Rapid epidemic expansion of the SARS-CoV-2 Omicron variant in southern Africa.

The SARS-CoV-2 epidemic in southern Africa has been characterized by three distinct waves. The first was associated with a mix of SARS-CoV-2 lineages, while the second and third waves were driven by the Beta (B.1.351) and Delta (B.1.617.2) variants, respectively1-3. In November 2021, genomic surveillance teams in South Africa and Botswana detected a new SARS-CoV-2 variant associated with a rapid resurgence of infections in Gauteng province, South Africa. Within three days of the first genome being uploaded, it was designated a variant of concern (Omicron, B.1.1.529) by the World Health Organization and, within three weeks, had been identified in 87 countries. The Omicron variant is exceptional for carrying over 30 mutations in the spike glycoprotein, which are predicted to influence antibody neutralization and spike function4. Here we describe the genomic profile and early transmission dynamics of Omicron, highlighting the rapid spread in regions with high levels of population immunity.

Archived rilpivirine-associated resistance mutations among ART-naive and virologically suppressed people living with HIV-1 subtype C in Botswana: implications for cabotegravir/rilpivirine use.

OBJECTIVES: Pre-existing rilpivirine resistance-associated mutations (RVP-RAMs) have been found to predict HIV-1 virological failure in those switching to long-acting injectable cabotegravir/rilpivirine. We here evaluated the prevalence of archived RPV-RAMs in a cohort of people living with HIV (PWH). METHODS: We analysed near full-length HIV-1 pol sequences from proviral DNA for the presence of RPV-RAMs, which were defined according to the 2022 IAS-USA drug resistance mutation list and Stanford HIV drug resistance database. RESULTS: RPV-RAMs were identified in 757/5805 sequences, giving a prevalence of 13.0% (95% CI 12%-13.9%). Amongst the ART-naive group, 137/1281 (10.7%, 95% CI 9.1%-12.5%) had at least one RPV-RAM. Of the 4524 PWH with viral suppression on ART (VL <400 copies/mL), 620 (13.7%, 95% CI 12.7%-14.7%) had at least one RPV-RAM. E138A was the most prevalent RPV-RAM in the ART-naive group (7.9%) and the ART-suppressed group (9.3%). The rest of the mutations observed (L100I, K101E, E138G, E138K, E138Q, Y181C, H221Y, M230L, A98G, V179D, G190A, G190E and M230I) were below a prevalence of 1%. CONCLUSIONS: RPV-RAMs were present in 10.7% of ART-naive and 13.7% of ART-suppressed PWH in Botswana. The most common RPV-RAM in both groups was E138A. Since individuals with the E138A mutation may be more likely to fail cabotegravir/rilpivirine, monitoring RPV-RAMs will be crucial for effective cabotegravir/rilpivirine implementation in this setting.

High concordance in plasma and CSF HIV-1 drug resistance mutations despite high cases of CSF viral escape in individuals with HIV-associated cryptococcal meningitis in Botswana.

OBJECTIVES: We compared the patterns of HIV-1 drug resistance mutations between the CSF and plasma of individuals with HIV-associated cryptococcal meningitis. METHODS: This is a cross-sectional study of archived CSF and plasma samples collected from ART-exposed participants recruited in the Phase 3 AmBisome Therapy Induction Optimisation randomized controlled trial (ISRCTN72509687) conducted in Botswana between 2018 and 2021. HIV-1 RT and protease genes were genotyped using next-generation sequencing and HIV-1 drug resistance mutations were compared between the CSF and plasma compartments stratified by thresholds of ≥20% and <20%. RESULTS: Overall, 66.7% (16/24) of participants had at least one HIV-1 drug resistance mutation in the CSF and/or plasma. A total of 15/22 (68.2%) participants had HIV-1 drug resistance mutations at ≥20% threshold in the plasma and of those, 11 (73.3%) had been on ART longer than 6 months. HIV-1 drug resistance mutations were highly concordant between the CSF and plasma at ≥20% threshold despite a substantial number of individuals experiencing CSF viral escape and with only 54.5% with CSF WBC count ≥20 cells/mm3. Minority HIV-1 drug resistance mutations were detected in 20.8% (5/24) of participants. There were no mutations in the CSF that were not detected in the plasma. CONCLUSIONS: There was high concordance in HIV-1 drug resistance mutations in the CSF and plasma, suggesting intercompartmental mixing and possibly a lack of compartmentalization. Some individuals harboured minority HIV-1 drug resistance mutations, demonstrating the need to employ more sensitive genotyping methods such as next-generation sequencing for the detection of low-abundance mutations.

