Changing Characteristics of Children With COVID-19 in Colorado Admitted During Different Variant Periods

BACKGROUND

Data are lacking on the impact of different severe acute respiratory syndrome coronavirus 2 variants in children and on pediatric vaccine effectiveness. We examined differences among children requiring hospital admission associated with coronavirus disease 2019 (COVID-19) during wild type, Delta and Omicron variant periods and calculated vaccine effectiveness at preventing symptomatic hospitalization during the Delta and Omicron variant periods.

METHODS

We conducted a retrospective review of children younger than 21 years of age hospitalized with symptomatic COVID-19. Characteristics were compared between variant periods using Kruskal-Wallis or generalized Fisher exact tests. We estimated vaccine effectiveness in preventing symptomatic hospitalization.

RESULTS

We included 115 children admitted during the wild type period, 194 during Delta and 226 during the Omicron periods. Median age (years) decreased (12.2 wild type, 5.9 Delta, 1.3 Omicron periods, P < 0.0001) over time. Children were less likely to have a comorbid condition, including diabetes or obesity, and had shorter admissions during Omicron compared with the wild type and Delta periods. Intensive care unit admissions and respiratory support requirements were highest during the Delta period (P = 0.05). Among children ≥12 years, adjusted vaccine effectiveness at preventing symptomatic hospitalization was 86% during Delta and 45% during Omicron periods.

CONCLUSIONS

Children hospitalized with COVID-19 during later variant periods were younger and less likely to have comorbidities. Children admitted during the Delta variant period required more intensive care and respiratory support compared to other variant periods. Vaccination was less effective at preventing symptomatic hospital admission during the Omicron period compared to the Delta period.

Global survival trends for brain tumors, by histology: analysis of individual records for 556,237 adults diagnosed in 59 countries during 2000-2014 (CONCORD-3)

BACKGROUND

Survival is a key metric of the effectiveness of a health system in managing cancer. We set out to provide a comprehensive examination of worldwide variation and trends in survival from brain tumors in adults, by histology.

METHODS

We analyzed individual data for adults (15-99 years) diagnosed with a brain tumor (ICD-O-3 topography code C71) during 2000-2014, regardless of tumor behavior. Data underwent a 3-phase quality control as part of CONCORD-3. We estimated net survival for 11 histology groups, using the unbiased nonparametric Pohar Perme estimator.

RESULTS

The study included 556,237 adults. In 2010-2014, the global range in age-standardized 5-year net survival for the most common sub-types was broad: in the range 20%-38% for diffuse and anaplastic astrocytoma, from 4% to 17% for glioblastoma, and between 32% and 69% for oligodendroglioma. For patients with glioblastoma, the largest gains in survival occurred between 2000-2004 and 2005-2009. These improvements were more noticeable among adults diagnosed aged 40-70 years than among younger adults.

CONCLUSIONS

To the best of our knowledge, this study provides the largest account to date of global trends in population-based survival for brain tumors by histology in adults. We have highlighted remarkable gains in 5-year survival from glioblastoma since 2005, providing large-scale empirical evidence on the uptake of chemoradiation at population level. Worldwide, survival improvements have been extensive, but some countries still lag behind. Our findings may help clinicians involved in national and international tumor pathway boards to promote initiatives aimed at more extensive implementation of clinical guidelines.

[Factors associated with loss to follow-up in HIV-infected patients, Ségou, Mali]

OBJECTIVE

to study the factors associatedlost to follow-up in People Living with HIV on antiretroviral therapy (ART) at the Ambulatory Treatment Center (ATC).

METHODS

This is a retrospective case-control study of two years. It concerned all HIV-infected patients aged 15 and over who were started on ART for at least 4 months. Each case was matched with two controls by sex and age ± 5 years.

RESULTS

The proportionlost to follow-up was 21%.The median age lost to follow-up was 36 years (IQR: 30-42 years), sex ratio was 1.4 in favor of women. The median initial CD4 cell count was 151 cells / mm3 (IQR: 51-245) versus 207 (IQR: 67-482) for controls and the median lost to follow-up was 6 months (IQR: 4-9 months): 5-16) for controls. In multivariate analysis, the factors associated lost to follow-up were: unmarried (adjusted OR = 3.84, P = 0.0346); the initial CD4 <200 cells / mm3 (adjusted OR = 3.88, P = 0.0393) and the duration of ARV <= 6 months (adjusted OR = 6.59, P = 0.0047). The protective factors against lost to follow-up were: Body Mass Index of the last visited > = 18.5 kg / m2 (adjusted OR = 0.07, P = 0.0069); (OR adjusted = 0.06, P = 0.0197) and initiation to ART in the rainy season (adjusted OR = 0.21, P = 0.0220).

CONCLUSION

These results can be supplemented by quantitative and qualitative studies.

