Genetic Diversity and Protective Efficacy of the RTS,S/AS01 Malaria Vaccine.

BACKGROUND: The RTS,S/AS01 vaccine targets the circumsporozoite protein of Plasmodium falciparum and has partial protective efficacy against clinical and severe malaria disease in infants and children. We investigated whether the vaccine efficacy was specific to certain parasite genotypes at the circumsporozoite protein locus. METHODS: We used polymerase chain reaction-based next-generation sequencing of DNA extracted from samples from 4985 participants to survey circumsporozoite protein polymorphisms. We evaluated the effect that polymorphic positions and haplotypic regions within the circumsporozoite protein had on vaccine efficacy against first episodes of clinical malaria within 1 year after vaccination. RESULTS: In the per-protocol group of 4577 RTS,S/AS01-vaccinated participants and 2335 control-vaccinated participants who were 5 to 17 months of age, the 1-year cumulative vaccine efficacy was 50.3% (95% confidence interval [CI], 34.6 to 62.3) against clinical malaria in which parasites matched the vaccine in the entire circumsporozoite protein C-terminal (139 infections), as compared with 33.4% (95% CI, 29.3 to 37.2) against mismatched malaria (1951 infections) (P=0.04 for differential vaccine efficacy). The vaccine efficacy based on the hazard ratio was 62.7% (95% CI, 51.6 to 71.3) against matched infections versus 54.2% (95% CI, 49.9 to 58.1) against mismatched infections (P=0.06). In the group of infants 6 to 12 weeks of age, there was no evidence of differential allele-specific vaccine efficacy. CONCLUSIONS: These results suggest that among children 5 to 17 months of age, the RTS,S vaccine has greater activity against malaria parasites with the matched circumsporozoite protein allele than against mismatched malaria. The overall vaccine efficacy in this age category will depend on the proportion of matched alleles in the local parasite population; in this trial, less than 10% of parasites had matched alleles. (Funded by the National Institutes of Health and others.).

Preliminary studies developing methods for the control of Chrysomya putoria, the African latrine fly, in pit latrines in The Gambia.

OBJECTIVE: To explore ways of controlling Chrysomya putoria, the African latrine fly, in pit latrines. As pit latrines are a major source of these flies, eliminating these important breeding sites is likely to reduce village fly populations, and may reduce the spread of diarrhoeal pathogens. METHODS: We treated 24 latrines in a Gambian village: six each with (i) pyriproxyfen, an insect juvenile hormone mimic formulated as Sumilarv(®) 0.5 G, a 0.5% pyriproxyfen granule, (ii) expanded polystyrene beads (EPB), (iii) local soap or (iv) no treatment as controls. Flies were collected using exit traps placed over the drop holes, weekly for five weeks. In a separate study, we tested whether latrines also function as efficient flytraps using the faecal odours as attractants. We constructed six pit latrines each with a built-in flytrap and tested their catching efficiency compared to six fish-baited box traps positioned 10 m from the latrine. Focus group discussions conducted afterwards assessed the acceptability of the flytrap latrines. RESULTS: Numbers of emerging C. putoria were reduced by 96.0% (95% CIs: 94.5-97.2%) 4-5 weeks after treatment with pyriproxyfen; by 64.2% (95% CIs: 51.8-73.5%) after treatment with local soap; by 41.3% (95% CIs = 24.0-54.7%) after treatment with EPB 3-5 weeks after treatment. Flytraps placed on latrines collected C. putoria and were deemed acceptable to local communities. CONCLUSIONS: Sumilarv 0.5 G shows promise as a chemical control agent, whilst odour-baited latrine traps may prove a useful method of non-chemical fly control. Both methods warrant further development to reduce fly production from pit latrines. A combination of interventions may prove effective for the control of latrine flies and the diseases they transmit.

[Malaria infection and nutritional status: results from a cohort survey of children from 6-59 months old in the Kivu province, Democratic Republic of the Congo]. / Infection palustre et état nutritionnel: résultats d'une cohorte d'enfants âgés de 6 à 59 mois au Kivu en République démocratique du Congo.

