Tropical Medicine and Infectious Disease

13 pages, 498 KiB

Open AccessArticle

Evaluation of Bait Acceptance and Immune Response in Local Dogs during an Oral Rabies Vaccination Field Study in Morocco

by Nadia Aboulfidaa, Florence Cliquet, Emmanuelle Robardet, Sami Darkaoui, Marine Wasniewski, Christian Kaiser, Katharina Bobe, Ad Vos and Ouafaa Fassi Fihri

Trop. Med. Infect. Dis. 2024, 9(7), 142; https://doi.org/10.3390/tropicalmed9070142 - 26 Jun 2024

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Abstract

The objective of this study was to evaluate the bait preference of three selected bait types by local dogs and the induced immunogenicity of the oral rabies vaccine strain SPBN GASGAS in Morocco. The vaccine strain, combined with different bait types, has been tested in many different settings, but not yet in northern Africa. Overall, bait consumption and preference were similar in other studies using the same materials (bait type and sachet). The intestine bait had the highest acceptance rate (97.6%, 95%CI: 87.4–99.9), followed by the egg bait (83.0%, 95%CI: 69.2–92.4). Only 52% (95%CI: 37.4–66.3) of the dogs showed an interest in the fish meal bait. However, considering the successful release of the contents of the sachet (blue-dyed water) into the oral cavity, the egg bait (65.7%, 95%CI: 47.8–80.9) scored better than the intestine bait (51.7%, 95%CI: 32.5–70.6). The dogs selected for the immunogenicity study were offered the egg bait containing a sachet filled with SPBN GASGAS (3.0ml, 10^7.5 FFU/mL) or were given the same dose by direct oral administration (d.o.a.). In addition, several dogs were vaccinated by the parenteral route (s.c.) using a commercially available inactivated rabies vaccine. Unfortunately, due to the COVID-19 pandemic and subsequent travel restrictions, it was not possible to collect blood samples directly after vaccination. The blood samples were collected pre-vaccination and on five occasions between 450 and 1088 days post vaccination. The seroconversion rate, as determined for rabies-virus-neutralizing antibodies by the FAVN test, was significantly lower than that found for binding antibodies, as determined by ELISA, for all blood samples collected post vaccination. No treatment effect (bait, d.o.a., s.c.) could be seen in the seroconversion rate. At 15 months post vaccination, 84.2% of the dogs offered vaccine bait still tested sero-positive in ELISA. Only after 3 years was a clear drop in the seroconversion rate observed in all three treatment groups. This study confirms the long-term immunogenicity of the oral rabies vaccine SPBN GASGAS in dogs under field conditions. Full article

(This article belongs to the Special Issue Treatment and Risk Assessment of Rabies)

12 pages, 1316 KiB

Open AccessArticle

Consistency of Multi-Month Antiretroviral Therapy Dispensing and Association with Viral Load Coverage among Pediatric Clients Living with HIV in Mozambique

by Ivete Meque, Nicole Herrera, Michelle M. Gill, Rui Guilaze, Amancio Nhangave, Jaciara Mussá, Nilesh Bhatt, Mahoudo Bonou and Lauren Greenberg

Trop. Med. Infect. Dis. 2024, 9(7), 141; https://doi.org/10.3390/tropicalmed9070141 - 26 Jun 2024

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Abstract

With the increase in uptake of multi-month antiretroviral therapy dispensing (MMD) for children, little is known about consistency of MMD receipt over time and its association with virological outcomes. This analysis aims to assess the uptake of 3-month MMD among children, consistent receipt of MMD after uptake, and clinical outcomes following transition to MMD in 16 health facilities in Gaza and Inhambane Provinces. This is a secondary analysis involving children <15 years living with HIV with clinical visits during the period from September 2019 to August 2020. Of 4383 children, 82% ever received MMD (at least one pickup of a 3-month MMD supply) during the study period but only 40% received it consistently (defined as MMD at every visit during the study period). Consistent MMD was most common among older children and children without indications of clinical instability. Overall viral load (VL) coverage was 40% (733/1851). Consistent MMD was significantly associated with lower odds of having a VL (0.78, 95% CI: 0.64–0.95). In conclusion, while receipt of a multi-month supply was common particularly during the early days of the COVID-19 pandemic, only a minority of children received consistent MMD; however, there is a need to ensure children with fewer visits still receive timely VL monitoring. Full article

(This article belongs to the Special Issue Living with HIV: Support, Care, and Treatment for Vulnerable Populations)

