Journal Article > ResearchFull Text
Epidemiol Infect. 2013 October 11; Volume 142 (Issue 8); DOI:10.1017/S0950268813002562
Grandesso F, Allan M, Jean-Simon PSJ, Boncy J, Blake A, et al.
Epidemiol Infect. 2013 October 11; Volume 142 (Issue 8); DOI:10.1017/S0950268813002562
SUMMARY Two community-based density case-control studies were performed to assess risk factors for cholera transmission during inter-peak periods of the ongoing epidemic in two Haitian urban settings, Gonaives and Carrefour. The strongest associations were: close contact with cholera patients (sharing latrines, visiting cholera patients, helping someone with diarrhoea), eating food from street vendors and washing dishes with untreated water. Protective factors were: drinking chlorinated water, receiving prevention messages via television, church or training sessions, and high household socioeconomic level. These findings suggest that, in addition to contaminated water, factors related to direct and indirect inter-human contact play an important role in cholera transmission during inter-peak periods. In order to reduce cholera transmission in Haiti intensive preventive measures such as hygiene promotion and awareness campaigns should be implemented during inter-peak lulls, when prevention activities are typically scaled back.
Journal Article > ResearchFull Text
Epidemics. 2015 September 3; Volume 14; 1-10.; DOI:10.1016/j.epidem.2015.08.001
Allan M, Grandesso F, Pierre R, Magloire R, Coldiron ME, et al.
Epidemics. 2015 September 3; Volume 14; 1-10.; DOI:10.1016/j.epidem.2015.08.001
BACKGROUND
Cholera is caused by Vibrio cholerae, and is transmitted through fecal-oral contact. Infection occurs after the ingestion of the bacteria and is usually asymptomatic. In a minority of cases, it causes acute diarrhea and vomiting, which can lead to potentially fatal severe dehydration, especially in the absence of appropriate medical care. Immunity occurs after infection and typically lasts 6-36 months. Cholera is responsible for outbreaks in many African and Asian developing countries, and caused localised and episodic epidemics in South America until the early 1990s. Haiti, despite its low socioeconomic status and poor sanitation, had never reported cholera before the recent outbreak that started in October 2010, with over 720,000 cases and over 8700 deaths (Case fatality rate: 1.2%) through 8 December 2014. So far, this outbreak has seen 3 epidemic peaks, and it is expected that cholera will remain in Haiti for some time.
METHODOLOGY/FINDINGS
To trace the path of the early epidemic and to identify hot spots and potential transmission hubs during peaks, we examined the spatial distribution of cholera patients during the first two peaks in Artibonite, the second-most populous department of Haiti. We extracted the geographic origin of 84,000 patients treated in local health facilities between October 2010 and December 2011 and mapped these addresses to 63 rural communal sections and 9 urban cities. Spatial and cluster analysis showed that during the first peak, cholera spread along the Artibonite River and the main roads, and sub-communal attack rates ranged from 0.1% to 10.7%. During the second peak, remote mountain areas were most affected, although sometimes to very different degrees even in closely neighboring locations. Sub-communal attack rates during the second peak ranged from 0.2% to 13.7%. The relative risks at the sub-communal level during the second phase showed an inverse pattern compared to the first phase.
CONCLUSION/SIGNIFICANCE
These findings demonstrate the value of high-resolution mapping for pinpointing locations most affected by cholera, and in the future could help prioritize the places in need of interventions such as improvement of sanitation and vaccination. The findings also describe spatio-temporal transmission patterns of the epidemic in a cholera-naïve country such as Haiti. By identifying transmission hubs, it is possible to target prevention strategies that, over time, could reduce transmission of the disease and eventually eliminate cholera in Haiti.
Cholera is caused by Vibrio cholerae, and is transmitted through fecal-oral contact. Infection occurs after the ingestion of the bacteria and is usually asymptomatic. In a minority of cases, it causes acute diarrhea and vomiting, which can lead to potentially fatal severe dehydration, especially in the absence of appropriate medical care. Immunity occurs after infection and typically lasts 6-36 months. Cholera is responsible for outbreaks in many African and Asian developing countries, and caused localised and episodic epidemics in South America until the early 1990s. Haiti, despite its low socioeconomic status and poor sanitation, had never reported cholera before the recent outbreak that started in October 2010, with over 720,000 cases and over 8700 deaths (Case fatality rate: 1.2%) through 8 December 2014. So far, this outbreak has seen 3 epidemic peaks, and it is expected that cholera will remain in Haiti for some time.
