Journal Article > ResearchFull Text
BMJ Glob Health. 1 December 2022; Volume 7 (Issue 12); e009674.; DOI:10.1136/bmjgh-2022-009674
Van Bortel W, Mariën J, Jacobs BKM, Sinzinkayo D, Sinarinzi P, et al.
BMJ Glob Health. 1 December 2022; Volume 7 (Issue 12); e009674.; DOI:10.1136/bmjgh-2022-009674
BACKGROUND
Long-lasting insecticidal nets (LLINs) are one of the key interventions in the global fight against malaria. Since 2014, mass distribution campaigns of LLINs aim for universal access by all citizens of Burundi. In this context, we assess the impact of LLINs mass distribution campaigns on malaria incidence, focusing on the endemic highland health districts. We also explored the possible correlation between observed trends in malaria incidence with any variations in climate conditions.
METHODS
Malaria cases for 2011—2019 were obtained from the National Health Information System. We developed a generalised additive model based on a time series of routinely collected data with malaria incidence as the response variable and timing of LLIN distribution as an explanatory variable to investigate the duration and magnitude of the LLIN effect on malaria incidence. We added a seasonal and continuous-time component as further explanatory variables, and health district as a random effect to account for random natural variation in malaria cases between districts.
RESULTS
Malaria transmission in Burundian highlands was clearly seasonal and increased non-linearly over the study period. Further, a fast and steep decline of malaria incidence was noted during the first year after mass LLIN distribution (p<0.0001). In years 2 and 3 after distribution, malaria cases started to rise again to levels higher than before the control intervention.
CONCLUSION
This study highlights that LLINs did reduce the incidence in the first year after a mass distribution campaign, but in the context of Burundi, LLINs lost their impact after only 1 year.
Long-lasting insecticidal nets (LLINs) are one of the key interventions in the global fight against malaria. Since 2014, mass distribution campaigns of LLINs aim for universal access by all citizens of Burundi. In this context, we assess the impact of LLINs mass distribution campaigns on malaria incidence, focusing on the endemic highland health districts. We also explored the possible correlation between observed trends in malaria incidence with any variations in climate conditions.
METHODS
Malaria cases for 2011—2019 were obtained from the National Health Information System. We developed a generalised additive model based on a time series of routinely collected data with malaria incidence as the response variable and timing of LLIN distribution as an explanatory variable to investigate the duration and magnitude of the LLIN effect on malaria incidence. We added a seasonal and continuous-time component as further explanatory variables, and health district as a random effect to account for random natural variation in malaria cases between districts.
RESULTS
Malaria transmission in Burundian highlands was clearly seasonal and increased non-linearly over the study period. Further, a fast and steep decline of malaria incidence was noted during the first year after mass LLIN distribution (p<0.0001). In years 2 and 3 after distribution, malaria cases started to rise again to levels higher than before the control intervention.
CONCLUSION
This study highlights that LLINs did reduce the incidence in the first year after a mass distribution campaign, but in the context of Burundi, LLINs lost their impact after only 1 year.
Journal Article > ResearchFull Text
PLOS One. 8 December 2014; Volume 9 (Issue 12); DOI:10.1371/journal.pone.0114702
Polonsky JA, Martinez-Pino I, Nackers F, Chonzi P, Manangazira P, et al.
PLOS One. 8 December 2014; Volume 9 (Issue 12); DOI:10.1371/journal.pone.0114702
Typhoid fever remains a significant public health problem in developing countries. In October 2011, a typhoid fever epidemic was declared in Harare, Zimbabwe - the fourth enteric infection epidemic since 2008. To orient control activities, we described the epidemiology and spatiotemporal clustering of the epidemic in Dzivaresekwa and Kuwadzana, the two most affected suburbs of Harare.
Journal Article > ResearchAbstract
Trans R Soc Trop Med Hyg. 13 November 2010; Volume 105 (Issue 1); DOI:10.1016/j.trstmh.2010.10.001
Luque Fernandez MA, Mason PR, Gray H, Bauernfeind A, Maes P
Trans R Soc Trop Med Hyg. 13 November 2010; Volume 105 (Issue 1); DOI:10.1016/j.trstmh.2010.10.001
This ecological study describes the cholera epidemic in Harare during 2008-2009 and identifies patterns that may explain transmission. Rates ratios of cholera cases by suburb were calculated by a univariate regression Poisson model and then, through an Empirical Bayes modelling, smoothed rate ratios were estimated and represented geographically. Mbare and southwest suburbs of Harare presented higher rate ratios. Suburbs attack rates ranged from 1.2 (95% Cl = 0.7-1.6) cases per 1000 people in Tynwald to 90.3 (95% Cl = 82.8-98.2) in Hopley. The identification of this spatial pattern in the spread, characterised by low risk in low density residential housing, and a higher risk in high density south west suburbs and Mbare, could be used to advocate for improving water and sanitation conditions and specific preparedness measures in the most affected areas.
