Journal Article > ResearchFull Text
Am J Trop Med Hyg. 2016 October 3; Volume 95 (Issue 6); 1389–1397 .; DOI:10.4269/ajtmh.16-0376
Tiffany A, Moundekeno FP, Traore A, Haile M, Sterk E, et al.
Am J Trop Med Hyg. 2016 October 3; Volume 95 (Issue 6); 1389–1397 .; DOI:10.4269/ajtmh.16-0376
Multiple community-based approaches can aid in quantifying mortality in the absence of reliable health facility data. Community-based sentinel site surveillance that was used to document mortality and the systems utility for outbreak detection was evaluated. We retrospectively analyzed data from 46 sentinel sites in three sous-préfectures with a reinforced malaria control program and one sous-préfecture without (Koundou) in Guinea. Deaths were recorded by key informants and classified as due to malaria or another cause. Malaria deaths were those reported as due to malaria or fever in the 3 days before death with no other known cause. Suspect Ebola virus disease (sEVD) deaths were those due to select symptoms in the EVD case definition. Deaths were aggregated by sous-préfecture and analyzed by a 6-month period. A total of 43,000 individuals were monitored by the surveillance system; 1,242 deaths were reported from July 2011-June 2014, of which 55.2% (N = 686) were reported as due to malaria. Malaria-attributable proportional mortality decreased by 26.5% (95% confidence interval [CI] = 13.9-33.1, P < 0.001) in the program area and by 6.6% (95% CI = -17.3-30.5, P = 0.589) in Koundou. Sixty-eight deaths were classified as sEVD and increased by 6.1% (95% CI = 1.3-10.8, P = 0.021). Seventeen sEVD deaths were reported from November 2013 to March 2014 including the first two laboratory-confirmed EVD deaths. Community surveillance can capture information on mortality in areas where data collection is weak, but determining causes of death remains challenging. It can also be useful for outbreak detection if timeliness of data collection and reporting facilitate real-time data analysis.
Journal Article > ResearchFull Text
N Engl J Med. 2016 January 7; Volume 374 (Issue 1); 23-32.; DOI:10.1056/NEJMoa1504605
Gignoux EM, Azman AS, de Smet M, Azuma P, Massaquoi M, et al.
N Engl J Med. 2016 January 7; Volume 374 (Issue 1); 23-32.; DOI:10.1056/NEJMoa1504605
BACKGROUND
Malaria treatment is recommended for patients with suspected Ebola virus disease (EVD) in West Africa, whether systematically or based on confirmed malaria diagnosis. At the Ebola treatment center in Foya, Lofa County, Liberia, the supply of artemether–lumefantrine, a first-line antimalarial combination drug, ran out for a 12-day period in August 2014. During this time, patients received the combination drug artesunate–amodiaquine; amodiaquine is a compound with anti–Ebola virus activity in vitro. No other obvious change in the care of patients occurred during this period.
METHODS
We fit unadjusted and adjusted regression models to standardized patient-level data to estimate the risk ratio for death among patients with confirmed EVD who were prescribed artesunate–amodiaquine (artesunate–amodiaquine group), as compared with those who were prescribed artemether–lumefantrine (artemether–lumefantrine group) and those who were not prescribed any antimalarial drug (no-antimalarial group).
RESULTS
Between June 5 and October 24, 2014, a total of 382 patients with confirmed EVD were admitted to the Ebola treatment center in Foya. At admission, 194 patients were prescribed artemether–lumefantrine and 71 were prescribed artesunate–amodiaquine. The characteristics of the patients in the artesunate–amodiaquine group were similar to those in the artemether–lumefantrine group and those in the no-antimalarial group. A total of 125 of the 194 patients in the artemether–lumefantrine group (64.4%) died, as compared with 36 of the 71 patients in the artesunate–amodiaquine group (50.7%). In adjusted analyses, the artesunate–amodiaquine group had a 31% lower risk of death than the artemether–lumefantrine group (risk ratio, 0.69; 95% confidence interval, 0.54 to 0.89), with a stronger effect observed among patients without malaria.
