• SARS and Carlo Urbani.

      Reilley, B; Van Herp, M; Sermand, D; Dentico, N; Médecins sans Frontières, USA. (Massachusetts Medical Society, 2003-05-15)
    • The Scenario Approach for Countries Considering the Addition of Oral Cholera Vaccination in Cholera Preparedness and Control Plans

      Deen, J; von Seidlein, L; Luquero, FJ; Troeger, C; Reyburn, R; Lopez, AL; Debes, A; Sack, DA (Elsevier, 2016-01-01)
      Oral cholera vaccination could be deployed in a diverse range of situations from cholera-endemic areas and locations of humanitarian crises, but no clear consensus exists. The supply of licensed, WHO-prequalified cholera vaccines is not sufficient to meet endemic and epidemic needs worldwide and so prioritisation is needed. We have developed a scenario approach to systematically classify situations in which oral cholera vaccination might be useful. Our scenario approach distinguishes between five types of cholera epidemiology based on experiences from around the world and provides evidence that we hope will spur the development of detailed guidelines on how and where oral cholera vaccines could, and should, be most rationally deployed.
    • Screening for Glucose-6-Phosphate Dehydrogenase Deficiency Using Three Detection Methods: A Cross-Sectional Survey in Southwestern Uganda

      Roh, ME; Oyet, C; Orikiriza, P; Wade, M; Mwanga-Amumpaire, J; Boum, Y; Kiwanuka, GN; Parikh, S (American Society of Tropical Medicine and Hygiene, 2016-09-26)
      Despite the potential benefit of primaquine in reducing Plasmodium falciparum transmission and radical cure of Plasmodium vivax and Plasmodium ovale infections, concerns over risk of hemolytic toxicity in individuals with glucose-6-phosphate dehydrogenase deficiency (G6PDd) have hampered its deployment. A cross-sectional survey was conducted in 2014 to assess the G6PDd prevalence among 631 children between 6 and 59 months of age in southwestern Uganda, an area where primaquine may be a promising control measure. G6PDd prevalence was determined using three detection methods: a quantitative G6PD enzyme activity assay (Trinity Biotech(®) G-6-PDH kit), a qualitative point-of-care test (CareStart(™) G6PD rapid diagnostic test [RDT]), and molecular detection of the G6PD A- G202A allele. Qualitative tests were compared with the gold standard quantitative assay. G6PDd prevalence was higher by RDT (8.6%) than by quantitative assay (6.8%), using a < 60% activity threshold. The RDT performed optimally at a < 60% threshold and demonstrated high sensitivity (≥ 90%) and negative predictive values (100%) across three activity thresholds (below 60%, 30%, and 40%). G202A allele frequency was 6.4%, 7.9%, and 6.8% among females, males, and overall, respectively. Notably, over half of the G202A homo-/hemizygous children expressed ≥ 60% enzyme activity. Overall, the CareStart(™) G6PD RDT appears to be a viable screening test to accurately identify individuals with enzyme activities below 60%. The low prevalence of G6PDd across all three diagnostic modalities and absence of severe deficiency in our study suggests that there is little barrier to the use of single-dose primaquine in this region.
    • Seasonal upsurge of pneumococcal meningitis in the Central African Republic

      Crellen, T; Rao, VB; Piening, T; Zeydner, J; Siddiqui, MR (F1000Research, 2018-10-19)
      A high incidence of bacterial meningitis was observed in the Central African Republic (CAR) from December 2015 to May 2017 in three hospitals in the northwest of the country that are within the African meningitis belt. The majority of cases were caused by Streptococcus pneumoniae (249/328; 75.9%), which occurred disproportionately during the dry season (November-April) with a high case-fatality ratio of 41.6% (95% confidence interval [CI] 33.0, 50.8%). High rates of bacterial meningitis during the dry season in the meningitis belt are typically caused by Neisseria meningitidis (meningococcal meningitis), and our observations suggest that the risk of contracting S. pneumoniae (pneumococcal) meningitis is increased by the same environmental factors. Cases of meningococcal meningitis (67/328; 20.4%) observed over the same period were predominantly type W and had a lower case fatality rate of 9.6% (95% CI 3.6, 21.8%). Due to conflict and difficulties in accessing medical facilities, it is likely that the reported cases represented only a small proportion of the overall burden and that there is high underlying prevalence of S. pneumoniae carriage in the community. Nationwide vaccination campaigns in the CAR against meningitis have been limited to the use of MenAfriVac, which targets only meningococcal meningitis type A. We therefore highlight the need for expanded vaccine coverage to prevent additional causes of seasonal outbreaks.
    • Selenium and iodine supplementation of rural Tibetan children affected by Kashin-Beck osteoarthropathy.

