Advances in Etiopathological Role and Control of HPV in Cervical Cancer Oncogenesis

The human papillomavirus (HPV) is a well-known oncovirus whose causal link in the occurrence and development of several cancers, such as cervical cancer (CC), has been well established. Indeed, numerous researches depicted the etiological role of HPV in CC pathogenesis in such a way as to develop efficient strategies, including early diagnoses and HPV vaccination, to mitigate HPV infection and CC occurrence. Despite the effectiveness of these strategies in preventing HPV infection, its persistence, and the progression to precancerous lesions and cancers, extensive work that could give a better understanding of other unknown factors favoring oncogenesis is much more needed. In this last decade, scarce or few but crucial and strategic studies have been carried out to improve and deepen our understanding of the etiopathological role of HPV in the progression towards the development of CC. In this review, we highlighted the recent findings on the pathological role of HPV in CC occurrence and the advances in novel adopted strategies to reduce HPV infection and prevent CC occurrence more effectively.

Could pooled samples method affect SARS-CoV-2 diagnosis accuracy using BGI and Sansure-Biotech RT-PCR kits used in Gabon, Central Africa?

This study aims at establishing specimens pooling approach for the detection of SARS-CoV-2 using the RT-PCR BGI and Sansure-Biotech kits used in Gabon. To validate this approach, 14 positive samples, stored at -20°C for three to five weeks were analyzed individually (as gold standard) and in pools of five, eight and ten in the same plate. We created 14 pools of 5, 8 and 10 samples using 40 μL from each of the selected positive samples mixed with 4, 7 and 9 confirmed negative counterparts in a total volume of 200 μL, 320 μL and 400 μL for the pools of 5, 8 and 10 respectively. Both individual and pooled samples testing was conducted according to the BGI and Sansure-Biotech RT-PCR protocols used at the Professor Daniel Gahouma Laboratory (PDGL). Furthermore, the pooling method was also tested by comparing results of 470 unselected samples tested in 94 pools and individually. Results of our experiment showed that using a BGI single positive sample with cycle threshold (Ct) value of 28.42, confirmed by individual testing, detection occurred in all the pools. On the contrary samples with Ct >31 were not detected in pools of 10 and for these samples (Ct value as high as 37.17) their detection was possible in pool of 8. Regarding the Sansure-Biotech kit, positive samples were detected in all the pool sizes tested, irrespective of their Ct values. The specificity of the pooling method was 100% for the BGI and Sansure-Biotech RT-PCR assays. The present study found an increase in the Ct values with pool size for the BGI and Sansure-Biotech assays. This trend was statistically significant (Pearson’s r = 0.978; p = 0,022) using the BGI method where the mean Ct values were 24.04±1.1, 26.74±1.3, 27.91±1.1 and 28.32±1.1 for the individual, pool of 5, 8 and 10 respectively. The testing of the 470 samples showed that one of the 94 pools had a positive test similar to the individual test using the BGI and Sansure-Biotech kits. The saving of time and economizing test reagents by using the pooling method were demonstrated in this study. Ultimately, the pooling method could be used for the diagnosis of SARS-CoV-2 without modifying the accuracy of results in Gabon. We recommend a maximum pool size of 8 for the BGI kit. For the Sansure-Biotech kit, a maximum pool size of 10 can be used without affecting its accuracy compared to the individual testing.

Unrecognized introduction of SARS-CoV-2 variants of concern to Central Africa: Import and local transmission of B.1.1.7 in Gabon in the very early stage of the variant spread to the African continent

The rapid spread of the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) variant of concern with higher infectivity has already resulted in the enormous increase in infection cases worldwide. We report an unrecognized introduction of the variant B.1.1.7 in Gabon in December 2020, which was the initial phase of the variant introduction to Africa. The B.1.1.7 variant was also detected in a hospitalized patient in January 2021, indicating a rapid spread of the variant in Gabon since its first detection. Phylogenetic analysis revealed that the detected B.1.1.7 variants originated from the distinct regions, strongly suggesting that the B.1.1.7 variant had been repeatedly introduced to Gabon since December 2020. These results provide insights on the unrecognized risks of infections with variants of concern, and show the necessity to conduct continuous genomic monitoring for immediate alert and control of novel SARS‐CoV‐2 variant infections.

