Congenital varicella syndrome

Epidemiology and factors influencing varicella infections in tropical countries including Sri Lanka

Varicella zoster virus (VZV) infections occur worldwide but the epidemiology differs between different geographical regions. Epidemiology of varicella is partly understood in tropical and subtropical regions. Various hypotheses showing differences in exposure rates in different age groups have been proposed. Exposure to VZV during late childhood or adolescent stage causes high morbidity, especially in high school children, university students and young work force in tropical nations. Exposure to VZV infection or sero-prevalence rates through anti-VZV immunoglobulin G appears to be lower in Sri Lanka, similar to other tropical countries prior to the millennium. In contrast, a more recent study in a group of antenatal women showed a relatively higher exposure rate to VZV when compared to the exposure rates prior to 2004 in Sri Lanka. Climatic factors, socioeconomic conditions, mobility and cultural practices appear to play a role in the differences in the exposure rates to VZV infection in the tropics. In most tropical Asian countries including Sri Lanka, routine vaccination against varicella is not carried out. Individuals with negative history for varicella take the vaccine when there is a necessity. Medical and nursing students take the vaccine prior to their clinical training to avoid adulthood varicella.

Presumptive varicella vaccination is warranted in Greek adolescents lacking a history of disease or household exposure

Current practice favors serotesting adolescents with a negative history of chickenpox rather than offering presumptive vaccination. Recent epidemiologic data from Greece indicate that a high proportion of adolescents (21.5%) are susceptible to chickenpox. We assessed the reliability of negative varicella history in relation to type of exposure in 311 children and 283 adolescents. In children with social or unknown exposure to varicella, a negative history had a high negative predictive value (NPV = 73.5), supporting the clinical practice of presumptive vaccination. Conversely, children with a negative history and household exposure had a low NPV (13.8), suggesting that pre-vaccination serologic testing is warranted. In conclusion, based on our local epidemiologic data, presumptive varicella vaccination should be offered to all adolescents with the exception of the subgroup of adolescents with household exposure.

Consequences of varicella in pregnancy: a report of four cases

Four infants are reported with varicella-Zoster virus (VZV) infection, whose mothers had varicella during the second-third trimester of pregnancy. Two newborns had neonatal varicella. One of them, whose mother contracted varicella 5 days before delivery, had a severe and complicated form of the disease. The infants who had herpes zoster did not have specific VZV-IgG antibodies at the onset of the disease.

CONCLUSION

These cases showed that varicella during the second-third trimester of pregnancy may have serious consequence for infants.