Prevalence survey of cytomegalovirus infection in children in Chengdu

Cytomegalovirus Retinitis Screening and Treatment in Human Immunodeficiency Virus Patients in Malawi: A Feasibility Study

Background

Cytomegalovirus retinitis is a treatable cause of blindness in people with human immunodeficiency virus (HIV) typically with CD4 counts <50 cells/mm³. Diagnosis is with indirect fundoscopy, and treatment is with intravitreal ganciclovir injections or systemic therapy. However, diagnosis and treatment are not widely available in Malawi, which has an adult HIV prevalence estimated at 10.6%. This study aimed to establish the prevalence of cytomegalovirus retinitis among people with HIV in Malawi and the feasibility of screening.

Methods

Patients with CD4 counts <200 cells/mm³ were examined from 2 HIV clinics in Lilongwe and the main government hospital. Data were collected on antiretroviral therapy, ocular symptoms, and visual acuity. Fundoscopy was performed to investigate for features of cytomegalovirus retinitis. Retinal photographs were reviewed by an ophthalmologist. Patients diagnosed with cytomegalovirus retinitis were offered weekly ganciclovir injections, because systemic treatment was not available.

Results

Five of the 102 people with HIV screened had cytomegalovirus retinitis (4.9%). All affected patients had CD4 counts <50 cells/mm³ (mean, 15 cells/mm³; range, 3-22 cells/mm³). Visual acuity was unhelpful in identifying those with cytomegalovirus retinitis. Symptomatically, only blurred vision was useful. Two patients consented to treatment, 1 of which improved but relapsed after defaulting.

Conclusions

Cytomegalovirus retinitis screening based on CD4 count is essential to early recognition because visual acuity and symptoms are unreliable. Cytomegalovirus retinitis is a significant yet neglected public health issue in Malawi. Oral valganciclovir is essential to reduce blindness and mortality in those diagnosed but is not yet available. Further screening and advocacy are needed.

The convergent epidemiology of tuberculosis and human cytomegalovirus infection

Although several factors are known to increase the risk of tuberculosis, the occurrence of tuberculosis disease in an infected individual is difficult to predict. We hypothesize that active human cytomegalovirus infection due to recent infection, reinfection or reactivation plays an epidemiologically relevant role in the aetiology of tuberculosis by precipitating the progression from latent tuberculosis infection to disease. The most compelling support for this hypothesis comes from the striking similarity in age-sex distribution between the two infections, important because the age-sex pattern of tuberculosis disease progression has not been convincingly explained. Cytomegalovirus infection and tuberculosis have other overlapping risk factors, including poor socio-economic status, solid organ transplantation and, possibly, sexual contact and whole blood transfusion. Although each of these overlaps could be explained by shared underlying risk factors, none of the epidemiological observations refute the hypothesis. If this interaction would play an epidemiologically important role, important opportunities would arise for novel approaches to controlling tuberculosis.

The convergent epidemiology of tuberculosis and human cytomegalovirus infection

Although several factors are known to increase the risk of tuberculosis, the occurrence of tuberculosis disease in an infected individual is difficult to predict. We hypothesize that active human cytomegalovirus infection due to recent infection, reinfection or reactivation plays an epidemiologically relevant role in the aetiology of tuberculosis by precipitating the progression from latent tuberculosis infection to disease. The most compelling support for this hypothesis comes from the striking similarity in age-sex distribution between the two infections, important because the age-sex pattern of tuberculosis disease progression has not been convincingly explained. Cytomegalovirus infection and tuberculosis have other overlapping risk factors, including poor socio-economic status, sexual contact, whole blood transfusion and solid organ transplantation. Although each of these overlaps could be explained by shared underlying risk factors, none of the epidemiological observations refute the hypothesis. If this interaction would play an epidemiologically important role, important opportunities would arise for novel approaches to controlling tuberculosis.

Cytomegalovirus retinitis: the neglected disease of the AIDS pandemic

The authors describe CMV retinitis in resource-poor settings and suggest possibilities for management.

The epidemiology of childhood cytomegalovirus infections in a large city of southern Italy

The present study was undertaken to determine the prevalence of cytomegalovirus infections among 4,790 infants and children living in the Bari area. Serum antibodies were measured by a microneutralization test. IgM antibodies were measured with a capture immunoenzymatic test. A high incidence of maternally derived antibody was found during the first 6 months of life (92.8%). The positivity rate declined during the second 6 months (86.9%) and between 1 and 4 years (86.6%) and increased again between 4 and 7 years (89.1%), between 7 and 10 years (90.6%) and between 10 and 15 years (91.7%). IgM-specific antibodies were found at a titer of 1:30 or greater in 42 subjects (0.9%) who also exhibited neutralizing antibody titers > or = 1:256. Infection in Bari is characteristic of cytomegalovirus-endemic areas where maternally derived immunity is immediately replaced by immunity due to primary infection.

Prevalence of cytomegalovirus infection in Italy

Between 1987 and 1989, the prevalence of antibody to cytomegalovirus (CMV) was determined, by the ELISA method, in serum samples from 1494 apparently healthy subjects, 3-18 years old. Subjects were selected by a systematic cluster sampling from five geographical areas in Italy. The overall prevalence of antibody was 64.2%, increasing from 54.4% in 4-6-year-olds to 73.3% in subjects 17-18 years old (P less than 0.01). Prevalence of antibody was significantly higher in females (P less than 0.05) and in subjects residing in the South of Italy (P less than 0.01). A significant association was found with sociodemographic factors. Subjects belonging to a household with six or more persons had a 1.5-fold risk (C.I. 95% = 1.11-2.04) and subjects whose fathers had less than 6 years of schooling had a 1.4-fold risk (C.I. 95% = 1.1-1.87) of previous exposure to CMV infection. The high prevalence (74.4%) of young women who are naturally immune when entering childbearing years does not guarantee that there will be a low risk of fetal infection.