Epidemiological Analysis of Malaria Outbreak in Ankesha District, Awi Zone, Amhara Region, Ethiopia, 2012: Weaknesses in Control Measures and Risk Factors

Abstract

While malaria is mostly an endemic disease in Ethiopia. It may also occur as outbreaks in areas with low seasonal transmission because of an increase in vector breeding sites, migration of infected people into a vector-rich area populated with susceptible individuals, breakdown of vector control measures and resistance of the vectors to insecticides. The aim of this study was to verify, investigate the outbreak epidemiologically and guide intervention measures. We reviewed data from health post records from 2007 to 2011 and screened randomly 50 fevers cases from the community members by Rapid Diagnostic Test/RDT/ to determine the baseline incidence of malaria in Ankesha District. We defined a confirmed malaria cases as any person with fever or fever with headache with plasmodium parasites by confirmed microscopy and RDT. We conduct descriptive epidemiological study and Entomological survey. A total of 2,061 confirmed malaria cases and one death (CFR=0.05%) were identified. Among the species distributions, plasmodium falciparum was accounted 1484 (72%). The alert threshold (Quartile for 5 th year's data/doubling the last year data) had been reached and crossed in 24 th March, 2012 in all health facilities. It showed highest peak between the epidemiological weeks of 17-27 in 2012. The median age was 17 years with a range 0.2 to 83 years. The highest age specific attack rate was in 5-14yr, 17.9 per1000 (642) population. Among sex distribution male comprise 53.3%. The attack rate was high in Azena Kebele which was 165per 1000(883) population in under-fives and 132 per 1000(745) population in>5 years old. Environmental assessment revealed the presence of multiple breeding sits, which was favorable for larvae of Anopheles mosquito. Arbitrarily 53 visited households were observed the LLIN bed net utilization, only 17 (32.1%) households were hanging in their ceiling directly to the bedding. And also IRS was not sprayed for last one years in all affected kebeles. The outbreak was caused by the breakage of Ayehu river formed high larva density, improper usage of LLIN's bed net and impediment / low coverage of IRS operation. Factors such as delayed detection and notification and inadequate surveillance were also instrumental for the outbreak. We recommended creates awareness giving health education, strengthen the surveillance system and implement a community based program on the LLINs utilization, IRS and environmental management.

Malaria outbreak investigation and contracting factors in Simada District, Northwest Ethiopia: a case–control study

“…The likelihood of occurrence of the outbreak in the current study area increased tenfolds in poorly controlled environment. Similar study finding was also reported from other part of Ethiopia [15].…”

“…Age group of 5–14 years and females were more affected with AR of 37 and 29 per 100 population. Studies in India [14], Ethiopia [15] and Zimbabwe [16] showed children and females were more attacked by malaria. The reason may be children have lower immunity and adult women do more activities that exposed them to mosquito breeding sites.…”

Risk factors associated with malaria outbreak in Laelay Adyabo district northern Ethiopia, 2017: case-control study design

“…Those who had mosquito breeding site around their houses were more likely to be diseased by malaria than those who didn’t have mosquito breeding site. This is similar with study done in Ankesha, Ameya, Setit Humera, and Asgede Tsimbla districts of Ethiopia [9, 10, 13, 14]. This could be due to the presence of mosquito breeding site that created suitable condition for reproduction of mosquito and infecting more people since most of the populations stayed out door during the night.…”

“…Median age of malaria patients were 16 years, which is in line with outbreak investigation done in Ankesha and Asgede Tsimbla districts, Ethiopia [10, 14], but younger than the study done in Guna Yala, Panama where the median age was 25 years [25]. This might be due to majority of the adolescents were spending more time outdoors in this area for agricultural and livestock keeping activities [6].…”