METHODOLOGY/FINDINGS
To trace the path of the early epidemic and to identify hot spots and potential transmission hubs during peaks, we examined the spatial distribution of cholera patients during the first two peaks in Artibonite, the second-most populous department of Haiti. We extracted the geographic origin of 84,000 patients treated in local health facilities between October 2010 and December 2011 and mapped these addresses to 63 rural communal sections and 9 urban cities. Spatial and cluster analysis showed that during the first peak, cholera spread along the Artibonite River and the main roads, and sub-communal attack rates ranged from 0.1% to 10.7%. During the second peak, remote mountain areas were most affected, although sometimes to very different degrees even in closely neighboring locations. Sub-communal attack rates during the second peak ranged from 0.2% to 13.7%. The relative risks at the sub-communal level during the second phase showed an inverse pattern compared to the first phase.
CONCLUSION/SIGNIFICANCE
These findings demonstrate the value of high-resolution mapping for pinpointing locations most affected by cholera, and in the future could help prioritize the places in need of interventions such as improvement of sanitation and vaccination. The findings also describe spatio-temporal transmission patterns of the epidemic in a cholera-naïve country such as Haiti. By identifying transmission hubs, it is possible to target prevention strategies that, over time, could reduce transmission of the disease and eventually eliminate cholera in Haiti.
Journal Article > ResearchFull Text
Lancet Global Health. 2016 November 1; Volume 4 (Issue 11); e856-e863.; DOI:10.1016/S2214-109X(16)30211-X
Azman AS, Parker LA, Rumunu J, Tadesse F, Grandesso F, et al.
Lancet Global Health. 2016 November 1; Volume 4 (Issue 11); e856-e863.; DOI:10.1016/S2214-109X(16)30211-X
BACKGROUND
Oral cholera vaccines represent a new effective tool to fight cholera and are licensed as two-dose regimens with 2-4 weeks between doses. Evidence from previous studies suggests that a single dose of oral cholera vaccine might provide substantial direct protection against cholera. During a cholera outbreak in May, 2015, in Juba, South Sudan, the Ministry of Health, Médecins Sans Frontières, and partners engaged in the first field deployment of a single dose of oral cholera vaccine to enhance the outbreak response. We did a vaccine effectiveness study in conjunction with this large public health intervention.
METHODS
We did a case-cohort study, combining information on the vaccination status and disease outcomes from a random cohort recruited from throughout the city of Juba with that from all the cases detected. Eligible cases were those aged 1 year or older on the first day of the vaccination campaign who sought care for diarrhoea at all three cholera treatment centres and seven rehydration posts throughout Juba. Confirmed cases were suspected cases who tested positive to PCR for Vibrio cholerae O1. We estimated the short-term protection (direct and indirect) conferred by one dose of cholera vaccine (Shanchol, Shantha Biotechnics, Hyderabad, India).
FINDINGS
Between Aug 9, 2015, and Sept 29, 2015, we enrolled 87 individuals with suspected cholera, and an 898-person cohort from throughout Juba. Of the 87 individuals with suspected cholera, 34 were classified as cholera positive, 52 as cholera negative, and one had indeterminate results. Of the 858 cohort members who completed a follow-up visit, none developed clinical cholera during follow-up. The unadjusted single-dose vaccine effectiveness was 80·2% (95% CI 61·5-100·0) and after adjusting for potential confounders was 87·3% (70·2-100·0).
INTERPRETATION
One dose of Shanchol was effective in preventing medically attended cholera in this study. These results support the use of a single-dose strategy in outbreaks in similar epidemiological settings.
