Fluorescein diacetate and rapid molecular testing for the early identification of rifampicin resistance in Mali

BACKGROUND: Non-conversion on auramine smear microscopy indicates a lack of treatment response, possibly associated with initial rifampicin-resistant tuberculosis (RR-TB). However, dead bacteria still stain positive and may be detected. Fluorescein diacetate smear microscopy (FDA) shows live mycobacteria only. Therefore, we studied the potential of 2-month (2M) FDA for the identification of initial RR-TB.METHODS: Between 2015 and 2018, we enrolled new smear-positive pulmonary TB patients from five local centres in Bamako, Mali. After baseline screening, sputum samples were collected at 1M, 2M, 5M and 18M. We used rpoB sequencing to identify initial RR-TB.RESULTS: Of 1359 patients enrolled, 1019 (75%) had rpoB sequencing results. Twenty-six (2.6%, 95%CI: 1.7-3.7) had mutations conferring rifampicin resistance. Most frequent rpoB mutations were located at the codons Asp435Val (42.4%) and Ser450Leu (34.7%). Among patients with initial RR-TB, 72.2% were FDA-negative at 2M (P = 0.2). The positive and negative predictive value of 5M FDA for culture-based failure was respectively 20.0% and 94.7%.CONCLUSION: FDA did not identify the majority of patients with initial RR-TB or culture-based failure. As the full spectrum of mutations identified on sequencing was identified using Xpert, our data support its rapid universal implementation in Mali.

[Contribution of the University Clinical Research Center's laboratoryin the diagnosis of SARS-CoV-2 in Mali]

INTRODUCTION

The rapid diagnostic capacities of laboratories in Mali have been an essential element in the response to COVID-19. The University Clinical Research center (UCRC) diagnosed the first cases of Mali COVID-19.

OBJECTIVE

The objective was to describe the contribution of the UCRC in the diagnosis of Covid-19 and to clinically and epidemiologically characterize the patients tested in the UCRC laboratory.

MATERIALS AND METHODS

A cross-sectional study was conducted during eight months of intense activity. The samples were sent from the National Institute of Public Health (INSP) to the UCRC.

RESULTS

The UCRC tested 12,406 contacts and suspected samples and confirmed the diagnosis in 1091 patients, or 9%. The most common symptoms were cough (48.78%), headache (34.14%), fatigue / weakness (34.14%), while (33.33%) of the patients were asymptomatic. The sample positivity rate among new cases decreased from May to September 2020, despite almost 230% of the number of samples tested.

CONCLUSION

The laboratory played a major role in the response and there may be a low transmission of the virus in the Malian community.

Diabetes Mellitus among new tuberculosis patients in Bamako, Mali

Introduction

Diabetes Mellitus (DM) increases worldwide, mostly in low- and middle-income countries. In Mali, the prevalence in the adult population is estimated at 1.8%, but tuberculosis (TB) patients are not systematically screened. The goal of our study was to determine the prevalence of DM among newly diagnosed TB patients.

Methods

We conducted a cross sectional study and a pilot prospective cohort study in four health centers in Bamako. All patients underwent fasting capillary-blood glucose (FCBG) test at Day 0, and repeated after one-week of TB treatment. Venous FBG test was performed for discrepancies between the two FCBG results. Thereafter, FCBG was performed for pilot study at month-2 (M2) and M5 of TB treatment.

Results

Two hundred and one patients were enrolled in this study. Impaired fasting blood glucose was identified in 17 (8.5%), of whom 11 (5.5%) had DM (VFBG >7 mmol/L). Among patients with DM, seven (63.6%) had successful TB treatment outcome, versus 142 (74.7%) of those without DM (p = 0.64), and (OR: 1.69, 95%CI 0.47–6.02).

Conclusion

The prevalence of DM among TB patients in Bamako exceeds that of the general population and screening at TB diagnosis suffices to identify those with DM. Systematic screening of both diseases will allow better treatment.

Kinetics of maternally-derived serogroup A, C, Y and W-specific meningococcal immunoglobulin G in Malian women and infants

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Immunisation with MCV during pregnancy resulted in an antibody response.

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Maternal immunization with MCV conveyed protective levels of MenA IgG at birth.

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Infant antibody levels declined over the first 3 months of life.

A prospective, randomised, controlled observer-blind trial measuring the efficacy and immunogenicity of trivalent influenza vaccine (TIV) and the immunogenicity of quadrivalent meningococcal conjugate vaccine (MCV) in pregnant women and their infants up to 6 months of age was conducted in Mali. Here we reported the immunogenicity of MCV, which was used as a comparator vaccine to TIV, in this population. Third-trimester pregnant Malian women were randomized to receive TIV or MCV. Blood samples were collected from women prior to vaccination, 28 days post-vaccination, at delivery and 3 and 6 months post-delivery and from infants at birth and 3 and 6 months of age. Meningococcal-specific serogroup (Men) A, C, Y and W-specific antibodies were measured by enzyme linked immunosorbent assay in a randomly selected subset of 50 mother-infant pairs where the mother had received MCV. At birth, 94.0% (47/50) of infants had MenA specific IgG levels ≥ 2 µg/mL decreasing to 72.9% and 30.4% at 3 and 6 months of age. For MenC, 81.3% (39/48) of infants had MenC specific IgG levels ≥ 2 µg/mL at birth decreasing to 29.4% and 17.8% at 3 and 6 months of age. For MenY, 89.6% (43/48) of infants had MenY specific IgG levels ≥ 2 µg/mL at birth decreasing to 64.6% and 62.5% at 3 and 6 months of age. For MenW, 89.6% (43/48) of infants had MenW specific IgG levels ≥ 2 μg/ml at birth decreasing to 62.5% and 41.7% at 3 and 6 months of age.

