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The Medicine Quality Research Group has published a new Medical Product Quality Report focussing on increasing issues around substandard and falsified (SF) COVID-19 vaccines. With the implementation of the key innovations of COVID-19 vaccines, there have been growing numbers of reports of SF vaccines in the public domain. Given the vital role they will play in ending the pandemic and protecting the global population but severe issues with equitable access, SF vaccines are highly likely to be a growing problem.
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Isoniazid resistance, mycobacterial genotype and outcome in Vietnamese adults with tuberculous meningitis.
SettingCentre for Tropical Diseases, a 500-bed hospital for infectious diseases in Ho Chi Minh City, Vietnam.ObjectiveThe factors that determine outcome in adults with tuberculous meningitis are poorly understood. The objective of the study was to investigate the relationship between admission clinical features, HIV infection, drug resistance, mycobacterial genotype and outcome in adults with tuberculous meningitis.DesignClinical and laboratory data were recorded prospectively for 56 Vietnamese adults with tuberculous meningitis confirmed by culture of cerebrospinal fluid. Variables associated with in-hospital mortality, IV infection, drug resistance and microbial genotype were assessed by univariate and multivariate analysis.ResultsAdmission coma score independently predicted death in hospital (OR 0.73, 95%CI 0.61-0.87, P = 0.001). HIV-infected adults with tuberculous meningitis were more likely to be infected with Mycobacterium tuberculosis resistant to isoniazid (P = 0.011) and streptomycin (P = 0.002). Isoniazid resistance, streptomycin resistance, HIV infection and microbial genotype were not associated with increased in-hospital mortality.ConclusionTreatment of tuberculous meningitis before the onset of coma saves lives. Resistance to isoniazid and/or streptomycin does not appear to affect outcome.
Cellular stress and injury responses in the brains of adult Vietnamese patients with fatal Plasmodium falciparum malaria
Immunohistochemical techniques have been used to investigate specific patterns of potentially reversible cellular injury, DNA damage, and apoptosis in the brainstems of Vietnamese patients who died of severe Plasmodium falciparum malaria. The degree and pattern of neuronal and glial stress responses were compared between patients with cerebral and non‐cerebral malaria (CM), and appropriate non‐malaria infected controls. The following markers were examined: (i) heat shock protein 70 (HSP70), for reversible injury; (ii) heme oxygenase‐1, for oxidative stress; (iii & iv) two DNA‐repair proteins, poly(ADP) ribose polymerase (PARP) and DNA‐dependent protein kinase catalytic subunit; (v) poly(ADP) ribose, an end‐product of PARP activity; and (vi) caspase‐3‐active, for apoptosis. Stress responses were found in a range of cell types as reflected by the widespread expression of HSP70. Oxidative stress predominated in the vicinity of vessels and haemorrhages. Some degree of DNA damage was found in the majority of malaria patients, but the distribution and frequency of the damage was much less than that observed in controls with irreversible neuronal injury. Similarly, caspase‐3‐active expression, as a measure of apoptosis, was no higher in the majority of malaria patients than the negative control cases, although 40% of CM cases expressed caspase‐3‐active in a small number of neurones of the pontine nuclei or within swollen axons of the pontocerebellar and corticospinal tracts. In conclusion, cells within the brainstem of all patients who died from severe malaria showed staining patterns indicative of considerable stress response and reversible neuronal injury. There was no evidence for a specific pattern of widespread irreversible cell damage in those patients with cerebral malaria.
AN ULTRASTRUCTURAL STUDY OF THE BRAIN IN FATAL PLASMODIUM FALCIPARUM MALARIA
Cerebral malaria (CM) is a major cause of death in severe Plasmodium falciparum malaria. We present quantitative electron microscopic findings of the neuropathologic features in a prospective clinicopathologic study of 65 patients who died of severe malaria in Thailand and Vietnam. Sequestration of parasitized red blood cells (PRBCs) in cerebral microvessels was significantly higher in the brains of patients with CM compared with those with non-cerebral malaria (NCM) in all parts of the brain (cerebrum, cerebellum, and medulla oblongata). There was a hierarchy of sequestration with more in the cerebrum and cerebellum than the brain stem. When cerebral sequestration was compared with the peripheral parasitemia pre mortem, there were 26.6 times more PRBCs in the brain microvasculature than in the peripheral blood. The sequestration index was significantly higher in CM patients (median = 50.7) than in NCM patients (median = 6.9) (P = 0.042). The degree of sequestration of P. falciparum-infected erythrocytes in cerebral microvessels is quantitatively associated with pre-mortem coma.
