Increased number of Herpes Zoster cases in Brazil related to the COVID-19 pandemic.

Coronavirus 2019 (COVID-19), caused by the pathogen SARS-CoV-2, was declared a pandemic in March 2020. Recently, studies have discussed reports of patients infected with COVID-19 associated with vesicular manifestations of Herpes Zoster. The objective of this study was to compare the data from the Unified Health System (SUS) on the number of diagnoses of Herpes Zoster from March to August from 2017 to 2019, with the same period in 2020, in the five Brazilian regions (North, Northeast, Southeast, South, and Midwest). The data were extracted from the public database (DATASUS) of Brazil's Ministry of Health. The data showed an increase in the number of Herpes Zoster diagnoses over the years and the negative impact from the COVID-19 disease, revealing an average increase corresponding to an extra 10.7 cases per million inhabitants during the pandemic in all Brazilian Regions. Therefore, although the association between HZ and COVID-19 is not well established, we observed in this study an increase in HZ cases during the COVID -19 pandemic, which suggests a correlation between these diseases.

Coronavirus 2019 (COVID-19), caused by the pathogen SARS-CoV-2, was declared a pandemic by the World Health Organization (WHO) in March 2020 (Recalcati, 2020). Studies have discussed reports of patients infected with COVID-19 associated with vesicular manifestations of Herpes Zoster (HZ) (Fernandez-Nieto et al., 2020, Llamas-Velasco et al., 2020, Marzano et al., 2020, Ortega-Quijano et al., 2020, Recalcati, 2020). Recalcati (2020) reported for the first time the involvement of skin manifestations with the COVID-19 infection.

Varicella and Herpes Zoster are diseases caused by the Varicella-zoster virus (VZV) (Elsaie and Nada, 2020), which in its initial phase causes chickenpox (“Chickenpox”). This virus remains latent within the dorsal root of the trigeminal ganglion, and after its reactivation, it manifests itself as HZ (Elsaie and Nada, 2020). The objective of this study was to compare the data from the Unified Health System (SUS) on the number of diagnoses of Herpes Zoster from March to August 2017–2019, with the same period of 2020, in the five Brazilian regions (North, Northeast, Southeast, South, and Midwest).

The analyzed data were extracted from the public database (DATASUS) (http://tabnet.datasus.gov.br/cgi/tabcgi.exe?sia/cnv/qauf.def) of Brazil’s Ministry of Health (Anon, 2020a). Table 1 shows an increase in the number of HZ diagnoses over the years, and Table 2 shows the negative impact of the COVID-19 disease, revealing an increase in the number of HZ diagnoses in all Brazilian Regions. Descriptive analysis showed that the percentage of new HZ cases per million inhabitants has increased in all Brazilian regions, ranging from +23.6% in the Northwest to +77.2% in Midwest Region. The overall Brazilian average increase reached +35.4%, corresponding to an average increase of over 10.7 cases per million inhabitants during the COVID-19 pandemic.

Table 1

The number of Herpes Zoster diagnoses reported by the Brazilian public health system in all geographical regions between March and August 2017–2020.

Regions of Brazil	State	Mar-Aug 2017 (n)	Mar-Aug 2018 (n)	Mar-Aug 2019 (n)	Mar-Aug 2020 (n)
North	Acre Amapá Amazonas Pará Rondônia Roraima Tocantins	474	583	630	708
Northeast	Alagoas Bahia Ceará Maranhão Paraíba Pernambuco Piauí Rio Grande do Norte Sergipe	2086	2272	2218	2709
Southeast	Espírito Santo Minas Gerais Rio de Janeiro São Paulo	1676	2053	2446	3003
South	Paraná Rio Grande do Sul Santa Catarina	1161	1185	1078	1447
Midwest	Distrito Federala Goiás Mato Grosso Mato Grosso do Sul	294	463	649	828
Total		5691	6556	7021	8695

The Federal District encompasses the capital of Brazil, Brasília.

Table 2

Difference between the average per million of inhabitants with Herpes Zoster diagnoses reported by the Brazilian public health system in all geographical regions between March and August from 2017 to 2019 compared to the same period in 2020.

Regions of Brazil	Mar-Aug 2017−2019 (n/per million)	Mar-Aug 2020 (n/per million)	Difference (%/per million)a
North	2.65	3.33	+25.7%
Northeast	10.32	12.75	+23.6%
Southwest	9.69	14.13	+45.8%
South	5.38	6.81	+26.6%
Midwest	2.2	3.9	+77.2%
Total	30.2	40.9	+35.4%

Increase in the number of Herpes Zoster diagnoses in 2020.

The association between HZ and COVID-19 is unknown to date, but an increase in HZ infections during the COVID-19 outbreak has been observed (Llamas-Velasco et al., 2020). The COVID-19 infection can cause changes in leukocyte levels, resulting in a decrease in cell count, mainly of CD4 + T cells, CD8 + T cells, B cells, and natural killer cells (Tartari et al., 2020). The interference of SARS−COV-2 in the dysregulation of the immune system associated with physical and mental stress may be one factor involved in the reactivation of VZV (Pona et al., 2020). In the presence of vesicular lesions, we emphasize the importance of HZ diagnoses through Tzanck smear, PCR test from vesicular fluid, or skin biopsy to exclude any infection by other viruses (Llamas-Velasco et al., 2020).

Regarding COVID-19 in Brazil, the updated data on 01/02/2021 from the Brazilian Ministry of Health, Coronavirus//BRAZIL (https://covid.saude.gov.br/COVID-19) (Coronavírus//BRASIL, n.d.) (Anon, 2020b) reported a total of 9,204,731 confirmed cases; 8,027,042 recovered cases; 224,504 confirmed deaths; incidence/100 thousand inhabitants.: 43,801; mortality/100 thousand inhabitants.: 106,8. One of the limitations of this study, we should mention cases not reported to the Brazilian public health system, which suggests that the actual incidence could be higher.

Therefore, although the association between HZ and COVID-19 is not well established, we observed in this study an increase in HZ cases during the COVID -19 pandemic, which suggests a correlation between these diseases. Controlled clinical studies are necessary to clarify whether this relationship is causal or circumstantial.

Conflict of interest

Authors do not have any commercial or financial conflict of interest.

Funding source

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Ethical approval

None.