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16 pages, 1570 KiB

Open AccessArticle

Identification and Functional Implications of the E5 Oncogene Polymorphisms of Human Papillomavirus Type 16

by Antônio Humberto P. da Silva-Júnior, Ruany Cristyne de Oliveira Silva, Ana Pavla A. Diniz Gurgel, Marconi Rêgo Barros-Júnior, Kamylla Conceição Gomes Nascimento, Daffany Luana Santos, Lindomar J. Pena, Rita de Cássia Pereira Lima, Marcus Vinicius de Aragão Batista, Bárbara Simas Chagas and Antonio Carlos de Freitas

Trop. Med. Infect. Dis. 2024, 9(7), 140; https://doi.org/10.3390/tropicalmed9070140 - 26 Jun 2024

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Abstract

The persistence of the human papillomavirus type 16 (HPV16) infection on the cervical epithelium contributes to the progression of cervical cancer. Studies have demonstrated that HPV16 genetic variants may be associated with different risks of developing cervical cancer. However, the E5 oncoprotein of HPV16, which is related to several cellular mechanisms in the initial phases of the infection and thus contributes to carcinogenesis, is still little studied. Here we investigate the HPV16 E5 oncogene variants to assess the effects of different mutations on the biological function of the E5 protein. We detected and analyzed the HPV16 E5 oncogene polymorphisms and their phylogenetic relationships. After that, we proposed a tertiary structure analysis of the protein variants, preferential codon usage, and functional activity of the HPV16 E5 protein. Intra-type variants were grouped in the lineages A and D using in silico analysis. The mutations in E5 were located in the T-cell epitopes region. We therefore analyzed the interference of the HPV16 E5 protein in the NF-kB pathway. Our results showed that the variants HPV16E5_49PE and HPV16E5_85PE did not increase the potential of the pathway activation capacity. This study provides additional knowledge about the mechanisms of dispersion of the HPV16 E5 variants, providing evidence that these variants may be relevant to the modulation of the NF-κB signaling pathway. Full article

(This article belongs to the Special Issue Molecular Epidemiology of Human Papillomavirus Infection)

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11 pages, 3137 KiB

Open AccessArticle

Investigating the Diagnostic and Therapeutic Potential of a T Cell Receptor (TCR)-like single Domain Antibody (sDAb)-Human IgG1 Antibody against Heat Shock Protein (HSP) 16KDa/HLA-A2 for Latent Tuberculosis

by Huaqiang Liu, Sylvia Annabel Dass, Matthew Tze Jian Wong, Venugopal Balakrishnan, Fazlina Nordin and Gee Jun Tye

Trop. Med. Infect. Dis. 2024, 9(7), 139; https://doi.org/10.3390/tropicalmed9070139 - 26 Jun 2024

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Abstract

Heat shock protein 16-kDa (HSP 16-kDa) is essential for the survival of Mycobacterium tuberculosis (M. tuberculosis) during the latent period; hence, a peptide–MHC presentation of HSP 16-kDa could be a potential diagnostic and therapeutic target for latent tuberculosis (LTB). This study aimed to generate a TCR-like single-domain antibody (sDAb)-human IgG1 antibody and subsequently investigate its diagnostic and therapeutic potential in LTB, utilizing a model cell presenting the target peptide. A previously generated TCR-like sDAB that can bind to HSP 16-kDa was first fused to a human IgG1 Fc-receptor via a linker. The fusion product, sDAb-IgG1, was expressed with HEK293-F and was subsequently purified. Its diagnostic potential was investigated via cell-based ELISA utilizing MCF-7 cells peptide-pulsed with HSP 16-kDa peptides. Investigation into the antibody-dependent cell-mediated cytotoxicity (ADCC) of MCF-7 cells was also conducted to investigate its therapeutic potential. Finally, TCR-like sDAb-IgG1 was successfully produced transiently with HEK-293F and was purified using protein A chromatography. The generated antibody was tested using cell-based ELISA, which demonstrated the effective binding of the TCR-like sDAb-IgG1 to the 16-kDa peptide–MHC on the cell surface. The ADCC assay also showed that the antibody effectively mediated the ADCC of MCF-7 cells with the help of 16-kDa peptide–MHC. This allows us to hypothesize the possible utility of the said antibody for both diagnostics and therapeutics of latent tuberculosis after more investigations with clinical samples. Full article

(This article belongs to the Special Issue The Epidemiology, Diagnosis and Treatment of Mycobacteria Infection (including TB and NTM))

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Trop. Med. Infect. Dis., Volume 9, Issue 7 (July 2024) – 4 articles

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