Full blood count and haemozoin-containing leukocytes in children with malaria: diagnostic value and association with disease severity

<p>Abstract</p> <p>Background</p> <p>Diligent and correct laboratory diagnosis and up-front identification of risk factors for progression to severe disease are the basis for optimal management of malaria.</p> <p>Methods</p> <p>Febrile children presenting to the Medical Research Unit at the Albert Schweitzer Hospital (HAS) in Lambaréné, Gabon, were assessed for malaria. Giemsa-stained thick films for qualitative and quantitative diagnosis and enumeration of malaria pigment, or haemozoin (Hz)-containing leukocytes (PCL) were performed, and full blood counts (FBC) were generated with a Cell Dyn 3000^®instrument.</p> <p>Results</p> <p>Compared to standard light microscopy of Giemsa-stained thick films, diagnosis by platelet count only, by malaria pigment-containing monocytes (PCM) only, or by pigment-containing granulocytes (PCN) only yielded sensitivities/specificities of 92%/93%; 96%/96%; and 85%/96%, respectively. The platelet count was significantly lower in children with malaria compared to those without (p < 0.001), and values showed little overlap between groups. Compared to microscopy, scatter flow cytometry as applied in the Cell-Dyn 3000^®instrument detected significantly more patients with PCL (p < 0.01). Both PCM and PCN numbers were higher in severe versus non-severe malaria yet reached statistical significance only for PCN (p < 0.0001; PCM: p = 0.14). Of note was the presence of another, so far ill-defined pigment-containing group of phagocytic cells, identified by laser-flow cytometry as lymphocyte-like gated events, and predominantly found in children with malaria-associated anaemia.</p> <p>Conclusion</p> <p>In the age group examined in the Lambaréné area, platelets are an excellent adjuvant tool to diagnose malaria. Pigment-containing leukocytes (PCL) are more readily detected by automated scatter flow cytometry than by microscopy. Automated Hz detection by an instrument as used here is a reliable diagnostic tool and correlates with disease severity. However, clinical usefulness as a prognostic tool is limited due to an overlap of PCL numbers recorded in severe versus non-severe malaria. However, this is possibly because of the instrument detection algorithm was not geared towards this task, and data lost during processing; and thus adjusting the instrument's algorithm may allow to establish a meaningful cut-off value.</p

Artesunate – amodiaquine combination therapy for falciparum malaria in young Gabonese children

BACKGROUND: Artesunate-amodiaquine combination for the treatment of childhood malaria is one of the artemisinin combination therapies (ACTs) recommended by National authorities in many African countries today. Effectiveness data on this combination in young children is scarce. METHODS: The effectiveness of three daily doses of artesunate plus amodiaquine combination given unsupervised (n = 32), compared with the efficacy when given under full supervision (n = 29) to children with falciparum malaria were assessed in an unrandomized study. RESULTS: 61 patients analysed revealed a PCR-corrected day-28 cure rate of 86 % (25 of 29 patients; CI 69 – 95 %) in the supervised group and 63 % (20 of 32 patients; CI 45 – 77 %) in the unsupervised group. The difference in outcome between both groups was statistically significant (p = 0.04). No severe adverse events were reported. CONCLUSION: The effectiveness of this short course regimen in young children with falciparum malaria could be augmented by increased adherence and improved formulation

Observed vs. unobserved therapy of uncomplicated Falciparum malariawith artesunate and amodiaquin in infants in Lambaréné, Gabon

