Seroprevalence of Herpes Simplex Virus Type 1 and Type 2 among ‎Egyptian Children Aged from One to 15 Years old: A Comparative Study ‎

• Herpes Simplex Virus -1 and 2 seroprevalence is high in Egypt among children aged from ‎one to 15 years old. ‎
• The prevalence is particularly high among children (10-15 years old). ‎
• The study is highlighting the necessity for ongoing surveillance of HSV-1 and 2 ‎seroprevalences. ‎
• Etiological surveillance of linked morbidities should be addressed in HSV patients. ‎

Table (1): The serum levels of IgM and IgG of HSV in the study cohort.

In this observational study, we evaluated the seroprevalence of HSV-1 and HSV-2 in Egyptian children, which proved to be widespread, especially among those over the age of ten. This is the first Egyptian study that we are aware of that looked at HSV seroprevalence in healthy children. Loutfy et al. [14], The seroprevalence of HSV-1 and 2 (IgG) was 69% in children with acute leukaemia and 80% in the standard control group. Moreover, they found that the prevalence was higher in children aged 5-10 years and older than ten years, supporting our findings. On the other hand, they showed that the prevalence was comparable between both genders (70% in males and 66.6% in females).

Regarding HSV-2, we found that the prevalence in children for more than ten years and less than 15 years was 12.2%. According to large-scale studies in Asia, the overall prevalence of HSV-2 seropositivity is around 10% [17,18]. A seropositive HSV-2 prevalence of 15 to 29% was reported in several investigations around the end of the twentieth century. However, these studies were largely hospital-based or focused on the adult population[19–21].

Many studies were conducted in the Middle East to estimate the seroprevalence of HSV; however, the data regarding healthy children were scanty. In Netherlands, the seroprevalence of HSV-1 ranged between 42.7% to 47.7% [22]. The authors have also found that adults who ever had sexual intercourse were more often seropositive for HSV-1 [adjusted Odds Ratio (aOR) 1.69 95 % CI 1.33-2.16] and HSV-2 (aOR 2.35 95 % CI 1.23-4.52). Age at sexual debut was the only sexual risk determinant associated with HSV-1 seropositivity. In another study conducted by Woestenberg et al. [23], Adults who ever had sexual intercourse were more often seropositive for HSV-1 [adjusted Odds Ratio (aOR) 1.69 95 % CI 1.33-2.16] and HSV-2 (aOR 2.35 95 % CI 1.23-4.52). Age at sexual debut was the only sexual risk determinant associated with HSV-1 seropositivity.

In the middle East and North African male populations residing in Qatar, country-specific HSV-1 seroprevalence was estimated for 10 national populations: 97.5% among Egyptians, 92.6% among Yemenis, 90.7% among Sudanese, 88.5% among Syrians, 86.5% among Jordanians, 82.3% among Qataris, 81.4% among Iranians, 81.4% among Lebanese, 80.5% among Palestinians, and 77.0% among Pakistanis[23]. Seroprevalence increased with age among Fertile Crescent and Qatari nationals. Seroprevalence increased from 70.0% among those aged ≤ 24 years up to 98.0% among those aged ≥55 years among Fertile Crescent nationals [23]. According to a recent comprehensive analysis, HSV-1 seroprevalence was 65 % in Middle Eastern youngsters[24]. This high level of HSV-1 indicates considerable HSV-1-related morbidity in these populations. The bulk of Middle East studies found seroprevalence increases with age at younger ages, which was consistent with most infections occurring in childhood. The average seroprevalence in Asian children was over 60%, while in adults, seroprevalence was roughly 30% higher than in children [25–27]. The age of children was also the strongest predictor of HSV-1 seroprevalence [28]. Although socioeconomic conditions can affect the prevalence of HSV-1, Chaabane et al. showed that 44% of the variation in seroprevalence is due to age [24]. According to Yousuf et al. [29], age accounts for roughly half of the range in seroprevalence in other countries, with the striking exception of Africa, where age accounts for 80% of the variation [29]. However, the role of early speculation cannot be neglected, especially in children.

The situation is slightly different in adults; young people had much lower HSV-1 seroprevalence than older adults [24]. Remarkably, In the Middle East and North Africa (MENA) region, there was inadequate evidence for HSV-1 sexual transmission to play a role. According to Chaabane et al., they were unable to find a single study in this region that looked into the role of HSV-1 in the aetiology of genital herpes[24]. However, in North America, the detection of HSV-1 in genital herpes was 34% higher than HSV-2 [25]. The differences in sexual culture between North America, Europe, and MENA can be attributed to differences in sexual transmission. The most common route for HSV-1 infection in early infants may be via non-sexual transmission. The most common mechanism of viral transmission among people was close contact between young children (for example, in daycare centres or among family members) and adults and children. HSV-1 serostatus may be affected by childhood hygiene and living conditions as well [30].

In wealthy countries, seroprevalence was found to be lower, showing a global link between HSV-1 infection and socioeconomic position [31]. Compared to those wealthy countries in MENA, such as Iran, Jordan, and Qatar, low to middle-income countries like Egypt, Sudan, and Yemen had the highest seroprevalence [32]. Asia's faster modernisation can explain this disparity between the Middle East and North Africa.

This epidemiological situation may end up constituting a public health risk. Genital herpes has been related to a higher risk of HIV infection [33]. Second, pregnant women with primary genital herpes can transfer HSV-1 to their newborns during labour and delivery, and neonatal HSV infections have a high risk of significant morbidity [34,35]. A rise in the frequency of ocular infection, in addition to vaginal infection, may be connected to age-specific HSV-1 seroprevalence [9].

Recommendations:

Since we evaluate only the seroprevalence of HSV1 and HSV2 among Egyptian children aged from one to 15. We recommend adding more questions in sociodemographic data to be more valuable in the study to find its relation to the seroprevalence of HSV1 and HSV2 among Egyptian children aged 1 to 15. Also, larger study with bigger sample sizes should be the logical forward step following the currently available literature.

In conclusion, HSV-1 and HSV-2 seroprevalence is high in Egypt, particularly among older children (10-15 years old), highlighting the necessity for ongoing surveillance of HSV-1 and 2 seroprevalences, as well as etiological surveillance of linked morbidities.

Acknowledgement: None

Funding Sources: None

Ethical considerations:

All participants were required to sign a consent before withdrawing the blood samples. This consent involves the potential risk and the detailed information about the study but not principally for the assays of Herpes simplex antibodies. The Institutional Review Board of MUST University authorised the usage of these serum samples.