ACUTE WATERY DIARRHEA OUTBREAK INVESTIGATION IN RAYA KOBBO DISTRICT, AMAHARA REGION OF ETHIOPIA-CONSEQUENCE OF DROUGHT AND POOR SANITATION: A CASE-CONTROL STUDY

Abstract

Background: Acute Watery Diarrhoea (AWD) is an acute bacterial infection of the intestine caused by ingestion of food or water containing Vibrio cholerae, serogroups O1 or O139. The outbreak of AWD in Raya Kobbo of Wollo zone district started during epidemiological week 33 of 2016 when 3-suspected cases reported to the town and rural health office. Three of the samples investigated in the 33 epidemiological weeks by RDT Kit confirmed that positive for Vibrio cholera. The index case was a 15-year-old male from town kebele 02 of the district. Stool specimen taken from index case on the date of reporting and positive for Vibrio cholerae o1.

Objective: We aimed to assess the magnitude and risk factors associated with acute watery diarrhoea in Raya Kobbo district, Northern Amahara region of Ethiopia in 2016.

Method: An age and sex matched case-control study design was conducted to investigate risk factors for AWD outbreak in Raya Kobbo. All the data collected from cases and controls were entered into a computer using MS Excel and Epi info. To determine the sample size we did not use  Epi info statistical calculation, because the numbers of cases were few. We established cases to control ratio of 1:3 with a total of 10 cases and 30 controls.

Result: Ten cases and zero deaths were registered during August 20 to September 1, 2016 in the two town kebeles and one rural kebele with an Attack Rate (AR) of 86, 23 and 33 per 100,000 populations in town kebeles of 02, 04 and Arefa rural kebele respectively. Among cases, 6 (60%) were males and four (30%) were in the age category of 21-25 years old which also the median interval age. The unadjusted matched analysis indicated that exposure to dirty latrine [OR = 7.67, 95% C.I (1.56, 37.78), P = 0.011] and contact of patient with diarrhoea and vomiting at home [OR = 9.0, 95% C.I (1.61, 50.27), P = 0.014] were at greater risk of having AWD. Cooking vegetables [OR=0.07, 95%C.I (0.01, 0.77), P=0.03] hand washing with soap [OR=0.78, 95%C.I (0.14, 0.81), P=0.04] and cleanliness around home [OR=0.10, 95%C.I (0.01, 0.87), P=0.01] were among protective factors.  

Conclusion: There was a significant association between dirty latrine and contact history with AWD. The most affected age group was adults 20-25 year-old. Health education and social mobilization on personal, community hygiene and sanitation particularly maintaining latrine sanitation at home was recommended.