Observation of a Nuclear Recoil Peak at the 100 eV Scale Induced by Neutron Capture.

Coherent elastic neutrino-nucleus scattering and low-mass dark matter detectors rely crucially on the understanding of their response to nuclear recoils. We report the first observation of a nuclear recoil peak at around 112 eV induced by neutron capture. The measurement was performed with a CaWO_{4} cryogenic detector from the NUCLEUS experiment exposed to a ^{252}Cf source placed in a compact moderator. We identify the expected peak structure from the single-γ de-excitation of ^{183}W with 3σ and its origin by neutron capture with 6σ significance. This result demonstrates a new method for precise, in situ, and nonintrusive calibration of low-threshold experiments.

Chronic obstructive pulmonary disease in sub-Saharan Africa.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide and an important cause of death in sub-Saharan Africa (SSA). We conducted a systematic review and meta-analysis on the prevalence of and risk factors for COPD in SSA.METHODS: We conducted a protocol-driven systematic literature search in MEDLINE, EMBASE, CINAHL and Global Health, supplemented by a manual search of the abstracts from thoracic conference proceedings from 2017 to 2020. We did a meta-analysis of COPD prevalence and its association with current smoking.RESULTS: We identified 831 titles, of which 27 were eligible for inclusion in the review and meta-analysis. The population prevalence of COPD ranged from 1.7% to 24.8% (pooled prevalence: 8%, 95% CI 6-11). An increased prevalence of COPD was associated with increasing age, smoking and biomass smoke exposure. The pooled odds ratio for the effect of current smoking (vs. never smoked) on COPD was 2.20 (95% CI 1.62-2.99).CONCLUSION: COPD causes morbidity and mortality in adults in SSA. Smoking is an important risk factor for COPD in SSA, and this exposure needs to be reduced through the combined efforts of clinicians, researchers and policymakers to address this debilitating and preventable lung disease.

Updated emm-typing protocol for Streptococcus pyogenes.

OBJECTIVES: PCR-based typing of the emm gene Streptococcus pyogenes often results in the amplification of multiple bands. This has resulted in the misclassification of strains into types based on non-emm gene sequences. We aimed to improve the specificity of the emm typing PCR reaction using a primer called CDC3, the sequence for which has been previously used to identify emm genes in silico. METHODS: The proposed primer CDC3 was validated in silico from a global database of 1688 GAS genomes and in vitro with 32 isolates. PCR reactions were performed on genomic DNA from each isolate, using the published CDC1 forward primer with the CDC2 reverse primer or the new CDC3 reverse primer. The products were examined by gel electrophoresis, and representative PCR products were sequenced. RESULTS: In 1688 S. pyogenes genomes, the previous CDC2 reverse primer annealed in silico in 1671 emm genes and also in 2109 non emm genes in close proximity, whereas the new CDC3 primer annealed in 1669 emm genes only. The remaining 19 genes without a CDC3 binding site were chimeric emm genes. The PCR pair CDC1+CDC3 produced a single band at appropriate molecular weight in all 32 isolates tested, while the CDC1+CDC2 pair produced more than one band in 13 of 32 isolates (40%). CONCLUSIONS: The new CDC3 primer is more specific for emm genes than the previous CDC2 primer and represents a simple solution to reduce the potential for mistyping S. pyogenes strains.

Accuracy of the health information system on malaria surveillance in Vietnam.

The health information system (HIS) is a key component of control programs and its accuracy is necessary for the assessment of disease risks, the formulation of priorities and the evaluation of the cost-effectiveness of different interventions. In order to assess the quality of the HIS in estimating malaria morbidity in Vietnam, we compared data obtained by a 2-year active (ACD) and passive case detection (PCD) study with those routinely collected at the local commune health centres (CHC) at three sites having different malaria epidemiology. The majority of malaria cases (80-95%) detected by ACD were missed by the HIS. Similarly, most malaria cases (50-90%) detected by PCD were also missed by the HIS, and this was proportional to the number of active private practitioners. Reasons for this low sensitivity are low CHC attendance, high attendance at private health facilities, widespread self-medication and attendance at central health facilities. In conclusion, although malaria has sharply decreased in Vietnam over the past 10 years, the current HIS greatly underestimates the malaria burden. Involvement of the private sector and the establishment of sentinel sites might improve the quality of data and the relevance of HIS in malaria control.