Die folgende Arbeit basiert auf einer Substudie über ein orales Therapieschema für unkomplizierte Episoden der Malaria tropica bei Kleinkindern in Gabun im Alter von 2 bis 30 Monaten, die gleichzeitig an einer übergeordneten IPTi-Studie teilnahmen. Im Gegensatz zu den meisten anderen Behandlungsstudien in diesem Bereich verglichen wir nicht verschiedene Wirkstoffe oder Schemata miteinander; stattdessen erhielten beide Gruppen dieselbe ACT (Artesunat und Amodiaquin für 3 Tage, eines der von der WHO empfohlenen Behandlungsregime: Eine Gruppe bekam alle drei Dosen in unserem Studienzentrum (= observierte Therapie), der anderen wurden die zweite und dritte Dosis mit nach Hause gegeben. Zudem waren unsere Studienteilnehmer im Vergleich zu anderen Studien relativ jung. Damit gehörten sie jedoch zu einer Altersgruppe, die in den hyper- und holoendemischen Transmissionsregionen Afrikas bereits schwer von der Malaria tropica und ihrer Komplikationen betroffen ist. Es zeigte sich, dass nach den gültigen Kriterien die Wirksamkeit i.S. der „effectivity“ (ausgedrückt in der Heilungsrate der observierten Gruppe an Tag 28) ausreichend hoch (um 95%) war, die Wirksamkeit i.S. der „effectiveness“ jedoch signifikant niedriger - nur um die 65% der nichtobservierten Gruppe waren an Tag 28 geheilt – und somit inakzeptabel war. Abgesehen von bekannten Complianceproblemen sind die schlechten Resultate der nichtobservierten Gruppe auf die schlechte gastrointestinale Verträglichkeit des Amodiaquins bei Kleinkindern und die aufwändige Zubereitung zurückzuführen (kein Kombinationspräparat verfügbar). Beide Medikamente stellten sich ansonsten als sicher heraus und zeigten kaum unerwünschte Wirkungen. Vor dem Hintergrund der zunehmenden Resistenzen der Parasiten gegenüber Monotherapien und dem folgenden Anstieg der Malariamorbidität und –mortalität besonders bei Kleinkindern und schwangeren Frauen in Afrika in den 80er und 90er Jahren erkannten die WHO, viele Nichtregierungsorganisationen und andere relevante Institutionen einen dringenden Handlungsbedarf, der zur Gründung nicht weniger „Public-Private Partnerships“ führte. Neben dem Einsatz von ITNs wurde die Entwicklung und Einführung wirksamer und kostengünstiger Kombinationstherapien mit Artemisininkomponente (ACTs) einer der Hauptwaffen gegen die Malaria. 2007 brachte zum Beispiel die „Drugs for Neglected Diseases Initiative“ eine patentfreie, fixe Artesunat & Amodiaquin-Kombination auf den Markt, die auch einfacher in der Zubereitung und Verabreichung ist, aber zum Studienzeitpunkt noch nicht zur Verfügung stand. Andere Strategien und Ziele im Kampf gegen die Malaria wie die Ausrottung des Vektormoskitos scheinen vor allem in Afrika unmöglich zu erreichen oder sind bisher von fraglichem Langzeitnutzen (wie zum Beispiel IPTi oder Impfstoffe). Daher bleibt die effektive, kostengünstige, sichere und schnelle Behandlung klinischer Malariaepisoden eine ständige Herausforderung mit hoher Priorität, besonders angesichts der ersten Berichte über das Auftreten von in vivo Resistenzen von Plasmodium falciparum gegen Artemisininen.The following thesis is based on a substudy on an oral treatment regimen for uncomplicated episodes of falciparum malaria in Gabonese infants (aged 2 to 30 months) which were simultaneously taking part in a larger IPTi study. In contrast to the majority of treatment studies in this area of research we did not compare different drugs or regimens. Instead, both groups of infants received the same ACT (a three day course of artesunate and amodiaquine, one of the ACTs recommended by the WHO), one group observed by us each time in our study centre, the others to take the second and third dose unobserved at home. Besides, our participants were quite young compared to other studies. Yet, they still belonged to an age group that is severely affected by falciparum malaria (including its complications) in hyper- and holoendemic regions of transmission in Africa. It could be demonstrated that according to the applicable criteria the effectivity (reflected in the cure rate of the observed group at day 28) was sufficiently high (about 95%), yet, the effectiveness - only about 65% of the members of the unobserved group were cured at day 28 - was significantly lower and therefore unacceptable. Apart from well-known compliance problems, the bad results of the unobserved group were due to poor GI-tolerability of amodiaquine in infants and the complicated mode of preparation (no fixed combination available). Both drugs proved to be safe and showed few adverse effects otherwise. Against the background of the parasites´ growing resistance to monotherapies and the consecutive increase in malaria morbidity and mortality particularly in African infants and pregnant women in the 80s and 90s an urgent need for action was perceived by the WHO, many NGOs and other relevant institutions, which resulted in the foundation of quite a few public-private partnerships. Apart from the use of ITNs the development and implementation of effective and affordable combination therapies (ACTs) became one of the mainstays to “roll back malaria”. In 2007, for example, the “Drugs for Neglected Diseases Initiative” launched a licence-free fixed combination of artesunate and amodiaquin which is also easier to prepare and administer but was not yet available at the time of our study. Other strategies and aims in the fight against malaria like eradication of the mosquito vector seem impossible to achieve especially in Africa or have not shown any reliable long-term benefit up to now (like, for instance, IPTi or vaccination). Therefore the effective, affordable, safe and quick treatment of clinical malaria episodes remains a constant challenge of high priority, particularly regarding the first reports indicating the emergence of in vivo resistance of Plasmodium falciparum against artemisinins

Comprehensive smoke-free policies attract more support from smokers in Europe than partial policies

Background: Support for smoke-free policies increases over time and particularly after implementation of the policy. In this study we examined whether the comprehensiveness of such policies moderates the effect on support among smokers. Methods: We analysed two waves (pre- and post-smoke-free legislation) of the International Tobacco Control (ITC) surveys in France, Germany, and the Netherlands, and two pre-legislation waves of the ITC surveys in UK as control. Of 6,903 baseline smokers, 4,945 (71.6%) could be followed up and were included in the analyses. Generalised Estimating Equations (GEE) were used to compare changes in support from pre- to post-legislation to the secular trend in the control country. Multiple logistic regression models were employed to identify predictors of individual change in support. Findings: In France, the comprehensive smoking ban was associated with sharp increases in support for a total smoking ban in drinking establishments and restaurants that were above secular trends. In Germany and the Netherlands, where smoke-free policies and compliance are especially deficient in drinking establishments, only support for a total smoking ban in restaurants increased above the secular trend. Notable prospective predictors of becoming supportive of smoking bans in these countries were higher awareness of cigarette smoke being dangerous to others and weekly visiting of restaurants. Conclusions: Our findings suggest that smoke-free policies have the potential to improve support once the policy is in place. This effect seems to be most pronounced with comprehensive smoking bans, which thus might be the most valid option for policy-makers despite their potential for creating controversy and resistance in the beginning

Impact of national smoke-free legislation on home smoking bans: findings from the International Tobacco Control Policy Evaluation Project Europe Surveys.

