Tuberculosis

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La Revue de Santé de la Méditerranée orientale, Vol. 14, No 3, 2008

Risk of Mycobacterium tuberculosis infection in Somalia: national tuberculin survey 2006
A. Munim,1 Y. Rajab, 1 A. Barker,2 M. Daniel 2 and B. Williams 3
2006 2006 101 10 364 2.2 3.2 1.5 1956 2.6 54 18 10 686 72

ABSTRACT To estimate the annual risk of tuberculosis (TB) infection (ARTI) in Somalia a tuberculinsurvey was conducted in February/March 2006. Stratified cluster sampling was carried out within the 18 regions and 101 randomly selected primary schools. Tuberculin testing was done in 10 680 grade 1 schoolchildren. Transverse tuberculin reaction size was measured 72 hours later. The number of children with a satisfactory test read was 10 364. The overall BCG coverage was 54%. Based on frequencydistribution of tuberculin reaction sizes, the ARTI in Somalia was estimated at 2.2% (confidence interval: 1.5%–3.2%). There was an annual decline of 2.6% comparing with a previous study in 1956. Risque d’infection à Mycobacterium tuberculosis en Somalie : enquête tuberculinique nationale 2006 RÉSUMÉ Afin d’estimer le risque annuel d’infection tuberculeuse en Somalie, une enquête tuberculinique a étéréalisée en février-mars 2006. Un échantillonnage en grappes stratifié a été effectué dans les 18 régions et dans 101 écoles primaires choisies au hasard. Un test tuberculinique a été pratiqué sur 10 680 écoliers de première année. Le diamètre de la réaction tuberculinique a été mesuré 72 heures plus tard. Le nombre d’enfants pour lesquels la lecture du test était satisfaisante était de 10 364. Lacouverture globale par le BCG était de 54 %. D’après la distribution de fréquence du diamètre de la réaction tuberculinique, le risque annuel d’infection tuberculeuse en Somalie a été estimé à 2,2 % (intervalle de confiance : 1,5 % - 3,2 %). Il y a eu une baisse annuelle de 2,6 % par rapport à une étude antérieure de 1956.

1 2

World Health Organization, Hargeisa, Somalia (Correspondence to A.Munim: munima@som.emro.who.int). Desmond Tutu Tuberculosis Centre, University of Stellenbosch, Cape Town, South Africa. 3 World Health Organization, Geneva, Switzerland. Received: 31/01/07; accepted: 25/06/07

٢٠٠٨ ،٣ ‫ﺍﳌﺠﻠﺔ ﺍﻟﺼﺤﻴﺔ ﻟﺸﺮﻕ ﺍﳌﺘﻮﺳﻂ، ﻣﻨﻈﻤﺔ ﺍﻟﺼﺤﺔ ﺍﻟﻌﺎﳌﻴﺔ، ﺍﳌﺠﻠﺪ ﺍﻟﺮﺍﺑﻊ ﻋﺸﺮ، ﺍﻟﻌﺪﺩ‬

Eastern Mediterranean Health Journal, Vol. 14, No. 3, 2008

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Introduction
Somalia is a countryin a complex emergency situation due to the long-lasting civil conflict and natural disasters. Somalia had an overall human development index (HDI) of 0.299 in 2002, which places the country among the 5 least developed countries in the world according to United Nations Development Programme (UNDP)/World Bank Socioeconomic Survey 2002 Somalia [1]. The extensive movement of people in Somalia, thelow literacy rate and widespread poverty have left the country in a precarious state. In the past Somalia has had an exceptionally high incidence and prevalence of pulmonary tuberculosis (TB) [2,3]. In a survey carried out by the World Health Organization (WHO) in 1955 and 1956 among children aged 8 to 12 years, the annual risk of TB infection (ARTI) was estimated at 8% [2]. In a survey carried outamong Somali refugees in the Ogaden region of Ethiopia in 1984 the ARTI was 4.8%, [4] and in a Finnish project carried out in 1986 in Burao, Somaliland, and Kismayo, South and Central zone, the ARTI at the age of 10 years was 3.7% (3.3%–4.1%) per year (here and elsewhere intervals given are 95% confidence intervals) with a cut-off at 5 mm and 2.9% (2.5%−3.3%) per year with a cutoff at 10 mm [5].From the 1986 survey, and assuming a Stýblo constant of 50 (40−60), the smear-positive incidence was then 185 (143−228) per 100 000 population per year using a cut-off at 5 mm, or 145 (105−180) per 100 000 population per year using a cut-off at 10 mm. The TB programme in Somalia currently assumes that the incidence is 162/100 000 population per year for smear-positive cases and 324/100 000...