Impact of previous SARS-CoV-2 infection on the rate of mortality in dengue. A preliminary report from Pakistan

A hidden dilemma; post COVID-19 first detection of Varicella zoster M4 genotype from Pakistan

OBJECTIVES

During the COVID-19 pandemic, the risk of childhood infectious diseases was increased. Post-COVID-19 escalation of chickenpox cases, becoming an emerging public health concern. Thus, the study was designed to compare chickenpox prevalence and Varicella zoster virus (VZV) genotypes circulating before, during, and post-COVID-19 in Pakistan.

METHODS

A total of 267 lesion specimens collected from tertiary care hospitals, and chickenpox outbreaks from Pakistan were analysed by a two-amplicon approach with phylogenetic analysis.

RESULTS

Among suspected cases, overall 178/267 were VZV positive. Majority (84.2 %; 150/178) cases were of post-COVID-19 pandemic time. Small outbreaks occurred soon after COVID-19 in Rawalpindi and Islamabad (Pakistan), 40 positive cases out of 178 cases were outbreak cases. There was first time detection of the M4 genotype, which was significantly associated with disease severity (p = 0.0006) and post-COVID-19 chickenpox outbreaks in 2021 (77.9 %; 46/59; p < 0.00001). However, in pre-COVID-19 only M2 genotype was detected. The M2 prevalence varied from 2019 (100 %; 19/19) to 2022 (3.2 %; 3/91). However, the most prevalent strain of 2022 belonged to the M1 genotype (64.8 %; 59/91).

CONCLUSION

A significant rise in chickenpox cases detected soon after COVID-19 in Pakistan, and oscillation of different VZV genotypes with first time detection of M4 genotype is an alarming situation. This demands further detailed genotypic studies on transmission dynamics of a rare M4 with other genotypes to protect the local population and restrict spread in other regions.

SARS-CoV-2 and Dengue Coinfection in Filipino Children: Epidemiology Profile, Clinical Presentation and Outcomes

BACKGROUND

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in dengue-endemic regions has raised concern on the possibility of coinfection, especially in children who bear the highest burden of illness. This study determined the incidence and described the profile of Filipino children with SARS-CoV-2 and dengue coinfection, and compared disease severity and outcome in children with coinfection to a matched group of children with SARS-CoV-2 monoinfection.

METHODS

This was a retrospective matched cohort study of pediatric patients 0-18 years old diagnosed with SARS-CoV-2 and dengue coinfection or SARS-CoV-2 monoinfection in the Philippines and reported to the Surveillance and Analysis of Coronavirus disease 2019 (COVID-19) in Children Nationwide registry from March 01, 2020 to June 30, 2022.

RESULTS

A total of 3,341 SARS-CoV-2 infections in children were reported. The SARS-CoV-2 and dengue coinfection incidence is 4.34% (n = 145). We matched 120 coinfections to monoinfections according to age, gender and timing of infection. More coinfection cases were classified as mild or moderate COVID-19, whereas more asymptomatic cases were seen in those with monoinfection. Rates were similar for severe and critical COVID-19 in both groups. Coinfections predominantly presented with typical dengue symptoms rather than COVID-19 symptoms and laboratory parameters. No differences in outcomes were observed between coinfection and monoinfection. The case fatality rates are 6.7% for coinfection and 5.0% for monoinfection.

CONCLUSIONS

One in every 25 SARS-CoV-2 infections had a dengue coinfection. Continued surveillance is needed to establish the interaction of SARS-CoV-2 and dengue virus, evaluate the impact of COVID-19 and/or dengue vaccination on coinfection and monitor complications of coinfection.

Antibodies against the SARS-CoV-2 S1-RBD cross-react with dengue virus and hinder dengue pathogenesis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread globally since December 2019. Several studies reported that SARS-CoV-2 infections may produce false-positive reactions in dengue virus (DENV) serology tests and vice versa. However, it remains unclear whether SARS-CoV-2 and DENV cross-reactive antibodies provide cross-protection against each disease or promote disease severity. In this study, we confirmed that antibodies against the SARS-CoV-2 spike protein and its receptor-binding domain (S1-RBD) were significantly increased in dengue patients compared to normal controls. In addition, anti-S1-RBD IgG purified from S1-RBD hyperimmune rabbit sera could cross-react with both DENV envelope protein (E) and nonstructural protein 1 (NS1). The potential epitopes of DENV E and NS1 recognized by these antibodies were identified by a phage-displayed random peptide library. In addition, DENV infection and DENV NS1-induced endothelial hyperpermeability in vitro were inhibited in the presence of anti-S1-RBD IgG. Passive transfer anti-S1-RBD IgG into mice also reduced prolonged bleeding time and decreased NS1 seral level in DENV-infected mice. Lastly, COVID-19 patients’ sera showed neutralizing ability against dengue infection in vitro. Thus, our results suggest that the antigenic cross-reactivity between the SARS-CoV-2 S1-RBD and DENV can induce the production of anti-SARS-CoV-2 S1-RBD antibodies that cross-react with DENV which may hinder dengue pathogenesis.