BACKGROUND: Dengue Fever (DF) is a viral disease primarily transmitted by Aedes (Ae.) aegypti mosquitoes. Outbreaks in Eastern Ethiopia were reported during 2014-2016. In May 2017, we investigated the first suspected DF outbreak from Kabridahar Town, Somali region (Eastern Ethiopia) to describe its magnitude, assess risk factors, and implement control measures. METHODS: Suspected DF cases were defined as acute febrile illness plus ≥2 symptoms (headache, fever, retro-orbital pain, myalgia, arthralgia, rash, or hemorrhage) in Kabridahar District residents. All reported cases were identified through medical record review and active searches. Severe dengue was defined as DF with severe organ impairment, severe hemorrhage, or severe plasma leakage. We conducted a neighborhood-matched case-control study using a subset of suspected cases and conveniently-selected asymptomatic community controls and interviewed participants to collect demographic and risk factor data. We tested sera by RT-PCR to detect dengue virus (DENV) and identify serotypes. Entomologists conducted mosquito surveys at community households to identify species and estimate larval density using the house index (HI), container index (CI) and Breteau index (BI), with BI≥20 indicating high density. RESULTS: We identified 101 total cases from May 12-31, 2017, including five with severe dengue (one death). The attack rate (AR) was 17/10,000. Of 21 tested samples, 15 (72%) were DENV serotype 2 (DENV 2). In the case-control study with 50 cases and 100 controls, a lack of formal education (AOR [Adjusted Odds Ratio] = 4.2, 95% CI [Confidence Interval] 1.6-11.2) and open water containers near the home (AOR = 3.0, 95% CI 1.2-7.5) were risk factors, while long-lasting insecticide treated-net (LLITN) usage (AOR = 0.21, 95% CI 0.05-0.79) was protective. HI and BI were 66/136 (49%) and 147 per 100 homes (147%) respectively, with 151/167 (90%) adult mosquitoes identified as Ae. aegypti. CONCLUSION: The epidemiologic, entomologic, and laboratory investigation confirmed a DF outbreak. Mosquito indices were far above safe thresholds, indicating inadequate vector control. We recommended improved vector surveillance and control programs, including best practices in preserving water and disposal of open containers to reduce Aedes mosquito density.
BACKGROUND:Dengue Fever (DF) is a viral disease primarily transmitted by Aedes (Ae.) aegypti mosquitoes. Outbreaks in Eastern Ethiopia were reported during 2014-2016. In May 2017, we investigated the first suspected DF outbreak from Kabridahar Town, Somali region (Eastern Ethiopia) to describe its magnitude, assess risk factors, and implement control measures. METHODS: Suspected DF cases were defined as acute febrile illness plus ≥2 symptoms (headache, fever, retro-orbital pain, myalgia, arthralgia, rash, or hemorrhage) in Kabridahar District residents. All reported cases were identified through medical record review and active searches. Severe dengue was defined as DF with severe organ impairment, severe hemorrhage, or severe plasma leakage. We conducted a neighborhood-matched case-control study using a subset of suspected cases and conveniently-selected asymptomatic community controls and interviewed participants to collect demographic and risk factor data. We tested sera by RT-PCR to detect dengue virus (DENV) and identify serotypes. Entomologists conducted mosquito surveys at community households to identify species and estimate larval density using the house index (HI), container index (CI) and Breteau index (BI), with BI≥20 indicating high density. RESULTS: We identified 101 total cases from May 12-31, 2017, including five with severe dengue (one death). The attack rate (AR) was 17/10,000. Of 21 tested samples, 15 (72%) were DENV serotype 2 (DENV 2). In the case-control study with 50 cases and 100 controls, a lack of formal education (AOR [Adjusted Odds Ratio] = 4.2, 95% CI [Confidence Interval] 1.6-11.2) and open water containers near the home (AOR = 3.0, 95% CI 1.2-7.5) were risk factors, while long-lasting insecticide treated-net (LLITN) usage (AOR = 0.21, 95% CI 0.05-0.79) was protective. HI and BI were 66/136 (49%) and 147 per 100 homes (147%) respectively, with 151/167 (90%) adult mosquitoes identified as Ae. aegypti. CONCLUSION: The epidemiologic, entomologic, and laboratory investigation confirmed a DF outbreak. Mosquito indices were far above safe thresholds, indicating inadequate vector control. We recommended improved vector surveillance and control programs, including best practices in preserving water and disposal of open containers to reduce Aedes mosquito density.
Authors: Audrey Lenhart; Nicolas Orelus; Rachael Maskill; Neal Alexander; Thomas Streit; P J McCall Journal: Trop Med Int Health Date: 2008-01 Impact factor: 2.622
Authors: Mohammed A Soghaier; Syed F Mahmood; Omrana Pasha; Syed I Azam; Mubarak M Karsani; Mutasim M Elmangory; Babiker A Elmagboul; Somia I Okoued; Sayed M Shareef; Hayat S Khogali; Emad Eltigai Journal: J Infect Public Health Date: 2013-11-05 Impact factor: 3.718
Authors: Khaled G Saied; Abdullah Al-Taiar; Abdulrahman Altaire; Ala Alqadsi; Enas F Alariqi; Maha Hassaan Journal: Int Health Date: 2015-04-08 Impact factor: 2.473
Authors: Lizet Sanchez; Veerle Vanlerberghe; Lázara Alfonso; Maria del Carmen Marquetti; Maria Guadalupe Guzman; Juan Bisset; Patrick van der Stuyft Journal: Emerg Infect Dis Date: 2006-05 Impact factor: 6.883
Authors: Anne L Wilson; Ramesh C Dhiman; Uriel Kitron; Thomas W Scott; Henk van den Berg; Steven W Lindsay Journal: PLoS Negl Trop Dis Date: 2014-10-09
Authors: Jane P Messina; Oliver J Brady; Nick Golding; Moritz U G Kraemer; G R William Wint; Sarah E Ray; David M Pigott; Freya M Shearer; Kimberly Johnson; Lucas Earl; Laurie B Marczak; Shreya Shirude; Nicole Davis Weaver; Marius Gilbert; Raman Velayudhan; Peter Jones; Thomas Jaenisch; Thomas W Scott; Robert C Reiner; Simon I Hay Journal: Nat Microbiol Date: 2019-06-10 Impact factor: 17.745
Authors: Beatrice R Egid; Mamadou Coulibaly; Samuel Kweku Dadzie; Basile Kamgang; Philip J McCall; Luigi Sedda; Kobie Hyacinthe Toe; Anne L Wilson Journal: Curr Res Parasitol Vector Borne Dis Date: 2022