CONCLUSIONS
Patients who were prescribed artesunate–amodiaquine had a lower risk of death from EVD than did patients who were prescribed artemether–lumefantrine. However, our analyses cannot exclude the possibility that artemether–lumefantrine is associated with an increased risk of death or that the use of artesunate–amodiaquine was associated with unmeasured patient characteristics that directly altered the risk of death.
Malaria treatment is recommended for patients with suspected Ebola virus disease (EVD) in West Africa, whether systematically or based on confirmed malaria diagnosis. At the Ebola treatment center in Foya, Lofa County, Liberia, the supply of artemether–lumefantrine, a first-line antimalarial combination drug, ran out for a 12-day period in August 2014. During this time, patients received the combination drug artesunate–amodiaquine; amodiaquine is a compound with anti–Ebola virus activity in vitro. No other obvious change in the care of patients occurred during this period.
METHODS
We fit unadjusted and adjusted regression models to standardized patient-level data to estimate the risk ratio for death among patients with confirmed EVD who were prescribed artesunate–amodiaquine (artesunate–amodiaquine group), as compared with those who were prescribed artemether–lumefantrine (artemether–lumefantrine group) and those who were not prescribed any antimalarial drug (no-antimalarial group).
RESULTS
Between June 5 and October 24, 2014, a total of 382 patients with confirmed EVD were admitted to the Ebola treatment center in Foya. At admission, 194 patients were prescribed artemether–lumefantrine and 71 were prescribed artesunate–amodiaquine. The characteristics of the patients in the artesunate–amodiaquine group were similar to those in the artemether–lumefantrine group and those in the no-antimalarial group. A total of 125 of the 194 patients in the artemether–lumefantrine group (64.4%) died, as compared with 36 of the 71 patients in the artesunate–amodiaquine group (50.7%). In adjusted analyses, the artesunate–amodiaquine group had a 31% lower risk of death than the artemether–lumefantrine group (risk ratio, 0.69; 95% confidence interval, 0.54 to 0.89), with a stronger effect observed among patients without malaria.
CONCLUSIONS
Patients who were prescribed artesunate–amodiaquine had a lower risk of death from EVD than did patients who were prescribed artemether–lumefantrine. However, our analyses cannot exclude the possibility that artemether–lumefantrine is associated with an increased risk of death or that the use of artesunate–amodiaquine was associated with unmeasured patient characteristics that directly altered the risk of death.
Journal Article > ResearchFull Text
PLoS Negl Trop Dis. 2018 January 22; Volume 12 (Issue 1); DOI:10.1371/journal.pntd.0006161
Dalziel BD, Lau MSY, Tiffany A, McClelland A, Zelner J, et al.
PLoS Negl Trop Dis. 2018 January 22; Volume 12 (Issue 1); DOI:10.1371/journal.pntd.0006161
In the recent 2014-2016 Ebola epidemic in West Africa, non-hospitalized cases were an important component of the chain of transmission. However, non-hospitalized cases are at increased risk of going unreported because of barriers to access to healthcare. Furthermore, underreporting rates may fluctuate over space and time, biasing estimates of disease transmission rates, which are important for understanding spread and planning control measures. We performed a retrospective analysis on community deaths during the recent Ebola epidemic in Sierra Leone to estimate the number of unreported non-hospitalized cases, and to quantify how Ebola reporting rates varied across locations and over time. We then tested if variation in reporting rates affected the estimates of disease transmission rates that were used in surveillance and response. We found significant variation in reporting rates among districts, and district-specific rates of increases in reporting over time. Correcting time series of numbers of cases for variable reporting rates led, in some instances, to different estimates of the time-varying reproduction number of the epidemic, particularly outside the capital. Future analyses that compare Ebola transmission rates over time and across locations may be improved by considering the impacts of differential reporting rates.