BACKGROUND: Despite a reduction in the magnitude of endemic malaria reported in recent years, malaria and protein-energy malnutrition (PEM) still remain major causes of morbidity and mortality in sub-Saharan Africa among children under five. The relationship between malaria and malnutrition remains a topic of controversy. We aimed to investigate malaria infection according to nutritional status in a community-based survey. METHODS: A cohort of 790 children aged 6 to 59 months and residing in eastern Democratic Republic of the Congo was followed-up from April 2009 to March 2010 with monthly visits. Data on nutritional status, morbidity between visits, use of insecticide-treated nets and malaria parasitemia were collected at each visit. The Z scores height for age, weight for age and weight for height were computed using the reference population defined by the WHO in 2006. Thresholds for Z scores were defined at -3 and -2. A binary logistic model of the generalized estimating equation (GEE) was used to quantify the association between PEM indicators and malaria parasitemia. Odds ratio (OR) and their 95% confidence interval (95% CI) were computed. RESULTS: After adjustment for season, children with severe stunting (height for age Z score<-3) were at lower risk of malaria parasitemia greater or equal to 5000 trophozoits/µL of blood as compared to those in with a better nutritional status (height for age Z score≥-2) (OR=0.48, 95% CI: 0.25-0.91). CONCLUSION: Severely stunted children are at a lower risk of high-level malaria parasitemia.

In silico characterisation of putative Plasmodium falciparum vaccine candidates in African malaria populations.

Genetic diversity of surface exposed and stage specific Plasmodium falciparum immunogenic proteins pose a major roadblock to developing an effective malaria vaccine with broad and long-lasting immunity. We conducted a prospective genetic analysis of candidate antigens (msp1, ama1, rh5, eba175, glurp, celtos, csp, lsa3, Pfsea, trap, conserved chrom3, hyp9, hyp10, phistb, surfin8.2, and surfin14.1) for malaria vaccine development on 2375 P. falciparum sequences from 16 African countries. We described signatures of balancing selection inferred from positive values of Tajima's D for all antigens across all populations except for glurp. This could be as a result of immune selection on these antigens as positive Tajima's D values mapped to regions with putative immune epitopes. A less diverse phistb antigen was characterised with a transmembrane domain, glycophosphatidyl anchors between the N and C- terminals, and surface epitopes that could be targets of immune recognition. This study demonstrates the value of population genetic and immunoinformatic analysis for identifying and characterising new putative vaccine candidates towards improving strain transcending immunity, and vaccine efficacy across all endemic populations.

Community-based distribution of sulfadoxine-pyrimethamine for intermittent preventive treatment of malaria during pregnancy improved coverage but reduced antenatal attendance in southern Malawi.

OBJECTIVE: To evaluate the impact of a 2-year programme for community-based delivery of sulfadoxine-pyrimethamine (SP) on intermittent preventive treatment during pregnancy coverage, antenatal clinic attendance and pregnancy outcome. METHODS: Fourteen intervention and 12 control villages in the catchment areas of Chikwawa and Ngabu Government Hospitals, southern Malawi, were selected. Village-based community health workers were trained in information, education and counselling on malaria control in pregnancy and the importance of attending antenatal clinics and promoted these messages to pregnant women. In the intervention group community health workers also distributed SP to pregnant women. RESULTS: In the control area, coverage of intermittent preventive treatment during pregnancy (>2 doses) was low before (44.1%) and during the intervention (46.1%). In the intervention area, coverage increased from 41.5% to 82.9% (P < 0.01). Antenatal clinic attendance (>2 visits) was maintained in control villages at above 90%, but fell in intervention villages from 87.3% to 51.5% (P < 0.01). Post-natal malaria parasitaemia prevalence fell in women from both study areas during the intervention phase (P < 0.05). Increasing the coverage of intermittent preventive treatment during pregnancy to >40% did not significantly improve maternal haemoglobin or reduce low birthweight prevalence. CONCLUSIONS: Better coverage of community-based intermittent preventive treatment during pregnancy can lower attendance at antenatal clinics; thus its effect on pregnancy outcome and antenatal attendance need to be monitored.

Mucosal lactoferrin response to genital tract infections is associated with iron and nutritional biomarkers in young Burkinabé women.