Hepatitis B infection among HIV infected individuals in Gabon: Occult hepatitis B enhances HBV DNA prevalence

In Gabon, a central African country, human immunodeficiency virus (HIV) and hepatitis B virus (HBV) are endemic. In a recent study, conducted in a semi-urban area (Franceville, Gabon), HBV infection was found to be more prevalent among HIV infected individuals. This study aims to investigate the prevalence and genetic diversity of hepatitis B virus infection among HIV infected individuals, predominantly under antiretroviral therapy, living in fully urbanized area: Libreville, capital of Gabon. Serological and molecular tests were performed to detect HBV infection among patients living with HIV/AIDS (PLHA). We used Monolisa HBsAg ULTRA, Anti-HBc Plus and Anti-HBs Plus EIA kits for serological analyses. HBV DNA viral load (HBV DNA VL) was determined by real time PCR and molecular characterization of HBV strains was performed by sequencing and phylogenetic analysis of partial HBV surface and core genes. At all, 70.2% of patients were under antiretroviral therapy. The prevalence of HBsAg was 8.8% (43/487). Detectable HBV DNA was found in 69.7% (30/43) of HBsAg positive patients and in 17.5% (24/137) HBsAg negative patients. HBV DNA VL was significantly higher among patient with CD4 cell counts less than 200 cells/mm³ than those with CD4 cell counts greater than 500 cells/mm³ (p = 0.008). We confirmed the presence of HBV sub-genotypes QS-A3 (40%), and A4 (20%) and HBV-E genotype (40%). The percentage of resistance to Lamivudine was high (40%) and varied according to the M204V/I motif. Occult hepatitis B infection (OBI) was found in patients with isolated HBcAb and among patients who had completed their HBsAg seroconversion. We detected HBV DNA for one patient without any HBV serological marker. This study provides a new landmark for the comprehension of HBV infection in PLHA in urban areas. OBI enhances HBV DNA prevalence and should be investigated in all HBsAg negative individuals.

Human papillomavirus genotypes distribution in cervical cancer cases in Gabon

Background

Cervical cancer is a real public health problem in African countries. The relation between HPV and cervical cancer is well established. However, it is known that the distribution of HPV genotypes differ geographically and this may influence the effectiveness of the three available vaccines, which among other HPV genotypes targets the genotypes 16 and 18 that cause about 70 % of cervical cancers cases. The objective of this study was to identify for the first time the HPV genotypes distribution in cervical cancer specimens obtained from Gabonese women.

Methods

A total of 105 cervical samples including 93 formalin-fixed paraffin embedded tissues collected between 2007 and 2013 and 12 fresh biopsies collected in August 2013 were investigated. The presence of HPV DNA was analyzed by nested PCR with primers MY09/11 and GP5+/6+ followed by sequencing for HPV genotyping.

Results

Amplification of the housekeeping gene (β-globin) with PCO4/GH20 primers was successful for 91.4 % (96/105) of the cervical cancer samples and HPV DNA was detected in all the 96 samples. Five different HPV genotypes were identified. HPV 16 [58.3 %; 95 % IC: 48.44–68.16] was the most common genotype followed by HPV 33 [25.0 %; 95 % IC: 16.34–33.66], HPV 18 [8.4 %; 95 % IC: 2.86–13.94], HPV 70 [7.3 %; 95 % IC: 2.1–12.5] and HPV 31 [1.1 %; 95 % IC: −0.986–3.186]. HPV 16 was also the most prevalent in all histological malignant lesions. It was found in 56.6 % of squamous cervical carcinoma and 69.2 % of adenocarcinoma. Concerning the HPV positive adenocarcinoma cases, HPV 18 was identified in 7.7 % (1/13).

Conclusion

These findings show the predominance of HPV 16 in cervical cancer cases among Gabonese women. However, HPV33 is more prevalent than HPV18. Our study suggests that HPV vaccines may be effective at reducing the burden of cervical cancer in Gabon.