Valerie D'ACremont
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Valerie D'ACremont has a total of 35 co-authors. Here are the top co-authors by number of shared publications:
- Blaise Genton
Swiss Tropical and Public Health Institute, Basel, Switzerland
5 shared publications Blaise Genton
Department of Ambulatory Care and Community Medicine, University of Lausanne, Lausanne, Switzerland
4 shared publicationsChristian Lengeler
3 shared publications- Christian Lengeler
Swiss Tropical and Public Health Institute, Basel, Switzerland
3 shared publications - Deo Mtasiwa
Ministry of Health and Social Welfare, P.O. Box 9083, Dar es Salaam, United Republic of Tanzania
2 shared publications Esther Kyungu
St-Francis Hospital, Ifakara, United Republic of Tanzania
2 shared publications
Latest Publications
- Open Access
- 2 May 2017
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 12 (5) , e0173314
Predictive value of clinical and laboratory features for the main febrile diseases in children living in Tanzania: A prospective observational study
To construct evidence-based guidelines for management of febrile illness, it is essential to identify clinical predictors for the main causes of fever, either to diagnose the disease when no laboratory test is available or to better target testing when a test is available. The objective was to investigate clinical predictors of several diseases in a cohort of febrile children attending outpatient clinics in Tanzania, whose diagnoses have been established after extensive clinical and laboratory workup. From April to December 2008, 1005 consecutive children aged 2 months to 10 years with temperature ≥38°C attending two outpatient clinics in Dar es Salaam were included. Demographic characteristics, symptoms and signs, comorbidities, full blood count and liver enzyme level were investigated by bi- and multi-variate analyses (Chan, et al., 2008). To evaluate accuracy of combined predictors to construct algorithms, classification and regression tree (CART) analyses were also performed. 62 variables were studied. Between 4 and 15 significant predictors to rule in (aLR+>1) or rule out (aLR+<1) the disease were found in the multivariate analysis for the 7 more frequent outcomes. For malaria, the strongest predictor was temperature ≥40°C (aLR+8.4, 95%CI 4.7–15), for typhoid abdominal tenderness (5.9,2.5–11), for urinary tract infection (UTI) age ≥3 years (0.20,0–0.50), for radiological pneumonia abnormal chest auscultation (4.3,2.8–6.1), for acute HHV6 infection dehydration (0.18,0–0.75), for bacterial disease (any type) chest indrawing (19,8.2–60) and for viral disease (any type) jaundice (0.28,0.16–0.41). Other clinically relevant and easy to assess predictors were also found: malaria could be ruled in by recent travel, typhoid by jaundice, radiological pneumonia by very fast breathing and UTI by fever duration of ≥4 days. The CART model for malaria included temperature, travel, jaundice and hepatomegaly (sensitivity 80%, specificity 64%); typhoid: age ≥2 years, jaundice, abdominal tenderness and adenopathy (46%,93%); UTI: age 3 days (45%,83%); viral disease: runny nose, cough and age <2 years (68%,76%). A better understanding of the relative performance of these predictors might be of great help for clinicians to be able to better decide when to test, treat, refer or simply observe a sick child, in order to decrease morbidity and mortality, but also to avoid unnecessary antimicrobial prescription. These predictors have been used to construct a new algorithm for the management of childhood illnesses called ALMANACH.