Protocol > Research Protocol
Fernandez MAL, Schomaker M, Mason PR, Fesselet JF, Baudot Y, et al.
18 June 2012
BACKGROUND
In highly populated African urban areas where access to clean water is a challenge, water source contamination is one of the most cited risk factors in a cholera epidemic. During the rainy season, where there is either no sewage disposal or working sewer system, runoff of rains follows the slopes and gets into the lower parts of towns where shallow wells could easily become contaminated by excretes. In cholera endemic areas, spatial information about topographical elevation could help to guide preventive interventions. This study aims to analyze the association between topographic elevation and the distribution of cholera cases in Harare during the cholera epidemic in 2008 and 2009.
METHODS
We developed an ecological study using secondary data. First, we described attack rates by suburb and then calculated rate ratios using whole Harare as reference. We illustrated the average elevation and cholera cases by suburbs using geographical information. Finally, we estimated a generalized linear mixed model (under the assumption of a Poisson distribution) with an Empirical Bayesian approach to model the relation between the risk of cholera and the elevation in meters in Harare. We used a random intercept to allow for spatial correlation of neighboring suburbs.
RESULTS
This study identifies a spatial pattern of the distribution of cholera cases in the Harare epidemic, characterized by a lower cholera risk in the highest elevation suburbs of Harare. The generalized linear mixed model showed that for each 100 meters of increase in the topographical elevation, the cholera risk was 30% lower with a rate ratio of 0.70 (95% confidence interval=0.66-0.76). Sensitivity analysis confirmed the risk reduction with an overall estimate of the rate ratio between 20% and 40%.
CONCLUSION
This study highlights the importance of considering topographical elevation as a geographical and environmental risk factor in order to plan cholera preventive activities linked with water and sanitation in endemic areas. Furthermore, elevation information, among other risk factors, could help to spatially orientate cholera control interventions during an epidemic.
In highly populated African urban areas where access to clean water is a challenge, water source contamination is one of the most cited risk factors in a cholera epidemic. During the rainy season, where there is either no sewage disposal or working sewer system, runoff of rains follows the slopes and gets into the lower parts of towns where shallow wells could easily become contaminated by excretes. In cholera endemic areas, spatial information about topographical elevation could help to guide preventive interventions. This study aims to analyze the association between topographic elevation and the distribution of cholera cases in Harare during the cholera epidemic in 2008 and 2009.
METHODS
We developed an ecological study using secondary data. First, we described attack rates by suburb and then calculated rate ratios using whole Harare as reference. We illustrated the average elevation and cholera cases by suburbs using geographical information. Finally, we estimated a generalized linear mixed model (under the assumption of a Poisson distribution) with an Empirical Bayesian approach to model the relation between the risk of cholera and the elevation in meters in Harare. We used a random intercept to allow for spatial correlation of neighboring suburbs.
RESULTS
This study identifies a spatial pattern of the distribution of cholera cases in the Harare epidemic, characterized by a lower cholera risk in the highest elevation suburbs of Harare. The generalized linear mixed model showed that for each 100 meters of increase in the topographical elevation, the cholera risk was 30% lower with a rate ratio of 0.70 (95% confidence interval=0.66-0.76). Sensitivity analysis confirmed the risk reduction with an overall estimate of the rate ratio between 20% and 40%.
CONCLUSION
This study highlights the importance of considering topographical elevation as a geographical and environmental risk factor in order to plan cholera preventive activities linked with water and sanitation in endemic areas. Furthermore, elevation information, among other risk factors, could help to spatially orientate cholera control interventions during an epidemic.
Journal Article > LetterFull Text
Nature. 17 June 2015; Volume 524 (Issue 7563); 97-101.; DOI:10.1038/nature14594
Carroll MW, Matthews DA, Hiscox JA, Elmore MJ, Pollakis G, et al.
