Epidemiology of laboratory confirmed measles virus cases in the southern nations of Ethiopia, 2007-2014.

BACKGROUND: In Ethiopia, measles case-based surveillance was introduced in 2004 as one strategy for measles control by laboratory confirmation of suspected cases. In this article, epidemiological distribution of laboratory-confirmed measles cases were reported from the Southern Nation Nationalities and Peoples Region (SNNPR) of Ethiopia between 2007 and 2014, as the region is one of the highly measles affected areas in Ethiopia. METHOD: A serum sample was collected from all measles suspected cases, and patient information was captured by case reporting format (CRF). Samples were transported to the National Measles Laboratory for Measles IgM testing by ELISA technique. Data entry and analysis were done using Epi-Info 3.5.4 software. RESULT: A total of 4810 samples were tested for measles IgM using ELISA technique and 1507 (31.3%) were found positive during 2007-2014 in SNNPR of Ethiopia. Patients with age 1-4 years were the most affected regardless of sex. The incidence of measles confirmed cases increased from 15 in 2007 to 180 in 2013 per million population. The highest percentage of laboratory-confirmed cases were found in 2014. Measles was found distributed throughout the regional state. CONCLUSION: Measles was found a public health important disease in SNNPR of Ethiopia, mostly affecting children 1-4 years. The incidence of measles cases is increasing from time to time. Additional research to determine the genotype of circulating measles virus, knowledge, attitude and practice of professionals and the population for measles vaccination and infection in the region is important. A wide age group measles vaccination campaign is highly recommended.

Epidemiology of laboratory confirmed measles virus cases in Amhara Regional State of Ethiopia, 2004-2014.

BACKGROUND: Measles is a highly contagious viral infection causing large outbreaks all over the world. Despite the availability of safe and cost effective vaccine, measles remained endemic with persistent periodic outbreaks in the Horn of Africa. The aim of this study is to characterize laboratory confirmed measles cases in Amhara Regional State, which was one of the highly affected regions in Ethiopia. METHOD: A suspected measles case was defined as any person presenting with fever, maculopapular rash and one or more of the three symptoms cough, coryza or conjunctivitis or a patient in whom a clinician suspects measles. A blood sample was collected for any measles suspected patient with a case based investigation form and specimen transported to the National Measles Laboratory in good condition where it was to be tested for Measles IgM antibody by ELISA technique. Data was entered and analyzed using Epi-Info 3.5.4 software. RESULT: A total of 6579 samples were tested for measles IgM among 7296 samples collected in Amhara Regional State over 11 years (2004-2014). Of the tested samples, 2412 (36.7%) were found positive, while 3965 and 202 samples were found to be negative and equivocal (compatible) respectively. Patients with age ≥ 10 years were the most affected. The highest number of laboratory confirmed measles cases were detected in 2014 and cases were occurred in all of the 11 zones of the state. A seasonal peak was noted in the hot-dry season of the year. CONCLUSION: Measles remains to be a public health problem in Amhara Regional State of Ethiopia, mostly affecting people ≥ 10 years of age. Measles virus was detected in all zones of the state, reaching its peak in the hot-dry season. To reduce the incidence of measles, it is highly recommended to improve routine immunization, and conduct a wide age group campaign. Additional research to evaluate the knowledge, attitudes and practices of the general population and health care professionals about measles infection and vaccination is important. Genotyping of circulating measles virus strain is recommended.

Epidemiology of rubella virus cases in the pre-vaccination era of Ethiopia, 2009-2015.

BACKGROUND: Rubella is a common mild rash illness caused by rubella virus. The majority of infections occur in children and young adults. The infection is the cause of a serious birth defect known as Congenital Rubella Syndrome (CRS) when a woman acquires infection early in pregnancy. Ethiopia has not yet established rubella virus surveillance and has not yet introduced rubella vaccine into the routine immunization program. We characterize the epidemiology of laboratory confirmed rubella virus cases collected through measles surveillance from 2009 to 2015 to better understand the burden of the disease in the country. METHODS: A descriptive analysis was made to characterize rubella cases reported through the national measles case based surveillance system. The measles case definition was used to capture potential rubella cases. A suspected measles case was a person with generalized rash and fever with cough, or coryza or conjunctivitis. Those cases whose sera were negative for measles IgM antibodies were tested for rubella IgM antibody. A confirmed rubella case was a person who tested positive for rubella IgM. Only laboratory confirmed rubella cases were analyzed in this article. RESULTS: Between 2009 and 2015, a total of 28,284 serum/plasma samples were collected and tested for measles IgM antibody and 11,151 (39.4%) were found positive. A total of 17,066 measles IgM negative or indeterminate samples were tested for rubella virus IgM and 2615 (15.3%) were found positive during the same period. Of 2615 confirmed rubella cases, 52.2% were females. The age of confirmed cases ranged from one month to 42 years with a mean age of 7.3 years. Three-fourth of all confirmed rubella cases were aged less than 10 years. The number of laboratory confirmed rubella cases linearly increased from 83 in 2009 to 856 in 2013 but dropped to 222 and 319 in 2014 and 2015 respectively. Higher number of cases occurred in the hot dry season (January through June) and in the central and western part of Ethiopia with 127 lab-confirmed outbreaks in the study period. CONCLUSIONS: Based on our analysis, rubella was found to be endemic throughout Ethiopia. Children below the age of 10 years were the most affected. The burden of rubella cases varied from year to year but had a seasonal peak in March. To better understand the magnitude of rubella prior to vaccine introduction, establishing rubella surveillance system, conducting sero-prevalence studies among child bearing age females and establishing CRS sentinel surveillance among young infants are critical.