Clinical and neurophysiological study of the effects of multiple doses of artemisinin on brain-stem function in Vietnamese patients.
The qinghaosu (artemisinin) group of drugs is the most important new class of antimalarials developed in the last fifty years. Although there has been no clinical evidence of neurotoxicity, an unusual pattern of damage to specific brain-stem nuclei has been reported in experimental animals receiving high doses of arteether or artemether. Detailed clinical examinations, audiometry, and brain stem auditory evoked potentials (BSAEPs) were assessed in 242 Vietnamese subjects who had previously received up to 21 antimalarial treatment courses of artemisinin or artesunate alone and 108 controls from the same location who had not received these drugs. There was no evidence of a drug effect on the clinical or neurophysiological parameters assessed. In this population there was no clinical or neurophysiological evidence of brain-stem toxicity that could be attributed to exposure to artemisinin or artesunate.
Nasal Carriage in Vietnamese Children of Streptococcus pneumoniae Resistant to Multiple Antimicrobial Agents
ABSTRACT Resistance to antimicrobial agents in Streptococcus pneumoniae is increasing rapidly in many Asian countries. There is little recent information concerning resistance levels in Vietnam. A prospective study of pneumococcal carriage in 911 urban and rural Vietnamese children, of whom 44% were nasal carriers, was performed. Carriage was more common in children <5 years old than in those ≥5 years old (192 of 389 [49.4%] versus 212 of 522 [40.6%]; P , 0.01). A total of 136 of 399 isolates (34%) had intermediate susceptibility to penicillin (MIC, 0.1 to 1 mg/liter), and 76 of 399 isolates (19%) showed resistance (MIC, >1.0 mg/liter). A total of 54 of 399 isolates (13%) had intermediate susceptibility to ceftriaxone, and 3 of 399 isolates (1%) were resistant. Penicillin resistance was 21.7 (95% confidence interval, 7.0 to 67.6) times more common in urban than in rural children (35 versus 2%; P , <0.001). More than 40% of isolates from urban children were also resistant to erythromycin, trimethoprim-sulfamethoxazole, chloramphenicol, and tetracycline. Penicillin resistance was independently associated with an urban location when the age of the child was controlled for. Multidrug resistance (resistance to three or more antimicrobial agent groups) was present in 32% of isolates overall but in 39% of isolates with intermediate susceptibility to penicillin and 86% of isolates with penicillin resistance. The predominant serotypes of the S. pneumoniae isolates were 19, 23, 14, 6, and 18. Almost half of the penicillin-resistant isolates serotyped were serotype 23, and these isolates were often multidrug resistant. This study suggests that resistance to penicillin and other antimicrobial agents is common in carriage isolates of S. pneumoniae from children in Vietnam.
An open label randomized controlled trial of tamoxifen combined with amphotericin B and fluconazole for cryptococcal meningitis
Background:Cryptococcal meningitis has high mortality. Flucytosine is a key treatment but is expensive and rarely available. The anticancer agent tamoxifen has synergistic anti-cryptococcal activity with amphotericin in vitro. It is off-patent, cheap, and widely available. We performed a trial to determine its therapeutic potential.Methods:Open label randomized controlled trial. Participants received standard care – amphotericin combined with fluconazole for the first 2 weeks – or standard care plus tamoxifen 300 mg/day. The primary end point was Early Fungicidal Activity (EFA) – the rate of yeast clearance from cerebrospinal fluid (CSF). Trial registration https://clinicaltrials.gov/ct2/show/NCT03112031.Results:Fifty patients were enrolled (median age 34 years, 35 male). Tamoxifen had no effect on EFA (−0.48log10 colony-forming units/mL/CSF control arm versus −0.49 tamoxifen arm, difference −0.005log10CFU/ml/day, 95% CI: −0.16, 0.15, p=0.95). Tamoxifen caused QTc prolongation.Conclusions:High-dose tamoxifen does not increase the clearance rate of Cryptococcus from CSF. Novel, affordable therapies are needed.Funding:The trial was funded through the Wellcome Trust Asia Programme Vietnam Core Grant 106680 and a Wellcome Trust Intermediate Fellowship to JND grant number WT097147MA.
