Immunological Responses to Varicella-Zoster Virus (VZV) in Basrah with Special Emphasis on the Pattern of Exposure

Abstract

The study aimed on the study of pattern of exposure and immunological responses to varicella-zoster virus (VZV) infection. Methods: A seroepidemiological study was carried out on 92 blood samples collected from children in primary health care centers and outpatient clinics of Al-Sader Teaching and Basrah maternity and children hospital during the period from January 2007 till March 2008. Serological responses were investigated by an enzyme-linked immunosorbent assay (ELISA) to detect VZV IgG antibody and cellular responses was detected by Erythrocyte rosette (E-Rosette) formation test. Results: The overall VZVantibody prevalence was 53.3% for both serologic and cellular responses. The degree and pattern of exposure to VZV cases plays important role in the seroconversion and responses to VZV infections. The greatest responses observed in those with direct contact (household) with chickenpox cases (68.6% and 74.3%) and the direct contact acquired from VZV infected mothers (80% for both serologic and cellular responses). Exposure to typical chickenpox cases confers higher serologic and cellular responses (75% and 94.4% respectively). Cellular responses to VZV infections lasted longer than that for serologic responses. Sever VZV infections confers significantly higher levels of immunity (100%) and the complication post VZV infections (Pneumonia and encephalitis) mostly associated with sever cases at earlier age groups rather than the mild VZV cases. The differences in immune responses to VZV infections between male and females was significant (P<0.05). The rates of exposure to VZV infections in urban areas are significantly higher than in rural areas (P<0.05). There was a significant decline in VZV immunity over time post infections and losses of protective immunity levels were quite evident few years post infection which stress the need for vaccination. (MJBU,30,2: 2012, Page 106-114)

Varicella infection in the Middle East: Prevalence, complications, and vaccination

“…The most affected age group was children < 10 years of age and 90% of adults have already VZV antibodies. [ 13 42 43 44 48 60 81 108 ] Furthermore, number of males, i.e., varicella-reported cases, was slightly higher than females in GCC countries and Iraq, and the varicella incidence in urban regions was higher than rural ones. [ 14 18 30 38 43 ] However, in Turkey, most studies have reported that there were no differences of VZV seroprevalence rate between rural and urban regions and/or sexes of children.…”

“…A seroepidemiological study has been conducted to study the pattern of exposure and immunological responses to VZV infection among 92 children from hospitals and clinics between 2007 and 2008. [ 42 ] The overall VZV antibody prevalence was 53.3% for both serologic and cellular responses. It was also found that a difference in the immune responses to VZV infections between male and females and the rates of exposure to VZV infections was higher in urban areas than in rural areas.…”

“…It was also found that a difference in the immune responses to VZV infections between male and females and the rates of exposure to VZV infections was higher in urban areas than in rural areas. [ 42 ] Another study on chickenpox has been performed in Iraq from 2007 to 2011. [ 43 ] It has reported a rise in the number of clinically registered chickenpox cases between 2007 and 2011, around 22% in 2007, 60% in 2008, 39% in 2009, 43% in 2010, and 74% in 2011.…”

Trend of chickenpox incident cases through absent vaccination in Najaf Governorate-Iraq from January 2009 to May 2014

“…In Iraq, Rate of occurrence of clinical chickenpox cases also showed an continuous rise in the occurrence that ranges from 73 per 100000 populations in 2007 to 408 per 100000 in 2011 while the frequency of clinical cases revealed a rise in the reported cases of chickenpox from 21798 case in 2007 through 59681 in 2008 to 74195 in2011 in all provinces of Iraq (12) . In Taif -Saudi Arabia, a descriptive study was done to show incidence of chickenpox cases over the period of five years starting Jan. 1st 2007 till Dec.31th 2011 revealed that a total of 3,382 incident cases with Varicella during this period (13) .…”

The clinical and economic burden of varicella in the Middle East: a systematic literature review

“…Based on the available SLR data, the seroprevalence of varicella in different age groups mentioned in Table 3 was shown to range from 27.6% to 94.6% in Iran, 74.4% to 88.5% in Saudi Arabia, 22.3% to 98.2% in Turkey, 91.0% in Syria, 80.6% to 88.0% in the UAE, and 92.2% in Qatar. 28,29,35,36,[39][40][41][42][43][44][45]48,49,53,54,[56][57][58][59][60] The large ranges in overall seroprevalence for Iran and Turkey are likely due to differences in the overall age of the study population as many studies from the Middle East suggest an increase in seroprevalence with increasing age (Iran, Turkey, and the UAE) ( Figure 2). Based on gender distribution, a comparable seroprevalence was observed in men and women in Saudi Arabia and Turkey.…”