      Moreno-Reyes, R; Mathieu, F; Boelaert, M; Begaux, F; Suetens, C; Rivera, M; Nève, J; Perlmutter, N; Vanderpas, J; Department of Nuclear Medicine, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium. rmorenor@ulb.ac.be (2003-07)
      BACKGROUND: Kashin-Beck disease is an osteoarthropathy endemic in selenium- and iodine-deficient areas around Lhasa, Tibet. OBJECTIVE: We assessed the efficacy of selenium supplementation on disease progression. DESIGN: A double-blind, randomized controlled trial of selenium supplementation was carried out in 324 children aged 5-15 y who had Kashin-Beck disease. Two hundred eighty children received iodized oil before being randomly assigned to receive selenium or placebo, and a control group of 44 subjects was not supplemented at all. Clinical and radiologic signs, selenium status, urinary iodine, and thyroid function were evaluated at baseline and at 12 mo. RESULTS: The frequencies of joint pain, decreased joint mobility, and radiologic abnormalities were not significantly different between the 3 groups at 12 mo. Height-for-age z scores increased significantly in the subjects who received placebo and iodine or selenium and iodine. In contrast, unsupplemented control subjects did not recover from growth retardation. Serum selenium concentrations at 12 mo were within the reference range and were significantly greater in the selenium-iodine group than in the placebo-iodine group. Serum thyroid hormone concentrations were within the reference ranges after the administration of iodine, and these values were not significantly affected by selenium supplementation. CONCLUSIONS: The results of this study do not rule out the possibility that selenium may help to prevent the occurrence of Kashin-Beck disease. However, selenium supplementation had no effect on established Kashin-Beck disease, growth, or thyroid function once iodine deficiency was corrected. These results suggest that iodine, but not selenium, deficiency should be corrected in Tibetan children with Kashin-Beck disease.
    • Sepsis Kills: Suspect It, Recognise It and Be Prompt With Treatment

      Lang, HJ; Tasker, RC (BMJ Publishing Group, 2016-10-24)
    • Sequential outbreaks due to a new strain of Neisseria meningitidis serogroup C in northern Nigeria, 2013-14

      Funk, Anna; Uadiale, Kennedy; Kamau, Charity; Caugant, Dominique A; Ango, Umar; Greig, Jane (Public Library of Science, 2014-12-29)
      Background Neisseria meningitidis serogroup C (NmC) outbreaks occur infrequently in the African meningitis belt; the most recent report of an outbreak of this serogroup was in Burkina Faso, 1979. Médecins sans Frontières (MSF) has been responding to outbreaks of meningitis in northwest Nigeria since 2007 with no reported cases of serogroup C from 2007-2012. MenAfrivac®, a serogroup A conjugate vaccine, was first used for mass vaccination in northwest Nigeria in late 2012. Reactive vaccination using polysaccharide ACYW135 vaccine was done by MSF in parts of the region in 2008 and 2009; no other vaccination campaigns are known to have occurred in the area during this period. We describe the general characteristics of an outbreak due to a novel strain of NmC in Sokoto State, Nigeria, in 2013, and a smaller outbreak in 2014 in the adjacent state, Kebbi. Methods Information on cases and deaths was collected using a standard line-list during each week of each meningitis outbreak in 2013 and 2014 in northwest Nigeria. Initial serogroup confirmation was by rapid Pastorex agglutination tests. Cerebrospinal fluid (CSF) samples from suspected meningitis patients were sent to the WHO Reference Laboratory in Oslo, where bacterial isolates, serogrouping, antimicrobial sensitivity testing, genotype characterisation and real-time PCR analysis were performed. Results In the most highly affected outbreak areas, all of the 856 and 333 clinically suspected meningitis cases were treated in 2013 and 2014, respectively. Overall attack (AR) and case fatality (CFR) rates were 673/100,000 population and 6.8% in 2013, and 165/100,000 and 10.5% in 2014. Both outbreaks affected small geographical areas of less than 150km2 and populations of less than 210,000, and occurred in neighbouring regions in two adjacent states in the successive years. Initial rapid testing identified NmC as the causative agent. Of the 21 and 17 CSF samples analysed in Oslo, NmC alone was confirmed in 11 and 10 samples in 2013 and 2014, respectively. Samples confirmed as NmC through bacterial culture had sequence type (ST)-10217. Conclusions These are the first recorded outbreaks of NmC in the region since 1979, and the sequence (ST)-10217 has not been identified anywhere else in the world. The outbreaks had similar characteristics to previously recorded NmC outbreaks. Outbreaks of NmC in 2 consecutive years in northern Nigeria indicate a possible emergence of this serogroup. Increased surveillance for multiple serogroups in the region is needed, along with consideration of vaccination with conjugate vaccines rather than for NmA alone.
    • Serological evaluation for Chagas disease in migrants from Latin American countries resident in Rome, Italy