Area of technical uncertainty for susceptibility testing of amoxicillin/clavulanate against Escherichia coli: analysis of automated system, Etest and disk diffusion methods compared to the broth microdilution reference

OBJECTIVES

The European Committee on Antimicrobial Susceptibility Testing (EUCAST) recently warned about an area of technical uncertainty (ATU) of amoxicillin/clavulanate (AMX/C) disk susceptibility testing against members of the Enterobacterales. Thus, we aimed to compare the reliability of three routine methods and to evaluate the impact of the ATU.

METHODS

286 Escherichia coli strains (including 159 AMX-resistant strains) were categorized for the two EUCAST AMX/C breakpoints by disk diffusion (Bio-Rad), the Phoenix automated system (Becton Dickinson) and the Etest (AES) compared to the broth microdilution reference method.

RESULTS

By microdilution, 84.2% of strains were AMX/C-susceptible using the urinary breakpoint (MIC ≤32 mg/L) and 62.2% using the systemic breakpoint (MIC ≤8 mg/L), with 63.6% of MICs between 4 and 16 mg/L. For the systemic breakpoint, category agreement (CA) and very major error (VME) were unacceptable for the Etest (71.7% and 27.3%), disk (73.1% and 23.4% at 19-mm cut-off) and to a lesser extent for the Phoenix system (83.6% and 10.5%). For disks, an unacceptable VME rate was observed for diameters up to 22 mm, probably due to overcharged disks. For the Etest, VMEs were high at 6 mg/L (46/63) and 8 mg/L (22/29). For the urinary breakpoint, CA was more acceptable for disk (88.9%) and Etest (84.3%) but was unevaluable for Phoenix.

CONCLUSION

AMX/C susceptibility testing of E. coli for systemic breakpoint was unreliable with the three routine methods, explained mainly by the high prevalence (~60%) of strains with microdilution MICs around the breakpoint (8 mg/L). Our data confirmed the EUCAST 19-20-mm ATU for disk and suggest introducing ATU for Etest MIC values of 6 and 8 mg/L.

Cost-Effectiveness of Three Alternative Boosted Protease Inhibitor-Based Second-Line Regimens in HIV-Infected Patients in West and Central Africa

BACKGROUND

While dolutegravir has been added by WHO as a preferred second-line option for the treatment of HIV infection, boosted protease inhibitor (bPI)-based regimens are still needed as alternative second-line options. Identifying optimal bPI-based second-line combinations is essential, given associated high costs and funding constraints in low- and middle-income countries. We assessed the cost-effectiveness of three alternative bPI-based second-line regimens in Burkina Faso, Cameroon and Senegal.

METHODS

We used data collected over 2010-2015 in the 2LADY trial/post-trial cohort. Patients with first-line antiretroviral therapy (ART) failure were randomly assigned to tenofovir/emtricitabine + lopinavir/ritonavir (TDF/FTC LPV/r; arm A), abacavir + didanosine + lopinavir/ritonavir (arm B), or tenofovir/emtricitabine + darunavir/ritonavir (arm C). Costs (US dollars, 2016), quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios were computed for each country over 24 months of follow-up and extrapolated to 5 years using a simulated patient-level Markov model. We assessed uncertainty using cost-effectiveness acceptability curves, scenarios and prices threshold analysis.

RESULTS

In each country, over 24 months, arm A was significantly less costly than arms B and C (incremental costs ranging from US$410-$US721 and US$468-US$546 for B and C vs A, respectively) and offered similar health benefits (incremental QALY: - 0.138 to 0.023 and - 0.179 to 0.028, respectively). Over 5 years, arm A remained the least costly, health benefits not being significantly different between arms. Compared with arms B and C, in each study country, Arm A had a ≥ 95% probability of being cost-effective for a large range of cost-effectiveness thresholds, irrespective of the scenario considered.

CONCLUSIONS

Using TDF/FTC LPV/r as a bPI-based second-line regimen provided the best economic value in the three study countries.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT00928187.

GloPID-R report on chikungunya, o'nyong-nyong and Mayaro virus, part 5: Entomological aspects

The GloPID-R (Global Research Collaboration for Infectious Disease Preparedness) chikungunya (CHIKV), o'nyong-nyong (ONNV) and Mayaro virus (MAYV) Working Group has been established to investigate natural history, epidemiology and clinical aspects of infection by these viruses. Here, we present a report dedicated to entomological aspects of CHIKV, ONNV and MAYV. Recent global expansion of chikungunya virus has been possible because CHIKV established a transmission cycle in urban settings using anthropophilic vectors such as Aedes albopictus and Aedes aegypti. MAYV and ONNV have a more limited geographic distribution, being confined to Africa (ONNV) and central-southern America (MAYV). ONNV is probably maintained through an enzootic cycle that has not been characterized yet, with Anopheles species as main vectors and humans as amplification hosts during epidemics. MAYV is transmitted by Haemagogus species in an enzootic cycle using non-human primates as the main amplification and maintenance hosts, and humans becoming sporadically infected when venturing in or nearby forest habitats. Here, we focused on the transmission cycle and natural vectors that sustain circulation of these viruses in their respective locations. The knowledge of the natural ecology of transmission and the capacity of different vectors to transmit these viruses is crucial to understand CHIKV emergence, and to assess the risk that MAYV and ONNV will expand on wide scale using anthropophilic mosquito species not normally considered primary vectors. Finally, the experts identified knowledge gaps and provided adapted recommendations, in order to address future entomological investigations in the right direction.