HIV-1 drug resistance mutations among individuals with low-level viraemia while taking combination ART in Botswana.

OBJECTIVES: To assess whether a single instance of low-level viraemia (LLV) is associated with the presence of drug resistance mutations (DRMs) and predicts subsequent virological failure (VF) in adults receiving ART in 30 communities participating in the Botswana Combination Prevention Project. METHODS: A total of 6078 HIV-1 C pol sequences were generated and analysed using the Stanford HIV drug resistance database. LLV was defined as plasma VL = 51-999 copies/mL and VF was defined as plasma VL ≥ 1000 copies/mL. RESULTS: Among 6078 people with HIV (PWH), 4443 (73%) were on ART for at least 6 months. Of the 332 persons on ART with VL > 50 copies/mL, 175 (4%) had VL ≥ 1000 copies/mL and 157 (4%) had LLV at baseline. The prevalence of any DRM was 57 (36%) and 78 (45%) in persons with LLV and VL ≥ 1000 copies/mL, respectively. Major DRMs were found in 31 (20%) with LLV and 53 (30%) with VL ≥ 1000 copies/mL (P = 0.04). Among the 135 PWH with at least one DRM, 17% had NRTI-, 35% NNRTI-, 6% PI- and 3% INSTI-associated mutations. Among the 3596 participants who were followed up, 1709 (48%) were on ART for ≥6 months at entry and had at least one subsequent VL measurement (median 29 months), 43 (3%) of whom had LLV. The OR of experiencing VF in persons with LLV at entry was 36-fold higher than in the virally suppressed group. CONCLUSIONS: A single LLV measurement while on ART strongly predicted the risk of future VF, suggesting the use of VL > 50 copies/mL as an indication for more intensive adherence support with more frequent VL monitoring.

Genetic diversity in L1 ORF of human papillomavirus in women with cervical cancer with and without human immunodeficiency virus in Botswana and Kenya.

BACKGROUND: The variation of human papillomavirus (HPV) genotypes shapes the risks of cervical cancer and these variations are not well defined in Africa. Nucleotide changes within the L1 gene, nucleotide variability, and phylogeny were explored in relation to HIV in samples from Botswana and Kenya. METHODS: A total of 98 HPV-positive cervical samples were sequenced to identify different HPV variants. Phylogenetic inferences were used to determine HPV genotypes and investigate the clustering of sequences between women living with HIV (WLWHIV) and -women not living with HIV (WNLWHIV). RESULTS: Out of 98 generated sequences, 83.7% (82/98) participants had high-risk (HR) HPV genotypes while 16.3% (16/98) had low-risk (LR) HPV genotypes. Among participants with HR-HPV genotypes, 47.6% (39/82) were coinfected with HIV. The prevalence of HR-HPV genotypes was statistically higher in the Botswana population compared to Kenya (p-value < 0.001). Multiple amino acid mutations were identified in both countries. Genetic diversity differed considerably among WLWHIV and WNLWHIV. The mean pairwise distances between HPV-16 between HIV and HIV/HPV as well as for HPV-18 were statistically significant. Six (6) new deleterious mutations were identified in the HPV genotypes based on the sequencing of the L1 region, HPV-16 (L441P, S343P), HPV-18 (S424P), HPV-45 (Q366H, Y365F), and HPV-84 (F458L). The majority of the patients with these mutations were co-infected with HIV. CONCLUSIONS: Genomic diversity and different genomic variants of HPV sequences were demonstrated. Candidate novel mutations within the L1 gene were identified in both countries which can be further investigated using functional assays.

The distribution of hepatitis B virus surface antigen polymorphisms at positions associated with vaccine escape.