[In vivo sensitivity of Plasmodium faciparum to chloroquine and sulfadoxine pyrimethamine in the Bobo Dioulasso region (1998-2001): risk factors associated with treatments failures to the two drugs]. / Sensibilité in vivo de Plasmodium falciparum à la chloroquine et à la sulfadoxine-pyrimethamine dans la région de Bobo Dioulasso (1998-2001): étude des facteurs de risque associés aux échecs thérapeutiques de ces deux médicaments.

The therapeutic efficacy of chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) was determined over a 4 year period (1998-2001) in Bobo Dioulasso, Burkina Faso, with an analysis of the risk factors associated to treatment failures to the 2 drugs. In total, 2008 children (6 months-15 years old) attending in 4 health centres (1 urban and 3 rural) were included in the study. Children were alternatively allocated to either CQ or SP The WHO 14-days in vivo field test was carried out. PCV was measured at day 0 and 14. CQ treatment failure was 24.4% (229/940), most of them being late failures. Between 1998 and 2001 a significant increase in CQ treatment failure (p < 0.001) was observed. SP showed a good efficacy with a total treatment failure of 4.4% (33/749). However; a significant increase of resistance to this drug (p=0.001) was also observed between 1998 and 2001. Among children with anaemia at day 0.85% (23/27) were no more anaemic by day 14 in the SP group, while in the CQ group the proportion was lower; 69% (27/39). However the difference between the two drugs was not significant (p > 0.1). Univariate analysis showed that the site, the age of children, the time of recruitment and the parasitaemia were significantly associated with CQ treatment failure. In the multivariate analysis these 4 variables remain significantly and independently associated with the risk of CQ treatment failure. After adjusting for the effect of the 3 other factors, the risk of treatment failure was reduced by half in rural area compared to urban area as well as in children of 5-15 years of age compared to those under 5. The risk of treatment failure was significantly increased in 2000-2001 (OR = 1.66, p < 0.05) as compared to the 2 previous years (1998-1999). It was also twice higher in children with parasitaemia > or = 16,000/microl than in those having a lower parasitaemia. For SP we have not observed such connexions with the univariate and multivariate analysis.

The contribution of health-care services to a sound and sustainable malaria-control policy.

HIV and AIDS, tuberculosis, and malaria, besides presenting a large mortality and morbidity burden in developing countries, are also responsible for poor economic development. In the past international agencies devoted resources and efforts to control malaria and other diseases without taking into account health-system performance and sustainability. Even assuming that the Global Fund to Fight AIDS, Tuberculosis, and Malaria (GFATM)--a recent international initiative--would provide the necessary funds, a poorly performing health-care system will not be able to use these funds optimally. Moreover, even if all interventions are cost-effective, their impact on mortality and morbidity will only be marginal if access to proper care is not guaranteed. It is the responsibility of scientists and health managers to highlight to donor agencies the importance of an accessible and well functioning health-care system at all levels for the control of specific diseases.

Malaria epidemiology in a rural area of the Mekong Delta: a prospective community-based study.

Over the past 10 years, the Mekong Delta region in Vietnam has experienced fast socio-economic development with subsequent changes in malaria vectors ecology. We conducted a 2-year prospective community-based study in a coastal rural area in the southern Mekong Delta to re-assess the malaria epidemiological situation and the dynamics of transmission. The incidence rate of clinical malaria, established on 558 individuals followed for 23 months by active case detection and biannual cross-sectional surveys, was 2.6/100 person-years. Over the 2-year study period, the parasite rate and malaria seroprevalence (Plasmodium falciparum and P. vivax) decreased significantly from 2.4% to almost 0%. Passive case detection (PCD) of clinical cases and serological follow-up of newborns carried out in a larger population confirmed the low and decreasing trend of malaria transmission. The majority of fever cases were seen in the private sector and most were unnecessarily treated with antimalarials. Training and involvement of the private sector in detection of malaria cases would greatly improve the quality of health care and health information system.