Prenatal care: missed opportunity for HBV prevention in women of childbearing age in rural Senegal

Background

Perinatal transmission of hepatitis B virus (HBV) constitutes an important risk in highly endemic countries including Senegal. Although the prevalence of chronic HBV infection is estimated at 11% in this country, specific data on women of childbearing age are sorely lacking. We described in this study the prevalence of the HBV antigen (HbsAg) in women of childbearing age in rural Senegal, as well as general knowledge on HBV and hepatitis B status awareness.

Methods

A cross-sectional study including HBV screening was conducted at home in the rural Niakhar area. Chronic HBV infection was determined through HBsAg detection using dried blood spots. Socio-demographic and behavioral data were collected through standardized face-to-face questionnaires. The analyzes included 368 women aged 15-49 (67% married; 65% with at least 1 child) enrolled from October 2018 to March 2019.

Results

Preliminary results show that 49 women (13%) had positive HBsAg. Only 68 women (18%) have already heard about HBV. Among them, 53% knew that there exists an HBV vaccine and 78%, 75% and 67% correctly answered that HBV can be transmitted through blood contact, childbirth and sexual intercourse, respectively.

Among the 233 (63%) women who had already given birth, 76% had attended at least 4 antenatal care sessions and 74% had given birth in a healthcare facility for their last pregnancy. However, only 1% reported to have already been screened for HBV. Main reasons reported for not having been screened were having never heard about this test (80%) and not having been offered screening during antenatal care sessions (10%).

Conclusions

General knowledge and awareness of HBV status are particularly low in women of childbearing age living in rural Senegal, despite high antenatal care sessions attendance. Given the high prevalence of chronic HBV infection found in this population, it is urgent to ensure systematic HVB screening and to provide adequate information to women during pregnancy.

Key messages

The prevalence of chronic HBV is high in women of childbearing age in Senegal. National recommendations for women attending antenatal care sessions should include HBV screening and counselling.

Hepatitis B vaccination status and vaccine immune response among children in rural Senegal

Background

Hepatitis B vaccination during childhood is key to reduce the prevalence of Hepatitis B virus (HBV) infection. In Senegal, a highly endemic country, the three-dose hepatitis B vaccine and the birth dose vaccine were introduced in the Expanded Programme on Immunization (EPI) in 2004 and 2016 respectively. This study aimed to determine chronic HBV infection prevalence, hepatitis B vaccination status and vaccine immunity among children in Senegal.

Methods

A cross-sectional study including HBV screening was conducted at home among children aged 6 months to 15 years (i.e. born after the introduction of the HBV vaccine in the EPI) in the rural zone of Niakhar. Dried Blood Spot (DBS) samples were collected for the detection of HBsAg, anti-HBc Ab and anti-HBs Ab using chemoluminescence. Vaccination status was assessed using information on vaccination cards. Detectable vaccine immunity was defined with an adjusted DBS threshold of DOI≥0.36 IU/mL (corresponding to 10 IU/mL in venous blood sampling).

Results

Between October and December 2018, 455 children were enrolled. Preliminary results show that 7/455 (1.5%) had been in contact with HBV (positive anti-HBc Ab) and 5/455 (1.1%) had chronic HBV infection (positive HBsAg).

Only 161/455 (35.4%) children had a vaccination card available. Among those, 150/161 (93.2%) received at least 3 doses of hepatitis B vaccine, of which 83/150 (55.3%) had detectable vaccine immunity. The proportion of children with detectable vaccine immunity was significantly higher in children &lt;5 years than in children aged 5-9 and 10-15 (72.3% versus 47.3%, p = 0.006 and 72.3% versus 14.3%, p &lt; 0.001).

Conclusions

Preliminary results suggest a low prevalence of HBV chronic infection among children born after the introduction of HBV vaccination in Senegal. However, detectable vaccine immunity rapidly decreases with age among vaccinated children, signalling a need for further studies on the immune response to HBV vaccination in this context.

Key messages

HBV chronic infection is low among children born after the introduction of HBV vaccination in Senegal. Further studies on the immune response to HBV vaccination in this context are needed.

Lack of effect of a poster-based intervention to reduce the number of blood culture samples collected

OBJECTIVE

To reduce the number of blood culture samples collected.