Nature. 17 June 2015; Volume 524 (Issue 7563); 97-101.; DOI:10.1038/nature14594
West Africa is currently witnessing the most extensive Ebola virus (EBOV) outbreak so far recorded. Until now, there have been 27,013 reported cases and 11,134 deaths. The origin of the virus is thought to have been a zoonotic transmission from a bat to a twoyear-old boy in December 2013 (ref. 2). From this index case the virus was spread by human-to-human contact throughout Guinea, Sierra Leone and Liberia. However, the origin of the particular virus in each country and time of transmission is not known and currently relies on epidemiological analysis, which may be unreliable owing to the difficulties of obtaining patient information. Here we trace the genetic evolution of EBOV in the current outbreak that has resulted in multiple lineages. Deep sequencing of 179 patient samples processed by the European Mobile Laboratory, the first diagnostics unit to be deployed to the epicentre of the outbreak in Guinea, reveals an epidemiological and evolutionary history of the epidemic from March 2014 to January 2015. Analysis of EBOV genome evolution has also benefited from a similar sequencing effort of patient samples from Sierra Leone. Our results confirm that the EBOV from Guinea moved into Sierra Leone, most likely in April or early May. The viruses of the Guinea/Sierra Leone lineage mixed around June/July 2014. Viral sequences covering August, September and October 2014 indicate that this lineage evolved independently within Guinea. These data can be used in conjunction with epidemiological information to test retrospectively the effectiveness of control measures, and provides an unprecedented window into the evolution of an ongoing viral haemorrhagic fever outbreak.
Journal Article > CommentaryAbstract
Waterlines. 1 January 2012; Volume 31 (Issue 1-2); DOI:10.3362/1756-3488.2012.010
Coloni F, Van der Bergh R, Sittaro F, Giandonato S, Loots G, et al.
Waterlines. 1 January 2012; Volume 31 (Issue 1-2); DOI:10.3362/1756-3488.2012.010
Journal Article > ResearchFull Text
PLOS Med. 1 March 2016; Volume 13 (Issue 3); DOI:10.1371/journal.pmed.1001967
Sissoko D, Laouenan C, Folkesson E, M’Lebing A, Beavogui A, et al.
PLOS Med. 1 March 2016; Volume 13 (Issue 3); DOI:10.1371/journal.pmed.1001967
Ebola virus disease (EVD) is a highly lethal condition for which no specific treatment has proven efficacy. In September 2014, while the Ebola outbreak was at its peak, the World Health Organization released a short list of drugs suitable for EVD research. Favipiravir, an antiviral developed for the treatment of severe influenza, was one of these. In late 2014, the conditions for starting a randomized Ebola trial were not fulfilled for two reasons. One was the perception that, given the high number of patients presenting simultaneously and the very high mortality rate of the disease, it was ethically unacceptable to allocate patients from within the same family or village to receive or not receive an experimental drug, using a randomization process impossible to understand by very sick patients. The other was that, in the context of rumors and distrust of Ebola treatment centers, using a randomized design at the outset might lead even more patients to refuse to seek care. Therefore, we chose to conduct a multicenter non-randomized trial, in which all patients would receive favipiravir along with standardized care. The objectives of the trial were to test the feasibility and acceptability of an emergency trial in the context of a large Ebola outbreak, and to collect data on the safety and effectiveness of favipiravir in reducing mortality and viral load in patients with EVD. The trial was not aimed at directly informing future guidelines on Ebola treatment but at quickly gathering standardized preliminary data to optimize the design of future studies.
Journal Article > ReviewFull Text
PLOS One. 8 January 2020; Volume 15 (Issue 1); DOI:10.1371/journal.pone.0226549
D Mello Guyett L, Gallandat K, Van der Bergh R, Taylor DL, Bulit G, et al.
PLOS One. 8 January 2020; Volume 15 (Issue 1); DOI:10.1371/journal.pone.0226549
INTRODUCTION:
Cholera remains a frequent cause of outbreaks globally, particularly in areas with inadequate water, sanitation and hygiene (WASH) services. Cholera is spread through faecal-oral routes, and studies demonstrate that ingestion of Vibrio cholerae occurs from consuming contaminated food and water, contact with cholera cases and transmission from contaminated environmental point sources. WASH guidelines recommending interventions for the prevention and control of cholera are numerous and vary considerably in their recommendations. To date, there has been no review of practice guidelines used in cholera prevention and control programmes.
METHODS:
We systematically searched international agency websites to identify WASH intervention guidelines used in cholera programmes in endemic and epidemic settings. Recommendations listed in the guidelines were extracted, categorised and analysed. Analysis was based on consistency, concordance and recommendations were classified on the basis of whether the interventions targeted within-household or community-level transmission.