- 2 May 2017
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 12 (5) , e0173314
Open AccessPredictive value of clinical and laboratory features for the main febrile diseases in children living in Tanzania: A prospective observational study
To construct evidence-based guidelines for management of febrile illness, it is essential to identify clinical predictors for the main causes of fever, either to diagnose the disease when no laboratory test is available or to better target testing when a test is available. The objective was to investigate clinical predictors of several diseases in a cohort of febrile children attending outpatient clinics in Tanzania, whose diagnoses have been established after extensive clinical and laboratory workup. From April to December 2008, 1005 consecutive children aged 2 months to 10 years with temperature ≥38°C attending two outpatient clinics in Dar es Salaam were included. Demographic characteristics, symptoms and signs, comorbidities, full blood count and liver enzyme level were investigated by bi- and multi-variate analyses (Chan, et al., 2008). To evaluate accuracy of combined predictors to construct algorithms, classification and regression tree (CART) analyses were also performed. 62 variables were studied. Between 4 and 15 significant predictors to rule in (aLR+>1) or rule out (aLR+<1) the disease were found in the multivariate analysis for the 7 more frequent outcomes. For malaria, the strongest predictor was temperature ≥40°C (aLR+8.4, 95%CI 4.7–15), for typhoid abdominal tenderness (5.9,2.5–11), for urinary tract infection (UTI) age ≥3 years (0.20,0–0.50), for radiological pneumonia abnormal chest auscultation (4.3,2.8–6.1), for acute HHV6 infection dehydration (0.18,0–0.75), for bacterial disease (any type) chest indrawing (19,8.2–60) and for viral disease (any type) jaundice (0.28,0.16–0.41). Other clinically relevant and easy to assess predictors were also found: malaria could be ruled in by recent travel, typhoid by jaundice, radiological pneumonia by very fast breathing and UTI by fever duration of ≥4 days. The CART model for malaria included temperature, travel, jaundice and hepatomegaly (sensitivity 80%, specificity 64%); typhoid: age ≥2 years, jaundice, abdominal tenderness and adenopathy (46%,93%); UTI: age 3 days (45%,83%); viral disease: runny nose, cough and age <2 years (68%,76%). A better understanding of the relative performance of these predictors might be of great help for clinicians to be able to better decide when to test, treat, refer or simply observe a sick child, in order to decrease morbidity and mortality, but also to avoid unnecessary antimicrobial prescription. These predictors have been used to construct a new algorithm for the management of childhood illnesses called ALMANACH.
- Open Access
- 2 April 2015
- Published by Springer Nature in BMC Health Services Research
- Vol. 15 (1) , 135
Can smartphones and tablets improve the management of childhood illness in Tanzania? A qualitative study from a primary health care worker’s perspective
The impact of the Integrated Management of Childhood Illness (IMCI) strategy has been less than anticipated because of poor uptake. Electronic algorithms have the potential to improve quality of health care in children. However, feasibility studies about the use of electronic protocols on mobile devices over time are limited. This study investigated constraining as well as facilitating factors that influence the uptake of a new electronic Algorithm for Management of Childhood Illness (ALMANACH) among primary health workers in Dar es Salaam, Tanzania. A qualitative approach was applied using in-depth interviews and focus group discussions with altogether 40 primary health care workers from 6 public primary health facilities in the three municipalities of Dar es Salaam, Tanzania. Health worker’s perceptions related to factors facilitating or constraining the uptake of the electronic ALMANACH were identified. In general, the ALMANACH was assessed positively. The majority of the respondents felt comfortable to use the devices and stated that patient’s trust was not affected. Most health workers said that the ALMANACH simplified their work, reduced antibiotic prescription and gave correct classification and treatment for common causes of childhood illnesses. Few HWs reported technical challenges using the devices and complained about having had difficulties in typing. Majority of the respondents stated that the devices increased the consultation duration compared to routine practice. In addition, health system barriers such as lack of staff, lack of medicine and lack of financial motivation were identified as key reasons for the low uptake of the devices. The ALMANACH built on electronic devices was perceived to be a powerful and useful tool. However, health system challenges influenced the uptake of the devices in the selected health facilities.
- 2 April 2015
- Published by Springer Nature in BMC Health Services Research
- Vol. 15 (1) , 135
Open AccessCan smartphones and tablets improve the management of childhood illness in Tanzania? A qualitative study from a primary health care worker’s perspective
The impact of the Integrated Management of Childhood Illness (IMCI) strategy has been less than anticipated because of poor uptake. Electronic algorithms have the potential to improve quality of health care in children. However, feasibility studies about the use of electronic protocols on mobile devices over time are limited. This study investigated constraining as well as facilitating factors that influence the uptake of a new electronic Algorithm for Management of Childhood Illness (ALMANACH) among primary health workers in Dar es Salaam, Tanzania. A qualitative approach was applied using in-depth interviews and focus group discussions with altogether 40 primary health care workers from 6 public primary health facilities in the three municipalities of Dar es Salaam, Tanzania. Health worker’s perceptions related to factors facilitating or constraining the uptake of the electronic ALMANACH were identified. In general, the ALMANACH was assessed positively. The majority of the respondents felt comfortable to use the devices and stated that patient’s trust was not affected. Most health workers said that the ALMANACH simplified their work, reduced antibiotic prescription and gave correct classification and treatment for common causes of childhood illnesses. Few HWs reported technical challenges using the devices and complained about having had difficulties in typing. Majority of the respondents stated that the devices increased the consultation duration compared to routine practice. In addition, health system barriers such as lack of staff, lack of medicine and lack of financial motivation were identified as key reasons for the low uptake of the devices. The ALMANACH built on electronic devices was perceived to be a powerful and useful tool. However, health system challenges influenced the uptake of the devices in the selected health facilities.