PATIENTS AND METHOD

We performed a cluster randomized controlled trial in adult acute care, and subacute care and rehabilitation wards in a university hospital in France. A poster associating an image of eyes looking at the reader with a summary of blood culture sampling guidelines was displayed in hospital wards in the intervention group. The incidence rate of blood cultures per 1000 days during pre- and post-intervention periods was calculated.

RESULTS

Thirty-one wards participated in the study. The median difference in blood cultures/1000 days between periods was -1.863 [-11.941; 1.007] in the intervention group and -5.824 [-14.763; -2.217] in the control group (P=0.27).

CONCLUSION

The intervention did not show the expected effect, possibly due to the choice of blood cultures as a target of good practice, but also to confounding factors such as the stringent policy of decreasing unnecessary costly testing.

Heterogeneity of virological suppression in the national antiretroviral programme of Cameroon (ANRS 12288 EVOLCAM)

OBJECTIVES

In terms of HIV infection, western and central Africa is the second most affected region world-wide, and the gap between the regional figures for the testing and treatment cascade and the Joint United Nations Programme on HIV/AIDS (UNAIDS) 90-90-90 targets is particularly worrying. We assessed the prevalence of virological suppression in patients routinely treated in 19 hospitals in Cameroon.

METHODS

A cross-sectional survey was performed in adult patients receiving antiretroviral therapy (ART) in the Centre and Littoral regions. The prevalences of virological suppression (<1000 HIV-1 RNA copies/mL) were compared among all 19 hospitals using the χ² test. Potential individual and health care-related determinants of virological suppression were assessed using multivariate logistic regression models.

RESULTS

A total of 1700 patients (74% women; median age 41 years; median time on ART 3.7 years) were included in the study. The prevalence of virological suppression was 82.4% overall (95% confidence interval 80.5-84.2%). It ranged from 57.1 to 97.4% according to the individual hospital (P < 0.001). After adjustment, virological suppression was associated with age, CD4 cell count at ART initiation, disclosure of HIV status to family members, interruption of ART for more than two consecutive days, and location of patient's residence and hospital (rural/urban). These factors did not explain the heterogeneity of virological suppression between the study hospitals (P < 0.001).

CONCLUSIONS

The overall prevalence of virological suppression was reassuring. Nevertheless, the heterogeneity of virological suppression among hospitals highlights that, in addition to programme-level data, health facility-level data are crucial in order to tailor the national AIDS programme's interventions with a view to achieving the third UNAIDS 90 target.

Vector competence of Culex antennatus and Anopheles coustani mosquitoes for Rift Valley fever virus in Madagascar

Culex antennatus (Diptera: Culicidae), Anopheles coustani (Diptera: Culicidae) and Anopheles squamosus/cydippis were found to be infected with Rift Valley fever virus (RVFV) during an epidemic that occurred in 2008 and 2009 in Madagascar. To understand the roles played by Cx. antennatus and An. coustani in virus maintenance and transmission, RVFV vector competence was assessed in each species. Mosquito body parts and saliva of mosquitoes that fed on RVFV-infected blood were tested for RVFV using real-time quantitative polymerase chain reaction (RT-qPCR) assays. Overall, viral RNA was detected in body parts and saliva at 5 days post-infection (d.p.i.) in both species. At 5 d.p.i., infection rates were 12.5% (3/24) and 15.8% (6/38), disseminated infection rates were 100% (3/3) and 100% (6/6), transmission rates were 33.3% (1/3) and 83.3% (5/6), and transmission efficiencies were 4.2% (1/24) and 13.2% (5/38) in Cx. antennatus and An. coustani, respectively. Although RVFV detected in saliva did not propagate on to Vero cells, these results support potential roles for these two mosquito species in the transmission of RVFV.

[Inclusion criteria and rating scales for RCTs in Psychiatry. The future of qualitative studies]

An inventory on the two critical dimensions that structure the Randomized Controlled Trial in Psychiatry, namely the definition of inclusion criteria for eligible patients for testing and the choice of psychometric methods of pathology assessment and its evolution during the experiment, considers the importance of increasingly numerous and precise international recommendations. Taking into account the formal constraints of industrial, questioning the cultural differences of the methodological approach of the tests, meeting the requirements of feasibility and ever increasing security, frequent cumbersome procedure often contrasts with the modest nature of the results. A better definition to include patients in randomized trials is desirable and it asks to return to the clinic studying the expectations of patients and their response to the therapeutic situation. Excessive standardization otherwise required for ensuring the objective nature of the assessment hampers the collection of original and varied clinical features of importance in the further definitions of indications. On the way to a resumption of the single case study, we can expect from qualitative methods applied to small groups of subjects, optimization principles of patient selection for the upcoming randomized trial and greater chance to address the relevant details of clinical response to the therapeutic situation. This is what has led to the discovery of psychotropic drugs and which is involved in the various modalities of the qualitative approach. For example, and beyond the exploration of clinical drug effects, the study of the experience of psychiatric inpatient care in the Healing Garden, conducted on a small group and on the basis of the narrative analysis of their experience, notes several operating thematic dimensions: a reduction in the perception of symptoms of the disease, the impression of regaining a foothold into reality, the interest of a differently perceived doctor-patient relationship, the advantage of renewed power to act and the recognition of the importance of support from others, patients recovering somehow « vitality » of touch with reality. This suggests the possibility to establish an appropriate rating scale for such a specific therapeutic situation and to provide a more accurate and efficient recruitment for a comparative objective demonstration. Moreover, this construction of meaning reinforces the therapeutic benefit of treatment in Healing Garden and offers new dimensions for research.