RESULTS:
Eight international guidelines were included in this review: three by non-governmental organisations (NGOs), one from a non-profit organisation (NPO), three from multilateral organisations and one from a research institution. There were 95 distinct recommendations identified, and concordance among guidelines was poor to fair. All categories of WASH interventions were featured in the guidelines. The majority of recommendations targeted community-level transmission (45%), 35% targeted within-household transmission and 20% both.
CONCLUSIONS:
Recent evidence suggests that interventions for effective cholera control and response to epidemics should focus on case-centred approaches and within-household transmission. Guidelines did consistently propose interventions targeting transmission within households. However, the majority of recommendations listed in guidelines targeted community-level transmission and tended to be more focused on preventing contamination of the environment by cases or recurrent outbreaks, and the level of service required to interrupt community-level transmission was often not specified. The guidelines in current use were varied and interpretation may be difficult when conflicting recommendations are provided. Future editions of guidelines should reflect on the inclusion of evidence-based approaches, cholera transmission models and resource-efficient strategies.
Cholera remains a frequent cause of outbreaks globally, particularly in areas with inadequate water, sanitation and hygiene (WASH) services. Cholera is spread through faecal-oral routes, and studies demonstrate that ingestion of Vibrio cholerae occurs from consuming contaminated food and water, contact with cholera cases and transmission from contaminated environmental point sources. WASH guidelines recommending interventions for the prevention and control of cholera are numerous and vary considerably in their recommendations. To date, there has been no review of practice guidelines used in cholera prevention and control programmes.
METHODS:
We systematically searched international agency websites to identify WASH intervention guidelines used in cholera programmes in endemic and epidemic settings. Recommendations listed in the guidelines were extracted, categorised and analysed. Analysis was based on consistency, concordance and recommendations were classified on the basis of whether the interventions targeted within-household or community-level transmission.
RESULTS:
Eight international guidelines were included in this review: three by non-governmental organisations (NGOs), one from a non-profit organisation (NPO), three from multilateral organisations and one from a research institution. There were 95 distinct recommendations identified, and concordance among guidelines was poor to fair. All categories of WASH interventions were featured in the guidelines. The majority of recommendations targeted community-level transmission (45%), 35% targeted within-household transmission and 20% both.
CONCLUSIONS:
Recent evidence suggests that interventions for effective cholera control and response to epidemics should focus on case-centred approaches and within-household transmission. Guidelines did consistently propose interventions targeting transmission within households. However, the majority of recommendations listed in guidelines targeted community-level transmission and tended to be more focused on preventing contamination of the environment by cases or recurrent outbreaks, and the level of service required to interrupt community-level transmission was often not specified. The guidelines in current use were varied and interpretation may be difficult when conflicting recommendations are provided. Future editions of guidelines should reflect on the inclusion of evidence-based approaches, cholera transmission models and resource-efficient strategies.
Journal Article > ResearchFull Text
Trop Med Int Health. 1 April 2010; Volume 15 (Issue 4); 480-488.; DOI:10.1111/j.1365-3156.2010.02478.x
Gerstl S, Dunkley S, Mukhtar A, Maes P, de Smet M, et al.
Trop Med Int Health. 1 April 2010; Volume 15 (Issue 4); 480-488.; DOI:10.1111/j.1365-3156.2010.02478.x
OBJECTIVE
Médecins Sans Frontières (MSF) runs a malaria control project in Bo and Pujehun districts (population 158 000) that includes the mass distribution, routine delivery and demonstration of correct use of free, long-lasting insecticide-treated nets (LLINs). In 2006/2007, around 65 000 LLINs were distributed. The aim of this follow-up study was to measure LLIN usage and ownership in the project area.
METHODS
Heads of 900 randomly selected households in 30 clusters were interviewed, using a standardized questionnaire, about household use of LLINs. The condition of any LLIN was physically assessed.
RESULTS
Of the 900 households reported, 83.4% owning at least one LLIN. Of the 16.6% without an LLIN, 91.9% had not participated in the MSF mass distribution. In 94.1% of the households reporting LLINs, the nets were observed hanging correctly over the beds. Of the 1135 hanging LLINs, 75.2% had no holes or 10 or fewer finger-size holes. The most common source of LLINs was MSF (75.2%). Of the 4997 household members, 67.2% reported sleeping under an LLIN the night before the study, including 76.8% of children under 5 years and 73.0% of pregnant women.