Hepatitis B virus (HBV) infects over 250 million people worldwide. Vaccination is effective at preventing infection, although several mutations within the "a" determinant region of the HBV surface antigen (HBsAg) are associated with vaccine escape. We evaluated the frequency, genotype, and global distribution of polymorphisms at sites associated with vaccine escape in 4244 unique full-length HBV genomes. The "a" determinant within the Surface gene was inspected for polymorphisms at sites identified previously associated with vaccine escape. Nearly, 268 (6.3%) sequences from 36 countries contained a polymorphism at a site associated with vaccine escape including 22 genotype A, 99 genotype B, 93 genotype C, 32 genotype D, 14 genotype E, 3 genotype F, 2 genotype G, and 3 genotype I. In genotype A, the most common polymorphism occurred at M133. In genotype B, Q129 and M133 occurred 45 and 51 times, respectively, accounting for 94% of polymorphisms. Polymorphisms at G145 were most frequent in genotype C, while P120 was most common in genotype D. Among all genotypes, polymorphisms at M133 were the most common and accounted for 30.9% of polymorphisms. Polymorphisms at T116, P120, F134, K141, and P142 occurred in geographically diverse locations, whereas polymorphisms at Q129, M133, D144, and G145 were concentrated in East Asia. While the sample size is large, this approach relied on convenience sampling within each country, and many countries have no data available, thereby highlighting the need for additional routine surveillance of surface antigen mutations associated with vaccine escape.

Molecular characterization of hepatitis B virus in blood donors in Botswana.

Hepatitis B virus (HBV) poses a significant threat to blood transfusion safety in sub-Saharan Africa (SSA) where allogeneic blood donations are screened serologically, and more sensitive nucleic acid tests (NATs) are utilized infrequently. HBV strains circulating among blood donors in Botswana are not yet characterized. We designed a cross-sectional study to determine the HBV sub-genotypes and prevalence of hepatitis B surface antigen (HBsAg) among blood donors between November 2014 and October 2015. A total of 12,575 blood donations were screened for HBsAg and 50 consecutive plasma samples were selected for genotyping from confirmed HBsAg+ donations. Overlapping Pol and complete S (Pol/S) open reading frames (ORFs) were sequenced from extracted HBV DNA. To identify any signature amino acids, mutations were compared to sequences from a cohort of chronic HBV patients co-infected with HIV and were treatment naïve. The prevalence of HBsAg+ blood donors was 1.02% (95% CI 0.9-1.2%), and the circulating sub-genotypes were A1 serotype adw2 (36.1%), D2 serotype ayw2 (2.9%), and D3 serotypes ayw 1/2 (58.3%). Prevalence of escape mutations was 14% from HBV isolates of blood donors and 15% from isolates of HBV/HIV co-infected patients (p = 0.6926). The escape mutations sP120L, sG130R, sY134H, and sD144A were identified predominantly among HBV isolates from blood donors. These escape mutations have been associated with accelerated HBV sequelae [e.g., liver cirrhosis (LC) and hepatocellular carcinoma (HCC)], failure to detect HBsAg, inability to respond to immunoglobulin (Ig) therapy, and HBV vaccine escape. Characterizing the HBV burden, circulating sub-genotypes, and clinically relevant mutations among blood donors in Botswana is important to elucidate the efficacy of currently available vaccines, predicting HBV-transmission patterns, understanding the cohort's risk to HBV-related complications, and to developing prevention strategies and effective genotype-based antiretroviral therapies.

Molecular characterization of hepatitis C virus in liver disease patients in Botswana: a retrospective cross-sectional study.

BACKGROUND: Hepatitis C virus (HCV) infection is a major cause of chronic liver disease globally. Direct acting antivirals (DAAs) have proven effective in curing HCV. However, the current standard of care (SOC) in Botswana remains PEGylated interferon-α (IFN-α) with ribavirin. Several mutations have been reported to confer resistance to interferon-based treatments. Therefore, there is a need to determine HCV genotypes in Botswana, as these data will guide new treatment guidelines and understanding of HCV epidemiology in Botswana. METHODS: This was a retrospective cross-sectional pilot study utilizing plasma obtained from 55 participants from Princess Marina Hospital in Gaborone, Botswana. The partial core region of HCV was amplified, and genotypes were determined using phylogenetic analysis. RESULTS: Four genotype 5a and two genotype 4v sequences were identified. Two significant mutations - K10Q and R70Q - were observed in genotype 5a sequences and have been associated with increased risk of hepatocellular carcinoma (HCC), while R70Q confers resistance to interferon-based treatments. CONCLUSION: Genotypes 5a and 4v are circulating in Botswana. The presence of mutations in genotype 5 suggests that some patients may not respond to IFN-based regimens. The information obtained in this study, in addition to the World health organization (WHO) recommendations, can be utilized by policy makers to implement DAAs as the new SOC for HCV treatment in Botswana.