Journal Article > ResearchFull Text
Malar J. 2016 May 28; Volume 15 (Issue 1); 298.; DOI:10.1186/s12936-016-1353-z
Tiffany A, Moundekeno FP, Traore A, Haile M, Sterk E, et al.
Malar J. 2016 May 28; Volume 15 (Issue 1); 298.; DOI:10.1186/s12936-016-1353-z
BACKGROUND
Malaria is one of the principal causes of morbidity and mortality in the Republic of Guinea, particularly in the highly endemic regions. To assist in malaria control efforts, a multi-component malaria control intervention was implemented in the hyperendemic region of Guéckédou Prefecture. The coverage of the intervention and its impact on malaria parasite prevalence were assessed.
METHODS
Five cross-sectional surveys using cluster-based sampling and stratified by area were conducted from 2011 to 2013 in three sous-préfectures of Guéckédou Préfecture that received the intervention: Guéckédou City, Tékoulo and Guendembou in addition to one comparison sous-préfecture that did not receive the intervention, Koundou. Surveys were repeated every 6 months, corresponding with the dry and rainy seasons. Rapid diagnostic tests (RDT) were used to diagnose malaria infection. In each selected household, bed net use and ownership were assessed.
RESULTS
A total of 35,123 individuals participated in the surveys. Malaria parasite prevalence declined in all intervention sous-préfectures from 2011 to 2013 (56.4-45.9 % in Guéckédou City, 64.9-54.1 % in Tékoulo and 69.4-56.9 % in Guendembou) while increasing in the comparison sous-préfecture (64.5-69 %). It was consistently higher in children 5-14 years of age followed by those 1-59 months and ≥15 years. Indicators of intervention coverage, the proportion of households reporting ownership of at least one bed net and the proportion of survey participants with fever who received treatment from a health facility or community health worker also increased significantly in the intervention areas.
CONCLUSIONS
Implementation of the multi-component malaria control intervention significantly reduced the prevalence of malaria in the sous-préfectures of intervention while also increasing the coverage of bed nets. However, malaria prevalence remains unacceptably high and disproportionately affects children <15 years of age. In such situations additional vector control interventions and age specific interventions should be considered.
Malaria is one of the principal causes of morbidity and mortality in the Republic of Guinea, particularly in the highly endemic regions. To assist in malaria control efforts, a multi-component malaria control intervention was implemented in the hyperendemic region of Guéckédou Prefecture. The coverage of the intervention and its impact on malaria parasite prevalence were assessed.
METHODS
Five cross-sectional surveys using cluster-based sampling and stratified by area were conducted from 2011 to 2013 in three sous-préfectures of Guéckédou Préfecture that received the intervention: Guéckédou City, Tékoulo and Guendembou in addition to one comparison sous-préfecture that did not receive the intervention, Koundou. Surveys were repeated every 6 months, corresponding with the dry and rainy seasons. Rapid diagnostic tests (RDT) were used to diagnose malaria infection. In each selected household, bed net use and ownership were assessed.
RESULTS
A total of 35,123 individuals participated in the surveys. Malaria parasite prevalence declined in all intervention sous-préfectures from 2011 to 2013 (56.4-45.9 % in Guéckédou City, 64.9-54.1 % in Tékoulo and 69.4-56.9 % in Guendembou) while increasing in the comparison sous-préfecture (64.5-69 %). It was consistently higher in children 5-14 years of age followed by those 1-59 months and ≥15 years. Indicators of intervention coverage, the proportion of households reporting ownership of at least one bed net and the proportion of survey participants with fever who received treatment from a health facility or community health worker also increased significantly in the intervention areas.
CONCLUSIONS
Implementation of the multi-component malaria control intervention significantly reduced the prevalence of malaria in the sous-préfectures of intervention while also increasing the coverage of bed nets. However, malaria prevalence remains unacceptably high and disproportionately affects children <15 years of age. In such situations additional vector control interventions and age specific interventions should be considered.
