Elimination of dog-mediated human rabies: the burden of human rabies in Africa

Hope exists for the elimination of dog-mediated human rabies in Africa. Momentum is gathering towards this goal, with an increasing number of successful demonstration projects showing that elimination is feasible. The Pan African Rabies Control Network is bringing Africa together against rabies, supported by the World Health Organization, the World Organisation for Animal Health and the Food and Agriculture Organization of the United Nations, which have a combined resolution to eliminate human deaths from dog-transmitted rabies by 2030. Furthermore, the inspiring examples of both rinderpest and smallpox eradication hold all the elements necessary to have confidence that this momentum can lead to success. Smallpox and rinderpest, whose last battles were fought on the African continent, highlight the simple fact that once the primary tools are available (such as vaccines), by far the greatest challenges lie within the realm of implementation. Science can effectively argue the subtleties of virology, immunology, vaccinology, etc. but it often fails to describe the science of implementation. In the face of other major diseases and socio-economic difficulties, rabies is not perceived as a threat by many African countries, despite the fact that the burden of the disease has been shown to be extensive. The challenge of mobilising mass interventions requires leadership and fortitude within resource-poor, infrastructurally challenged, politically uninterested and often bureaucratically restricted environments. Continent-wide elimination remains a daunting prospect for investors, who often lack insight into environmental disease dynamics, which is essential for enabling the implementation of strategic, community-based interventions. Implementation in Africa needs to be seen through African eyes. It needs local community support, and it needs effective transport and procurement systems and systems of self-development with a view to sustainability. The Aidto- Africa model needs to be replaced by a model that empowers communities to act, demonstrates that success is possible and stimulates the expansion of control efforts.

Baseline gut microbiota predicts clinical response and colitis in metastatic melanoma patients treated with ipilimumab

Background

Ipilimumab, an immune checkpoint inhibitor targeting CTLA-4, prolongs survival in a subset of patients with metastatic melanoma (MM) but can induce immune-related adverse events, including enterocolitis. We hypothesized that baseline gut microbiota could predict ipilimumab anti-tumor response and/or intestinal toxicity.

Patients and methods

Twenty-six patients with MM treated with ipilimumab were prospectively enrolled. Fecal microbiota composition was assessed using 16S rRNA gene sequencing at baseline and before each ipilimumab infusion. Patients were further clustered based on microbiota patterns. Peripheral blood lymphocytes immunophenotypes were studied in parallel.

Results

A distinct baseline gut microbiota composition was associated with both clinical response and colitis. Compared with patients whose baseline microbiota was driven by Bacteroides (cluster B, n = 10), patients whose baseline microbiota was enriched with Faecalibacterium genus and other Firmicutes (cluster A, n = 12) had longer progression-free survival (P = 0.0039) and overall survival (P = 0.051). Most of the baseline colitis-associated phylotypes were related to Firmicutes (e.g. relatives of Faecalibacterium prausnitzii and Gemmiger formicilis), whereas no colitis-related phylotypes were assigned to Bacteroidetes. A low proportion of peripheral blood regulatory T cells was associated with cluster A, long-term clinical benefit and colitis. Ipilimumab led to a higher inducible T-cell COStimulator induction on CD4+ T cells and to a higher increase in serum CD25 in patients who belonged to Faecalibacterium-driven cluster A.

Conclusion

Baseline gut microbiota enriched with Faecalibacterium and other Firmicutes is associated with beneficial clinical response to ipilimumab and more frequent occurrence of ipilimumab-induced colitis.

Elements for optimizing a one-step enzymatic bio-refinery process of shrimp cuticles: Focus on enzymatic proteolysis screening

This article complements an earlier work published in 2015 Baron et al. (2015) that showed the interest of a shrimp shells bio-refining process. We compare here the effect of eleven commercial proteases at pH 3.5 or 4.0 on a residual amount of shrimp shells proteins after 6 h at 50 °C. The two pH are obtained when respectively 40 and 25 mmol of formic acid are added to 5 g of mild dried shell. Deproteinisation yield above 95% are obtained. Residual amino acids profile in the solid phase was identical for the eleven proteases except for pepsin which was similar to the raw material profile. A significant relative increase in the proportion of Glycine is observed for the ten other cases. Likewise, shapes of size exclusion chromatograms of the dissolved phase are similar except with pepsin.

Immunisation coverage in the rural Eastern Cape - are we getting the basics of primary care right? Results from a longitudinal prospective cohort study

BACKGROUND

Immunisations are one of the most cost-effective public health interventions available and South Africa (SA) has implemented a comprehensive immunisation schedule. However, there is disagreement about the level of immunisation coverage in the country and few studies document the immunisation coverage in rural areas.

OBJECTIVE

To examine the successful and timely delivery of immunisations to children during the first 2 years of life in a deeply rural part of the Eastern Cape Province of SA.

