battle against malignancy. In this review, we discuss the impact of carcinogenic viruses in SSA with a focus on regional epidemiology.

Primary Epstein-Barr Virus Infection in Healthy Children in Saudi Arabia: A Single Hospital-Based Study

BACKGROUND

Primary Epstein-Barr virus (EBV) infection presents typically with features of infectious mononucleosis (IM) but it may present with atypical symptoms. We aim to evaluate the epidemiological, clinical and laboratory characteristics of primary EBV infection in children in western Saudi Arabia.

METHODS

A retrospective analysis of the electronic data of all children who were admitted to the hospital and were tested for EBV-viral capsid antigen (VCA) IgM in the period from 1 January 2018 to 31 December 2019. All data of the children with positive EBV-VCA IgM were collected. Patients were divided into two groups; IM and the non-typical presentations groups.

RESULTS

Fort-two patients had positive EBV-VCA IgM; 71% had IM and 29% had non-typical presentations. IM was more common in early childhood (46.7%). The non-typical presentations were more in infants below 1 year (50%). Adolescents were less affected (6.7% and 16.7%, respectively). Time to diagnose EBV in the non-typical presentations group was longer than IM group; [3.4 (3.2-4.6) vs. 4.7 (4.1-5.5), p = 0.039]. The total leucocytes count was higher in the IM syndrome group compared to the non-typical presentation group [11 (10.3-17.7) vs. 5.5 (4.5-6.4), p < 0.0001].

CONCLUSIONS

Primary EBV infection in healthy children in Saudi Arabia occurs more frequently in the younger age groups. IM syndrome occurs more frequently in early childhood. The non-typical presentation occurs more frequently in infants. While adolescents are less commonly affected by primary EBV.

Epstein-Barr virus in multiple sclerosis

Recent seroepidemiologic and pathologic evidence suggests that prior infection with Epstein-Barr virus (EBV) may be necessary for the development of multiple sclerosis (MS). EBV infects more than 90% of all humans, most of whom remain healthy. In contrast, 99% of MS patients have evidence of prior infection with EBV. EBV infects resting B lymphocytes, immortalizing them into long-lived memory B cells that survive largely undetected by the immune system in the peripheral circulation. MS patients show elevated titers to EBV years before developing any neurologic symptoms. Postmortem pathologic analysis of brains of patients with MS has revealed diffuse EBV-associated B-cell dysregulation in all forms of MS. Theories of pathogenesis of EBV in MS include antigenic mimicry, immortalization of B-cell clones, and cytotoxic T-cell dysfunction against virally infected B cells. This article reviews the existing evidence of the relationship between EBV and MS and considers the therapeutic implication of this evidence.

A role of late Epstein-Barr virus infection in multiple sclerosis

OBJECTIVE

To assess Epstein-Barr virus (EBV) seroconversion in a high multiple sclerosis (MS) prevalence area and to evaluate the recall of diagnosed infectious mononucleosis in MS patients.

METHODS

The study was based on information or blood samples, or both, from schoolchildren, young MS patients and matched controls. EBV serology was performed on 1154 blood samples.

RESULTS

We demonstrate that more than one third of the population in a high MS prevalence area is seronegative to EBV at puberty. This is in contrast to the virtually complete seroconversion to EBV early in life in individuals from areas with a low prevalence of MS. Furthermore, we demonstrate that recall of diagnosed infectious mononucleosis (IM), but not recall of common childhood diseases, is significantly more frequent among MS patients than healthy controls. All MS patients, including patients without prior immunosuppressive treatment, were EBV seropositive.

CONCLUSION

During or after puberty, EBV is transmitted to a major proportion of the population in an MS high-prevalence area. Together with our previous documentation of an association between late infection with EBV and an increased risk of developing MS, these data support a role of EBV infection in MS.

Seroepidemiological study of Epstein-Barr virus infection in Bangladesh

A seroepidemiological study was carried out on 502 sera to determine the prevalence of EBV infection in a group of Bangladeshi people (age range: 15 days-90 years). All sera were tested for IgG antibody to the EBV viral capsid antigen (VCA) by a commercially available enzyme linked immunosorbent assay (ELISA) and the negative sera were checked subsequently by indirect immunofluorescence (IF) methods. The prevalence of EBV infection in the study group was 81.27%. 42.37% of infants had antibodies to EBV by the age of 1 year. A significant rise in the percentage of seropositives between 0-1- and 1-2-year-old children was demonstrated, indicating a high rate of primary infection at these ages. The prevalence of IgG antibody to VCA was 87.93% in the 2-10 years age group and was sustained at over 85% thereafter. Higher ELISA values were more common both in the 0-2- and > 25-year age groups, the latter being statistically significant (P < 0.025). Similar higher values were also observed in females as compared to males (P = 0.05). Eighteen out of 109 negative sera and two equivocal sera by ELISA were found to be positive by indirect IF, indicating a negative predictive value of 82% for ELISA. The concordance between the two methods was 97% with ELISA proving to be less sensitive than indirect IF. It is concluded that the prevalence of EBV infection in Bangladeshi population is similar to that observed in other developing countries and that ELISA can be used for seroepidemiological surveys; however, the sera negative by ELISA should be checked routinely by indirect IF.

The spectrum of acute Epstein-Barr virus infection in Saudi children

Most of the primary infections caused by Epstein-Barr virus in children are asymptomatic. In symptomatic patients, clinical presentation is variable. We describe 33 patients admitted to Suleimania Children's Hospital, Riyadh from 1409 too 1411H (1988 to 1990G) with acute primary infection caused by Epstein-Barr virus. The clinical presentation was mostly with upper respiratory tract infection, fever, lymphadenopathy, and hepatosplenomegaly. Three patients had arthralgia and three had neurological manifestations. Only four patients had atypical lymphocytes > 10%. Elevated serum alanine and aspartate aminotransferase levels were found in about 54.55 of the patients.

Tonsillitis and respiratory infections of viral aetiology in a developing country

Among 75 clinically diagnosed cases of tonsillitis, 55 (73.3%) were found to be of viral aetiology. Serological and virological investigations identified adenovirus as the main causative agent in children as well as in adults. In only two instances, both in children, was an association with respiratory syncytial virus (RSV) in tonsillitis detected, an extremely rare finding. A cross-sectional sero-epidemiological study of respiratory infections caused by adenovirus, RSV, influenza (A,B) and para-influenza (types 1,2,3) viruses was carried out in 289 Saudi children (newborn to 15 years of age) and 86 adults (healthy male blood donors and pregnant women) using a single serological technique. In children as well as in adults, adenoviruses were the most predominant respiratory pathogens, with no marked variation in age-specific antibody prevalence rates.