- Top Cited Papers
- 27 February 2014
- Published by Massachusetts Medical Society in New England Journal of Medicine
- Vol. 370 (9) , 809-817
Beyond Malaria — Causes of Fever in Outpatient Tanzanian Children
As the incidence of malaria diminishes, a better understanding of nonmalarial fever is important for effective management of illness in children. In this study, we explored the spectrum of causes of fever in African children.
- 27 February 2014
- Published by Massachusetts Medical Society in New England Journal of Medicine
- Vol. 370 (9) , 809-817
Top Cited PapersBeyond Malaria — Causes of Fever in Outpatient Tanzanian Children
As the incidence of malaria diminishes, a better understanding of nonmalarial fever is important for effective management of illness in children. In this study, we explored the spectrum of causes of fever in African children.
- 8 May 2013
- Vol. 9 (385) , 979-84
[Imported malaria: safer and more efficacious drugs?].
In response to the spread of parasite resistance to old antimalarial drugs, the large-scale implementation of artemisinine-based combinations has allowed to improving patient survival and reducing parasite transmission. Even though decreased susceptibility of parasites to artemisinine has been observed in South-East Asia, this phenomenon has no practical implications for travelers with uncomplicated malaria. The combination of artemether-lumefantrine is still very effective and safe, be it for P. falciparum or vivax. Intravenous administration of artesunate has allowed to significantly reducing case fatality rate of severe malaria patients when compared to quinine treatment in endemic areas. Artesunate is also recommended in travelers, but with close monitoring, especially for hematological parameters, in order to confirm its superiority.
- 8 May 2013
- Vol. 9 (385) , 979-84
[Imported malaria: safer and more efficacious drugs?].
In response to the spread of parasite resistance to old antimalarial drugs, the large-scale implementation of artemisinine-based combinations has allowed to improving patient survival and reducing parasite transmission. Even though decreased susceptibility of parasites to artemisinine has been observed in South-East Asia, this phenomenon has no practical implications for travelers with uncomplicated malaria. The combination of artemether-lumefantrine is still very effective and safe, be it for P. falciparum or vivax. Intravenous administration of artesunate has allowed to significantly reducing case fatality rate of severe malaria patients when compared to quinine treatment in endemic areas. Artesunate is also recommended in travelers, but with close monitoring, especially for hematological parameters, in order to confirm its superiority.
- Open Access
- 16 November 2012
- Published by Springer Nature in Malaria Journal
- Vol. 11 (1) , 377
Safety of falciparum malaria diagnostic strategy based on rapid diagnostic tests in returning travellers and migrants: a retrospective study
Rapid diagnostic tests for malaria (RDTs) allow accurate diagnosis and prompt treatment. Validation of their usefulness in travellers with fever was needed. The safety of a strategy to diagnose falciparum malaria based on RDT followed by immediate or delayed microscopy reading at first attendance was evaluated in one referral hospital in Switzerland.
- 16 November 2012
- Published by Springer Nature in Malaria Journal
- Vol. 11 (1) , 377
Open AccessSafety of falciparum malaria diagnostic strategy based on rapid diagnostic tests in returning travellers and migrants: a retrospective study
Rapid diagnostic tests for malaria (RDTs) allow accurate diagnosis and prompt treatment. Validation of their usefulness in travellers with fever was needed. The safety of a strategy to diagnose falciparum malaria based on RDT followed by immediate or delayed microscopy reading at first attendance was evaluated in one referral hospital in Switzerland.