METHODS

From January to April 2013, a cohort of sequential births (N=470) in the area surrounding Zithulele Hospital in the OR Tambo District of the Eastern Cape was recruited and followed up at home at 3, 6, 9, 12 and 24 months post birth, up to May 2015. Immunisation coverage was determined using Road-to-Health cards.

RESULTS

The percentages of children with all immunisations up to date at the time of interview were: 48.6% at 3 months, 73.3% at 6 months, 83.9% at 9 months, 73.3% at 12 months and 73.2% at 24 months. Incomplete immunisations were attributed to stock-outs (56%), lack of awareness of the immunisation schedule or of missed immunisations by the mother (16%) and lack of clinic attendance by the mother (19%). Of the mothers who had visited the clinic for baby immunisations, 49.8% had to make multiple visits because of stock-outs. Measles coverage (of at least one dose) was 85.2% at 1 year and 96.3% by 2 years, but 20.6% of babies had not received a second measles dose (due at 18 months) by 2 years. Immunisations were often given late, particularly the 14-week immunisations.

CONCLUSIONS

Immunisation rates in the rural Eastern Cape are well below government targets and indicate inadequate provision of basic primary care. Stock-outs of basic childhood immunisations are common and are, according to mothers, the main reason for their children's immunisations not being up to date. There is still much work to be done to ensure that the basics of disease prevention are being delivered at rural clinics in the Eastern Cape, despite attempts to re-engineer primary healthcare in SA.

Fourier Transform Infrared spectroscopy discloses different types of cell death in flow cytometrically sorted cells

Fourier Transform Infrared (FTIR) spectroscopy is a label free methodology showing promise in characterizing different types of cell death. Cervical adenocarcinoma (HeLa) and African monkey kidney (Vero) cells were treated with a necrosis inducer (methanol), novel apoptotic inducers (diphenylphosphino gold (I) complexes) and positive control, auranofin. Following treatment, cells stained with annexin-V and propidium iodide were sorted using a Fluorescence Activated Cell Sorter (FACS Aria) to obtain populations consisting of either viable, necrotic or apoptotic cells. Transmission Electron Microscopy confirmed successful sorting of all three populations. Four bands were identified which could discriminate between viable and necrotic cells namely 989 cm(-1), 2852 cm(-1), 2875 cm(-1) and 2923 cm(-1). In HeLa cells viable and induced apoptosis could be distinguished by 1294 cm(-1), while four bands were different in Vero cells namely; 1626 cm(-1), 1741 cm(-1), 2852 cm(-1) 2923 cm(-1). Principal Component Analysis showed separation between the different types of cell death and the loadings plots indicated an increase in an additional band at 1623 cm(-1) in dead cells. FTIR spectroscopy can be developed into an invaluable tool for the assessment of specific types of chemically induced cell death with notably different molecular signatures depending on whether the cells are cancerous and mechanism of cell death.

Evaluation of a rapid immunodiagnostic test kit for detection of African lyssaviruses from brain material

A rapid immunodiagnostic test kit was evaluated against a selection of isolates of lyssavirus genotypes occurring in Africa. The test was carried out in parallel comparison with the fluorescent antibody test (FAT) and isolates representing previously established phylogenetic groups from each genotype were included. The specificity of the rapid immunodiagnostic test compared favourably with the FAT and was found to detect all representatives of genotypes 1, 2, 3 and 4 in brain samples of either field cases or suckling mouse brain inoculates.

Evaluation of real-time nucleic acid sequence-based amplification for detection of Chikungunya virus in clinical samples

The Chikungunya virus (CHIKV) is a member of the genus Alphavirus that is transmitted to humans by Aedes mosquitoes. In 2005 and 2006, the Indian Ocean island of La Réunion was hit with an unprecedented CHIKV fever outbreak that infected 300 000 people. In the present study, we describe the evaluation of real-time nucleic acid sequence-based amplification (RT-NASBA) for the detection of CHIKV in clinical samples. A co-extracted and co-amplified chimerical CHIKV RNA sequence was used as an internal control to eliminate false-negative results. The detection threshold of the assay was determined from quantified CHIKV-positive plasma, and estimated to be 200 copies per NASBA reaction. The specificity of the assay was determined using blast analyses and non-cross-reactivity using an O'nyong-nyong virus culture and 250 CHIKV RT-PCR-negative plasma samples. A 100 % specificity was found and no invalid result was obtained, showing the good quality of the nucleic acid extraction. The assay was then evaluated using 252 CHIKV-positive RT-PCR plasma samples. The samples were all tested positive, including those with low viral load. This evaluation showed that the RT-NASBA is a rapid (5 h from sample nucleic acid extraction to detection), sensitive, specific and reliable method for the routine diagnosis of CHIKV in clinical samples.