BACKGROUND/OBJECTIVES: The iron-binding affinity of vaginal lactoferrin (Lf) reduces iron available to genital pathogens. We describe host reproductive, nutritional, infection and iron biomarker profiles affecting vaginal Lf concentration in young nulliparous and primigravid women in Burkina Faso. SUBJECTS/METHODS: Vaginal eluates from women who had participated in a randomized, controlled periconceptional iron supplementation trial were used to measure Lf using a competitive double-sandwich ELISA. For this analysis samples from both trial arms were combined and pregnant and non-pregnant cohorts compared. Following randomization Lf was measured after 18 months (end assessment) for women remaining non-pregnant, and at two antenatal visits for those becoming pregnant. Associations between log Lf levels and demographic, anthropometric, infection and iron biomarker variables were assessed using linear mixed models. RESULTS: Lf samples were available for 712 non-pregnant women at end assessment and for 303 women seen at an antenatal visit. Lf concentrations of pregnant women were comparable to those of non-pregnant, sexually active women. Lf concentration increased with mid-upper-arm circumference, (P = 0.047), body mass index (P = 0.018), Trichomonas vaginalis (P < 0.001) infection, bacterial vaginosis (P < 0.001), serum C-reactive protein (P = 0.048) and microbiota community state types III/IV. Adjusted Lf concentration was positively associated with serum hepcidin (P = 0.047), serum ferritin (P = 0.018) and total body iron stores (P = 0.042). There was evidence that some women maintained persistently high or low Lf concentrations from before, and through, pregnancy. CONCLUSION: Lf concentrations increased with genital infection, higher BMI, MUAC, body iron stores and hepcidin, suggesting nutritional and iron status influence homeostatic mechanisms controlling vaginal Lf responses.

A randomised trial to assess the efficacy and safety of chlorproguanil/dapsone + artesunate for the treatment of uncomplicated Plasmodium falciparum malaria.

We tested the efficacy and safety of chlorproguanil/dapsone co-administered with artesunate (CD+A) for the treatment of uncomplicated Plasmodium falciparum malaria in children compared with amodiaquine+sulfadoxine/pyrimethamine (AQ+SP) at two different sites in Rwanda. The trial was open label and 800 patients were randomly assigned to AQ+SP (n=400) or CD+A (n=400). Patients were hospitalised for 3 days and then followed-up weekly until Day 28 after treatment. Clinical and parasitological outcomes were recorded. Results showed that neither treatment was adequately efficacious. At one site, the adequate clinical and parasitological response (ACPR), PCR-adjusted, was 73.3% in the CD+A arm and 87.8% in the AQ+SP arm (P<0.001), and at the second site the ACPR, PCR-adjusted, was 70.5% in the CD+A arm and 38.1% in the AQ+SP arm (P<0.001). The combination CD+A is considered an alternative to, or replacement for, SP in Africa because CD has been shown to be effective in patients for whom SP treatment has failed and, with its short half-life, it is expected to exert less selection pressure for resistant parasites than SP. However, the results of this trial indicate that in an area of high SP resistance, CD+A may not be the best choice.

[Protein-energy malnutrition and malaria-related morbidity in children under 59 months in the Kivu region of the Democratic Republic of the Congo]. / Malnutrition protéino-énergétique et morbidité liée au paludisme t chez les enfants de 0-59 mois dans la région du Kivu, République Démocratique du Congo.

In the Kivu region located in east of the Democratic Republic of the Congo, malnutrition and malaria is a major cause of morbidity and mortality. The relationship between malaria and malnutrition is unclear and has never been studied in the Kivu region. This report presents an analysis of data from 5695 children aged 0 to 5 years, admitted to the paediatric ward of Lwiro hospital between November 1992 and February 2004. The weight/age (W/A) index and weight/height (W/H) index expressed with standard deviation in relation to the reference median were calculated (Z score). The association between protein-energetic malnutrition and malaria infection and nutritional indicators was measured based on prevalence ratios determined by univariate analysis and adjusted Odds Ratio (OR) derived using a multivariate model. The prevalence of malaria at the time of admission was 35.8 % (n=5695). The W/A and W/H indexes and serum albumin level were correlated with malaria-related morbidity. Logistic regression showed that high malaria OR was associated with both anthropometric nutritional indicators [WHZ > -2: OR (CI 95 %) 1.7 (1.4-2.2)] [WAZ > -2: OR (CI 95 %) 1.3 (1.1-1.6)] and biological nutritional indicators [serum albumin > or = 23 g/L: OR (CI 95 %) 1.6 (1.2-2.1)]. Our findings indicate that malnourished children at admission have a lower risk of malaria infection.

Maternal pneumococcal nasopharyngeal carriage and risk factors for neonatal carriage after the introduction of pneumococcal conjugate vaccines in The Gambia.