Objectives: To measure changes in prevalence and predictors of home smoking bans (HSBs) among smokers in four European countries after the implementation of national smoke-free legislation. Design: Two waves of the International Tobacco Control Policy Evaluation Project Europe Surveys, which is a prospective panel study. Pre- and post-legislation data were used from Ireland, France, Germany and the Netherlands. Two pre-legislation waves from the UK were used as control. Participants: 4634 respondents from the intervention countries and 1080 from the control country completed both baseline and follow-up and were included in the present analyses. Methods: Multiple logistic regression models to identify predictors of having or of adopting a total HSB, and Generalised Estimating Equation models to compare patterns of change after implementation of smoke-free legislation to a control country without such legislation. Results: Most smokers had at least partial smoking restrictions in their home, but the proportions varied significantly between countries. After implementation of national smoke-free legislation, the proportion of smokers with a total HSB increased significantly in all four countries. Among continuing smokers, the number of cigarettes smoked per day either remained stable or decreased significantly. Multiple logistic regression models indicated that having a young child in the household and supporting smoking bans in bars were important correlates of having a pre-legislation HSB. Prospective predictors of imposing a HSB between survey waves were planning to quit smoking, supporting a total smoking ban in bars and the birth of a child. Generalised Estimating Equation models indicated that the change in total HSB in the intervention countries was greater than that in the control country. Conclusions: The findings suggest that smoke-free legislation does not lead to more smoking in smokers' homes. On the contrary, our findings demonstrate that smoke-free legislation may stimulate smokers to establish total smoking bans in their homes

Effectiveness of the European Union text-only cigarette health warnings:findings from four countries

Background: The European Commission requires tobacco products sold in the European Union to display standardized text health warnings. This article examines the effectiveness of the text health warnings among daily cigarette smokers in four Member States. Methods: Data were drawn from nationally representative samples of smokers from the International Tobacco Control Policy Evaluation Project surveys in France (2007), Germany (2007), the Netherlands (2008) and the UK (2006). We examined: (i) smokers’ ratings of the health warnings on warning salience, thoughts of harm and quitting and forgoing of cigarettes; (ii) impact of the warnings using a Labels Impact Index (LII), with higher scores signifying greater impact; and (iii) differences on the LII by demographic characteristics and smoking behaviour. Results: Scores on the LII differed significantly across countries. Scores were highest in France, lower in the UK, and lowest in Germany and the Netherlands. Across all countries, scores were significantly higher among low-income smokers, smokers who had made a quit attempt in the past year and smokers who smoked fewer cigarettes per day. Conclusion: The impact of the health warnings varies greatly across countries. Impact tended to be highest in countries with more comprehensive tobacco control programmes. Because the impact of the warnings was highest among smokers with the lowest socioeconomic status (SES), this research suggests that health warnings could be more effective among smokers from lower SES groups. Differences in warning label impact by SES should be further investigated

Malaria and asymptomatic parasitaemia in Gabonese infants under the age of 3 months

We determined the incidence of both malaria and asymptomatic parasitaemia in infants under the age of 3 months within the framework of a longitudinal cohort study in Lambaréné, Gabon, between December 2002 and July 2004. Of 878 infants who were included at birth, we identified malaria in three infants and, additionally, asymptomatic parasitaemia in six infants. The malaria incidence density was 1.1/1000 person-months or 0.1% of observations. Our findings underpin the notion that the incidence of malaria and parasitaemia in infants below the age of 3 months is very lo

Deep learning-based image analysis identifies a DAT-negative subpopulation of dopaminergic neurons in the lateral Substantia nigra

International audienceAbstract Here we present a deep learning-based image analysis platform (DLAP), tailored to autonomously quantify cell numbers, and fluorescence signals within cellular compartments, derived from RNAscope or immunohistochemistry. We utilised DLAP to analyse subtypes of tyrosine hydroxylase (TH)-positive dopaminergic midbrain neurons in mouse and human brain-sections. These neurons modulate complex behaviour, and are differentially affected in Parkinson’s and other diseases. DLAP allows the analysis of large cell numbers, and facilitates the identification of small cellular subpopulations. Using DLAP, we identified a small subpopulation of TH-positive neurons (~5%), mainly located in the very lateral Substantia nigra (SN), that was immunofluorescence-negative for the plasmalemmal dopamine transporter (DAT), with ~40% smaller cell bodies. These neurons were negative for aldehyde dehydrogenase 1A1, with a lower co-expression rate for dopamine-D2-autoreceptors, but a ~7-fold higher likelihood of calbindin-d28k co-expression (~70%). These results have important implications, as DAT is crucial for dopamine signalling, and is commonly used as a marker for dopaminergic SN neurons