OPTIMIZATION OF DRIED BLOOD SPOT ASSAYS FOR HEPATITIS B VIRUS SURFACE ANTIBODY QUANTIFICATION.

Dried blood spot (DBS) cards can be used as an alternative sample collection method to plasma, however, there is no optimized elution protocol for DBS cards specifically for hepatitis B surface antibody (anti-HBs) testing. The study aimed to develop a DBS elution protocol for anti-HBs quantification. Our study sought to determine the ideal phosphate-buffered saline (PBS) buffer volume to use by comparing three PBS volumes (300uL, 450uL, and 500uL), and the optimal time to agitate DBS discs on a plate shaker (1hr, 2hrs, 3hrs, and 4hrs) to yield DBS anti-HBs concentrations that are comparable to corresponding plasma anti-HBs concentrations. The optimal DBS storage temperature (25°C, -20°C, and -80°C) was investigated to determine the ideal long-term storage temperature of the cards. Residual samples were used for optimization (2019-2021). A total of 50 DBS-plasma pairs was used throughout the study, with plasma anti-HBs concentrations being used as the golden standard to compare. The analysis of results was carried out by determining the p-values of the Wilcoxon sign rank. A two-way analysis of variance (ANOVA) was also performed to determine the impact of PBS elution volumes, elution time, and storage temperature on the anti-HBs concentration of DBS samples on STATA Version 15.0. No statistically significant difference between the DBS-plasma anti-HBs pairs was observed when using 450 or 500uL of PBS buffer and when samples were agitated for 3 hours (p=0.594, p=0.499 respectively). The optimal storage temperature for DBS cards was 25°C because the results showed no statistically significant difference between DBS-plasma anti-HBs titers (p=0.594). The two-way ANOVA analysis showed that elution volumes and time had no statistically significant impact on the DBS anti-HBs concentrations, p=0.948 and p=0.381 respectively. Storage temperature had a statistically significant impact on the DBS anti-HBs concentrations, p=0.002. The optimized DBS elution protocol for anti-HBs quantification will help monitor vaccine efficacy in infants due to the low sample volumes required compared to plasma and also can be used for anti-HBs testing in resource-limited areas around the country.

Hepatitis B surface antigen loss in individuals with chronic hepatitis B virus and HIV-1 infections in Botswana.

OBJECTIVES: We sought to determine hepatitis B surface antigen (HBsAg) loss and its predictors among people with chronic hepatitis B (CHB) infections and HIV (PWH) in Botswana. METHODS: Archived plasma samples from a cohort of PWH in Botswana (2013-2018) with 3 yearly time-points were used. Samples were screened for HBsAg, immunoglobulin M HBV core antibodies (anti-HBc IgM) and HBV e-antigen (HBeAg) at all time points. HBV deoxyribonucleic acid (DNA) quantification was done at baseline. The Wilcoxon rank-sum was used to compare continuous variables while the chi-squared test and Fishers exact test were used for categorical data wherever appropriate. Logistic regression was used to assess predictors of seroclearance. RESULTS: Of 141 participants with HBsAg-positive serology (HBsAg+) at baseline, 92.2% (131/141) [95% confidence interval (CI) 87.4-96.1] were persistently HBsAg+ at year 1. We report a HBsAg loss of 7.1% (10/141) (95% CI 3.9-12.6) among participants with negative HBeAg and negative IgM serologies. HBsAg loss was 6.3% (7/111) among antiretroviral therapy (ART)-experienced participants and 10.7% (3/28) (95% CI 0.4-5.0) in ART-naive participants. Most participants who had positive anti-HBc IgM serology and did not lose HBsAg were on either lamivudine (3TC)-based therapy or non-tenofovir disoproxil fumarate (TDF)-based therapy, except for one participant. The participants also had varying HBeAg status. HBsAg loss was independent of HIV viral load, CD4 + cell count, age, and sex. CONCLUSION: We report a HBsAg loss of 6.3% over a 3-year period among ART-experienced CHB participants. Future studies that focus on HBsAg loss in mono-infected patients and the possible correlation between HBeAg status and HBsAg loss are warranted.