CONCLUSION
Our results show that MSF achieved good usage with freely distributed LLINs. It is one of the few areas where results almost achieve the new targets set in 2005 by Roll Back Malaria to have at least 80% of pregnant women and children under 5 years using LLINs by 2010.
Médecins Sans Frontières (MSF) runs a malaria control project in Bo and Pujehun districts (population 158 000) that includes the mass distribution, routine delivery and demonstration of correct use of free, long-lasting insecticide-treated nets (LLINs). In 2006/2007, around 65 000 LLINs were distributed. The aim of this follow-up study was to measure LLIN usage and ownership in the project area.
METHODS
Heads of 900 randomly selected households in 30 clusters were interviewed, using a standardized questionnaire, about household use of LLINs. The condition of any LLIN was physically assessed.
RESULTS
Of the 900 households reported, 83.4% owning at least one LLIN. Of the 16.6% without an LLIN, 91.9% had not participated in the MSF mass distribution. In 94.1% of the households reporting LLINs, the nets were observed hanging correctly over the beds. Of the 1135 hanging LLINs, 75.2% had no holes or 10 or fewer finger-size holes. The most common source of LLINs was MSF (75.2%). Of the 4997 household members, 67.2% reported sleeping under an LLIN the night before the study, including 76.8% of children under 5 years and 73.0% of pregnant women.
CONCLUSION
Our results show that MSF achieved good usage with freely distributed LLINs. It is one of the few areas where results almost achieve the new targets set in 2005 by Roll Back Malaria to have at least 80% of pregnant women and children under 5 years using LLINs by 2010.
Journal Article > ResearchFull Text
J Infect Dis. 30 June 2016; Volume 214 (Issue suppl 3); S145-S152.; DOI:10.1093/infdis/jiw198
Poliquin PG, Vogt F, Kasztura M, Leung A, Deschambault Y, et al.
J Infect Dis. 30 June 2016; Volume 214 (Issue suppl 3); S145-S152.; DOI:10.1093/infdis/jiw198
BACKGROUND
Ebola viruses (EBOVs) are primarily transmitted by contact with infected body fluids. Ebola treatment centers (ETCs) contain areas that are exposed to body fluids through the care of patients suspected or confirmed to have EBOV disease. There are limited data documenting which areas/fomites within ETCs pose a risk for potential transmission. This study conducted environmental surveillance in 2 ETCs in Freetown, Sierra Leone, during the 2014–2016 West African Ebola outbreak.
METHODS
ETCs were surveyed over a 3-week period. Sites to be swabbed were identified with input from field personnel. Swab samples were collected and tested for the presence of EBOV RNA. Ebola-positive body fluid-impregnated cotton pads were serially sampled.
RESULTS
General areas of both ETCs were negative for EBOV RNA. The immediate vicinity of patients was the area most likely to be positive for EBOV RNA. Personal protective equipment became positive during patient care, but chlorine solution washes rendered them negative.
CONCLUSIONS
Personal protective equipment and patient environs do become positive for EBOV RNA, but careful attention to decontamination seems to remove it. EBOV RNA was not detected in general ward spaces. Careful attention to decontamination protocols seems to be important in minimizing the presence of EBOV RNA within ETC wards.
Ebola viruses (EBOVs) are primarily transmitted by contact with infected body fluids. Ebola treatment centers (ETCs) contain areas that are exposed to body fluids through the care of patients suspected or confirmed to have EBOV disease. There are limited data documenting which areas/fomites within ETCs pose a risk for potential transmission. This study conducted environmental surveillance in 2 ETCs in Freetown, Sierra Leone, during the 2014–2016 West African Ebola outbreak.
METHODS
ETCs were surveyed over a 3-week period. Sites to be swabbed were identified with input from field personnel. Swab samples were collected and tested for the presence of EBOV RNA. Ebola-positive body fluid-impregnated cotton pads were serially sampled.
RESULTS
General areas of both ETCs were negative for EBOV RNA. The immediate vicinity of patients was the area most likely to be positive for EBOV RNA. Personal protective equipment became positive during patient care, but chlorine solution washes rendered them negative.
CONCLUSIONS
Personal protective equipment and patient environs do become positive for EBOV RNA, but careful attention to decontamination seems to remove it. EBOV RNA was not detected in general ward spaces. Careful attention to decontamination protocols seems to be important in minimizing the presence of EBOV RNA within ETC wards.