OBJECTIVES: Pneumococcal nasopharyngeal carriage occurs early in life. However, the role of vertical transmission is not well understood. The aims of this study were to describe carriage among mothers and their newborns, and to assess for risk factors for neonatal carriage. METHODS: In a nested retrospective cohort study, we analysed data from the control arm of a randomized controlled trial conducted in The Gambia 2 to 3 years after introduction of pneumococcal conjugate vaccine (PCV) 13. Nasopharyngeal swabs were collected from 374 women and their newborns on the day of delivery, then 3, 6, 14 and 28 days later. Pneumococci were isolated and serotyped using conventional microbiologic methods. RESULTS: Carriage increased from 0.3% (1/373) at birth to 37.2% (139/374) at day 28 (p <0.001) among neonates and from 17.1% (64/374) to 24.3% (91/374) (p 0.015) among women. In both groups, PCV13 vaccine-type (VT) serotypes accounted for approximately one-third of the pneumococcal isolates, with serotype 19A being the most common VT. Maternal carriage (adjusted odds ratio (OR) = 2.82; 95% confidence interval (CI), 1.77-4.80), living with other children in the household (adjusted OR = 4.06; 95% CI, 1.90-8.86) and dry season (OR = 1.98; 95% CI, 1.15-3.43) were risk factors for neonatal carriage. Over half (62.6%) of the neonatal carriage was attributable to living with other children in the same household. CONCLUSIONS: Three years after the introduction of PCV in The Gambia, newborns are still rapidly colonized with pneumococcus, including PCV13 VT. Current strategies for pneumococcal control in Africa do not protect this age group beyond the herd effect.

A randomised trial to assess the safety and efficacy of artemether-lumefantrine (Coartem) for the treatment of uncomplicated Plasmodium falciparum malaria in Rwanda.

Coartem is a fixed-dose combination of artemether-lumefantrine that, given in six doses, provides effective treatment for children with uncomplicated Plasmodium falciparum infection in areas with highly endemic and multidrug-resistant malaria. In Rwanda since 2001, amodiaquine+sulfadoxine-pyrimethamine (AQ+SP) has been the first-line treatment, but resistance to this combination has rapidly emerged and spread. Coartem was considered as a possible alternative, and a randomised, open-label, clinical trial to test its safety, tolerability and efficacy was carried out in 2004-2005. Five hundred children aged 12-59 months with uncomplicated P. falciparum malaria were randomly allocated to AQ+SP or Coartem. Patients were followed up until day 28 after treatment. Adverse events and clinical and parasitological outcomes were recorded. Adequate clinical and parasitological response (ACPR) was significantly higher in children treated with Coartem than in those treated with AQ+SP: the PCR-adjusted 28-day ACPR was 96.68% for Coartem and 79.35% for AQ+SP. Both treatments rapidly cleared parasitaemia and fever, although parasite clearance was significantly faster in children treated with Coartem. Mean packed cell volume increased in all patients, with no significant differences between treatments. Coartem proved to be more efficacious than AQ+SP, with a good safety and tolerability profile.

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.

Maternal anaemia as an indicator for monitoring malaria control in pregnancy in sub-Saharan Africa.

DESIGN: Malarial anaemia is a major problem in many developing countries and often occurs more frequently in first pregnancies, as primigravidae are more susceptible to Plasmodium falciparum malaria and are at excess risk of malarial anaemia. OBJECTIVE AND METHODS: To analyse the excess risk of anaemia in primigravidae as a potential indicator of malaria control and exposure in pregnant women living in sub-Saharan Africa. The sensitivity, specificity and predictive values for anaemia in first compared with later pregnancies are calculated for 27 studies from malarious and 7 studies from nonmalarious areas. SETTING: Surveys of pregnancy anaemia reported for highly malarious and nonmalarious areas. RESULTS: In malarious areas, the weighted odds ratio for excess anaemia (haemoglobin [Hb] <11 g/dl) in primigravidae compared with multigravidae for all studies was 1.34 (95% CI 1.14-1.58). At an Hb cutoff below 8 g/dl, the weighted odds ratio was 1.79 (95% CI 1.52-2.10). In nonmalarious areas, there was no increased risk of anaemia in primigravidae with Hb below 11 g/dl (OR 0.80; 95% CI 0.63-1.90) or below 8 g/dl (OR 0.82, 95% CI 0.51-1.28). CONCLUSIONS: In view of the consistency of results across highly malarious areas compared with nonmalarious areas, maternal anaemia has the potential to be used for surveillance of malaria control in pregnancy. Based on the analysis, an anaemia nomogram is developed for use as a surveillance indicator in malarious areas in sub-Saharan Africa.

Maternal colonization with Staphylococcus aureus and Group B streptococcus is associated with colonization in newborns.

