Reactivation of Kaposi's sarcoma-associated herpesvirus (KSHV) by SARS-CoV-2 in non-hospitalised HIV-infected patients.

BACKGROUND: While acute SARS-CoV-2 infection and associated inflammation resulted in substantial morbidity and mortality during the COVID-19 pandemic, particularly in unvaccinated patients, long-term effects of SARS-CoV-2 exposure for reactivation of latent oncogenic herpesviruses, such as KSHV, is unknown. METHODS: We performed a longitudinal observational cross-sectional study on 407 non-hospitalised adult HIV-infected (CD4 count <350 cells/µL) patients attending antiretroviral therapy services in Gugulethu, South Africa, from October 2020 to April 2023. FINDINGS: KSHV seroprevalence was 53.5%; the quarterly SARS-CoV-2 seroprevalence increased from 76.2% (before roll-out of COVID-19 vaccinations) to 94.9%, with 32.2% being self-reportedly vaccinated against COVID-19. Over the course of recruitment, the quarterly percentage of patients with detectable KSHV viral load (VL) in the peripheral blood increased from 3.3% to 69.2%. The presence of KSHV VL was significantly associated with SARS-CoV-2 RBD antibody titers in unvaccinated (median RBD IgG OD 1.24 [IQR 0.82-2.42] in non-reactivated versus 2.83 [IQR 1.08-4.72] in reactivated patients, p = 0.0030) but not in vaccinated patients (median RBD IgG OD 5.13 [IQR 4.11-6.36] in non-reactivated versus 4.53 [IQR 2.90-5.92] in reactivated patients, p = 0.086). Further logistic regression revealed significantly higher odds of KSHV reactivation in unvaccinated, previously SARS-CoV-2 exposed patients (p = 0.015, adjusted OR 1.28 [95% CI: 1.05-1.55]), but not vaccinated patients (p = 0.080, adjusted OR 0.83 [95% CI: 0.67-1.02]). Interestingly, detectable KSHV VL was not associated with increased inflammatory markers such as C-reactive protein and interleukin-6. INTERPRETATION: High, and most likely repeated, exposure to SARS-CoV-2 in unvaccinated individuals may have long-term consequences for reactivation of KSHV infection as shown here in the context of HIV-infected patients with impaired immune functions. Post-pandemic prevention and/or monitoring strategies of potential KSHV-associated pathologies in high-risk patients with immunodeficiencies are therefore highly recommended. FUNDING: This research was funded by the EDCTP2 programme (Training and Mobility Action TMA2018SF-2446).

The Impact of Co-Infections for Human Gammaherpesvirus Infection and Associated Pathologies.

The two oncogenic human gammaherpesviruses Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV) cause significant disease burden, particularly in immunosuppressed individuals. Both viruses display latent and lytic phases of their life cycle with different outcomes for their associated pathologies. The high prevalence of infectious diseases in Sub-Saharan Africa (SSA), particularly HIV/AIDS, tuberculosis, malaria, and more recently, COVID-19, as well as their associated inflammatory responses, could potentially impact either virus' infectious course. However, acute or lytically active EBV and/or KSHV infections often present with symptoms mimicking these predominant diseases leading to misdiagnosis or underdiagnosis of oncogenic herpesvirus-associated pathologies. EBV and/or KSHV infections are generally acquired early in life and remain latent until lytic reactivation is triggered by various stimuli. This review summarizes known associations between infectious agents prevalent in SSA and underlying EBV and/or KSHV infection. While presenting an overview of both viruses' biphasic life cycles, this review aims to highlight the importance of co-infections in the correct identification of risk factors for and diagnoses of EBV- and/or KSHV-associated pathologies, particularly in SSA, where both oncogenic herpesviruses as well as other infectious agents are highly pervasive and can lead to substantial morbidity and mortality.

SARS-CoV-2 Infection Is Associated with Uncontrolled HIV Viral Load in Non-Hospitalized HIV-Infected Patients from Gugulethu, South Africa.

In South Africa, high exposure to SARS-CoV-2 occurs primarily in densely populated, low-income communities, which are additionally burdened by highly prevalent Human Immunodeficiency Virus (HIV). With the aim to assess SARS-CoV-2 seroprevalence and its association with HIV-related clinical parameters in non-hospitalized patients likely to be highly exposed to SARS-CoV-2, this observational cross-sectional study was conducted at the Gugulethu Community Health Centre Antiretroviral clinic between October 2020 and June 2021, after the first COVID-19 wave in South Africa and during the second and beginning of the third wave. A total of 150 adult (median age 39 years [range 20−65 years]) HIV-infected patients (69% female; 31% male) were recruited. 95.3% of the cohort was on antiretroviral therapy (ART), had a median CD4 count of 220 cells/µL (range 17−604 cells/µL) and a median HIV viral load (VL) of 49 copies/mL (range 1−1,050,867 copies/mL). Furthermore, 106 patients (70.7%) were SARS-CoV-2 seropositive, and 0% were vaccinated. When stratified for HIV VL, patients with uncontrolled HIV viremia (HIV VL > 1000 copies/mL) had significantly higher odds of SARS-CoV-2 seropositivity than patients with HIV VL < 1000 copies/mL, after adjusting for age, sex and ART status (p = 0.035, adjusted OR 2.961 [95% CI: 1.078−8.133]). Although the cause−effect relationship could not be determined due to the cross-sectional study design, these results point towards a higher risk of SARS-CoV-2 susceptibility among viremic HIV patients, or impaired HIV viral control due to previous co-infection with SARS-CoV-2.

