Papers by Umberto D'Alessandro
PLoS ONE, 2014
Objective: To evaluate the coverage and timeliness of the Expanded Programme on Immunisation (EPI... more Objective: To evaluate the coverage and timeliness of the Expanded Programme on Immunisation (EPI) in The Gambia.
PLoS ONE, 2013
Background: While coverage of long-lasting insecticide-treated nets (LLIN) has steadily increased... more Background: While coverage of long-lasting insecticide-treated nets (LLIN) has steadily increased, a growing number of studies report gaps between net ownership and use. We conducted a mixed-methods social science study assessing the importance of net preference and use after OlysetH LLINs were distributed through a mass campaign in rural communities surrounding Iquitos, the capital city of the Amazonian region of Peru.
PLoS ONE, 2013
Background: Over the last years, the number of clinical trials carried out in low-income countrie... more Background: Over the last years, the number of clinical trials carried out in low-income countries with poor medical infrastructure and limited access to health care has increased. In these settings, the decision of participating in a clinical study may be influenced by factors related to participants' vulnerability that limit the efficacy of the informed consent.
Malaria Journal, 2010
Background: Despite Vietnam's success in reducing malaria mortality and morbidity over the last d... more Background: Despite Vietnam's success in reducing malaria mortality and morbidity over the last decade, malaria persists in the forested and mountainous areas of the central and southern provinces, where more than 50% of the clinical cases and 90% of severe cases and malaria deaths occur.
PLoS ONE, 2010
Background: While IPTp-SP is currently being scaled up in sub-Saharan Africa (SSA), the coverage ... more Background: While IPTp-SP is currently being scaled up in sub-Saharan Africa (SSA), the coverage with the required $2 doses of SP remains considerably short of the Roll Back Malaria (RBM) goal of 80%, not to mention of the recently advocated universal coverage.
PLoS ONE, 2013
Background: Long-lasting insecticidal hammocks (LLIHs) are being evaluated as an additional malar... more Background: Long-lasting insecticidal hammocks (LLIHs) are being evaluated as an additional malaria prevention tool in settings where standard control strategies have a limited impact. This is the case among the Ra-glai ethnic minority communities of Ninh Thuan, one of the forested and mountainous provinces of Central Vietnam where malaria morbidity persist due to the sylvatic nature of the main malaria vector An. dirus and the dependence of the population on the forest for subsistence -as is the case for many impoverished ethnic minorities in Southeast Asia.
Tropical Medicine & International Health
Antimicrobial agents and chemotherapy, Jan 21, 2015
Plasmodium vivax resistance to chloroquine (PvCQR) is currently reported in almost all vivax ende... more Plasmodium vivax resistance to chloroquine (PvCQR) is currently reported in almost all vivax endemic countries. In Vietnam, despite a first report on PvCQR published in the early 2000s, P.vivax was still considered sensitive to CQ. Between May 2009 and December 2011, a 2-year cohort study was conducted in Central Vietnam to assess the recommended radical cure regimen based on a 10-day course Primaquine (0.5mg/kg/day) together with 3 days CQ (25mg/kg). We hereby report the results of the first 28-day follow-up estimating the cumulative risk of P. vivax recurrences together with the corresponding CQ blood concentrations among other endpoints. Out of 260 recruited P.vivax patients, 240 completed treatment and were followed up to day 28 according to the WHO guidelines. Eight patients (3.45%) had a P.vivax recurrent infection, at day 14 (n=2), day 21 (n=1) and day 28 (n=5). Chloroquine blood concentrations, available in 3/8 recurrent infections (day 14,21,28) were above the minimal inhib...
The American journal of tropical medicine and hygiene
In two cross-sectional surveys carried out in the rural health district of Boromo, Burkina Faso, ... more In two cross-sectional surveys carried out in the rural health district of Boromo, Burkina Faso, malaria infection was evaluated in 295 pregnant women in May 2003 and 288 pregnant women in December 2003. Malaria prevalence, all P. falciparum infection, was higher in December (32.2%) than in May (11.9%) (P < 0.0001). In both surveys primigravidae had a significantly higher risk of infection than multigravidae (P < 0.0001). Such risk decreased significantly and progressively with gestational age, the highest risk being during the first trimester. Women who had not attended the antenatal clinic had also a significantly higher risk of malaria infection. Despite the high antenatal clinic attendance and the use (or misuse) of chloroquine chemoprophylaxis, malaria remains an important problem for pregnant women living in the rural district of Boromo. This requires a major effort by the health authorities to guarantee all pregnant women have access to and use preventive measures.
