High rate of virological failure and HIV drug resistance in semi-rural Gabon and implications for dolutegravir-based regimen efficacy

BACKGROUND

The projected UNAIDS goal of ending AIDS by 2030 requires significant global efforts to improve current and future ART strategies. In this study, we assessed viral load (VL) suppression and acquired drug resistance, as well as future efficacy of dolutegravir-based combinations for patients living in semi-rural regions of Gabon.

METHODS

Eligible study participants were adults receiving ART and recruited between 2018 and 2019 in Franceville, Gabon. VL testing was conducted to assess VL suppression and HIV drug resistance (HIVDR) testing was performed to identify resistance mutations and assess their impact on ongoing and future ART regimens.

RESULTS

We recruited 219 participants overall. The median time on ART was 27 months and 216/219 participants were on first-line ART. VL suppression (VL < 1000 copies/mL) was 57.1% (95% CI 50.5-63.8) overall; 59.4% (51.4-67.5) and 52.2% (40.3-64.2) for women and men, respectively. The overall prevalence of HIVDR was 21.9% among the study population and 67.2% among those who failed ART. Presence of both NRTI and NNRTI mutations was found in 84.6% of sequences with drug resistance mutations, and full activity of a dolutegravir-based first-line regimen including tenofovir disoproxil fumarate/lamivudine/dolutegravir was expected only for 5/39 patients with a resistant virus.

CONCLUSIONS

This study shows a very low rate of VL suppression in a semi-rural context in Africa. Moreover, the high burden of HIVDR has affected both current and newly recommended ART strategies. Better management of ART in resource-limited settings is still a challenging ambition.

First investigation of pathogenic bacteria, protozoa and viruses in rodents and shrews in context of forest-savannah-urban areas interface in the city of Franceville (Gabon)

Rodents are reservoirs of numerous zoonotic diseases caused by bacteria, protozoans, or viruses. In Gabon, the circulation and maintenance of rodent-borne zoonotic infectious agents are poorly studied and are often limited to one type of pathogen. Among the three existing studies on this topic, two are focused on a zoonotic virus, and the third is focused on rodent Plasmodium. In this study, we searched for a wide range of bacteria, protozoa and viruses in different organs of rodents from the town of Franceville in Gabon. Samples from one hundred and ninety-eight (198) small mammals captured, including two invasive rodent species, five native rodent species and 19 shrews belonging to the Soricidae family, were screened. The investigated pathogens were bacteria from the Rickettsiaceae and Anaplasmataceae families, Mycoplasma spp., Bartonella spp., Borrelia spp., Orientia spp., Occidentia spp., Leptospira spp., Streptobacillus moniliformis, Coxiella burnetii, and Yersinia pestis; parasites from class Kinetoplastida spp. (Leishmania spp., Trypanosoma spp.), Piroplasmidae spp., and Toxoplasma gondii; and viruses from Paramyxoviridae, Hantaviridae, Flaviviridae and Mammarenavirus spp. We identified the following pathogenic bacteria: Anaplasma spp. (8.1%; 16/198), Bartonella spp. (6.6%; 13/198), Coxiella spp. (5.1%; 10/198) and Leptospira spp. (3.5%; 7/198); and protozoans: Piroplasma sp. (1%; 2/198), Toxoplasma gondii (0.5%; 1/198), and Trypanosoma sp. (7%; 14/198). None of the targeted viral genes were detected. These pathogens were found in Gabonese rodents, mainly Lophuromys sp., Lemniscomys striatus and Praomys sp. We also identified new genotypes: Candidatus Bartonella gabonensis and Uncultured Anaplasma spp. This study shows that rodents in Gabon harbor some human pathogenic bacteria and protozoans. It is necessary to determine whether the identified microorganisms are capable of undergoing zoonotic transmission from rodents to humans and if they may be responsible for human cases of febrile disease of unknown etiology in Gabon.

Carotenogenesis in carrot roots

The factors affecting carotenoid formation in carrot roots are described in detail, and their significance for the evaluation of field trials and for the breeding of carrots of a good colour are discussed. (Abstract retrieved from CAB Abstracts by CABI’s permission)