Journal Article > ResearchFull Text
PLOS One. 2014 December 8; 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. 2014 December 8; 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 > LetterSubscription Only
N Engl J Med. 2008 November 27; Volume 359 (Issue 22); 2398-400.; DOI:10.1056/NEJMc0805644
Cox HS, Sibilia C, Feuerriegel S, Kalon S, Polonsky JA, et al.
N Engl J Med. 2008 November 27; Volume 359 (Issue 22); 2398-400.; DOI:10.1056/NEJMc0805644
Journal Article > ResearchFull Text
PLOS Med. 2021 April 1; Volume 18 (Issue 4); e1003587.; DOI:10.1371/journal.pmed.1003587
Polonsky JA, Ivey M, Mazhar KA, Rahman Z, le Polain de Waroux O, et al.
PLOS Med. 2021 April 1; Volume 18 (Issue 4); e1003587.; DOI:10.1371/journal.pmed.1003587
BACKGROUND
Unrest in Myanmar in August 2017 resulted in the movement of over 700,000 Rohingya refugees to overcrowded camps in Cox's Bazar, Bangladesh. A large outbreak of diphtheria subsequently began in this population.
METHODS AND FINDINGS
Data were collected during mass vaccination campaigns (MVCs), contact tracing activities, and from 9 Diphtheria Treatment Centers (DTCs) operated by national and international organizations. These data were used to describe the epidemiological and clinical features and the control measures to prevent transmission, during the first 2 years of the outbreak. Between November 10, 2017 and November 9, 2019, 7,064 cases were reported: 285 (4.0%) laboratory-confirmed, 3,610 (51.1%) probable, and 3,169 (44.9%) suspected cases. The crude attack rate was 51.5 cases per 10,000 person-years, and epidemic doubling time was 4.4 days (95% confidence interval [CI] 4.2-4.7) during the exponential growth phase. The median age was 10 years (range 0-85), and 3,126 (44.3%) were male. The typical symptoms were sore throat (93.5%), fever (86.0%), pseudomembrane (34.7%), and gross cervical lymphadenopathy (GCL; 30.6%). Diphtheria antitoxin (DAT) was administered to 1,062 (89.0%) out of 1,193 eligible patients, with adverse reactions following among 229 (21.6%). There were 45 deaths (case fatality ratio [CFR] 0.6%). Household contacts for 5,702 (80.7%) of 7,064 cases were successfully traced. A total of 41,452 contacts were identified, of whom 40,364 (97.4%) consented to begin chemoprophylaxis; adherence was 55.0% (N = 22,218) at 3-day follow-up. Unvaccinated household contacts were vaccinated with 3 doses (with 4-week interval), while a booster dose was administered if the primary vaccination schedule had been completed. The proportion of contacts vaccinated was 64.7% overall. Three MVC rounds were conducted, with administrative coverage varying between 88.5% and 110.4%. Pentavalent vaccine was administered to those aged 6 weeks to 6 years, while tetanus and diphtheria (Td) vaccine was administered to those aged 7 years and older. Lack of adequate diagnostic capacity to confirm cases was the main limitation, with a majority of cases unconfirmed and the proportion of true diphtheria cases unknown.
CONCLUSIONS
To our knowledge, this is the largest reported diphtheria outbreak in refugee settings. We observed that high population density, poor living conditions, and fast growth rate were associated with explosive expansion of the outbreak during the initial exponential growth phase. Three rounds of mass vaccinations targeting those aged 6 weeks to 14 years were associated with only modestly reduced transmission, and additional public health measures were necessary to end the outbreak. This outbreak has a long-lasting tail, with Rt oscillating at around 1 for an extended period. An adequate global DAT stockpile needs to be maintained. All populations must have access to health services and routine vaccination, and this access must be maintained during humanitarian crises.
Unrest in Myanmar in August 2017 resulted in the movement of over 700,000 Rohingya refugees to overcrowded camps in Cox's Bazar, Bangladesh. A large outbreak of diphtheria subsequently began in this population.