Maternal immunization with MCV conveyed protective levels of IgG at birth through to 3 months of age in the majority of infants.

Risk factors for loss to follow-up, transfer or death among people living with HIV on their first antiretroviral therapy regimen in Mali

OBJECTIVES

Risk factors for loss to follow-up (LTFU) were assessed for people living with HIV (PLHIV) at various reference out-patient clinics (expertise level II) and hospitals (expertise level III) in Mali.

METHODS

HIV-1-positive adults starting antiretroviral therapy (ART) in 2006-2013 were eligible for inclusion. Risk factors for LTFU, defined as no visit in the 6 months preceding the last database update, were assessed with the Cox model, taking into account the competing risks of transfer and death. Potential risk factors at the start of ART were demographic and socioeconomic variables, World Health Organization (WHO) stage, CD4 count, period of ART initiation, type of ART, region of care, expertise level and distance from home.

RESULTS

We included 9821 PLHIV, 33% of whom were male, starting ART at nine out-patient clinics and seven hospitals [five and two in the capital Bamako and four and five in the 'regions' (i.e. districts outside the capital), respectively] with a median (interquartile range) CD4 count of 153 (56-270) cells/μL. Five-year cumulative incidences of LTFU, transfer and death were 35.2, 9.7 and 6.7%, respectively. People followed at Bamako hospitals > 5 km from home, at regional hospitals or at regional out-patient clinics < 5 km from home were at higher risk of LTFU than people followed at Bamako out-patient clinics, whereas people followed at regional out-patient clinics 5-50 km away from home were at lower risk for LTFU. Deaths were less frequent at hospitals, whether in Bamako or in the regions, than at Bamako out-patient clinics, and more frequent at regional out-patient clinics.

CONCLUSIONS

Expertise level and distance to care were associated with LTFU. Stigmatization may play a role for PLHIV living close to the centres in the regions.

Virology. Mutation rate and genotype variation of Ebola virus from Mali case sequences

The occurrence of Ebola virus (EBOV) in West Africa during 2013-2015 is unprecedented. Early reports suggested that in this outbreak EBOV is mutating twice as fast as previously observed, which indicates the potential for changes in transmissibility and virulence and could render current molecular diagnostics and countermeasures ineffective. We have determined additional full-length sequences from two clusters of imported EBOV infections into Mali, and we show that the nucleotide substitution rate (9.6 × 10(-4) substitutions per site per year) is consistent with rates observed in Central African outbreaks. In addition, overall variation among all genotypes observed remains low. Thus, our data indicate that EBOV is not undergoing rapid evolution in humans during the current outbreak. This finding has important implications for outbreak response and public health decisions and should alleviate several previously raised concerns.

High level of HIV-1 resistance in patients failing long-term first-line antiretroviral therapy in Mali

OBJECTIVES

In resource-limited settings, few data are available on virological failure after long-term first-line antiretroviral therapy. This study characterized the genotypic resistance patterns at the time of failure after at least 36 months of a first-line regimen in Mali, West Africa.

METHODS

Plasma samples from 84 patients who were receiving first-line antiretroviral treatment and with an HIV-1 RNA viral load (VL) >1000 copies/mL were analysed. Genotypic resistance testing was performed and HIV-1 drug resistance was interpreted according to the latest version of the National Agency for HIV and Hepatitis Research algorithm.

RESULTS

At the time of resistance testing, patients had been treated for a median of 60 months (IQR 36-132 months) and had a median CD4 cell count of 292 cells/mm(3) (IQR 6-1319 cells/mm(3)), a median HIV-1 RNA level of 28266 copies/mL (IQR 1000-2 93 495 copies/mL) and a median genotypic susceptibility score of 1 (IQR 1-4). The prevalence of nucleoside reverse transcriptase inhibitor (NRTI) and non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance mutations was 78% and 82%, respectively. Viruses were resistant to at least one drug in 92% of cases. Although etravirine and rilpivirine were not used in the first-line regimens, viruses were resistant to etravirine in 34% of cases and to rilpivirine in 49% of cases. The treatment duration, median number of NRTI and NNRTI mutations and some reverse transcriptase mutations (T215Y/F/N, L210W, L74I, M41L and H221Y) were associated with the VL at virological failure.