The American journal of tropical medicine and hygiene
Malaria preventive strategies in pregnancy were assessed in a health center randomized trial comp... more Malaria preventive strategies in pregnancy were assessed in a health center randomized trial comparing intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp-SP) with and without community based promotional activities in rural Burkina Faso. The study involved 2,240 secundigravidae and secundigravidae and evaluated factors associated with antenatal clinic (ANC) attendance and uptake of IPTp-SP. With promotion, 64.2% completed > or = 3 ANC visits compared with 44.7% without (P = 0.05). Complete uptake of IPTp-SP was 71.8% with and 49.1% without promotion (P = 0.008). The IPTp-SP uptake was lowest in adolescents delivering during high malaria transmission with (29%) or without promotion (30%). Uptake of SP was higher during the low transmission season than in the high transmission season (adjusted odds ratio = 2.17, 95% confidence interval = 1.59-3.03). Community sensitization increased ANC attendance and IPTp-SP uptake. Adolescents were the most difficult to reach, ...
The American journal of tropical medicine and hygiene, Jan 17, 2015
Malaria control along the Vietnam-Cambodia border presents a challenge for both countries' ma... more Malaria control along the Vietnam-Cambodia border presents a challenge for both countries' malaria elimination targets as the region is forested, inhabited by ethnic minority populations, and potentially characterized by early and outdoor malaria transmission. A mixed methods study assessed the vulnerability to malaria among the Jarai population living on both sides of the border in the provinces of Ratanakiri (Cambodia) and Gia Lai (Vietnam). A qualitative study generated preliminary hypotheses that were quantified in two surveys, one targeting youth (N = 498) and the other household leaders (N = 449). Jarai male youth, especially in Cambodia, had lower uptake of preventive measures (57.4%) and more often stayed overnight in the deep forest (35.8%) compared with the female youth and the adult population. Among male youth, a high-risk subgroup was identified that regularly slept at friends' homes or outdoors, who had fewer bed nets (32.5%) that were torn more often (77.8%). ...
The purpose of this study was to identify the determinants of adherence to malaria&amp;amp;am... more The purpose of this study was to identify the determinants of adherence to malaria&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;np pagenum=&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;034&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;/&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; treatment (co-blistered AS-AQ) among health care providers, medicine sellers and patients in the northeastern region of the Democratic Republic of Congo. A cross-sectional study was carried out on health care providers, medicine sellers and patients in 13 health zones between March and June 2009. Only 69% of the cases of uncomplicated malaria were treated with AS-AQ, including 62.3% of cases treated using the correct dosages. The availability of AS-AQ, the intention to prescribe AS-AQ, longer consultations, providing explanations to patients, working in rural areas, training on the new policy, and the availability of treatment guidelines were found to be significantly associated with treatment adherence among health care providers. The limited availability of AS-AQ, the adverse effects of the treatment, the use of low-quality AS-AQ and the availability of cheap illegal antimalarial drugs were the main factors associated with non-adherence. Among patients, non-adherence was related to the perceived adverse effects of malaria treatment. The results suggest that improving the?accessibility and quality of AS-AQ and the quality of communication with patients, the provision of appropriate training to healthcare providers, the provision of treatment guidelines and appropriate supervision are needed to promote the use of AS-AQ.
Malaria Journal, 2015
As indicators of burden of malaria have substantially decreased in The Gambia, reaching a pre-eli... more As indicators of burden of malaria have substantially decreased in The Gambia, reaching a pre-elimination status may be attainable. Achieving this goal requires in-depth understanding of the current burden of Plasmodium falciparum infection. A nationwide cross-sectional survey was conducted in 2012 to determine the prevalence of P. falciparum infection, and to describe its heterogeneity and associated risk factors. Finger-prick blood samples were collected for microscopy, species-specific PCR and haemoglobin measurement. A total of 9,094 participants were included and median age was 11.9Â years (IQR 5, 28). Overall prevalence of P. falciparum was 16.01Â % with marked heterogeneity between sites (4.32-36.75Â %) and within villages in each site (1.63-49.13Â %). Across all sites, 51.17Â % (745/1,456) of infections were asymptomatic and 35.61Â % (448/1,258) were sub-microscopic. The odds of P. falciparum infection were higher in older children; 5-15Â years (ORÂ =Â 1.90; 95Â % CI 1.60-2.26), adults (ORÂ =Â 1.48; 95Â % CI 1.24-1.78) and participants with moderate anaemia (ORÂ =Â 1.62; 95Â % CI 1.32-1.99). The current malaria control interventions are not sufficient to interrupt transmission in The Gambia as malaria prevalence is still relatively high in the eastern part of the country. New interventions aiming at interrupting transmission are needed and should be urgently evaluated.