METHODS AND FINDINGS
Data were collected during mass vaccination campaigns (MVCs), contact tracing activities, and from 9 Diphtheria Treatment Centers (DTCs) operated by national and international organizations. These data were used to describe the epidemiological and clinical features and the control measures to prevent transmission, during the first 2 years of the outbreak. Between November 10, 2017 and November 9, 2019, 7,064 cases were reported: 285 (4.0%) laboratory-confirmed, 3,610 (51.1%) probable, and 3,169 (44.9%) suspected cases. The crude attack rate was 51.5 cases per 10,000 person-years, and epidemic doubling time was 4.4 days (95% confidence interval [CI] 4.2-4.7) during the exponential growth phase. The median age was 10 years (range 0-85), and 3,126 (44.3%) were male. The typical symptoms were sore throat (93.5%), fever (86.0%), pseudomembrane (34.7%), and gross cervical lymphadenopathy (GCL; 30.6%). Diphtheria antitoxin (DAT) was administered to 1,062 (89.0%) out of 1,193 eligible patients, with adverse reactions following among 229 (21.6%). There were 45 deaths (case fatality ratio [CFR] 0.6%). Household contacts for 5,702 (80.7%) of 7,064 cases were successfully traced. A total of 41,452 contacts were identified, of whom 40,364 (97.4%) consented to begin chemoprophylaxis; adherence was 55.0% (N = 22,218) at 3-day follow-up. Unvaccinated household contacts were vaccinated with 3 doses (with 4-week interval), while a booster dose was administered if the primary vaccination schedule had been completed. The proportion of contacts vaccinated was 64.7% overall. Three MVC rounds were conducted, with administrative coverage varying between 88.5% and 110.4%. Pentavalent vaccine was administered to those aged 6 weeks to 6 years, while tetanus and diphtheria (Td) vaccine was administered to those aged 7 years and older. Lack of adequate diagnostic capacity to confirm cases was the main limitation, with a majority of cases unconfirmed and the proportion of true diphtheria cases unknown.
CONCLUSIONS
To our knowledge, this is the largest reported diphtheria outbreak in refugee settings. We observed that high population density, poor living conditions, and fast growth rate were associated with explosive expansion of the outbreak during the initial exponential growth phase. Three rounds of mass vaccinations targeting those aged 6 weeks to 14 years were associated with only modestly reduced transmission, and additional public health measures were necessary to end the outbreak. This outbreak has a long-lasting tail, with Rt oscillating at around 1 for an extended period. An adequate global DAT stockpile needs to be maintained. All populations must have access to health services and routine vaccination, and this access must be maintained during humanitarian crises.
Journal Article > ResearchFull Text
Confl Health. 2010 November 8; Volume 4 (Issue 17); DOI:10.1186/1752-1505-4-17
Alberti KP, Grellety E, Lin YD, Polonsky JA, Coppens K, et al.
Confl Health. 2010 November 8; Volume 4 (Issue 17); DOI:10.1186/1752-1505-4-17
BACKGROUND
The province of North Kivu in the Democratic Republic of Congo has been afflicted by conflict for over a decade. After months of relative calm, offences restarted in September 2008. We did an epidemiological study to document the impact of violence on the civilian population and orient pre-existing humanitarian aid.
METHODS
In May 2009, we conducted three cross-sectional surveys among 200 000 resident and displaced people in North Kivu (Kabizo, Masisi, Kitchanga). The recall period covered an eight month period from the beginning of the most recent offensives to the survey date. Heads of households provided information on displacement, death, violence, theft, and access to fields and health care.
RESULTS
Crude mortality rates (per 10 000 per day) were below emergency thresholds: Kabizo 0.2 (95% CI: 0.1-0.4), Masisi 0.5 (0.4-0.6), Kitchanga 0.7 (0.6-0.9). Violence was the reported cause in 39.7% (27/68) and 35.8% (33/92) of deaths in Masisi and Kitchanga, respectively. In Masisi 99.1% (897/905) and Kitchanga 50.4% (509/1020) of households reported at least one member subjected to violence. Displacement was reported by 39.0% of households (419/1075) in Kitchanga and 99.8% (903/905) in Masisi. Theft affected 87.7% (451/514) of households in Masisi and 57.4% (585/1019) in Kitchanga. Access to health care was good: 93.5% (359/384) of the sick in Kabizo, 81.7% (515/630) in Masisi, and 89.8% (651/725) in Kitchanga received care, of whom 83.0% (298/359), 87.5% (451/515), and 88.9% (579/651), respectively, did not pay.
CONCLUSIONS
Our results show the impact of the ongoing war on these civilian populations: one third of deaths were violent in two sites, individuals are frequently subjected to violence, and displacements and theft are common. While humanitarian aid may have had a positive impact on disease mortality and access to care, the population remains exposed to extremely high levels of violence.
The province of North Kivu in the Democratic Republic of Congo has been afflicted by conflict for over a decade. After months of relative calm, offences restarted in September 2008. We did an epidemiological study to document the impact of violence on the civilian population and orient pre-existing humanitarian aid.