CONCLUSIONS

This study demonstrated a high level of resistance to NRTIs and NNRTIs, compromising second-generation NNRTIs, for patients who stayed on long-term first-line regimens. It is crucial to expand the accessibility of virological testing in resource-limited settings to limit the expansion of resistance and preserve second-line treatment efficacy.

[Prevalence of antiphospholipid antibodies in patients with sickle cell disease]

Structural abnormalities in erythrocyte membrane are more and more claimed as a determinant factor in the sickle cell disease pathogenesis. This being would have been provided by a new anionic phospholipids distribution and conformation. Phosphatidyl-serine exposing and phosphatidic acid enhancing would induce specific immunoglobulins synthesis. In this study, assessment of antiphospholipid antibodies prevalence was carried out among sickle cell trait patients (n = 35) and homozygous patients (n = 59) as compared to healthy subjects (n = 39). Antiphospholipid antibodies, assayed by ELISA procedure, were significantly higher among the homozygous patients than the sickle cell trait patients ones and highlighted as compared to healthy subjects. Pathologic data were only observed among homozygous patients. These specific antibodies, associated with thrombosis and haemolysis, would have constitute a morbid link and a therapeutic target of this sickness, dominated by homodynamic troubles.

[Defects in peroxidation of erythrocyte phospholipids in sickle cell trait]

The sickle cell disease pathophysiology is provided by several events including deoxyhemoglobin S polymerization and hemorrheological troubles. Classically, such disorders have been known to concern only the homozygous SS and heterozygous SC profiles. However, troubles are more and more described since early years in the sickle cell trait patients and the pathogenesis factors are unknown. Our study focussed on phospholipids which are the basic and functional constituent elements of erythrocyte plasmic membrane. Assaying the membrane lipids extracted by Folch method and lipid standards (cholesterol, phosphatidic acid, lysophosphatidyl-choline, phosphatidyl-choline, lysophosphatidyl-ethanolamine, phosphatidyl-ethanolamine, sphingomyelin) was carried out by HPLC among 91 sickle cell trait patients as compared to 78 healthy subjects. The main abnormalities observed were an empoverishement in phosphatidyl-choline contrasting with an accumulation of membrane lysophosphatidyl-choline, lysophosphatidyl-ethanolamine, phosphatidic acid and sphingomyelin in sickle cell patients. These results suggest that sickle cell trait harmlessness is not actual. The accumulation of lysophosphatidyl-choline, by its cytolytic biomembrane perturbing properties, predispose therefore the sickled red cell to the haemolysis phenomena and allow to forecast deeper disturbances among homozygous subjects. These morbid disorders attributable to lipid peroxidation would justify an antioxidant treatment during the sickle cell disease.

[Assessment of the level of urinary iodine deficiency in children of Senegalese central regions]

Iodine deficiency disorders (IDD) are a major public health problem in Senegal, where strategies of salt iodization were adopted in the southern and eastern regions. The aim of this study led in four districts (Koungheul, Bambey, Mekhe and Kebemer), was to estimate by a questionnaire, the women knowleges, attitudes and practices (KAP) concerning IDD, and to measure children urinary iodine excretion by the Sandell-Kolthoff method to assess a potential deficiency. Six hundred ninety eight households were selected covering 1336 women (age 15 to 49 years) and 400 children (age 6 to 12 years). Sixty three per cent of the women knew the goiter, 89% of them considered that it was a disease and only 0.6% knew the role of iodized salt in the treatment. On the other hand, 20% of the children presented a normal range of urinary iodine excretion superior to 100 microg/l, the deficiency was light (50 to 100 microg/l) in 38% of the children, moderate (25 to 50 microg/l) in 27% and severe (< 25 microg/l) in 15% of them. These results show that other Senegalese regions are concerned by iodine deficiency disorders and need information, education and iodine supplementation programmes, notably for children and young women.

[Protein profile of Senegalese children presenting with nephrotic syndrome]

In Senegal, nephrotic syndrome usually occurs upon malnutrition that confers it its specificity and has brought us to establish the proteinic profile of Senegalese children suffering from it, in the aim to improve its treatment. Twenty children on the average of six years, hospitalized for nephrotic syndrome, were chosen. They were compared to 20 healthy children of the same age group, and 20 other children hospitalized for a non-renal inflammatory syndrome. For each subject were dosed total blood proteins and albumin. The protein electrophoresis has permitted to evaluate the alpha-1, alpha-2, beta and gamma globulins. We have observed predominance of boys with a 2.33 sex ratio. Our patients presenting a nephrotic syndrome were about six years old; no case has been noted before two years. Total proteins and albumin have decreased respectively to 52.10 g/l and 16 g/l. This diminishing is essentially linked to the massive urinary escape of plasmatic proteins and would explain partly the increase of lipids. The alpha-1 globulins were equally lowered but the alpha-2 globulins were increased by 40% of total proteins. Beta globulins have decreased, following the evolution of gamma globulins. In Senegal, The early age of nephrotic syndrome occurrence and the biological perturbations of the proteinic profile, recommend global and quick treatment considering food recovery and nutrition. The correction of these parameters being able to constitute in one hand an element of accessible and reliable supervision, and one the other hand the basis of complete treatment.