Simultaneous detection and quantitation of Chikungunya, dengue and West Nile viruses by multiplex RT-PCR assays and dengue virus typing using high resolution melting

Chikungunya (CHIKV), Dengue (DENV) and West Nile (WNV) viruses are arthropod-borne viruses that are able to emerge or re-emerge in many regions due to climatic changes and increase in travel. Since these viruses produce similar clinical signs it is important for physicians and epidemiologists to differentiate them rapidly. A molecular method was developed for their detection and quantitation in plasma samples and a DENV typing technique were developed. The method consisted in performing two multiplex real-time one-step RT-PCR assays, to detect and quantify the three viruses. Both assays were conducted in a single run, from a single RNA extract containing a unique coextracted and coamplified composite internal control. The quantitation results were close to the best detection thresholds obtained with simplex RT-PCR techniques. The differentiation of DENV types was performed using a High Resolution Melting technique. The assays enable the early diagnosis of the three arboviruses during viremia, including cases of coinfection. The method is rapid, specific and highly sensitive with a potential for clinical diagnosis and epidemiological surveillance. A DENV positive sample can be typed conveniently using the High Resolution Melting technique using the same apparatus.

Kinetics modeling of alginate alkaline extraction from Laminaria digitata

Alginates being depolymerized during their alkaline extraction, reducing extraction time could help producing higher rheological quality alginates. The purpose of the present work is to study fresh Laminaria digitata destructuration during alkaline extraction and its link to extraction kinetics. Both alginate extraction yield and mean diameter of algae particles were followed for different values of agitation level and initial size of algae pieces. Results highlighted the existence of a link between extraction yield and algal destructuration. Those elements and the specificity of L.digitata structure have been taken into account to propose a kinetics model based on a fluid-particle reaction with decreasing size particles. The model parameters have been adjusted thanks to acquisition data and its predictive capacity was assessed by validation data. Provided predictions appeared to be relevant and the model structure suitability was confirmed, as extraction yield kinetics specific shape was quite reliably described.

Molecular and serological diagnosis of Chikungunya virus infection

INTRODUCTION

In 2005-2006, during the Chikungunya virus outbreak in La Réunion (Indian Ocean), we urgently established the molecular and serological methods for the diagnosis of Chikungunya virus (CHIKV) from various types of samples.

METHODS

CHIKV RNA was detected using a highly sensitive real-time RT PCR assay. A co-extracted and co-amplified internal control RNA was used to identify RT PCR inhibitors. Depending on their nature samples were pretreated before nucleic acid extraction. Viral loads were measured using a synthetic RNA calibrator. CHIKV immunoglobulin (Ig) G and M antibodies were detected by ELISA either from sera or from blood absorbed on filter paper.

RESULTS

CHIKV RNA was found in various types of samples such as plasma, cerebrospinal fluid, and placenta, but was not found in some samples including maternal milk and synovial samples. Detection of IgG from filter paper absorbed blood is specific and sensitive. Routine data showed that maternally transferred IgG and naturally acquired IgM persist at least 12 and 18 months, respectively.

DISCUSSION

The techniques enabled the diagnosis of chikungunya in known and newly described forms of the disease. They are used for routine diagnosis and large scale surveys.

[Lemierre syndrome variant: Hepatic abscesses and hepatic venous thrombosis due to Fusobacterium nucleatum septicemia]

INTRODUCTION

Like Fusobacterium necrophorum, Fusobacterium nucleatum is capable causing Lemierre's syndrome. Various locations of venous thrombosis have been described associated with Fusobacterium sp. septicemia.

EXEGESIS

We describe a 43-year old alcoholic patient with F.nucleatum septicemia complicated with hepatic abscesses, middle hepatic venous thrombosis, osteomyelitis and infiltrative pneumonia. A pancreatic prosthesis was the only potentially identified infectious entrance.

CONCLUSION

Our patient showed an alternative presentation of Lemierre's syndrome, a "digestive variant". To the best of our knowledge, this is the first report of Fusobacterium septicemia associated with hepatic venous thrombosis. This report is close to the cases of portal thrombosis and opens the clinical sphere of the lemierre's syndrome, whose incidence is increasing.

Unexpected high testis-specific transcriptional activity of the cyclin T1 promoter in transgenic mice

The ubiquitously expressed cyclin T1 gene encodes for a protein involved in human immunodeficiency virus type 1 (HIV-1) transcription activation. The goat gene was recently shown to share an expression pattern similar to that of its endogenous counterpart when incorporated into mice using a BAC insert. To assess if its promoter could target ubiquitous expression of the bovine Prnp in transgenic mice, two constructs carrying either 1 or 30 kb of cyclin T1 5'-flanking sequences were built and microinjected. Both constructs resulted in the unexpected high male germ cell-specific expression of the prion protein. These data re-question the suspected location of the cyclin T1 gene regulatory elements.