High Prevalence of Hepatitis B Virus Drug Resistance Mutations to Lamivudine among People with HIV/HBV Coinfection in Rural and Peri-Urban Communities in Botswana.

(1) Background: We aimed to determine the prevalence of hepatitis B virus (HBV) resistance-associated mutations (RAMs) in people with HBV and human immunodeficiency virus (HBV/HIV) in Botswana. (2) Methods: We sequenced HBV deoxyribonucleic acid (DNA) from participants with HBV/HIV from the Botswana Combination Prevention Project study (2013-2018) using the Oxford Nanopore GridION platform. Consensus sequences were analyzed for genotypic and mutational profiles. (3) Results: Overall, 98 HBV sequences had evaluable reverse transcriptase region coverage. The median participant age was 43 years (IQR: 37, 49) and 66/98 (67.4%) were female. Most participants, i.e., 86/98 (87.8%) had suppressed HIV viral load (VL). HBV RAMs were identified in 61/98 (62.2%) participants. Most RAMs were in positions 204 (60.3%), 180 (50.5%), and 173 (33.3%), mostly associated with lamivudine resistance. The triple mutations rtM204V/L180M/V173L were the most predominant (17/61 [27.9%]). Most participants (96.7%) with RAMs were on antiretroviral therapy for a median duration of 7.5 years (IQR: 4.8, 10.5). Approximately 27.9% (17/61) of participants with RAMs had undetectable HBV VL, 50.8% (31/61) had VL < 2000 IU/mL, and 13/61 (21.3%) had VL ≥ 2000 IU/mL. (4) Conclusions: The high prevalence of lamivudine RAMs discourages the use of ART regimens with 3TC as the only HBV-active drug in people with HIV/HBV.

Persistence and risk factors of occult hepatitis B virus infections among antiretroviral therapy-naïve people living with HIV in Botswana.

Aim: This study aimed to determine the kinetics of occult hepatitis B virus infections (OBI) among people with HIV (PWH). Methods: The study used archived plasma samples from longitudinal HIV natural history studies. We identified new OBI cases and assessed risk factors for OBI using Cox proportional hazards regression analysis. Results: At baseline, 8 of 382 [(2.1%) (95% CI: 1.06-4.1)] samples tested positive for hepatitis B surface antigen (HBsAg+). Of the 374 HBsAg-negative samples, 76 had sufficient sample volume for HBV DNA screening. OBI positivity (OBI+) at baseline was reported in 11 of 76 [14.7 95% CI (8.3-24.1)] HBsAg-negative (HBsAg-) participants. Baseline HBsAg-negative samples with sufficient follow-up samples (n = 90) were used for analysis of newly identified OBI cases. Participants contributed 129.74 person-years to the study and were followed for a median of 1.02 years (IQR: 1.00-2.00). Cumulatively, there were 34 newly identified OBI cases from the 90 participants, at the rate of 26.2/100 person-years (95% CI: 18.7-36.7). Newly identified OBI cases were more common among men than women (61.1% vs. 31.9%) and among participants with CD4+ T-cell counts ≤450 cells/mL (p-value = 0.02). Most of the newly identified OBI cases [55.9% (19/34)] were possible reactivations as they were previously HBV core antibody positive. Conclusion: There was a high rate of newly identified OBI among young PWH in Botswana, especially in men and in participants with lower CD4+ T-cell counts. OBI screening in PWH should be considered because of the risk of transmission, possible reactivation, and risk factors for the development of chronic liver disease, including hepatocellular carcinoma.

Hepatitis B Virus Prevalence among HIV-Uninfected People Living in Rural and Peri-Urban Areas in Botswana.