Kaposi's Sarcoma-Associated Herpesvirus, but Not Epstein-Barr Virus, Co-infection Associates With Coronavirus Disease 2019 Severity and Outcome in South African Patients.

In South Africa, the Coronavirus Disease 2019 (COVID-19) pandemic is occurring against the backdrop of high Human Immunodeficiency Virus (HIV), tuberculosis and non-communicable disease burdens as well as prevalent herpesviruses infections such as Epstein-Barr virus (EBV) and Kaposi's sarcoma-associated herpesvirus (KSHV). As part of an observational study of adults admitted to Groote Schuur Hospital, Cape Town, South Africa during the period June-August 2020 and assessed for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, we measured KSHV serology and KSHV and EBV viral load (VL) in peripheral blood in relation to COVID-19 severity and outcome. A total of 104 patients with PCR-confirmed SARS-CoV-2 infection were included in this study. 61% were men and 39% women with a median age of 53 years (range 21-86). 29.8% (95% CI: 21.7-39.1%) of the cohort was HIV positive and 41.1% (95% CI: 31.6-51.1%) were KSHV seropositive. EBV VL was detectable in 84.4% (95% CI: 76.1-84.4%) of the cohort while KSHV DNA was detected in 20.6% (95% CI: 13.6-29.2%), with dual EBV/KSHV infection in 17.7% (95% CI: 11.1-26.2%). On enrollment, 48 [46.2% (95% CI: 36.8-55.7%)] COVID-19 patients were classified as severe on the WHO ordinal scale reflecting oxygen therapy and supportive care requirements and 30 of these patients [28.8% (95% CI: 20.8-38.0%)] later died. In COVID-19 patients, detectable KSHV VL was associated with death after adjusting for age, sex, HIV status and detectable EBV VL [p = 0.036, adjusted OR = 3.17 (95% CI: 1.08-9.32)]. Furthermore, in HIV negative COVID-19 patients, there was a trend indicating that KSHV VL may be related to COVID-19 disease severity [p = 0.054, unstandardized co-efficient 0.86 (95% CI: -0.015-1.74)] in addition to death [p = 0.008, adjusted OR = 7.34 (95% CI: 1.69-31.49)]. While the design of our study cannot distinguish if disease synergy exists between COVID-19 and KSHV nor if either viral infection is indeed fueling the other, these data point to a potential contribution of KSHV infection to COVID-19 outcome, or SARS-CoV-2 infection to KSHV reactivation, particularly in the South African context of high disease burden, that warrants further investigation.

Transcriptomic Analysis of a Susceptible African Maize Line to Fusarium verticillioides Infection.

Maize (Zea mays L.) is a staple crop providing food security to millions of people in sub Saharan Africa. Fusarium verticillioides, an important fungal pathogen, infects maize causing 'Fusarium Ear Rot' disease, which decreases maize kernel yield and the quality of the crop harvested. Currently, no African maize line is completely resistant to infection by F. verticillioides. This study investigated an African maize line, Zea mays CML144, infected with F. verticillioides. Analysis of morphological characteristics showed significant differences between mock-infected and infected plants. RNA-sequencing (RNA-seq) was conducted on plants 14 days post-inoculation to identify differentially expressed genes (DEGs) involved in F. verticillioides infection. Analysis of RNA-seq data revealed DEGs that were both significantly up- and down-regulated in the infected samples compared to the mock-infected control. The maize TPS1 and cytochrome P450 genes were up-regulated, suggesting that kauralexins were involved in the CML144 defense response. This was substantiated by kauralexin analyses, which showed that kauralexins, belonging to class A and B, accumulated in infected maize tissue. Gene ontology terms relating to response to stimulus, chemical stimulus and carbohydrate metabolic processes were enriched, and the genes belonging to these GO-terms were down-regulated. Quantitative real-time PCR was performed on selected DEGs and measurement of phytoalexin accumulation validated the RNA-seq data and GO-analysis results. A comparison of DEGs from this study to DEGs found in F. verticillioides (ITEM 1744) infected susceptible (CO354) and resistant (CO441) maize genotypes in a previous study, matched 18 DEGs with 17 up-regulated and one down-regulated, respectively. This is the first transcriptomic study on the African maize line, CML144, in response to F. verticillioides infection.