Oral cholera vaccines represent a new effective tool to fight cholera and are licensed as two-dose regimens with 2-4 weeks between doses. Evidence from previous studies suggests that a single dose of oral cholera vaccine might provide substantial direct protection against cholera. During a cholera outbreak in May, 2015, in Juba, South Sudan, the Ministry of Health, Médecins Sans Frontières, and partners engaged in the first field deployment of a single dose of oral cholera vaccine to enhance the outbreak response. We did a vaccine effectiveness study in conjunction with this large public health intervention.
METHODS
We did a case-cohort study, combining information on the vaccination status and disease outcomes from a random cohort recruited from throughout the city of Juba with that from all the cases detected. Eligible cases were those aged 1 year or older on the first day of the vaccination campaign who sought care for diarrhoea at all three cholera treatment centres and seven rehydration posts throughout Juba. Confirmed cases were suspected cases who tested positive to PCR for Vibrio cholerae O1. We estimated the short-term protection (direct and indirect) conferred by one dose of cholera vaccine (Shanchol, Shantha Biotechnics, Hyderabad, India).
FINDINGS
Between Aug 9, 2015, and Sept 29, 2015, we enrolled 87 individuals with suspected cholera, and an 898-person cohort from throughout Juba. Of the 87 individuals with suspected cholera, 34 were classified as cholera positive, 52 as cholera negative, and one had indeterminate results. Of the 858 cohort members who completed a follow-up visit, none developed clinical cholera during follow-up. The unadjusted single-dose vaccine effectiveness was 80·2% (95% CI 61·5-100·0) and after adjusting for potential confounders was 87·3% (70·2-100·0).
INTERPRETATION
One dose of Shanchol was effective in preventing medically attended cholera in this study. These results support the use of a single-dose strategy in outbreaks in similar epidemiological settings.
Journal Article > CommentaryFull Text
Bull World Health Organ. 2018 June 1; Volume 96 (Issue 6); 428-435.; DOI:10.2471/BLT.17.207175
Mbangombe M, Pezzoli L, Reeder B, Kabuluzi S, Msyamboza K, et al.
Bull World Health Organ. 2018 June 1; Volume 96 (Issue 6); 428-435.; DOI:10.2471/BLT.17.207175
PROBLEM
With limited global supplies of oral cholera vaccine, countries need to identify priority areas for vaccination while longer-term solutions, such as water and sanitation infrastructure, are being developed.
APPROACH
In 2017, Malawi integrated oral cholera vaccine into its national cholera control plan. The process started with a desk review and analysis of previous surveillance and risk factor data. At a consultative meeting, researchers, national health and water officials and representatives from nongovernmental and international organizations reviewed the data and local epidemiological knowledge to determine priority districts for oral cholera vaccination. The final stage was preparation of an application to the global oral cholera vaccine stockpile for non-emergency use.
LOCAL SETTING
Malawi collects annual data on cholera and most districts have reported cases at least once since the 1970s.
RELEVANT CHANGES
The government’s application for 3.2 million doses of vaccine to be provided over 20 months in 12 districts was accepted in April 2017. By April 2018, over 1 million doses had been administered in five districts. Continuing surveillance in districts showed that cholera outbreaks were notably absent in vaccinated high-risk areas, despite a national outbreak in 2017–2018.
LESSONS LEARNT
Augmenting advanced mapping techniques with local information helped us extend priority areas beyond those identified as high-risk based on cholera incidence reported at the district level. Involvement of the water, sanitation and hygiene sectors is key to ensuring that short-term gains from cholera vaccine are backed by longer-term progress in reducing cholera transmission.
With limited global supplies of oral cholera vaccine, countries need to identify priority areas for vaccination while longer-term solutions, such as water and sanitation infrastructure, are being developed.
APPROACH
In 2017, Malawi integrated oral cholera vaccine into its national cholera control plan. The process started with a desk review and analysis of previous surveillance and risk factor data. At a consultative meeting, researchers, national health and water officials and representatives from nongovernmental and international organizations reviewed the data and local epidemiological knowledge to determine priority districts for oral cholera vaccination. The final stage was preparation of an application to the global oral cholera vaccine stockpile for non-emergency use.
LOCAL SETTING
Malawi collects annual data on cholera and most districts have reported cases at least once since the 1970s.