(1) Background: we determined the prevalence of the hepatitis B virus (HBV) amongst people without human immunodeficiency virus (HIV) in rural and peri-urban areas in Botswana. (2) Methods: We screened for the hepatitis B surface antigen (HBsAg) from archived plasma samples of people without HIV (n = 2135) randomly selected from the Botswana Combination Prevention Program (BCPP) (2013-2018). We sequenced 415 bp of the surface region using BigDye sequencing chemistry. (3) Results: The median age of participants was 31 (IQR: 24-46) and 64% (1360/2135) were female. HBV prevalence was 4.0% (86/2135) [95% CI: 3.3-4.9]) and ranged between 0-9.2%. Older participants (>35 years) had increased odds of HBV positivity (OR: 1.94; 95% CI: [1.32-2.86]; p = 0.001). Thirteen samples were sequenced and seven (53.8%) were genotype A, three (23.1%) were genotype D and genotype E each. Clinically significant mutations were identified in the surface region, but no classic drug resistance mutations were identified. (4) Conclusions: We report an HBV prevalence of 4.0% (95% CI 3.3-4.9) among people without HIV in rural and peri-urban communities in Botswana with varying rates in different communities. A comprehensive national HBV program is required in Botswana to guide HBV prevention, testing and management.

Low-Level Viremia among Adults Living with HIV on Dolutegravir-Based First-Line Antiretroviral Therapy Is a Predictor of Virological Failure in Botswana.

We evaluated subsequent virologic outcomes in individuals experiencing low-level virem ia (LLV) on dolutegravir (DTG)-based first-line antiretroviral therapy (ART) in Botswana. We used a national dataset from 50,742 adults who initiated on DTG-based first-line ART from June 2016-December 2022. Individuals with at least two viral load (VL) measurements post three months on DTG-based first-line ART were evaluated for first and subsequent episodes of LLV (VL:51-999 copies/mL). LLV was sub-categorized as low-LLV (51-200 copies/mL), medium-LLV (201-400 copies/mL) and high-LLV (401-999 copies/mL). The study outcome was virologic failure (VF) (VL ≥ 1000 copies/mL): virologic non-suppression defined as single-VF and confirmed-VF defined as two-consecutive VF measurements after an initial VL < 1000 copies/mL. Cox regression analysis identified predictive factors of subsequent VF. The prevalence of LLV was only statistically different at timepoints >6-12 (2.8%) and >12-24 (3.9%) (p-value < 0.01). LLV was strongly associated with both virologic non-suppression (adjusted hazards ratio [aHR] = 2.6; 95% CI: 2.2-3.3, p-value ≤ 0.001) and confirmed VF (aHR = 2.5; 95% CI: 2.4-2.7, p-value ≤ 0.001) compared to initially virally suppressed PLWH. High-LLV (HR = 3.3; 95% CI: 2.9-3.6) and persistent-LLV (HR = 6.6; 95% CI: 4.9-8.9) were associated with an increased hazard for virologic non-suppression than low-LLV and a single-LLV episode, respectively. In a national cohort of PLWH on DTG-based first-line ART, LLV > 400 copies/mL and persistent-LLV had a stronger association with VF. Frequent VL testing and adherence support are warranted for individuals with VL > 50 copies/mL.

High prevalence of pre-treatment and acquired HIV-1 drug resistance mutations among non-citizens living with HIV in Botswana.

Background: Approximately 30,000 non-citizens are living with HIV in Botswana, all of whom as of 2020 are eligible to receive free antiretroviral treatment (ART) within the country. We assessed the prevalence of HIV-1 mutational profiles [pre-treatment drug resistance (PDR) and acquired drug resistance (ADR)] among treatment-experienced (TE) and treatment-naïve (TN) non-citizens living with HIV in Botswana. Methods: A total of 152 non-citizens living with HIV were enrolled from a migrant HIV clinic at Independence Surgery, a private practice in Botswana from 2019-2021. Viral RNA isolated from plasma samples were genotyped for HIV drug resistance (HIVDR) using Sanger sequencing. Major known HIV drug resistance mutations (DRMs) in the pol region were determined using the Stanford HIV Drug Resistance Database. The proportions of HIV DRMs amongst TE and TN non-citizens were estimated with 95% confidence intervals (95% CI) and compared between the two groups. Results: A total of 60/152 (39.5%) participants had a detectable viral load (VL) >40 copies/mL and these were included in the subsequent analyses. The median age at enrollment was 43 years (Q1, Q3: 38-48). Among individuals with VL > 40 copies/mL, 60% (36/60) were treatment-experienced with 53% (19/36) of them on Atripla. Genotyping had a 62% (37/60) success rate - 24 were TE, and 13 were TN. A total of 29 participants (78.4, 95% CI: 0.12-0.35) had major HIV DRMs, including at least one non-nucleoside reverse transcriptase inhibitor (NNRTI) associated DRM. In TE individuals, ADR to any antiretroviral drug was 83.3% (20/24), while for PDR was 69.2% (9/13). The most frequent DRMs were nucleoside reverse transcriptase inhibitors (NRTIs) M184V (62.1%, 18/29), NNRTIs V106M (41.4%, 12/29), and K103N (34.4%, 10/29). No integrase strand transfer inhibitor-associated DRMs were reported. Conclusion: We report high rates of PDR and ADR in ART-experienced and ART-naïve non-citizens, respectively, in Botswana. Given the uncertainty of time of HIV acquisition and treatment adherence levels in this population, routine HIV-1C VL monitoring coupled with HIVDR genotyping is crucial for long-term ART success.

