ABSTRACT
Investment in Africa over the past year with regards to SARS-CoV-2 genotyping has led to a massive increase in the number of sequences, exceeding 100,000 genomes generated to track the pandemic on the continent. Our results show an increase in the number of African countries able to sequence within their own borders, coupled with a decrease in sequencing turnaround time. Findings from this genomic surveillance underscores the heterogeneous nature of the pandemic but we observe repeated dissemination of SARS-CoV-2 variants within the continent. Sustained investment for genomic surveillance in Africa is needed as the virus continues to evolve, particularly in the low vaccination landscape. These investments are very crucial for preparedness and response for future pathogen outbreaks. One-Sentence SummaryExpanding Africa SARS-CoV-2 sequencing capacity in a fast evolving pandemic.
ABSTRACT
High-throughput serological tests that can detect neutralizing antibodies against SARS-CoV-2 are desirable for serosurveillance and vaccine efficacy evaluation. Although the conventional neutralization test (cVNT) remains the gold standard to confirm the presence of neutralizing antibodies in sera, the test is too labour-intensive for massive screening programs and less reproducible as live virus and cell culture is involved. Here, we performed an independent evaluation of a commercially available surrogate virus neutralization test (sVNT, GenScript cPass) that can be done without biosafety level 3 containment in less than 2 hours. When using the cVNT and a Luminex multiplex immunoassay (MIA) as reference, the sVNT obtained a sensitivity of 94% (CI 90-96%) on a panel of 317 immune sera that were obtained from hospitalized and mild COVID-19 cases from Belgium and a sensitivity of 89% (CI 81-93%) on a panel of 184 healthcare workers from the Democratic Republic of Congo. We also found strong antibody titer correlations (rs>0.8) among the different techniques used. In conclusion, our evaluation suggests that the sVNT could be a powerful tool to monitor/detect neutralising antibodies in cohort and population studies. The technique could be especially useful for vaccine evaluation studies in sub-Saharan Africa where the basic infrastructure to perform cVNTs is lacking.
ABSTRACT
INTRODUCTION: Parvovirus B19 (PVB19) is one of several viruses transmissible by blood transfusion. Levels of exposure to PVB19 among HIV-infected voluntary blood donors are comparable to those among HIV-negative controls because, in blood donors, the PVB19 infection is transmitted mainly via the respiratory route. Thus, we hypothesize that the seroprevalence of PVB19 in HIV-positive blood donors is equal to the seroprevalence of PVB19 in HIV-negative blood donors. The objective of this study was to compare the seroprevalence of PVB19 between asymptomatic HIV-positive and HIV-negative blood donors. METHODS: A random sample of 360 eligible blood donors were firstly examined for HIV antibodies by using ELISA automaton and so were categorized as HIV-positive donors and HIV-negative donors. Then the two categories of donors were examined for PVB19 IgG and IgM by using ELISA kits. The seroprevalence of PVB19 in HIV-positive donors was compared to that of HIV-negative donors by using chi-square test or Fisher's exact test. All statistical analyzes were performed with SPSS 21. RESULTS: The prevalences of PVB19 IgG and IgM in HIV-positive blood donors were 92.1% (35 of 38) and 44.7% (17 of 38), respectively and those in control group were 89.1% (287 of 322) and 46.3% (149 of 322), respectively. But for both IgG and IgM the difference was not statistically significant (p > 0.05). CONCLUSION: This research confirms our hypothesis: the seroprevalence of PVB19 in HIV-positive blood donors is equal to the seroprevalence of PVB19 in HIV-negative blood donors.
Subject(s)
Blood Donors , HIV Infections/epidemiology , Parvoviridae Infections/epidemiology , Parvovirus B19, Human/isolation & purification , Adolescent , Adult , Coinfection , Democratic Republic of the Congo , Enzyme-Linked Immunosorbent Assay , Female , HIV Infections/diagnosis , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Male , Middle Aged , Parvoviridae Infections/diagnosis , Seroepidemiologic Studies , Young AdultABSTRACT
Like the majority of emerging infectious diseases, HIV and HTLV are of zoonotic origin. Here we assess the risk of cross-species transmissions of their simian counterparts, SIV and STLV, from non-human primates (NHP) to humans in the Democratic Republic of Congo (DRC). A total of 331 samples, derived from NHP bushmeat, were collected as dried blood spots (DBS, n = 283) or as tissue samples (n = 36) at remote forest sites mainly in northern and eastern DRC. SIV antibody prevalences in DBS were estimated with a novel high throughput immunoassay with antigens representing the actual known diversity of HIV/SIV lineages. Antibody-positive samples were confirmed by PCR and sequence analysis. Screening for STLV infection was done with universal primers in tax, and new strains were further characterized in LTR. SIV and STLV infection in tissue samples was done by PCR only. Overall, 5 and 15.4% of NHP bushmeat was infected with SIV and STLV, respectively. A new SIV lineage was identified in Allen's swamp monkeys (Allenopithecus nigroviridis). Three new STLV-1 subtypes were identified in Allen's swamp monkeys (Allenopithecus nigroviridis), blue monkeys (Cercopithecus mitis), red-tailed guenons (Cercopithecus ascanius schmidti) and agile mangabeys (Cercocebus agilis). SIV and STLV prevalences varied according to species and geographic region. Our study illustrates clearly, even on a small sample size from a limited number of geographic areas, that our knowledge on the genetic diversity and geographic distribution of simian retroviruses is still limited and that humans continue to be exposed to relative high proportions on infected NHP bushmeat.