OBJECTIVES: Although Staphylococcus aureus and Group B streptococcus (GBS) are major causes of neonatal sepsis in sub-Saharan Africa, it is unclear how these bacteria are transmitted to the neonate. METHODS: In a cohort of 377 Gambian women and their newborns, nasopharyngeal swabs were collected at delivery (day 0), and 3, 6, 14 and 28 days later. Breast milk samples and vaginal swabs were collected from the mother. Staphylococcus aureus and GBS were isolated using conventional microbiological methods. RESULTS: Most women were carriers of S. aureus (264 out of 361 with all samples collected, 73.1%) at some point during follow up and many were carriers of GBS (114 out of 361, 31.6%). Carriage of S. aureus was common in all three maternal sites and GBS was common in the vaginal tract and breast milk. Among newborns, carriage of S. aureus peaked at day 6 (238 out of 377, 63.1%) and GBS at day 3 (39 out of 377, 10.3%). Neonatal carriage of S. aureus at day 6 was associated with maternal carriage in the breast milk adjusted OR 2.54; 95% CI 1.45-4.45, vaginal tract (aOR 2.55; 95% CI 1.32-4.92) and nasopharynx (aOR 2.49; 95% CI 1.56-3.97). Neonatal carriage of GBS at day 6 was associated with maternal carriage in the breast milk (aOR 3.75; 95% CI 1.32-10.65) and vaginal tract (aOR 3.42; 95% CI 1.27-9.22). CONCLUSIONS: Maternal colonization with S. aureus or GBS is a risk factor for bacterial colonization in newborns.

Interleukin-10 and soluble tumor necrosis factor receptor II are potential biomarkers of Plasmodium falciparum infections in pregnant women: a case-control study from Nanoro, Burkina Faso.

BACKGROUND: Diagnosis of malaria in pregnancy is problematic due to the low sensitivity of conventional diagnostic tests (rapid diagnostic test and microscopy), which is exacerbated due to low peripheral parasite densities, and lack of clinical symptoms. In this study, six potential biomarkers to support malaria diagnosis in pregnancy were evaluated. METHODS: Blood samples were collected from pregnant women at antenatal clinic visits and at delivery. Microscopy and real-time PCR were performed for malaria diagnosis and biomarker analyses were performed by ELISA (interleukin 10, IL-10; tumor necrosis factor-α, TNF-α; soluble tumor necrosis factor receptor II, sTNF-RII; soluble fms-like tyrosine kinase 1, sFlt-1; leptin and apolipoprotein B, Apo-B). A placental biopsy was collected at delivery to determine placental malaria. RESULTS: IL-10 and sTNF-RII were significantly higher at all time-points in malaria-infected women (p < 0.001). Both markers were also positively associated with parasite density (p < 0.001 and p = 0.003 for IL-10 and sTNF-RII respectively). IL-10 levels at delivery, but not during pregnancy, were negatively associated with birth weight. A prediction model was created using IL-10 and sTNF-RII cut-off points. For primigravidae the model had a sensitivity of 88.9% (95%CI 45.7-98.7%) and specificity of 83.3% (95% CI 57.1-94.9%) for diagnosing malaria during pregnancy. For secundi- and multigravidae the sensitivity (81.8% and 56.5% respectively) was lower, while specificity (100.0% and 94.3% respectively) was relatively high. Sub-microscopic infections were detected in 2 out of 3 secundi- and 5 out of 12 multigravidae. CONCLUSIONS: The combination of biomarkers IL-10 and sTNF-RII have the potential to support malaria diagnosis in pregnancy. Additional markers may be needed to increase sensitivity and specificity, this is of particular importance in populations with sub-microscopic infections or in whom other inflammatory diseases are prevalent.

[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.

Oral azithromycin given during labour decreases bacterial carriage in the mothers and their offspring: a double-blind randomized trial.