RELEVANT CHANGES
The government’s application for 3.2 million doses of vaccine to be provided over 20 months in 12 districts was accepted in April 2017. By April 2018, over 1 million doses had been administered in five districts. Continuing surveillance in districts showed that cholera outbreaks were notably absent in vaccinated high-risk areas, despite a national outbreak in 2017–2018.
LESSONS LEARNT
Augmenting advanced mapping techniques with local information helped us extend priority areas beyond those identified as high-risk based on cholera incidence reported at the district level. Involvement of the water, sanitation and hygiene sectors is key to ensuring that short-term gains from cholera vaccine are backed by longer-term progress in reducing cholera transmission.
Journal Article > ResearchFull Text
Trop Med Int Health. 2006 July 1; Volume 11 (Issue 7); DOI:10.1111/j.1365-3156.2006.01655.x
Grandesso F, Hagerman A, Kamara S, Lam E, Checchi F, et al.
Trop Med Int Health. 2006 July 1; Volume 11 (Issue 7); DOI:10.1111/j.1365-3156.2006.01655.x
OBJECTIVE: In 2004, Sierra Leone adopted artesunate plus amodiaquine as first-line antimalarial treatment. We evaluated the efficacy of this combination in Kailahun, where a previous study had shown 70.2% efficacy of amodiaquine in monotherapy. METHODS: Method and outcome classification of the study complied with WHO guidelines. Children 6-59 months with uncomplicated malaria were followed-up for 28 days. PCR genotyping was used to distinguish recrudescence from reinfection. Reinfections were reclassified as cured. RESULTS: Of 172 children who were referred to the study clinic, 126 satisfied inclusion criteria and were enrolled. No early treatment failures were reported. The day 14, efficacy was 98.2% (95% CI: 93.8-99.8). Of 65 recurrent parasitaemias analysed by PCR, 17 were recrudescences. The PCR-adjusted day 28 efficacy was 84.5% (95% CI: 76.4-90.7). All true failures occurred in the last 8 days of follow-up. Of 110 children who completed the 28-day follow-up, 54 (49.1%) experienced a novel infection. CONCLUSION: The efficacy of this combination was disappointing. The high reinfection rate suggested little prophylactic effect. In Kailahun a more efficacious combination might be necessary in the future. The efficacy of AS + AQ needs to be monitored in Kailahun and in the other regions of Sierra Leone.
Conference Material > Poster
Akem TE, Schramm B, Akeen WW, Singh SN, Adimw M, et al.
Epicentre Scientific Day 2024. 2024 May 23
Journal Article > ResearchFull Text
Bull World Health Organ. 2018 September 27; Volume 96 (Issue 12); 817-825.; DOI:10.2471/BLT.17.206417
Grandesso F, Rafael F, Chipeta S, Alley I, Saussier C, et al.
Bull World Health Organ. 2018 September 27; Volume 96 (Issue 12); 817-825.; DOI:10.2471/BLT.17.206417
OBJECTIVE
To evaluate vaccination coverage, identify reasons for non-vaccination and assess satisfaction with two innovative strategies for distributing second doses in an oral cholera vaccine campaign in 2016 in Lake Chilwa, Malawi, in response to a cholera outbreak.
METHODS
We performed a two-stage cluster survey. The population interviewed was divided in three strata according to the second-dose vaccine distribution strategy: (i) a standard strategy in 1477 individuals (68 clusters of 5 households) on the lake shores; (ii) a simplified cold-chain strategy in 1153 individuals (59 clusters of 5 households) on islands in the lake; and (iii) an out-of-cold-chain strategy in 295 fishermen (46 clusters of 5 to 15 fishermen) in floating homes, called zimboweras.
FINDING
Vaccination coverage with at least one dose was 79.5% (1153/1451) on the lake shores, 99.3% (1098/1106) on the islands and 84.7% (200/236) on zimboweras. Coverage with two doses was 53.0% (769/1451), 91.1% (1010/1106) and 78.8% (186/236), in the three strata, respectively. The most common reason for non-vaccination was absence from home during the campaign. Most interviewees liked the novel distribution strategies.