Usefulness and accuracy of MALDI-TOF mass spectrometry as a supplementary tool to identify mosquito vector species and to invest in development of international database

Arthropod-borne diseases are important causes of morbidity and mortality. The identification of vector species relies mainly on morphological features and/or molecular biology tools. The first method requires specific technical skills and may result in misidentifications, and the second method is time-consuming and expensive. The aim of the present study is to assess the usefulness and accuracy of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) as a supplementary tool with which to identify mosquito vector species and to invest in the creation of an international database. A total of 89 specimens belonging to 10 mosquito species were selected for the extraction of proteins from legs and for the establishment of a reference database. A blind test with 123 mosquitoes was performed to validate the MS method. Results showed that: (a) the spectra obtained in the study with a given species differed from the spectra of the same species collected in another country, which highlights the need for an international database; (b) MALDI-TOF MS is an accurate method for the rapid identification of mosquito species that are referenced in a database; (c) MALDI-TOF MS allows the separation of groups or complex species, and (d) laboratory specimens undergo a loss of proteins compared with those isolated in the field. In conclusion, MALDI-TOF MS is a useful supplementary tool for mosquito identification and can help inform vector control.

Significant Change in Marine Plankton Structure and Carbon Production After the Addition of River Water in a Mesocosm Experiment

Rivers are known to be major contributors to eutrophication in marine coastal waters, but little is known on the short-term impact of freshwater surges on the structure and functioning of the marine plankton community. The effect of adding river water, reducing the salinity by 15 and 30%, on an autumn plankton community in a Mediterranean coastal lagoon (Thau Lagoon, France) was determined during a 6-day mesocosm experiment. Adding river water brought not only nutrients but also chlorophyceans that did not survive in the brackish mesocosm waters. The addition of water led to initial increases (days 1-2) in bacterial production as well as increases in the abundances of bacterioplankton and picoeukaryotes. After day 3, the increases were more significant for diatoms and dinoflagellates that were already present in the Thau Lagoon water (mainly Pseudo-nitzschia spp. group delicatissima and Prorocentrum triestinum) and other larger organisms (tintinnids, rotifers). At the same time, the abundances of bacterioplankton, cyanobacteria, and picoeukaryote fell, some nutrients (NH₄⁺, SiO₄^3-) returned to pre-input levels, and the plankton structure moved from a trophic food web based on secondary production to the accumulation of primary producers in the mesocosms with added river water. Our results also show that, after freshwater inputs, there is rapid emergence of plankton species that are potentially harmful to living organisms. This suggests that flash flood events may lead to sanitary issues, other than pathogens, in exploited marine areas.

Effectiveness of Fipronil as a Systemic Control Agent Against Xenopsylla cheopis (Siphonaptera: Pulicidae) in Madagascar

Fipronil was evaluated as a systemic control agent for the rat flea Xenopsylla cheopis (Rothschild), the main vector of Yersinia pestis (Yersin), the causative agent of plague, in Madagascar. The effectiveness of fipronil as a systemic control agent against X. cheopis was assessed by determining the toxicity values of the "Lethal Dose 50" (LD50). Two techniques were used to evaluate the systemic action of the insecticide on the vector: 1) an artificial feeding device filled with blood-fipronil mixture from which X. cheopis was fed and 2) rodent hosts, Rattus norvegicus (Berkenhout) and Rattus rattus (L.), which fed on fipronil-treated bait. As a standardized control method, the susceptibility of X. cheopis to fipronil was evaluated by exposure to impregnated paper within World Health Organization (WHO) insecticide test protocol to compare its effect to the systemic activity of the studied insecticide. Results showed that when administered in a systemic way, fipronil appears to be more effective: the toxicity level was evaluated to be ninefold higher compared with the WHO test. Compared with other methods, which require indiscriminate dusting of rodent burrows and human dwellings, fipronil applied in a systemic way enables the direct targeting of the plague vector. Thus, this method appears to be a superior alternative to fipronil-dusting for the control of the main plague vector in Madagascar. However, subsequent tests in the field are necessary to confirm the suitability of fipronil administration in a systemic way on large scales.