- Open Access
- 2 November 2011
- Published by Springer Nature in Malaria Journal
- Vol. 10 (1) , 332
Low quality of routine microscopy for malaria at different levels of the health system in Dar es Salaam
Background: Laboratory capacity to confirm malaria cases in Tanzania is low and presumptive treatment of malaria is being practiced widely. In malaria endemic areas WHO now recommends systematic laboratory testing when suspecting malaria. Currently, the use of Rapid Diagnostic Tests (RDTs) is recommended for the diagnosis of malaria in lower level peripheral facilities, but not in health centres and hospitals. In this study, the following parameters were evaluated: (1) the quality of routine microscopy, and (2) the effects of RDT implementation on the positivity rate of malaria test results at three levels of the health system in Dar es Salaam, Tanzania. Methods: During a baseline cross-sectional survey, routine blood slides were randomly picked from 12 urban public health facilities in Dar es Salaam, Tanzania. Sensitivity and specificity of routine slides were assessed against expert microscopy. In March 2007, following training of health workers, RDTs were introduced in nine public health facilities (three hospitals, three health centres and three dispensaries) in a near-to-programmatic way, while three control health facilities continued using microscopy. The monthly malaria positivity rates (PR) recorded in health statistics registers were collected before (routine microscopy) and after (routine RDTs) the intervention in all facilities. Results: At baseline, 53% of blood slides were reported as positive by the routine laboratories, whereas only 2% were positive by expert microscopy. Sensitivity of routine microscopy was 71.4% and specificity was 47.3%. Positive and negative predictive values were 2.8% and 98.7%, respectively. Median parasitaemia was only three parasites per 200 white blood cells (WBC) by routine microscopy compared to 1226 parasites per 200 WBC by expert microscopy. Before RDT implementation, the mean test positivity rates using routine microscopy were 43% in hospitals, 62% in health centres and 58% in dispensaries. After RDT implementation, mean positivity rates using routine RDTs were 6%, 7% and 8%, respectively. The sensitivity and specificity of RDTs using expert microscopy as reference were 97.0% and 96.8%. The positivity rate of routine microscopy remained the same in the three control facilities: 71% before versus 72% after. Two cross-sectional health facility surveys confirmed that the parasite rate in febrile patients was low in Dar es Salaam during both the rainy season (13.6%) and the dry season (3.3%). Conclusions: The quality of routine microscopy was poor in all health facilities, regardless of their level. Over-diagnosis was massive, with many false positive results reported as very low parasitaemia (1 to 5 parasites per 200 WBC). RDTs should replace microscopy as first-line diagnostic tool for malaria in all settings, especially in hospitals where the potential for saving lives is greatest.
- 2 November 2011
- Published by Springer Nature in Malaria Journal
- Vol. 10 (1) , 332
Open AccessLow quality of routine microscopy for malaria at different levels of the health system in Dar es Salaam
Background: Laboratory capacity to confirm malaria cases in Tanzania is low and presumptive treatment of malaria is being practiced widely. In malaria endemic areas WHO now recommends systematic laboratory testing when suspecting malaria. Currently, the use of Rapid Diagnostic Tests (RDTs) is recommended for the diagnosis of malaria in lower level peripheral facilities, but not in health centres and hospitals. In this study, the following parameters were evaluated: (1) the quality of routine microscopy, and (2) the effects of RDT implementation on the positivity rate of malaria test results at three levels of the health system in Dar es Salaam, Tanzania. Methods: During a baseline cross-sectional survey, routine blood slides were randomly picked from 12 urban public health facilities in Dar es Salaam, Tanzania. Sensitivity and specificity of routine slides were assessed against expert microscopy. In March 2007, following training of health workers, RDTs were introduced in nine public health facilities (three hospitals, three health centres and three dispensaries) in a near-to-programmatic way, while three control health facilities continued using microscopy. The monthly malaria positivity rates (PR) recorded in health statistics registers were collected before (routine microscopy) and after (routine RDTs) the intervention in all facilities. Results: At baseline, 53% of blood slides were reported as positive by the routine laboratories, whereas only 2% were positive by expert microscopy. Sensitivity of routine microscopy was 71.4% and specificity was 47.3%. Positive and negative predictive values were 2.8% and 98.7%, respectively. Median parasitaemia was only three parasites per 200 white blood cells (WBC) by routine microscopy compared to 1226 parasites per 200 WBC by expert microscopy. Before RDT implementation, the mean test positivity rates using routine microscopy were 43% in hospitals, 62% in health centres and 58% in dispensaries. After RDT implementation, mean positivity rates using routine RDTs were 6%, 7% and 8%, respectively. The sensitivity and specificity of RDTs using expert microscopy as reference were 97.0% and 96.8%. The positivity rate of routine microscopy remained the same in the three control facilities: 71% before versus 72% after. Two cross-sectional health facility surveys confirmed that the parasite rate in febrile patients was low in Dar es Salaam during both the rainy season (13.6%) and the dry season (3.3%). Conclusions: The quality of routine microscopy was poor in all health facilities, regardless of their level. Over-diagnosis was massive, with many false positive results reported as very low parasitaemia (1 to 5 parasites per 200 WBC). RDTs should replace microscopy as first-line diagnostic tool for malaria in all settings, especially in hospitals where the potential for saving lives is greatest.
