• Environmental risk factors for clinical malaria: a case-control study in the Grau region of Peru.

      Guthmann, J P; Hall, A J; Jaffar, S; Palacios, A; Lines, J; Llanos-Cuentas, A; Department of Infectious and Tropical Disease, Infectious Disease Epidemiology Unit, London School of Hygiene and Tropical Medicine, UK. jguthmann@epicentre.msf.org (2001)
      The role of environmental risk factors in clinical malaria has been studied mainly in Africa and Asia, few investigations have been carried out in Latin America. Field observations in northern coastal Peru, where the prevalence of malaria is high during the agricultural season, suggested that the risk of disease varied according to the characteristics of the house and the house environment. Environmental determinants of the risk of clinical malaria were therefore investigated through a case-control study: 323 clinical cases of malaria, recruited through community-based active case-finding, and 969 age-, sex- and village-matched controls were recruited into the study over a period of 12 months ending June 1997. Residual spraying of houses in the previous 6 months, living more than 100 m from a canal, a level of education equal to primary school or above and working in agriculture conferred significant protection from the risk of developing clinical malaria. The presence of spaces between the wall and roof in the subject's bedroom (eaves) and a house aged > 4 years statistically significantly increased the risk of disease. Based on these results we discuss possible control measures for malaria in this area of the country.
    • Glucose-6-Phosphate Dehydrogenase Deficiency, Chlorproguanil-Dapsone with Artesunate and Post-treatment Haemolysis in African children treated for uncomplicated Malaria

      Van Malderen, Carine; Van Geertruyden, Jean-Pierre; Machevo, Sonia; González, Raquel; Bassat, Quique; Talisuna, Ambrose; Yeka, Adoke; Nabasumba, Carolyn; Piola, Patrice; Daniel, Atwine; et al. (2012-04-30)
      Malaria is a leading cause of mortality, particularly in sub-Saharan African children. Prompt and efficacious treatment is important as patients may progress within a few hours to severe and possibly fatal disease. Chlorproguanil-dapsone-artesunate (CDA) was a promising artemisinin-based combination therapy (ACT), but its development was prematurely stopped because of safety concerns secondary to its associated risk of haemolytic anaemia in glucose-6-phosphate dehydrogenase (G6PD)-deficient individuals. The objective of the study was to assess whether CDA treatment and G6PD deficiency are risk factors for a post-treatment haemoglobin drop in African children<5 years of age with uncomplicated malaria.
    • Human African trypanosomiasis amongst urban residents in Kinshasa: a case-control study.

      Robays, J; Ebeja, A; Lutumba, P; Miaka mia Bilenge, C; Kande Betu Ku Mesu, V; De Deken, R; Makabuza, J; Deguerry, M; Van der Stuyft, P; Boelaert, M; et al. (2004-08)
      BACKGROUND: Increasing numbers of human African trypanosomiasis (HAT) cases have been reported in urban residents of Kinshasa, Democratic Republic Congo since 1996. We set up a case-control study to identify risk factors for the disease. METHODS: All residents of the urban part of Kinshasa with parasitologically confirmed HAT and presenting for treatment to the city's specialized HAT clinics between 1 August, 2002 and 28 February, 2003 were included as cases. We defined the urban part as the area with contiguous habitation and a population density >5000 inhabitants per square kilometre. A digital map of the area was drawn based on a satellite image. For each case, two serologically negative controls were selected, matched on age, sex and neighbourhood. Logistic regression models were fitted to control for confounding. RESULTS: The following risk factors were independently associated with HAT: travel, commerce and cultivating fields in Bandundu, and commerce and cultivating fields in the rural part of Kinshasa. No association with activities in the city itself was found. DISCUSSION: In 2002, the emergence of HAT in urban residents of Kinshasa appears mainly linked to disease transmission in Bandundu and rural Kinshasa. We recommend to intensify control of these foci, to target HAT screening in urban residents to people with contact with these foci, to increase awareness of HAT amongst health workers in the urban health structures and to strengthen disease surveillance.
    • "I Wasted 3 Years, Thinking It's Not a Problem": Patient and Health System Delays in Diagnosis of Leprosy in India: A Mixed-Methods Study

      Muthuvel, T; Govindarajulu, S; Isaakidis, P; Shewade, HD; Rokade, V; Singh, R; Kamble, S (Public Library of Science, 2017-01-12)
      Worldwide, leprosy is one of the major causes of preventable disability. India contributes to 60% of global leprosy burden. With increasing numbers of leprosy with grade 2 disability (visible disability) at diagnosis, we aimed to determine risk factors associated with grade 2 disability among new cases and explore patients and providers' perspectives into reasons for late presentation.
    • A long-lasting measles epidemic in Maroua, Cameroon 2008-2009: mass vaccination as response to the epidemic.