CONCLUSION
Vaccination coverage on the shores of Lake Chilwa was moderately high and the innovative distribution strategies tailored to people living on the lake provided adequate coverage, even among hard-to-reach communities. Community engagement and simplified delivery procedures were critical for success. Off-label, out-of-cold-chain administration of oral cholera vaccine should be considered as an effective strategy for achieving high coverage in hard-to-reach communities. Nevertheless, coverage and effectiveness must be monitored over the short and long term.
To evaluate vaccination coverage, identify reasons for non-vaccination and assess satisfaction with two innovative strategies for distributing second doses in an oral cholera vaccine campaign in 2016 in Lake Chilwa, Malawi, in response to a cholera outbreak.
METHODS
We performed a two-stage cluster survey. The population interviewed was divided in three strata according to the second-dose vaccine distribution strategy: (i) a standard strategy in 1477 individuals (68 clusters of 5 households) on the lake shores; (ii) a simplified cold-chain strategy in 1153 individuals (59 clusters of 5 households) on islands in the lake; and (iii) an out-of-cold-chain strategy in 295 fishermen (46 clusters of 5 to 15 fishermen) in floating homes, called zimboweras.
FINDING
Vaccination coverage with at least one dose was 79.5% (1153/1451) on the lake shores, 99.3% (1098/1106) on the islands and 84.7% (200/236) on zimboweras. Coverage with two doses was 53.0% (769/1451), 91.1% (1010/1106) and 78.8% (186/236), in the three strata, respectively. The most common reason for non-vaccination was absence from home during the campaign. Most interviewees liked the novel distribution strategies.
CONCLUSION
Vaccination coverage on the shores of Lake Chilwa was moderately high and the innovative distribution strategies tailored to people living on the lake provided adequate coverage, even among hard-to-reach communities. Community engagement and simplified delivery procedures were critical for success. Off-label, out-of-cold-chain administration of oral cholera vaccine should be considered as an effective strategy for achieving high coverage in hard-to-reach communities. Nevertheless, coverage and effectiveness must be monitored over the short and long term.
MSF Ethics Review Board > Templates & procedures
Gerstl S, Grandesso F, Siddiqui R, Greig J, du Cros PAK, et al.
2022 October 25
Journal Article > ResearchFull Text
Malar J. 2011 May 18; Volume 10 (Issue 1); 132.; DOI:10.1186/1475-2875-10-132
De Beaudrap P, Nabasumba C, Grandesso F, Turyakira E, Schramm B, et al.
Malar J. 2011 May 18; Volume 10 (Issue 1); 132.; DOI:10.1186/1475-2875-10-132
BACKGROUND
Malaria is a major public health problem, especially for children. However, recent reports suggest a decline in the malaria burden. The aim of this study was to assess the change in the prevalence of malaria infection among children below five years of age between 2004 and 2010 in a mesoendemic area of Uganda and to analyse the risk factors of malaria infection.
METHODS
Two cross-sectional surveys were conducted in 2004 and in 2010 at the end of the rainy and dry seasons to measure the prevalence of P. falciparum infection among children less than five years of age. Rapid diagnostic tests and blood smears were used to diagnose malaria infection. In 2010, sampling was stratified by urban and rural areas. In each selected household, knowledge of malaria and bed nets, and bed net ownership and use, were assessed.
RESULTS
In 2004 and 2010, respectively, a total of 527 and 2,320 (999 in the urban area and 1,321 in rural areas) children less than five years old were enrolled. Prevalence of malaria infection declined from 43% (95% CI: 34-52) in 2004, to 23% (95% CI: 17-30) in rural areas in 2010 and 3% (95% CI: 2-5) in the urban area in 2010. From the rainy to dry season in 2010, prevalence decreased from 23% to 10% (95% CI: 6-14) in rural areas (P = 0.001) and remained stable from 3% to 4% (95% CI: 1-7) in the urban area (P = 0.9). The proportion of households reporting ownership and use of at least one bed net increased from 22.9% in 2004 to 64.7% in the urban area and 44.5% in rural areas in 2010 (P < 0.001). In 2010, the risk of malaria infection was consistently associated with child age and household wealth. In rural areas, malaria infection was also associated with geographic factors.