Journal Article > ResearchFull Text
PLoS Negl Trop Dis. 2016 August 23; Volume 10 (Issue 8); DOI:10.1371/journal.pntd.0004899
Kuehne A, Lynch E, Marshall E, Tiffany A, Alley I, et al.
PLoS Negl Trop Dis. 2016 August 23; Volume 10 (Issue 8); DOI:10.1371/journal.pntd.0004899
Between March 2014 and July 2015 at least 10,500 Ebola cases including more than 4,800 deaths occurred in Liberia, the majority in Monrovia. However, official numbers may have underestimated the size of the outbreak. Closure of health facilities and mistrust in existing structures may have additionally impacted on all-cause morbidity and mortality. To quantify mortality and morbidity and describe health-seeking behaviour in Monrovia, Médecins sans Frontières (MSF) conducted a mobile phone survey from December 2014 to March 2015. We drew a random sample of households in Monrovia and conducted structured mobile phone interviews, covering morbidity, mortality and health-seeking behaviour from 14 May 2014 until the day of the survey. We defined an Ebola-related death as any death meeting the Liberian Ebola case definition. We calculated all-cause and Ebola-specific mortality rates. The sample consisted of 6,813 household members in 905 households. We estimated a crude mortality rate (CMR) of 0.33/10,000 persons/day (95%CI:0.25-0.43) and an Ebola-specific mortality rate of 0.06/10,000 persons/day (95%-CI:0.03-0.11). During the recall period, 17 Ebola cases were reported including those who died. In the 30 days prior to the survey 277 household members were reported sick; malaria accounted for 54% (150/277). Of the sick household members, 43% (122/276) did not visit any health care facility. The mobile phone-based survey was found to be a feasible and acceptable alternative method when data collection in the community is impossible. CMR was estimated well below the emergency threshold of 1/10,000 persons/day. Non-Ebola-related mortality in Monrovia was not higher than previous national estimates of mortality for Liberia. However, excess mortality directly resulting from Ebola did occur in the population. Importantly, the small proportion of sick household members presenting to official health facilities when sick might pose a challenge for future outbreak detection and mitigation. Substantial reported health-seeking behaviour outside of health facilities may also suggest the need for adapted health messaging and improved access to health care.
Journal Article > ResearchFull Text
Proc Natl Acad Sci U S A. 2017 February 13 (Issue 9)
Lau MSY, Dalziel BD, Funk S, McClelland A, Tiffany A, et al.
Proc Natl Acad Sci U S A. 2017 February 13 (Issue 9)
The unprecedented scale of the Ebola outbreak in Western Africa (2014-2015) has prompted an explosion of efforts to understand the transmission dynamics of the virus and to analyze the performance of possible containment strategies. Models have focused primarily on the reproductive numbers of the disease that represent the average number of secondary infections produced by a random infectious individual. However, these population-level estimates may conflate important systematic variation in the number of cases generated by infected individuals, particularly found in spatially localized transmission and superspreading events. Although superspreading features prominently in first-hand narratives of Ebola transmission, its dynamics have not been systematically characterized, hindering refinements of future epidemic predictions and explorations of targeted interventions. We used Bayesian model inference to integrate individual-level spatial information with other epidemiological data of community-based (undetected within clinical-care systems) cases and to explicitly infer distribution of the cases generated by each infected individual. Our results show that superspreaders play a key role in sustaining onward transmission of the epidemic, and they are responsible for a significant proportion ([Formula: see text]61%) of the infections. Our results also suggest age as a key demographic predictor for superspreading. We also show that community-based cases may have progressed more rapidly than those notified within clinical-care systems, and most transmission events occurred in a relatively short distance (with median value of 2.51 km). Our results stress the importance of characterizing superspreading of Ebola, enhance our current understanding of its spatiotemporal dynamics, and highlight the potential importance of targeted control measures.