      Pane, S; Giancola, ML; Piselli, P; Corpolongo, A; Repetto, E; Bellagamba, R; Cimaglia, C; Carrara, S; Ghirga, P; Oliva, A; et al. (BioMed Central, 2018-05-08)
      Chagas disease (CD) is a systemic parasitic infection caused by the protozoan Trypanosoma cruzi, whose chronic phase may lead to cardiac and intestinal disorders. Endemic in Latin America where it is transmitted mainly by vectors, large-scale migrations to other countries have turned CD into a global health problem because of its alternative transmission routes through blood transfusion, tissue transplantation, or congenital. Aim of this study was to compare the performance of two commercially available tests for serological diagnosis of CD in a group of Latin American migrants living in a non-endemic setting (Rome, Italy). The study was based on a cross-sectional analysis of seroprevalence in this group. Epidemiological risk factors associated to CD were also evaluated in this study population.
    • Seroprevalence and risk factors of recent infection with hepatitis E virus during an acute outbreak in an urban setting in Chad, 2017

      Vernier, L; Lenglet, A; Hogema, BM; Moussa, AM; Ariti, C; Vollmer, S; Irwin, A; Alfani, P; Sang, S; Kamau, C (BioMed Central, 2018-06-26)
      From September 2016-April 2017, Am Timan, Chad, experienced a large HEV outbreak in an urban setting with a limited impact in terms of morbidity and mortality. To better understand HEV epidemiology in this context, we estimated the seroprevalence of anti-HEV antibodies (IgM and IgG) and assessed the risk factors for recent HEV infections (positive anti-HEV IgM) during this outbreak.
    • Shedding of Ebola Virus in an Asymptomatic Pregnant Woman

      Akerlund, Emma; Prescott, Joseph; Tampellini, Livia (Massachusetts Medical Society, 2015-06-18)
    • Shigella dysenteriae serotype 1 in west Africa: intervention strategy for an outbreak in Sierra Leone.

      Guerin, P J; Brasher, C; Baron, E; Mic, D; Grimont, F; Ryan, M; Aavitsland, P; Legros, D; Division of Infectious Disease Control, Norwegian Institute of Public Health, Oslo, Norway. philippe.guerin@epicentre.msf.org (Elsevier, 2003-08-30)
      In November 1999, a Médecins Sans Frontières team based in the southeastern part of Sierra Leone reported an increased number of cases of bloody diarrhoea. Shigella dysenteriae serotype 1 (Sd1) was isolated in the early cases. A total of 4218 cases of dysentery were reported in Kenema district from December, 1999, to March, 2000. The overall attack rate was 7.5%. The attack rate was higher among children younger than 5 years than in the rest of the population (11.2% vs 6.8%; relative risk=1.6; 95% CI 1.5-1.8). The case fatality was 3.1%, also higher for children younger than 5 years (6.1% vs 2.1%; relative risk=2.9; 95% CI 2.1-4.1]). Among 583 patients regarded at increased risk of death who were treated with ciprofloxacin in isolation centres, case fatality was 0.9%. A 5-day ciprofloxacin regimen, targeted to the most severe cases of bloody diarrhoea, was highly effective. This is the first time a large outbreak caused by Sd1 has been reported in west Africa.
    • Should outbreak response immunization be recommended for measles outbreaks in middle- and low-income countries? An update.

      Cairns, K Lisa; Perry, Robert T; Ryman, Tove K; Nandy, Robin K; Grais, RFebecca F; Global Immunization Division, US Centers for Disease Control and Prevention, Atlanta, Georgia 30306, USA. kfc4@cdc.gov (2011-07)
      Measles caused mortality in >164,000 children in 2008, with most deaths occurring during outbreaks. Nonetheless, the impact and desirability of conducting measles outbreak response immunization (ORI) in middle- and low-income countries has been controversial. World Health Organization guidelines published in 1999 recommended against ORI in such settings, although recently these guidelines have been reversed for countries with measles mortality reduction goals.
    • Single-dose oral ciprofloxacin prophylaxis as a response to a meningococcal meningitis epidemic in the African meningitis belt: A 3-arm, open-label, cluster-randomized trial

      Coldiron, ME; Assao, B; Page, A; Hitchings, MDT; Alcoba, G; Ciglenecki, I; Langendorf, C; Mambula, C; Adehossi, E; Sidikou, F; et al. (Public Library of Science, 2018-06-26)
      Antibiotic prophylaxis for contacts of meningitis cases is not recommended during outbreaks in the African meningitis belt. We assessed the effectiveness of single-dose oral ciprofloxacin administered to household contacts and in village-wide distributions on the overall attack rate (AR) in an outbreak of meningococcal meningitis.
    • Snakebite and snake identification: empowering neglected communities and health-care providers with AI

      De Castaneda, RR; Durso, AM; Ray, N; Fernandez, JL; Williams, DJ; Alcoba, G; Chappuis, F; Salathe, M; Bolon, I (Elsevier, 2019-09-01)
    • South-Asian tsunami.