The value of specialist care-infectious disease specialist referrals-why and for whom? A retrospective cohort study in a French tertiary hospital

This study evaluated the impact of infectious disease (ID) specialist referrals on outcomes in a tertiary hospital in France. This study tackled methodological constraints (selection bias, endogeneity) using instrumental variables (IV) methods in order to obtain a quasi-experimental design. In addition, we investigated whether certain characteristics of patients have a bearing on the impact of the intervention. We used the payments database and ID department files to obtain data for adults admitted with an ID diagnosis in the North Hospital, Marseille from 2012 to 2014. Comparable cohorts were obtained using coarsened exact matching and analysed using IV models. Mortality, readmissions, cost (payer perspective) and length of stay (LoS) were analysed. We recorded 15,393 (85.97%) stays, of which 2,159 (14.03%) benefited from IDP consultations. The intervention was seen to significantly lower the risk of inpatient mortality (marginal effect (M.E) = -19.06%) and cost of stay (average treatment effect (ATE) = - €5,573.39). The intervention group was seen to have a longer LoS (ATE = +4.95 days). The intervention conferred a higher reduction in mortality and cost for stays that experienced ICU care (mortality: odds ratio (OR) =0.09, M.E cost = -8,328.84 €) or had a higher severity of illness (mortality: OR=0.35, M.E cost = -1,331.92 €) and for patients aged between 50 and 65 years (mortality: OR=0.28, M.E cost = -874.78 €). This study shows that ID referrals are associated with lower risk of inpatient mortality and cost of stay, especially when targeted to certain subgroups.

A penicillin- and metronidazole-resistant Clostridium botulinum strain responsible for an infant botulism case

The clinical course of a case of infant botulism was characterized by several relapses despite therapy with amoxicillin and metronidazole. Botulism was confirmed by identification of botulinum toxin and Clostridium botulinum in stools. A C. botulinum A2 strain resistant to penicillins and with heterogeneous resistance to metronidazole was isolated from stool samples up to 110 days after onset. Antibiotic susceptibility was tested by disc agar diffusion and MICs were determined by Etest. Whole genome sequencing allowed detection of a gene cluster composed of blaCBP for a novel penicillinase, blaI for a regulator, and blaR1 for a membrane-bound penicillin receptor in the chromosome of the C. botulinum isolate. The purified recombinant penicillinase was assayed. Resistance to β-lactams was in agreement with the kinetic parameters of the enzyme. In addition, the β-lactamase gene cluster was found in three C. botulinum genomes in databanks and in two of 62 genomes of our collection, all the strains belonging to group I C. botulinum. This is the first report of a C. botulinum isolate resistant to penicillins. This stresses the importance of antibiotic susceptibility testing for adequate therapy of botulism.

Prolonged delay for controlling KPC-2-producing Klebsiella pneumoniae outbreak: the role of clinical management

BACKGROUND

Carbapenemase-producing Enterobacteriaceae (CPE) are becoming of immediate concern for infection control policies. Prompt detection of CPE on health care setting admission is crucial to halt the spread of an outbreak. We report a cluster of 13 Klebsiella pneumoniae carbapenemase (KPC)-2-producing K pneumoniae cases in a tertiary care hospital.The objective of this study was to identify contributing factors originating the outbreak.

METHODS

An outbreak investigation was conducted using descriptive epidemiology, observation of health care practices, and interviews of management staff. A root cause analysis was performed to identify patent and latent failures of infection control measures using the association of litigation and risk management method.

RESULTS

The main patent failure was the delay in identifying KPC-2-producing K pneumoniae carriers. Contributing factors were work and environmental factors: understaffing, lack of predefined protocols, staff members' characteristics, and underlying patients' characteristics. Latent failures were as follows: no promotion of the national guidelines for prevention of CPE transmission, no clear procedure for the management of patients hospitalized abroad, no clear initiative for promoting a culture of quality in the hospital, biologic activity recently outsourced to a private laboratory, and poor communication among hospital members.

CONCLUSION

Clinical management should be better promoted to control hospital outbreaks and should include team work and safety culture.

Benefits of task-shifting HIV care to nurses in terms of health-related quality of life in patients initiating antiretroviral therapy in rural district hospitals in Cameroon [Stratall Agence Nationale de Recherche sur le SIDA (ANRS) 12110/Ensemble pour une Solidarité Thérapeutique Hospitalière en Réseau (ESTHER) substudy]

OBJECTIVES

The World Health Organization (WHO) recommends task-shifting HIV care to nurses in low-resource settings with limited numbers of physicians. However, the effect of such task-shifting on the health-related quality of life (HRQL) of people living with HIV (PLHIV) has seldom been evaluated. We aimed to investigate the effect of task-shifting HIV care to nurses on HRQL outcomes in PLHIV initiating antiretroviral therapy (ART) in rural district hospitals in Cameroon.