      Luquero, Francisco J; Pham-Orsetti, Heloise; Cummings, D A T; Ngaunji, Philippe E; Nimpa, Marcelino; Fermon, Florence; Ngoe, Ndong; Sosler, Stephen; Strebel, Peter; Grais, Rebecca F; et al. (2011-07)
      A measles outbreak occurred in Maroua, Cameroon, from January 2008 to April 2009. In accordance with recent World Health Organization guidelines, an outbreak-response immunization (ORI) was conducted in January 2009. The aim of this study was to investigate the causes of the epidemic in order to guide vaccination strategies.
    • Low lopinavir plasma or hair concentrations explain second-line protease inhibitor failures in a resource-limited setting.

      van Zyl, Gert Uves; van Mens, Thijs E; McIlleron, Helen; Zeier, Michele; Nachega, Jean B; Decloedt, Eric; Malavazzi, Carolina; Smith, Peter; Huang, Yong; van der Merwe, Lize; et al. (2011-04)
      In resource-limited settings, many patients, with no prior protease inhibitor (PI) treatment on a second-line, high genetic barrier, ritonavir-boosted PI-containing regimen have virologic failure.
    • Measles epidemic in the urban community of Niamey: transmission patterns, vaccine efficacy and immunization strategies, Niger, 1990 to 1991.

      Malfait, P; Jataou, I M; Jollet, M C; Margot, A; De Benoist, A C; Moren, A; Epicentre, Paris, France. (1994-01)
      From October 1, 1990, until April 28, 1991, 13,578 cases of measles were reported in the urban community of Niamey, Niger. Vaccine coverages (one dose of Schwarz vaccine given after 9 months) in urban community of Niamey were, respectively, 63% at the age of 12 months and 73% at 24 months before the epidemic. Incidence rates were the highest among children ages 6 to 8 months and 9 to 11 months and 22% of the cases were less than 1 year old. Vaccine efficacy estimates ranged from 86 to 94% according to age groups and the method used (screening method, case control study, retrospective cohort study). The risk of transmission of illness increased with the intensity of contact with a case. Contact with a health facility 7 to 22 days before onset of rash was not a risk factor. Seasonal migrants in Niamey were more likely to develop measles. Recommendations included implementation of an early two dose schedule of measles immunization during the outbreak, vaccination offered at each contact with a health facility, radio and television advertising for measles immunization and distribution of vitamin A to all measles cases.
    • Outbreak of Beriberi in a Prison in Côte d'Ivoire.

      Ahoua, L; Etienne, W; Fermon, F; Godain, G; Brown, V; Kadjo, K; Bouaffou, K; Legros, D; Guerin, P J; Epicentre, 42 boulevard Richard Lenoir, Paris 75011, France. lahoua@epicentre.msf.org (2007-09)
      BACKGROUND: A beriberi outbreak occurred in the Maison d'Arrêt et de Correction d'Abidjan (MACA), a detention center in Abidjan, Côte d'Ivoire, between October 2002 and April 2003. OBJECTIVE: A retrospective investigation was conducted to document the outbreak in April 2003. METHODS: A descriptive analysis and a case-control study were performed. A probable case patient was defined as a person detained in the center between October 2002 and April 2003 with at least two of the following symptoms: bilateral leg edema, dyspnea, positive squat test, motor deficiencies, and paresthesia. A definite case patient was defined as a probable case patient who showed clinical improvement under thiamin treatment. RESULTS: Of 712 cases reported, 115 (16%) were probable and 597 (84%) were definite. The overall attack rate was 14.1%, and the case fatality rate was 1.0% (7/712). The highest attack rate was reported in the building housing prisoners with long-term sentences (16.9%). All patients were male, and the mean age was 28 years. During the period studied, the penal ration provided a fifth of the quantity of thiamin recommended by international standards. After adjustment for potential confounders, a history of cholera infection (adjusted odds ratio [OR(a)], 12.9; 95% confidence interval [CI], 2.9 to 54.1) and incarceration in the building for severe penalties (OR(a), 4.8; 95% CI, 1.3 to 18.5) were associated with the disease. CONCLUSIONS: Beriberi has been underreported among prisoners. Further attention should be given to its risk factors, especially a history of acute diarrhea. Systematic food supplementation with vitamins and micronutrients should be discussed when the penal ration does not provide the necessary nutrient intake recommended according to international standards.
    • Outbreak of West Nile virus causing severe neurological involvement in children, Nuba Mountains, Sudan, 2002.

      Depoortere, E; Kavle, J; Keus, K; Zeller, H; Murri, S; Legros, D; Epicentre, Paris, France. evelyn.depoortere@msf.be (Wiley-Blackwell, 2004-06)
      An atypical outbreak of West Nile virus (WNV) occurred in Ngorban County, South Kordophan, Sudan, from May to August 2002. We investigated the epidemic and conducted a case-control study in the village of Limon. Blood samples were obtained for cases and controls. Patients with obvious sequelae underwent cerebrospinal fluid (CSF) sampling as well. We used enzyme-linked immunosorbent assay (ELISA) and neutralization tests for laboratory diagnosis and identified 31 cases with encephalitis, four of whom died. Median age was 36 months. Bivariate analysis did not reveal any significant association with the risk factors investigated. Laboratory analysis confirmed presence of IgM antibodies caused by WNV in eight of 13 cases, indicative of recent viral infection. The unique aspects of the WNW outbreak in Sudan, i.e. disease occurrence solely among children and the clinical domination of encephalitis, involving severe neurological sequelae, demonstrate the continuing evolution of WNV virulence. The spread of such a virus to other countries or continents cannot be excluded.
    • Practical Field Epidemiology to Investigate a Cholera Outbreak in a Mozambican Refugee Camp in Malawi, 1988.