Journal Article > ResearchFull Text
PLoS Curr. 2015 February 10; DOI:10.1371/currents.outbreaks
Camacho A, Kucharski AJ, Aki-Sawyerr Y, White M, Flasche S, et al.
PLoS Curr. 2015 February 10; DOI:10.1371/currents.outbreaks
Between August and November 2014, the incidence of Ebola virus disease (EVD) rose dramatically in several districts of Sierra Leone. As a result, the number of cases exceeded the capacity of Ebola holding and treatment centres. During December, additional beds were introduced, and incidence declined in many areas. We aimed to measure patterns of transmission in different regions, and evaluate whether bed capacity is now sufficient to meet future demand.
Journal Article > CommentaryFull Text
Am J Trop Med Hyg. 2014 December 15; Volume 92 (Issue 2); DOI:10.4269/ajtmh.14-0753
Olliaro PL, Lasry E, Tiffany A
Am J Trop Med Hyg. 2014 December 15; Volume 92 (Issue 2); DOI:10.4269/ajtmh.14-0753
On October 29, 2014, 4 days before the annual meeting of the American Society of Tropical Medicine and Hygiene (ASTMH) to be held in New Orleans, LA, meeting registrants received an e-mail letter from the Louisiana Department of Health and Hospitals stating "we have requested that any individuals that will be traveling to Louisiana following a trip to the West African countries of Guinea, Liberia, and Sierra Leone or have had contact with an Ebola-infected individual remain in a self-quarantine for the 21 days following their relevant travel history…we see no use in you traveling to New Orleans to simply be confined to your room." This communication made it clear that those recently in countries experiencing the 2014 Ebola epidemic would not be able to participate in the meeting. The ASTMH sent their own communication stating that the Society did not agree with the State's policy, but had no choice but to abide. However inconvenient and upsetting this decision might have been, what really matters transcends the mere disturbance of long-planned schedules. More broadly, we lost on five levels.
Journal Article > ResearchFull Text
PLOS One. 2016 August 31; Volume 11 (Issue 8); e0161311.; DOI:10.1371/journal.pone.0161311
Kuehne A, Tiffany A, Lasry E, Janssens M, Besse C, et al.
PLOS One. 2016 August 31; Volume 11 (Issue 8); e0161311.; DOI:10.1371/journal.pone.0161311
BACKGROUND
In October 2014, during the Ebola outbreak in Liberia healthcare services were limited while malaria transmission continued. Médecins Sans Frontières (MSF) implemented a mass drug administration (MDA) of malaria chemoprevention (CP) in Monrovia to reduce malaria-associated morbidity. In order to inform future interventions, we described the scale of the MDA, evaluated its acceptance and estimated the effectiveness.
METHODS
MSF carried out two rounds of MDA with artesunate/amodiaquine (ASAQ) targeting four neighbourhoods of Monrovia (October to December 2014). We systematically selected households in the distribution area and administered standardized questionnaires. We calculated incidence ratios (IR) of side effects using poisson regression and compared self-reported fever risk differences (RD) pre- and post-MDA using a z-test.
FINDINGS
In total, 1,259,699 courses of ASAQ-CP were distributed. All households surveyed (n = 222; 1233 household members) attended the MDA in round 1 (r1) and 96% in round 2 (r2) (212/222 households; 1,154 household members). 52% (643/1233) initiated ASAQ-CP in r1 and 22% (256/1154) in r2. Of those not initiating ASAQ-CP, 29% (172/590) saved it for later in r1, 47% (423/898) in r2. Experiencing side effects in r1 was not associated with ASAQ-CP initiation in r2 (IR 1.0, 95%CI 0.49-2.1). The incidence of self-reported fever decreased from 4.2% (52/1229) in the month prior to r1 to 1.5% (18/1229) after r1 (p<0.001) and decrease was larger among household members completing ASAQ-CP (RD = 4.9%) compared to those not initiating ASAQ-CP (RD = 0.6%) in r1 (p<0.001).