Malaria Journal, 2015
Background: Ex vivo assays are usually carried out on parasite isolates collected from patients w... more Background: Ex vivo assays are usually carried out on parasite isolates collected from patients with uncomplicated Plasmodium falciparum malaria, from which pregnant women are usually excluded as they are often asymptomatic and with relatively low parasite densities. Nevertheless, P. falciparum parasites infecting pregnant women selectively sequester in the placenta and may have a different drug sensitivity profile compared to those infecting other patients. The drug sensitivity profile of P. falciparum isolates from infected pregnant women recruited in a treatment efficacy trial conducted in Burkina Faso was determined in an ex vivo study.
Bulletin of the World Health Organization, 2015
Multimedia informed consent tool, the Gambia Muhammed Olanrewaju Afolabi et al.
Parasites & Vectors, 2015
Background: Focal screening and treatment (FSAT) of malaria infections has recently been introduc... more Background: Focal screening and treatment (FSAT) of malaria infections has recently been introduced in Peru to overcome the inherent limitations of passive case detection (PCD) and further decrease the malaria burden. Here, we used a relatively straightforward mathematical model to assess the potential of FSAT as elimination strategy for Plasmodium falciparum malaria in the Peruvian Amazon Region.
Malaria Journal, 2015
Background: As the disease burden in the Gambia has reduced considerably over the last decade, he... more Background: As the disease burden in the Gambia has reduced considerably over the last decade, heterogeneity in malaria transmission has become more marked, with infected but asymptomatic individuals maintaining the reservoir. The identification, timely diagnosis and treatment of malaria-infected individuals are crucial to further reduce or eliminate the human parasite reservoir. This ethnographic study focused on the relationship between local beliefs of the cause of malaria and treatment itineraries of suspected cases. Methods: An ethnographic qualitative study was conducted in twelve rural communities in the Upper River Region and the Central River Region in the Gambia. The data collection methods included in-depth interviews, participant observation, informal conversations, and focus group discussions. Results: While at first glance, the majority of people seek biomedical treatment for 'malaria', there are several constraints to seeking treatment at health centres. Certain folk illnesses, such as Jontinooje and Kajeje, translated and interpreted as 'malaria' by healthcare professionals, are often not considered to be malaria by local populations but rather as self-limiting febrile illnessesconsequently not leading to seeking care in the biomedical sector. Furthermore, respondents reported delaying treatment at a health centre while seeking financial resources, and consequently relying on herbal treatments. In addition, when malaria cases present symptoms, such as convulsions, hallucinations and/or loss of consciousness, the illness is often interpreted as having a supernatural aetiology, leading to diagnosis and treatment by traditional healers.
The Lancet. Infectious diseases, Jan 13, 2015
Artemether-lumefantrine is the most widely used artemisinin-based combination therapy for malaria... more Artemether-lumefantrine is the most widely used artemisinin-based combination therapy for malaria, although treatment failures occur in some regions. We investigated the effect of dosing strategy on efficacy in a pooled analysis from trials done in a wide range of malaria-endemic settings. We searched PubMed for clinical trials that enrolled and treated patients with artemether-lumefantrine and were published from 1960 to December, 2012. We merged individual patient data from these trials by use of standardised methods. The primary endpoint was the PCR-adjusted risk of Plasmodium falciparum recrudescence by day 28. Secondary endpoints consisted of the PCR-adjusted risk of P falciparum recurrence by day 42, PCR-unadjusted risk of P falciparum recurrence by day 42, early parasite clearance, and gametocyte carriage. Risk factors for PCR-adjusted recrudescence were identified using Cox's regression model with frailty shared across the study sites. We included 61 studies done between...
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Papers by Umberto D'Alessandro