- Open Access
- 29 April 2011
- Published by Springer Nature in Malaria Journal
- Vol. 10 (1) , 107
Reduction of anti-malarial consumption after rapid diagnostic tests implementation in Dar es Salaam: a before-after and cluster randomized controlled study
Presumptive treatment of all febrile patients with anti-malarials leads to massive over-treatment. The aim was to assess the effect of implementing malaria rapid diagnostic tests (mRDTs) on prescription of anti-malarials in urban Tanzania.
- 29 April 2011
- Published by Springer Nature in Malaria Journal
- Vol. 10 (1) , 107
Open AccessReduction of anti-malarial consumption after rapid diagnostic tests implementation in Dar es Salaam: a before-after and cluster randomized controlled study
Presumptive treatment of all febrile patients with anti-malarials leads to massive over-treatment. The aim was to assess the effect of implementing malaria rapid diagnostic tests (mRDTs) on prescription of anti-malarials in urban Tanzania.
- Open Access
- 1 September 2010
- Published by Oxford University Press (OUP) in Clinical Infectious Diseases
- Vol. 51 (5) , 506-511
Withholding Antimalarials in Febrile Children Who Have a Negative Result for a Rapid Diagnostic Test
Background. The availability of a rapid diagnostic test for malaria (RDTm) allows accurate diagnosis at all levels of health facilities. The objectiv
- 1 September 2010
- Published by Oxford University Press (OUP) in Clinical Infectious Diseases
- Vol. 51 (5) , 506-511
Open AccessWithholding Antimalarials in Febrile Children Who Have a Negative Result for a Rapid Diagnostic Test
Background. The availability of a rapid diagnostic test for malaria (RDTm) allows accurate diagnosis at all levels of health facilities. The objectiv
- Open Access
- 22 August 2010
- Published by Springer Nature in Malaria Journal
- Vol. 9 (1) , 240
Reduction in the proportion of fevers associated with Plasmodium falciparum parasitaemia in Africa: a systematic review
Malaria is almost invariably ranked as the leading cause of morbidity and mortality in Africa. There is growing evidence of a decline in malaria transmission, morbidity and mortality over the last decades, especially so in East Africa. However, there is still doubt whether this decline is reflected in a reduction of the proportion of malaria among fevers. The objective of this systematic review was to estimate the change in the Proportion of Fevers associated with Plasmodium falciparum parasitaemia (PFPf) over the past 20 years in sub-Saharan Africa.
- 22 August 2010
- Published by Springer Nature in Malaria Journal
- Vol. 9 (1) , 240
Open AccessReduction in the proportion of fevers associated with Plasmodium falciparum parasitaemia in Africa: a systematic review
Malaria is almost invariably ranked as the leading cause of morbidity and mortality in Africa. There is growing evidence of a decline in malaria transmission, morbidity and mortality over the last decades, especially so in East Africa. However, there is still doubt whether this decline is reflected in a reduction of the proportion of malaria among fevers. The objective of this systematic review was to estimate the change in the Proportion of Fevers associated with Plasmodium falciparum parasitaemia (PFPf) over the past 20 years in sub-Saharan Africa.