METHODS
In May 2009, we conducted three cross-sectional surveys among 200 000 resident and displaced people in North Kivu (Kabizo, Masisi, Kitchanga). The recall period covered an eight month period from the beginning of the most recent offensives to the survey date. Heads of households provided information on displacement, death, violence, theft, and access to fields and health care.
RESULTS
Crude mortality rates (per 10 000 per day) were below emergency thresholds: Kabizo 0.2 (95% CI: 0.1-0.4), Masisi 0.5 (0.4-0.6), Kitchanga 0.7 (0.6-0.9). Violence was the reported cause in 39.7% (27/68) and 35.8% (33/92) of deaths in Masisi and Kitchanga, respectively. In Masisi 99.1% (897/905) and Kitchanga 50.4% (509/1020) of households reported at least one member subjected to violence. Displacement was reported by 39.0% of households (419/1075) in Kitchanga and 99.8% (903/905) in Masisi. Theft affected 87.7% (451/514) of households in Masisi and 57.4% (585/1019) in Kitchanga. Access to health care was good: 93.5% (359/384) of the sick in Kabizo, 81.7% (515/630) in Masisi, and 89.8% (651/725) in Kitchanga received care, of whom 83.0% (298/359), 87.5% (451/515), and 88.9% (579/651), respectively, did not pay.
CONCLUSIONS
Our results show the impact of the ongoing war on these civilian populations: one third of deaths were violent in two sites, individuals are frequently subjected to violence, and displacements and theft are common. While humanitarian aid may have had a positive impact on disease mortality and access to care, the population remains exposed to extremely high levels of violence.
Journal Article > CommentaryFull Text
Am J Trop Med Hyg. 2014 February 10; Volume 90 (Issue 5); DOI:10.4269/ajtmh.13-0374
Polonsky JA, Wamala JF, De Clerck H, Van Herp M, Sprecher A, et al.
Am J Trop Med Hyg. 2014 February 10; Volume 90 (Issue 5); DOI:10.4269/ajtmh.13-0374
Outbreaks of Ebola and Marburg virus diseases have recently increased in frequency in Uganda. This increase is probably caused by a combination of improved surveillance and laboratory capacity, increased contact between humans and the natural reservoir of the viruses, and fluctuations in viral load and prevalence in this reservoir. The roles of these proposed explanations must be investigated to guide appropriate responses to the changing epidemiological profile. Other African settings in which multiple filoviral outbreaks have occurred could also benefit from such information.
Journal Article > ResearchFull Text
Popul Health Metr. 2012 September 4 (Issue 1); DOI:10.1186/1478-7954-10-18.
Caleo GNC, Sy AP, Balandine S, Polonsky JA, Palma PP, et al.
Popul Health Metr. 2012 September 4 (Issue 1); DOI:10.1186/1478-7954-10-18.
During 2010, a community-based, sentinel site prospective surveillance system measured mortality, acute malnutrition prevalence, and the coverage of a Médecins Sans Frontières (MSF) intervention in four sous-préfectures of Lobaye prefecture in southwestern Central African Republic. We describe this surveillance system and its evaluation.
Journal Article > ResearchFull Text
Confl Health. 2013 January 22; Volume 7 (Issue 1); DOI:10.1186/1752-1505-7-1
Polonsky JA, Ronsse A, Ciglenecki I, Rull M, Porten K
Confl Health. 2013 January 22; Volume 7 (Issue 1); DOI:10.1186/1752-1505-7-1
Following a rapid influx of over 200,000 displaced Somalis into the Dadaab refugee camp complex in Kenya, Médecins Sans Frontières conducted a mortality and nutrition survey of the population living in Bulo Bacte, a self-settled area surrounding Dagahaley camp (part of this complex).
Journal Article > ResearchFull Text
Emerg Infect Dis. 2016 March 1; Volume 22 (Issue 3); 410-416.; DOI:10.3201/eid2203.141970
Luquero FJ, Rondy M, Boncy J, Munger A, Mekaoui H, et al.
Emerg Infect Dis. 2016 March 1; Volume 22 (Issue 3); 410-416.; DOI:10.3201/eid2203.141970
The 2010 cholera epidemic in Haiti was one of the largest cholera epidemics ever recorded. To estimate the magnitude of the death toll during the first wave of the epidemic, we retrospectively conducted surveys at 4 sites in the northern part of Haiti. Overall, 70,903 participants were included; at all sites, the crude mortality rates (19.1-35.4 deaths/1,000 person-years) were higher than the expected baseline mortality rate for Haiti (9 deaths/1,000 person-years). This finding represents an excess of 3,406 deaths (2.9-fold increase) for the 4.4% of the Haiti population covered by these surveys, suggesting a substantially higher cholera mortality rate than previously reported.