Rotavirus-associated acute diarrhea outbreak in West Shewa Zone of Oromia Regional State, Ethiopia, 2017.

INTRODUCTION: Rotavirus causes severe-diarrheal diseases in infants. An estimation of 138 million rotavirus-associated diarrheal cases and 215,000 deaths occur every year globally. In December 2016, West-Shewa zone in Ethiopia reported unidentified gastrointestinal diarrhea outbreak. We investigated to identify the causative agent of the outbreak to support response operations. METHODS: Medical records were reviewed, and the daily line list was collected from health facilities. Descriptive data analysis was done by time, person and place. Stool specimens were first tested by antigen capture enzyme immunoassay (EIA) technique and further confirmed by reverse-transcription polymerase chain reaction (RT-PCR) as a gold standard. The product of RT-PCR was genotyped for each gene using G1-G4, G8-G9 and G12 primers for VP7 gene and P(4), P(6), P(8) and P(14) primers for VP4 gene. RESULTS: A total of 1,987 diarrheal cases (5.7 per 1000) and five deaths (case-fatality rate 0.25%) were identified and epidemiologically-linked to confirmed rotavirus from December 2016 to February 2017. Among the cases, 1,946 (98%) were < 5 children. Fourteen (74%) of the 19 tested stool specimens were positive for rotavirus by EIA and RT-PCR. Majority of strains detected were G12P(6) (25%) and G-negative P(8) (25%) followed by G9P(8) (19%), G1P(8) (13%) and G3/G2 P(8), G12P(8), and G-negative P(6) (6% each). CONCLUSION: Diarrheal outbreak which occurred in West-Shewa zone of Ethiopia was associated with rotavirus and relatively more affected districts with low vaccination coverage. Routine rotavirus vaccination quality and coverage should be evaluated and the surveillance system needs to be strengthened to detect, prevent and control a similar outbreak.

Impact of rotavirus vaccine introduction and genotypic characteristics of rotavirus strains in children less than 5 years of age with gastroenteritis in Ethiopia: 2011-2016.

INTRODUCTION: A monovalent rotavirus vaccine was introduced in the Ethiopian Expanded Program on Immunization from November 2013. We compared impact of rotavirus vaccine introduction on rotavirus associated acute diarrhea hospitalizations and genotypic characteristics of rotavirus strains pre-and post-vaccine introduction. METHODS: Sentinel surveillance for diarrhea among children <5 years of age was conducted at 3 hospitals in Addis Ababa, Ethiopia from 2011 to 2017. Stool specimens were collected from enrolled children and tested using an antigen capture enzyme immunoassay. Rotavirus positive samples (156 from pre- and 141 from post-vaccination periods) were further characterized by rotavirus genotyping methods to identify the predominant G and P types circulating during the surveillance era. RESULTS: A total of 788 children were enrolled during the pre- (July 2011-June 2013) and 815 children during the post-vaccination (July 2014-June 2017) periods. The proportion of diarrhea hospitalizations due to rotavirus among children <5 years of age declined by 17% from 24% (188/788) in the pre-vaccine period and to 20% (161/185) in post-vaccine introduction era. Similarly, a reduction of 18% in proportion of diarrhea hospitalizations due to rotavirus in children <12 months of age in the post (27%) vs pre-vaccine (33%) periods was observed. Seasonal peaks of rotavirus declined following rotavirus vaccine introduction. The most prevalent circulating strains were G12P[8] in 2011 (36%) and in 2012 (27%), G2P[4] (35%) in 2013, G9P[8] (19%) in 2014, G3P[6] and G2P[4] (19% each) in 2015, and G3P[8] (29%) in 2016. DISCUSSION: Following rotavirus vaccine introduction in Ethiopia, a reduction in rotavirus associated hospitalizations was seen in all age groups with the greatest burden in children <12 months of age. A wide variety of rotavirus strains circulated in the pre- and post-vaccine introduction periods.

Hospital-based surveillance for rotavirus gastroenteritis in children younger than 5 years of age in Ethiopia: 2007-2012.

BACKGROUND: Rotavirus surveillance was initiated in Ethiopia to estimate the burden of rotavirus gastroenteritis in children <5 years of age, to generate data to assist the policy-making process for new vaccine introduction and to monitor impact of vaccination on disease burden after introduction. METHODS: Sentinel surveillance was conducted at 3 hospitals in Addis Ababa, Ethiopia using a standardized WHO surveillance protocol from August 2007 to March 2012. Children <5 years of age, hospitalized for the primary reason of treatment for acute gastroenteritis, were enrolled, stool samples were collected and tested for group A rotavirus using an enzyme immunoassay. Confirmed positive specimens were further characterized by rotavirus genotyping. RESULTS: A total of 1841 children were enrolled and 21% were rotavirus positive. Children 6-12 months of age had the highest proportion of rotavirus (36%) followed by children <6 months of age (23%). There was no significant difference between sexes. Significant differences in clinical characteristics, such as vomiting, vomiting episodes, cases with vomiting and diarrhea among rotavirus positive cases, were observed. Rotavirus circulated year round with peak prevalence from October through January. The most prevalent detected genotypes were G1P[8] (20%), G12P[8] (17%) and G3P[6] (15%), respectively. CONCLUSIONS: Rotavirus infection is common in Ethiopian children. A safe and effective intervention against the infection is needed to prevent severity of the disease. Rotavirus vaccine introduction is planned before the end of 2013. The established surveillance system and the data generated can be used to monitor the impact of rotavirus vaccination program on severe disease.