METHODS

Outcomes in PLHIV were longitudinally collected in the 2006-2010 Stratall trial. PLHIV were followed up for 24 months by nurses and/or physicians. Six HRQL dimensions were assessed during face-to-face interviews using the WHO Quality of Life (WHOQOL)-HIV BREF scale: physical health; psychological health; independence level; social relationships; environment; and spirituality/religion/personal beliefs. The degree of task-shifting was estimated using a consultant ratio (i.e. the ratio of nurse-led to physician-led visits). The effect of task-shifting and other potential correlates on HRQL dimensions was explored using a Heckman two-stage approach based on linear mixed models to adjust for the potential bias caused by missing data in the outcomes.

RESULTS

Of 1424 visits in 440 PLHIV (70.5% female; median age 36 years; median CD4 count 188 cells/μL at enrolment), 423 (29.7%) were task-shifted to nurses. After multiple adjustment, task-shifting was associated with higher HRQL level for four dimensions: physical health [coefficient 0.7; 95% confidence interval (CI) 0.1-1.2; P = 0.01], psychological health (coefficient 0.5; 95% CI 0.0-1.0; P = 0.05), independence level (coefficient 0.6; 95% CI 0.1-1.1; P = 0.01) and environment (coefficient 0.6; 95% CI 0.1-1.0; P = 0.02).

CONCLUSIONS

Task-shifting HIV care to nurses benefits the HRQL of PLHIV. Together with the previously demonstrated comparable clinical effectiveness of physician-based and nurse-based models of HIV care, our results support the WHO recommendation for task-shifting.

Patterns of adherence to antiretroviral therapy and HIV drug resistance over time in the Stratall ANRS 12110/ESTHER trial in Cameroon

OBJECTIVES

The emergence of HIV drug resistance is a crucial issue in Africa, where second-line antiretroviral therapy (ART) is limited, expensive and complex. We assessed the association between adherence patterns and resistance emergence over time, using an adherence measure that distinguishes low adherence from treatment interruptions, in rural Cameroon.

METHODS

We performed a cohort study among patients receiving nonnucleoside reverse transcriptase inhibitor (NNRTI)-based ART in nine district hospitals, using data from the Stratall trial (2006-2010). Genotypic mutations associated with antiretroviral drug resistance were assessed when 6-monthly HIV viral loads were > 5000 HIV-1 RNA copies/mL. ART adherence data were collected using face-to-face questionnaires. Combined indicators of early (1-3 months) and late (6 months to t - 1; t is the time point when the resistance had been detected) adherence were constructed. Multivariate logistic regression and Cox models were used to assess the association between adherence patterns and early (at 6 months) and late (after 6 months) resistance emergence, respectively.

RESULTS

Among 456 participants (71% women; median age 37 years), 45 developed HIV drug resistance (18 early and 27 late). Early low adherence (< 80%) and treatment interruptions (> 2 days) were associated with early resistance [adjusted odds ratio (95% confidence interval) 8.51 (1.30-55.61) and 5.25 (1.45-18.95), respectively]. Early treatment interruptions were also associated with late resistance [adjusted hazard ratio (95% confidence interval) 3.72 (1.27-10.92)].

CONCLUSIONS

The emergence of HIV drug resistance on first-line NNRTI-based regimens was associated with different patterns of adherence over time. Ensuring optimal early adherence through specific interventions, adequate management of drug stocks, and viral load monitoring is a clinical and public health priority in Africa.

Nationwide inventory of mosquito biodiversity (Diptera: Culicidae) in Belgium, Europe

To advance our restricted knowledge on mosquito biodiversity and distribution in Belgium, a national inventory started in 2007 (MODIRISK) based on a random selection of 936 collection points in three main environmental types: urban, rural and natural areas. Additionally, 64 sites were selected because of the risk of importing a vector or pathogen in these sites. Each site was sampled once between May and October 2007 and once in 2008 using Mosquito Magnet Liberty Plus traps. Diversity in pre-defined habitat types was calculated using three indices. The association between species and environmental types was assessed using a correspondence analysis. Twenty-three mosquito species belonging to traditionally recognized genera were found, including 21 indigenous and two exotic species. Highest species diversity (Simpson 0.765) and species richness (20 species) was observed in natural areas, although urban sites scored also well (Simpson 0.476, 16 species). Four clusters could be distinguished based on the correspondence analysis. The first one is related to human modified landscapes (such as urban, rural and industrial sites). A second is composed of species not associated with a specific habitat type, including the now widely distributed Anopheles plumbeus. A third group includes species commonly found in restored natural or bird migration areas, and a fourth cluster is composed of forest species. Outcomes of this study demonstrate the effectiveness of the designed sampling scheme and support the choice of the trap type. Obtained results of this first country-wide inventory of the Culicidae in Belgium may serve as a basis for risk assessment of emerging mosquito-borne diseases.