      Moren, A; Stefanaggi, S; Antona, D; Bitar, D; Etchegorry, M G; Tchatchioka, M; Lungu, G; Epicentre, Paris, France. (1991-02)
      Of all populations affected by cholera, refugees are at particular risk of infection due to overcrowding and poor sanitation. Between 15 March and 17 May 1988, 951 cases of cholera were registered at the cholera treatment centre in a Mozambican refugee camp in Malawi. The epidemic duration was 65 days. Vibrio cholerae biotype E1 Tor serotype Inaba was isolated. To identify high-risk groups and potential risk of acquiring the disease, an epidemiologic investigation was conducted. The attack rate of recorded cases was 2.6% with a range from 0.9 to 5.1% for different sections of the camp. The case fatality rate was 3.3% and decreased from week 1 to week 6. The epidemic started in the section near the market place and radiated out. A matched-pair case-control study of food and water consumption was performed early in the outbreak. It showed that cases were more likely to use shallow wells (surface wells) instead of boreholes compared to controls (OR = 4.5, CI = 1.0-20.8, P = 0.04) and that cases were more likely to have had contact with the market than controls (OR = 3.5, CI = 0.7-16.8, P = 0.09). None of the food items available at the market was more likely to be preferred by cases than controls. Recommendations included early case finding and treatment, temporary closure of the market, tetracycline prophylaxis of contacts, and water chlorination.
    • Risk factors for buruli ulcer: a case control study in Cameroon

      Pouillot, Régis; Matias, Gonçalo; Wondje, Christelle Mbondji; Portaels, Françoise; Valin, Nadia; Ngos, François; Njikap, Adelaïde; Marsollier, Laurent; Fontanet, Arnaud; Eyangoh, Sara; et al. (2007-12-19)
      BACKGROUND: Buruli ulcer is an infectious disease involving the skin, caused by Mycobacterium ulcerans. This disease is associated with areas where the water is slow-flowing or stagnant. However, the exact mechanism of transmission of the bacillus and the development of the disease through human activities is unknown. METHODOLOGY/PRINCIPAL FINDINGS: A case-control study to identify Buruli ulcer risk factors in Cameroon compared case-patients with community-matched controls on one hand and family-matched controls on the other hand. Risk factors identified by the community-matched study (including 163 pairs) were: having a low level of education, swamp wading, wearing short, lower-body clothing while farming, living near a cocoa plantation or woods, using adhesive bandages when hurt, and using mosquito coils. Protective factors were: using bed nets, washing clothes, and using leaves as traditional treatment or rubbing alcohol when hurt. The family-matched study (including 118 pairs) corroborated the significance of education level, use of bed nets, and treatment with leaves. CONCLUSIONS/SIGNIFICANCE: Covering limbs during farming activities is confirmed as a protective factor guarding against Buruli ulcer disease, but newly identified factors including wound treatment and use of bed nets may provide new insight into the unknown mode of transmission of M. ulcerans or the development of the disease.
    • Risk factors for visceral leishmaniasis in a new epidemic site in Amhara Region, Ethiopia

      Bashaye, Seife; Nombela, Nohelly; Argaw, Daniel; Mulugeta, Abate; Herrero, Merce; Nieto, Javier; Chicharro, Carmen; Cañavate, Carmen; Aparicio, Pilar; Vélez, Iván Darío; et al. (2009-07-01)
      We conducted a case-control study to evaluate risk factors for visceral leishmaniasis during an epidemic in a previously unaffected district of Ethiopia. We also collected blood and bone marrow specimens from dogs in the outbreak villages. In multivariable analyses of 171 matched case-control pairs, dog ownership, sleeping under an acacia tree during the day, and habitually sleeping outside at night were associated with significantly increased risk. Specimens from 7 (3.8%) dogs were positive by immunofluorescent antibody test (IFAT) and both enzyme-linked immunosorbent assays (ELISAs), whereas Leishmania DNA was detected in 5 (2.8%) bone marrow aspirates (from 3 seropositive and 2 seronegative dogs). Insecticide-treated nets may only protect a portion of those at risk. Further research on the vectors, the role of the dog in the transmission cycle, and the effect of candidate interventions are needed to design the best strategy for control.
    • Single-Dose Cholera Vaccine in Response to an Outbreak in Zambia

      Ferreras, E; Chizema-Kawesha, E; Blake, A; Chewe, O; Mwaba, J; Zulu, G; Poncin, M; Rakesh, A; Page, AL; Stoitsova, S; et al. (Massachusetts Medical Society, 2018-02-08)