Concomitant Bacteremia in Adults With Severe Falciparum Malaria
Abstract Background Approximately 6% of children hospitalized with severe falciparum malaria in Africa are also bacteremic. It is therefore recommended that all children with severe malaria should receive broad-spectrum antibiotics in addition to parenteral artesunate. Empirical antibiotics are not recommended currently for adults with severe malaria. Methods Blood cultures were performed on sequential prospectively studied adult patients with strictly defined severe falciparum malaria admitted to a single referral center in Vietnam between 1991 and 2003. Results In 845 Vietnamese adults with severe falciparum malaria admission blood cultures were positive in 9 (1.07%: 95% confidence interval [CI], .37–1.76%); Staphylococcus aureus in 2, Streptococcus pyogenes in 1, Salmonella Typhi in 3, Non-typhoid Salmonella in 1, Klebsiella pneumoniae in 1, and Haemophilus influenzae type b in 1. Bacteremic patients presented usually with a combination of jaundice, acute renal failure, and high malaria parasitemia. Four bacteremic patients died compared with 108 (12.9%) of 836 nonbacteremic severe malaria patients (risk ratio, 3.44; 95% CI, 1.62–7.29). In patients with >20% parasitemia the prevalence of concomitant bacteremia was 5.2% (4/76; 95% CI, .2–10.3%) compared with 0.65% (5/769; 0.08–1.2%) in patients with <20% parasitemia, a risk ratio of 8.1 (2.2–29.5). Conclusions In contrast to children, the prevalence of concomitant bacteremia in adults with severe malaria is low. Administration of empirical antibiotics, in addition to artesunate, is warranted in the small subgroup of patients with very high parasitemias, emphasizing the importance of quantitative blood smear microscopy assessment, but it is not indicated in most adults with severe falciparum malaria.
Xpert MTB/RIF Ultra for the Diagnosis of Tuberculous Meningitis: A Small Step Forward
AbstractThe delayed diagnosis of tuberculous meningitis (TBM) leads to poor outcomes, yet the current diagnostic methods for identifying Mycobacterium tuberculosis in cerebrospinal fluid (CSF) are inadequate. The first comparative study of the new GeneXpert MTB/RIF Ultra (Xpert Ultra) for TBM diagnosis suggested increased sensitivity of Xpert Ultra. Two subsequent studies have shown Xpert Ultra has improved sensitivity, but has insufficient negative predictive value to exclude TBM. Collecting and processing large volumes of CSF for mycobacterial testing are important for optimal diagnostic test performance. But clinical, radiological, and laboratory parameters remain essential for TBM diagnosis and empiric therapy is often needed. We therefore caution against the use of Xpert Ultra as a single diagnostic test for TBM; it cannot be used to “rule out” TBM.
Insights into malaria susceptibility using genome-wide data on 17,000 individuals from Africa, Asia and Oceania
AbstractThe human genetic factors that affect resistance to infectious disease are poorly understood. Here we report a genome-wide association study in 17,000 severe malaria cases and population controls from 11 countries, informed by sequencing of family trios and by direct typing of candidate loci in an additional 15,000 samples. We identify five replicable associations with genome-wide levels of evidence including a newly implicated variant on chromosome 6. Jointly, these variants account for around one-tenth of the heritability of severe malaria, which we estimate as ~23% using genome-wide genotypes. We interrogate available functional data and discover an erythroid-specific transcription start site underlying the known association inATP2B4, but are unable to identify a likely causal mechanism at the chromosome 6 locus. Previously reported HLA associations do not replicate in these samples. This large dataset will provide a foundation for further research on the genetic determinants of malaria resistance in diverse populations.