An Oxford Nanopore Technology-Based Hepatitis B Virus Sequencing Protocol Suitable For Genomic Surveillance Within Clinical Diagnostic Settings.

Chronic hepatitis B virus (HBV) infection remains a significant public health concern, particularly in Africa, where there is a substantial burden. HBV is an enveloped virus, with isolates being classified into ten phylogenetically distinct genotypes (A - J) determined based on full-genome sequence data or reverse hybridization-based diagnostic tests. In practice, limitations are noted in that diagnostic sequencing, generally using Sanger sequencing, tends to focus only on the S-gene, yielding little or no information on intra-patient HBV genetic diversity with very low-frequency variants and reverse hybridization detects only known genotype-specific mutations. To resolve these limitations, we developed an Oxford Nanopore Technology (ONT)-based HBV genotyping protocol suitable for clinical virology, yielding complete HBV genome sequences and extensive data on intra-patient HBV diversity. Specifically, the protocol involves tiling-based PCR amplification of HBV sequences, library preparation using the ONT Rapid Barcoding Kit, ONT GridION sequencing, genotyping using Genome Detective software, recombination analysis using jpHMM and RDP5 software, and drug resistance profiling using Geno2pheno software. We prove the utility of our protocol by efficiently generating and characterizing high-quality near full-length HBV genomes from 148 left-over diagnostic Hepatitis B patient samples obtained in the Western Cape province of South Africa, providing valuable insights into the genetic diversity and epidemiology of HBV in this region of the world.

Low Prevalence of Nirmatrelvir-Ritonavir Resistance-Associated Mutations in SARS-CoV-2 Lineages From Botswana.

Background: We evaluated naturally occurring nirmatrelvir-ritonavir (NTV/r) resistance-associated mutations (RAMs) among severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains from Botswana, a country with no NTV/r use to date, in order to recommend the usage of the agent for high-risk patients with coronavirus disease 2019 (COVID-19). Methods: We conducted a retrospective analysis using 5254 complete SARS-CoV-2 sequences from Botswana (September 2020-September 2023). We evaluated the mutational landscape of SARS-CoV-2 3-Chymotrypsin-like protease (3CLpro) relative to the highlighted list of RAMs granted Food and Drug Administration Emergency Use Authorization in 2023. Results: The sequenced 5254 samples included Beta variants of concerns (VOCs; n = 323), Delta VOCs (n = 1314), and Omicron VOCs (n = 3354). Overall, 77.8% of the sequences exhibited at least 1 polymorphism within 76/306 amino acid positions in the nsp5 gene. NTV/rRAMs were identified in 34/5254 (0.65%; 95% CI, 0.43%-0.87%) and occurred at 5 distinct positions. Among the NTV/r RAMS detected, A191V was the most prevalent (24/34; 70.6%). Notably, T21I mutation had a prevalence of 20.6% (7/34) and coexisted with either K90R (n = 3) polymorphism in Beta sequences with RAMs or P132H (n = 3) polymorphism for Omicron sequences with RAMs. Other NTV/r RAMs detected included P108S, with a prevalence of 5.88% (2/34), and L50F, with a prevalence of 2.94% (1/34). NTV/r RAMs were significantly higher (P < .001) in Delta (24/35) compared with Beta (4/34) and Omicron (6/34) sequences. Conclusions: The frequency of NTV/r RAMs in Botswana was low. Higher rates were observed in Delta VOCs compared to Omicron and Beta VOCs. As NTV/r use expands globally, continuous surveillance for drug-resistant variants is essential, given the RAMs identified in our study.