CONCLUSIONS
This study reports a significant drop in the prevalence of malaria infection among children below five years of age, paralleled by an uptake in bed-net use. However, prevalence remains unacceptably high in rural areas and is strongly associated with poverty.
Malaria is a major public health problem, especially for children. However, recent reports suggest a decline in the malaria burden. The aim of this study was to assess the change in the prevalence of malaria infection among children below five years of age between 2004 and 2010 in a mesoendemic area of Uganda and to analyse the risk factors of malaria infection.
METHODS
Two cross-sectional surveys were conducted in 2004 and in 2010 at the end of the rainy and dry seasons to measure the prevalence of P. falciparum infection among children less than five years of age. Rapid diagnostic tests and blood smears were used to diagnose malaria infection. In 2010, sampling was stratified by urban and rural areas. In each selected household, knowledge of malaria and bed nets, and bed net ownership and use, were assessed.
RESULTS
In 2004 and 2010, respectively, a total of 527 and 2,320 (999 in the urban area and 1,321 in rural areas) children less than five years old were enrolled. Prevalence of malaria infection declined from 43% (95% CI: 34-52) in 2004, to 23% (95% CI: 17-30) in rural areas in 2010 and 3% (95% CI: 2-5) in the urban area in 2010. From the rainy to dry season in 2010, prevalence decreased from 23% to 10% (95% CI: 6-14) in rural areas (P = 0.001) and remained stable from 3% to 4% (95% CI: 1-7) in the urban area (P = 0.9). The proportion of households reporting ownership and use of at least one bed net increased from 22.9% in 2004 to 64.7% in the urban area and 44.5% in rural areas in 2010 (P < 0.001). In 2010, the risk of malaria infection was consistently associated with child age and household wealth. In rural areas, malaria infection was also associated with geographic factors.
CONCLUSIONS
This study reports a significant drop in the prevalence of malaria infection among children below five years of age, paralleled by an uptake in bed-net use. However, prevalence remains unacceptably high in rural areas and is strongly associated with poverty.
Journal Article > ResearchFull Text
Lancet. 2005 April 23; Volume 365 (Issue 9469); DOI:10.1016/S0140-6736(05)66416-1
Piola P, Fogg C, Bajunirwe F, Biraro S, Grandesso F, et al.
Lancet. 2005 April 23; Volume 365 (Issue 9469); DOI:10.1016/S0140-6736(05)66416-1
BACKGROUND: The six-dose regimen of artemether-lumefantrine is effective and is among combination therapies prioritised to replace antimalarials that no longer work in Africa. However, its effectiveness has not been assessed in the field, and could be compromised by poor adherence, incorrect timing of doses, and insufficient intake of fatty foods with every dose. Our aim, therefore, was to assess the effectiveness of artemether-lumefantrine prescribed under routine outpatient conditions, compared with its efficacy when given under supervision to inpatients with acute uncomplicated falciparum malaria. METHODS: We did a randomised trial to compare the efficacy, safety, and pharmacokinetics of artemether-lumefantrine when given in a supervised (all doses observed with fatty-food intake; n=313) or unsupervised (first dose supervised followed by outpatient treatment with nutritional advice; n=644) setting to patients of all ages (weight >10 kg) with acute, uncomplicated falciparum malaria in Mbarara, Uganda. Our primary endpoint was 28 day, PCR-adjusted, parasitological cure rate. Analysis was by intention to treat and evaluability analysis. FINDINGS: 38 patients were lost to follow-up and one withdrew consent. Day-28 cure rates were 97.7% (296 of 303) and 98.0% (603 of 615) in the supervised and unsupervised groups, respectively. We recorded 15 non-severe, drug-related adverse events, all of which resolved. INTERPRETATION: Artemether-lumefantrine has a high cure rate irrespective of whether given under supervision with food or under conditions of routine clinic practice. If used as first-line treatment, artemether-lumefantrine could make a substantial contribution to malaria control in Africa, though cost is an issue.