Bacterial sepsis remains a leading cause of death among neonates with Staphylococcus aureus, group B streptococcus (GBS) and Streptococcus pneumoniae identified as the most common causative pathogens in Africa. Asymptomatic bacterial colonization is an intermediate step towards sepsis. We conducted a phase III, double-blind, placebo-controlled randomized trial to determine the impact of giving one oral dose of azithromycin to Gambian women in labour on the nasopharyngeal carriage of S. aureus, GBS or S. pneumoniae in the newborn at day 6 postpartum. Study participants were recruited in a health facility in western Gambia. They were followed for 8 weeks and samples were collected during the first 4 weeks. Between April 2013 and April 2014 we recruited 829 women who delivered 843 babies, including 13 stillbirths. Sixteen babies died during the follow-up period. No maternal deaths were observed. No serious adverse events related to the intervention were reported. According to the intent-to-treat analysis, prevalence of nasopharyngeal carriage of the bacteria of interest in the newborns at day 6 was lower in the intervention arm (28.3% versus 65.1% prevalence ratio 0.43; 95% CI 0.36-0.52, p <0.001). At the same time-point, prevalence of any bacteria in the mother was also lower in the azithromycin group (nasopharynx, 9.3% versus 40.0%, p <0.001; breast milk, 7.9% versus 21.6%, p <0.001; and the vaginal tract, 13.2% versus 24.2%, p <0.001). Differences between arms lasted for at least 4 weeks. Oral azithromycin given to women in labour decreased the carriage of bacteria of interest in mothers and newborns and may lower the risk of neonatal sepsis. Trial registrationClinicalTrials.gov Identifier NCT01800942.

Hepatitis E virus infection and acute-on-chronic liver failure in West Africa: a case-control study from The Gambia.

BACKGROUND: In sub-Saharan Africa, it is unknown whether hepatitis E virus (HEV) infection is a common precipitating event of acute-on-chronic liver failure (ACLF). AIMS: To estimate the prevalence of HEV infection in general population and assess whether HEV is a common trigger of ACLF in cirrhotic patients in The Gambia, West Africa. METHODS: We first conducted an HEV sero-survey in healthy volunteers. We then tested cirrhotic patients with ACLF (cases) and compensated cirrhosis (controls) for anti-HEV IgG as a marker of exposure to HEV, and anti-HEV IgA and HEV RNA as a marker of recent infection. We also described the characteristics and survival of the ACLF cases and controls. RESULTS: In the healthy volunteers (n = 204), 13.7% (95% CI: 9.6-19.2) were positive for anti-HEV IgG, and none had positive HEV viraemia. After adjusting for age and sex, the following were associated with positive anti-HEV IgG: being a Christian, a farmer, drinking water from wells, handling pigs and eating pork. In 40 cases (median age: 45 years, 72.5% male) and 71 controls (39 years, 74.6% male), ≥70% were infected with hepatitis B virus. Although hepatitis B flare and sepsis were important precipitating events of ACLF, none had marker of acute HEV. ACLF cases had high (70.0%) 28-day mortality. CONCLUSIONS: Hepatitis E virus infection is endemic in The Gambia, where both faecal-oral route (contaminated water) and zoonotic transmission (pigs/pork meat) may be important. However, acute HEV was not a common cause of acute-on-chronic liver failure in The Gambia.

Validation of an apicoplast genome target for the detection of Plasmodium species using polymerase chain reaction and loop mediated isothermal amplification.

The genome of the Plasmodium apicoplast, which has a higher copy number compared with current targets for molecular diagnosis of malaria, appears to be a suitable target for detection of submicroscopic infections that are capable of sustaining transmission. Novel primers targeting a conserved segment of the apicoplast (PFC10_AP|0010:rRNA) were designed and used in a number of different high throughput platforms such as single-step PCR (ssPCR), nested PCR (nPCR) and loop-mediated isothermal amplification (LAMP) for parasite detection. Replicates of ten-fold serial dilutions of Plasmodium falciparum 3D7 DNA, with equivalent parasite density ranges of 200,000 to 0.2 parasites/µL, were used to determine the limit of detection and repeatability of each assay. A panel of 184 archived DNA samples extracted from either EDTA whole blood or dried blood spots, from across West Africa and South East Asia was used to determine the diagnostic performance of the assays. All assays amplified the 2 parasites/µL dilution except the ssPCR, which amplified two of the three replicates. Using an 18S rRNA PCR as reference, the sensitivity was 98% (95% CI 93-100%) for the LAMP assay, 87% (95% CI 79-93%) for ssPCR and 100% (95% CI 97-100%) for nPCR. Specificity was 91% (95% CI 83-96%) for LAMP, 82% (95% CI 72-90%) for ssPCR and 66% (95% CI 54-76%) for nPCR. The apicoplast genome-based nPCR detected more positive samples overall than the reference method. Discrepant samples were confirmed as true positives using a probe-based real-time quantitative PCR assay. The results show that the apicoplast genome is a suitable target for molecular diagnosis of malaria.

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.