CONCLUSIONS
The reduction in self-reported fever cases following the intervention suggests that MDAs may be effective in reducing cases of fever during Ebola outbreaks. Despite high coverage, initiation of ASAQ-CP was low. Combining MDAs with longer term interventions to prevent malaria and to improve access to healthcare may reduce both the incidence of malaria and the proportion of respondents saving their treatment for future malaria episodes.
In October 2014, during the Ebola outbreak in Liberia healthcare services were limited while malaria transmission continued. Médecins Sans Frontières (MSF) implemented a mass drug administration (MDA) of malaria chemoprevention (CP) in Monrovia to reduce malaria-associated morbidity. In order to inform future interventions, we described the scale of the MDA, evaluated its acceptance and estimated the effectiveness.
METHODS
MSF carried out two rounds of MDA with artesunate/amodiaquine (ASAQ) targeting four neighbourhoods of Monrovia (October to December 2014). We systematically selected households in the distribution area and administered standardized questionnaires. We calculated incidence ratios (IR) of side effects using poisson regression and compared self-reported fever risk differences (RD) pre- and post-MDA using a z-test.
FINDINGS
In total, 1,259,699 courses of ASAQ-CP were distributed. All households surveyed (n = 222; 1233 household members) attended the MDA in round 1 (r1) and 96% in round 2 (r2) (212/222 households; 1,154 household members). 52% (643/1233) initiated ASAQ-CP in r1 and 22% (256/1154) in r2. Of those not initiating ASAQ-CP, 29% (172/590) saved it for later in r1, 47% (423/898) in r2. Experiencing side effects in r1 was not associated with ASAQ-CP initiation in r2 (IR 1.0, 95%CI 0.49-2.1). The incidence of self-reported fever decreased from 4.2% (52/1229) in the month prior to r1 to 1.5% (18/1229) after r1 (p<0.001) and decrease was larger among household members completing ASAQ-CP (RD = 4.9%) compared to those not initiating ASAQ-CP (RD = 0.6%) in r1 (p<0.001).
CONCLUSIONS
The reduction in self-reported fever cases following the intervention suggests that MDAs may be effective in reducing cases of fever during Ebola outbreaks. Despite high coverage, initiation of ASAQ-CP was low. Combining MDAs with longer term interventions to prevent malaria and to improve access to healthcare may reduce both the incidence of malaria and the proportion of respondents saving their treatment for future malaria episodes.
Journal Article > ResearchFull Text
Philos Trans R Soc Lond B Biol Sci. 2017 April 10; Volume 372 (Issue 1721); 20160302.; DOI:10.1098/rstb.2016.0302
Funk S, Ciglenecki I, Tiffany A, Gignoux EM, Camacho A, et al.
Philos Trans R Soc Lond B Biol Sci. 2017 April 10; Volume 372 (Issue 1721); 20160302.; DOI:10.1098/rstb.2016.0302
The Ebola epidemic in West Africa was stopped by an enormous concerted effort of local communities and national and international organizations. It is not clear, however, how much the public health response and behavioural changes in affected communities, respectively, contributed to ending the outbreak. Here, we analyse the epidemic in Lofa County, Liberia, lasting from March to November 2014, by reporting a comprehensive time line of events and estimating the time-varying transmission intensity using a mathematical model of Ebola transmission. Model fits to the epidemic show an alternation of peaks and troughs in transmission, consistent with highly heterogeneous spread. This is combined with an overall decline in the reproduction number of Ebola transmission from early August, coinciding with an expansion of the local Ebola treatment centre. We estimate that healthcare seeking approximately doubled over the course of the outbreak, and that isolation of those seeking healthcare reduced their reproduction number by 62% (mean estimate, 95% credible interval (CI) 59-66). Both expansion of bed availability and improved healthcare seeking contributed to ending the epidemic, highlighting the importance of community engagement alongside clinical intervention.This article is part of the themed issue 'The 2013-2016 West African Ebola epidemic: data, decision-making and disease control'.