      Guthmann, J P; Sauvageot, D; De Filippi, L; Burny, M E; Brown, V (2005)
    • Spatial and Temporal Dynamics of Superspreading Events in the 2014-2015 West Africa Ebola Epidemic

      Lau, MSY; Dalziel, BD; Funk, S; McClelland, A; Tiffany, A; Riley, S; Metcalf, CJE; Grenfell, BT (National Academy of Sciences, 2017-02-13)
      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.
    • Spatial dynamics of meningococcal meningitis in Niger: observed patterns in comparison with measles

      Bharti, N; Broutin, H; Grais, RF F; Ferrari, M J; Djibo, A; Tatem, A J; Grenfell, B T; Department of Ecology and Evolutionary Biology and Center for Health and Wellbeing, Woodrow Wilson School of Public and International Affairs, Princeton University, Princeton NJ, USA; MIVEGEC, UMR CNRS 5290, IRD 224, UM1, UM2, Montpellier, France; Epicentre, Paris, France; Department of Biology, Department of Statistics, and Center for Infectious Disease Dynamics, Penn State University, PA, USA; Ministry of Health, Niamey, Niger; Emerging Pathogens Institute and Department of Geography, University of Florida, Gainesville FL, USA; Fogarty International Center, National Institutes of Health, Bethesda MD, USA (Cambridge University Press, 2011-10-05)
      SUMMARYThroughout the African meningitis belt, meningococcal meningitis outbreaks occur only during the dry season. Measles in Niger exhibits similar seasonality, where increased population density during the dry season probably escalates measles transmission. Because meningococcal meningitis and measles are both directly transmitted, we propose that host aggregation also impacts the transmission of meningococcal meningitis. Although climate affects broad meningococcal meningitis seasonality, we focus on the less examined role of human density at a finer spatial scale. By analysing spatial patterns of suspected cases of meningococcal meningitis, we show fewer absences of suspected cases in districts along primary roads, similar to measles fadeouts in the same Nigerien metapopulation. We further show that, following periods during no suspected cases, districts with high reappearance rates of meningococcal meningitis also have high measles reintroduction rates. Despite many biological and epidemiological differences, similar seasonal and spatial patterns emerge from the dynamics of both diseases. This analysis enhances our understanding of spatial patterns and disease transmission and suggests hotspots for infection and potential target areas for meningococcal meningitis surveillance and intervention.
    • Spatial epidemiology and climatic predictors of paediatric dengue infections captured via sentinel site surveillance, Phnom Penh Cambodia 2011-2012.

      Lover, Andrew A; Buchy, Philippe; Rachline, Anne; Moniboth, Duch; Huy, Rekol; Meng, Chour Y; Leo, Yee Sin; Yuvatha, Kdan; Sophal, Ung; Chantha, Ngan; et al. (2014-06-28)
      Dengue is a major contributor to morbidity in children aged twelve and below throughout Cambodia; the 2012 epidemic season was the most severe in the country since 2007, with more than 42,000 reported (suspect or confirmed) cases.
    • Strategies for access to affordable hepatitis C testing and treatment in Asia

      Khwairakpam, G; Burry, J (2019-01)
      With increasing availability of generic direct-acting antivirals (DAAs) and associated price reductions, various governments, multilateral institutions, and donors have started providing testing and treatment for hepatitis C virus (HCV) infection. More data on the quality of these generic medicines and on cost-effectiveness of their use are becoming widely available. This review seeks to describe some of the treatment programs for HCV that are evolving in Cambodia, India, Indonesia, Malaysia, Myanmar, and Thailand.
    • Sub-national variation in measles vaccine coverage and outbreak risk: a case study from a 2010 outbreak in Malawi

      Kundrick, A; Huang, Z; Carran, S; Kagoli, M; Grais, RFF; Hurtado, N; Ferrari, M (BioMed Central, 2018-06-15)
      Despite progress towards increasing global vaccination coverage, measles continues to be one of the leading, preventable causes of death among children worldwide. Whether and how to target sub-national areas for vaccination campaigns continues to remain a question. We analyzed three metrics for prioritizing target areas: vaccination coverage, susceptible birth cohort, and the effective reproductive ratio (RE) in the context of the 2010 measles epidemic in Malawi.