Journal Article > ResearchFull Text
PLOS One. 2018 March 14; Volume 13 (Issue 3); DOI:10.1371/journal.pone.0194276
Gignoux EM, Polonsky JA, Ciglenecki I, Bichet M, Coldiron ME, et al.
PLOS One. 2018 March 14; Volume 13 (Issue 3); DOI:10.1371/journal.pone.0194276
In 2013, a large measles epidemic occurred in the Aketi Health Zone of the Democratic Republic of Congo. We conducted a two-stage, retrospective cluster survey to estimate the attack rate, the case fatality rate, and the measles-specific mortality rate during the epidemic. 1424 households containing 7880 individuals were included. The estimated attack rate was 14.0%, (35.0% among children aged <5 years). The estimated case fatality rate was 4.2% (6.1% among children aged <5 years). Spatial analysis and linear regression showed that younger children, those who did not receive care, and those living farther away from Aketi Hospital early in the epidemic had a higher risk of measles related death. Vaccination coverage prior to the outbreak was low (76%), and a delayed reactive vaccination campaign contributed to the high attack rate. We provide evidences suggesting that a comprehensive case management approach reduced measles fatality during this epidemic in rural, inaccessible resource-poor setting.
Journal Article > ResearchFull Text
PLoS Curr. 2013 January 7; Volume 5; ecurrents.dis.6aec18e84816c055b8c2a06456811c7a.; DOI:10.1371/currents.dis.6aec18e84816c055b8c2a06456811c7a
Polonsky JA, Luquero FJ, Francois G, Rousseau C, Caleo GNC, et al.
PLoS Curr. 2013 January 7; Volume 5; ecurrents.dis.6aec18e84816c055b8c2a06456811c7a.; DOI:10.1371/currents.dis.6aec18e84816c055b8c2a06456811c7a
BACKGROUND
In January 2010, Haiti was struck by a powerful earthquake, killing and wounding hundreds of thousands and leaving millions homeless. In order to better understand the severity of the crisis, and to provide early warning of epidemics or deteriorations in the health status of the population, Médecins Sans Frontières established surveillance for infections of epidemic potential and for death rates and malnutrition prevalence.
METHODS
Trends in infections of epidemic potential were detected through passive surveillance at health facilities serving as sentinel sites. Active community surveillance of death rates and malnutrition prevalence was established through weekly home visits.
RESULTS
There were 102,054 consultations at the 15 reporting sites during the 26 week period of operation. Acute respiratory infections, acute watery diarrhoea and malaria/fever of unknown origin accounted for the majority of proportional morbidity among the diseases under surveillance. Several alerts were triggered through the detection of immediately notifiable diseases and increasing trends in some conditions. Crude and under-5 death rates, and acute malnutrition prevalence, were below emergency thresholds.
CONCLUSION
Disease surveillance after disasters should include an alert and response component, requiring investment of resources in informal networks that improve sensitivity to alerts as well as on the more common systems of data collection, compilation and analysis. Information sharing between partners is necessary to strengthen early warning systems. Community-based surveillance of mortality and malnutrition is feasible but requires careful implementation and validation.
In January 2010, Haiti was struck by a powerful earthquake, killing and wounding hundreds of thousands and leaving millions homeless. In order to better understand the severity of the crisis, and to provide early warning of epidemics or deteriorations in the health status of the population, Médecins Sans Frontières established surveillance for infections of epidemic potential and for death rates and malnutrition prevalence.
METHODS
Trends in infections of epidemic potential were detected through passive surveillance at health facilities serving as sentinel sites. Active community surveillance of death rates and malnutrition prevalence was established through weekly home visits.
RESULTS
There were 102,054 consultations at the 15 reporting sites during the 26 week period of operation. Acute respiratory infections, acute watery diarrhoea and malaria/fever of unknown origin accounted for the majority of proportional morbidity among the diseases under surveillance. Several alerts were triggered through the detection of immediately notifiable diseases and increasing trends in some conditions. Crude and under-5 death rates, and acute malnutrition prevalence, were below emergency thresholds.
CONCLUSION
Disease surveillance after disasters should include an alert and response component, requiring investment of resources in informal networks that improve sensitivity to alerts as well as on the more common systems of data collection, compilation and analysis. Information sharing between partners is necessary to strengthen early warning systems. Community-based surveillance of mortality and malnutrition is feasible but requires careful implementation and validation.