Journal Article > ResearchFull Text
Pediatr Infect Dis J. 1994 January 1
Malfait P, Jataou IM, Jollet MC, Margot A, De Benoist AC, et al.
Pediatr Infect Dis J. 1994 January 1
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.
Journal Article > ResearchFull Text
Int J Epidemiol. 1990 December 1
Porter JDH, Gastellu-Etchegorry M, Navarre I, Lungu G, Moren A
Int J Epidemiol. 1990 December 1
Between November 1988 and January 1989, measles outbreaks occurred in 11 Mozambican refugee camps in Malawi with five camps principally affected. A total of 1214 cases were reported. Despite the reduction of the age of measles vaccination to six months in 1987, attack rates were highest in children aged 6-9 months (10-26%); rates were also high in the 0-5 month age group (3-21%). The case-fatality rate was high among children less than five years old (15-21%). Children were being inappropriately vaccinated, either being vaccinated at less than six months of age (2-29%) or failing to receive a second dose if vaccinated at six months (0-25%). With vaccine coverage between 66-87%, vaccine efficacy in children less than five years old was estimated to be more than 90% in the camps principally affected. Reduction of the age of vaccination leads to logistical problems in vaccine delivery in refugee situations. These outbreaks again indicate the need to improve vaccine coverage with the existing Schwarz vaccine, and also highlight the urgent need for an effective single dose measles vaccine for children less than nine months of age.
Journal Article > ResearchFull Text
Pediatr Infect Dis J. 1998 November 1
Kaninda AV, Legros D, Jataou IM, Malfait P, Maisonneuve M, et al.
Pediatr Infect Dis J. 1998 November 1
BACKGROUND: An Expanded Programme on Immunization was started in late 1987 in Niger, including vaccination against measles with one dose of standard titer Schwarz vaccine given to infants after 9 months of age. During epidemics an early two-dose strategy was implemented (one dose between 6 and 8 months and one dose after 9 months). From January 1, 1995, until May 7, 1995, 13 892 measles cases were reported in Niamey, Niger. METHODS: A retrospective cohort study was conducted in a crowded area of Niamey at the end of the outbreak to assess the effectiveness of measles vaccine in standard (after 9 months) and early (before 9 months) immunization strategies under field conditions. RESULTS: Highest measles incidence rates were observed among children <1 year of age. Vaccine effectiveness estimates increased with age at vaccination from 78% with a single dose administered at 6 months of age to 95% at 9 months. Vaccine effectiveness with the early two dose strategy was 93%. CONCLUSIONS: Immunization with a single dose of standard titer Schwarz vaccine before 9 months of age provided higher clinical protection than expected from seropositivity studies. The early two dose strategy is justified in contexts where measles incidence is high before 9 months of age. Our results raise the issue of lowering the recommended age for measles vaccination in developing countries.
Journal Article > LetterSubscription Only
Lancet. 1992 July 18; Volume 340 (Issue 8812); 176-177.; DOI:10.1016/0140-6736(92)93252-i
Manoncourt S, Doppler B, Enten F, Nur A, Mohamed AO, et al.
Lancet. 1992 July 18; Volume 340 (Issue 8812); 176-177.; DOI:10.1016/0140-6736(92)93252-i
Journal Article > ResearchFull Text
J Trop Med Hyg. 1991 February 1; Volume 94 (Issue 1); 1-7.
Moren A, Stefanaggi S, Antona D, Bitar D, Etchegorry MG, et al.
J Trop Med Hyg. 1991 February 1; Volume 94 (Issue 1); 1-7.
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.