Safety of AZD1222 COVID-19 vaccine and low Incidence of SARS-CoV-2 infection in Botswana following ChAdOx1(AZD1222) vaccination: A single-arm open-label interventional study - final study results.

Objectives: We report the final analysis of the single-arm open-label study evaluating the safety and COVID-19 incidence after AZD1222 vaccination in Botswana conducted between September 2021 and August 2022. Methods: The study included three groups of adults (>18 years), homologous AZD1222 primary series and booster (AZ2), heterologous primary series with one dose AZD1222, and AZD1222 booster (HPS), and primary series other than AZD1222 and AZD1222 booster (OPS). We compared the incidence of AEs in participants with and without prior COVID-19 infection using an exact test for rate ratios. Results: Among 10,894 participants, 9192 (84.4%) were enrolled at first vaccine dose, 521 (4.8%) at second vaccine, and 1181 (10.8%) at the booster vaccine. Of 10,855 included in the full analysis set, 1700 received one dose of AZD1222; 5377 received two doses; 98 received a heterologous series including one AZD1222 and a booster; 30 in the HPS group; 1058 in the OPS group; and 2592 in the AZ2 group. No laboratory-confirmed COVID-19 hospitalizations or deaths were reported. The incidence of laboratory-confirmed symptomatic COVID infection for the AZ2 group was 6.22 (95% confidence interval: 2.51-12.78) per 1000 participant-years (1000-PY) and 3.5 (95% confidence interval: 0.42-12.57) per 1000-PY for AZ2+booster group. Most adverse events were mild, with higher incidence in participants with prior COVID-19 infection. Individuals with prior COVID-19 exposure exhibited higher binding antibody responses. No differences in outcomes were observed by HIV status. Conclusion: AZD1222 is safe, effective, and immunogenic for people living with and without HIV.

Rapid dynamic changes of FL.2 variant: A case report of COVID-19 breakthrough infection.

We investigated intra-host genetic evolution using two SARS-CoV-2 isolates from a fully vaccinated (primary schedule x2 doses of AstraZeneca plus a booster of Pfizer), >70-year-old woman with a history of lymphoma and hypertension who presented a SARS-CoV-2 infection for 3 weeks prior to death due to COVID-19. Two full genome sequences were determined from samples taken 13 days apart with both belonging to Pango lineage FL.2: the first detection of this Omicron sub-variant in Botswana. FL.2 is a sub-lineage of XBB.1.9.1. The repertoire of mutations and minority variants in the Spike protein differed between the two time points. Notably, we also observed deletions within the ORF1a and Membrane proteins; both regions are associated with high T-cell epitope density. The internal milieu of immune-suppressed individuals may accelerate SARS-CoV-2 evolution; hence, close monitoring is warranted.

Determining Potential Link between Environmental and Clinical Isolates of Cryptococcus neoformans/Cryptococcus gattii Species Complexes Using Phenotypic and Genotypic Characterisation.

Opportunistic infections due to Cryptococcus neoformans and C. gattii species complexes continue to rise unabated among HIV/AIDS patients, despite improved antifungal therapies. Here, we collected a total of 20 environmental and 25 presumptive clinical cryptococcal isolates from cerebrospinal fluid (CSF) samples of 175 patients enrolled in an ongoing clinical trial Ambition 1 Project (Botswana-Harvard Partnership). Identity confirmation of the isolates was done using MALDI-TOF MS and PCR. We describe the diversity of the isolates by PCR fingerprinting and sequencing (Oxford Nanopore Technology) of the intergenic spacer region. Mating types of the isolates were determined by amplification of the MAT locus. We report an unusual prevalence of 42.1% of C. neoformans x C. deneoformans hybrids Serotype AD (n = 16), followed by 39.5% of C. neoformans Serotype A (n = 15), 5.3% of C. deneoformans, Serotype D (n = 2), 7.9% of C. gattii (n = 3), and 5.3% of C. tetragattii (n = 2) in 38 representative isolates that have been characterized. Mating type-specific PCR performed on 38 representative environmental and clinical isolates revealed that 16 (42.1%) were MATa/MATα hybrids, 17 (44.7%) were MATα, and five (13.2%) possessed MATa mating type. We used conventional and NGS platforms to demonstrate a potential link between environmental and clinical isolates and lay a foundation to further describe mating patterns/history in Botswana.