Diel activity patterns of male Aedes albopictus in the laboratory

This study was conducted to investigate the flight and dispersal behavior of male Aedes albopictus under laboratory conditions. Two different methods, the Observer and Ethovision software devices, were used to determine the total duration, the mean and maximum flight speed, and the distance covered by these mosquitoes. During 24 h, mosquitoes were more active from 0800 to 1200 h and from 1700 to 2100 h than during the rest of the day. Male Ae. albopictus displayed different activities at different times. The flight activity was 47 min and 57 sec over 24 h. During this period, sugar-fed males flew an average distance of 236.20 m at an average speed of 8.5 cm/sec. The unfed males flew significantly faster than recently fed males, with maximum flight speeds of 44.9 cm/sec and 33.6 cm/sec, respectively. The time used for resting (22 h 2 min +/- 13 min) was significantly higher (P < 0.0001) than walking and flying times (68 min +/- 10 sec and 49 min +/- 5 min, respectively). Overall, both methods allowed observations on flight activity, and the camera recordings allowed these activities to be quantified.

A review of control methods and resistance mechanisms in stored-product insects

This review describes the major stored-product insect species and their resistance to insecticides. The economic importance of the control of those pests is highlighted with a loss of more than one billion US dollars per year worldwide. A detailed common description of species resistance throughout the world has been developed, and we observed 28 recurrent studied species involved in resistance cases disseminated on the five continents. The different mechanisms, including behavioral resistance, were studied particularly on Oryzaephilus surinamensis. The role of detoxifying enzymes and studies on the genetic resistance, involving the kdr mutation mechanisms and the transmission of the genes of resistance, are also described. A chapter clarifying definitions on cross and multiple resistance is enclosed.

[Sterile insect technique: targeted control without insecticide]

Sterile insect technique (SIT) is a method of disease vector control technique that consists of releasing overwhelming numbers of sterile males. This method provides an environmentally friendly alternative to insecticides. Another advantage of SIT in comparison with other methods is to provide a targeted species-specific approach. In Reunion Island, SIT has been proposed as a basis for developing a viable method of vector control against Aedes albopictus and Anopheles arabiensis. The technique has already been successfully tested on fly and mosquito species for more than 40 years. The CRVOI (Centre de Recherche et de Veille sur les Maladies Emergentes dans l'Océan Indien) is carrying out studies to determine the feasibility of SIT for control of Anopheles arabiensis (vector of malaria) and Aedes albopictus (vector of chikungunya and dengue) on Reunion Island and other islands in the Indian Ocean region.

Noninvasive molecular methods to identify live scarab larvae: an example of sympatric pest and nonpest species in New Zealand

Despite the negative impact that many scarab larvae have on agro-ecosystems, very little attention has been paid to their taxonomy. Their often extremely similar morphological characteristics have probably contributed to this impediment, which has also meant that they are very difficult to identify in the field. Molecular methods can overcome this challenge and are particularly useful for the identification of larvae to enable management of pest species occurring sympatrically with nonpest species. However, the invasive collection of DNA samples for such molecular methods is not compatible with subsequent behavioural, developmental or fitness studies. Two noninvasive DNA sampling and DNA analysis methods suitable for the identification of larvae from closely related scarab species were developed here. Using the frass and larval exuviae as sources of DNA, field-collected larvae of Costelytra zealandica (White) and Costelytra brunneum (Broun) (Scarabaeidae: Melolonthinae) were identified by multiplex PCR based on the difference in size of the resulting PCR products. This study also showed that small quantities of frass can be used reliably even 7 days after excretion. This stability of the DNA is of major importance in ecological studies where timeframes rarely allow daily monitoring. The approach developed here is readily transferable to the study of any holometabolous insect species for which morphological identification of larval stages is difficult.

Sexual performance of male mosquito Aedes albopictus

Issues of male fertility must be addressed to support the development of a sterile insect technique (SIT) programme for the control of Aedes albopictus Skuse (Diptera: Culicidae) populations on Reunion Island in the Indian Ocean. The mating ability of a local strain of Ae. albopictus was tested using several batches of females and different cage sizes under laboratory conditions. Individual males were able to inseminate up to 14 females at an average of 9.5 females per male when exposed to 20 females over 7 days. Males filled between three and 27 spermathecal capsules at an average of 15.5 capsules per male. The average number of females inseminated per male was 5.3 when two virgin females were introduced to one male and replaced every day for 12 days, and 8.6 when 10 virgin females were introduced to one male and replaced every day for 14 days. A continuous decrease in the number of both inseminated females and filled spermathecal capsules was observed over time, until no mating occurred after 14 days. The high number of females inseminated by one male and the duration of male activity may have strong implications for SIT control of mosquitoes.