Evaluation of Intussusception after Monovalent Rotavirus Vaccination in Africa.

BACKGROUND: Postlicensure evaluations have identified an association between rotavirus vaccination and intussusception in several high- and middle-income countries. We assessed the association between monovalent human rotavirus vaccine and intussusception in lower-income sub-Saharan African countries. METHODS: Using active surveillance, we enrolled patients from seven countries (Ethiopia, Ghana, Kenya, Malawi, Tanzania, Zambia, and Zimbabwe) who had intussusception that met international (Brighton Collaboration level 1) criteria. Rotavirus vaccination status was confirmed by review of the vaccine card or clinic records. The risk of intussusception within 1 to 7 days and 8 to 21 days after vaccination among infants 28 to 245 days of age was assessed by means of the self-controlled case-series method. RESULTS: Data on 717 infants who had intussusception and confirmed vaccination status were analyzed. One case occurred in the 1 to 7 days after dose 1, and 6 cases occurred in the 8 to 21 days after dose 1. Five cases and 16 cases occurred in the 1 to 7 days and 8 to 21 days, respectively, after dose 2. The risk of intussusception in the 1 to 7 days after dose 1 was not higher than the background risk of intussusception (relative incidence [i.e., the incidence during the risk window vs. all other times], 0.25; 95% confidence interval [CI], <0.001 to 1.16); findings were similar for the 1 to 7 days after dose 2 (relative incidence, 0.76; 95% CI, 0.16 to 1.87). In addition, the risk of intussusception in the 8 to 21 days or 1 to 21 days after either dose was not found to be higher than the background risk. CONCLUSIONS: The risk of intussusception after administration of monovalent human rotavirus vaccine was not higher than the background risk of intussusception in seven lower-income sub-Saharan African countries. (Funded by the GAVI Alliance through the CDC Foundation.).

Epidemiology of measles in the metropolitan setting, Addis Ababa, Ethiopia, 2005-2014: a retrospective descriptive surveillance data analysis.

BACKGROUND: Measles is a highly infectious and serious respiratory viral disease which caused by a virus. It is a significant cause of illness and death worldwide. This data analysis was conducted to describe the trend and determine the reporting rate of measles cases in Addis Ababa to make recommendation for the government of the city to strengthening measles control interventions. METHODS: We obtained and extracted ten years (2005-2014) Addis Ababa city's measles surveillance data from national database. We carried out retrospective descriptive data analysis by time, place and person variables. We calculated cumulative and specific reporting rates by dividing measles cases (lab confirmed, epidemiologically linked and compatible cases) to respective population and multiplying by 100,000. We divided average of ten years measles cases to midyear population and multiplied by 100,000 to calculate annualized reporting rate. We analyzed non-measles febrile rash rate by dividing laboratory negative cases to total population and multiplying by 100,000. RESULTS: A total of 4203 suspected measles cases were identified. Among them 1154 (27.5%) were laboratory confirmed, 512 (12.2%) were clinically compatible, 52 (1.2%) were epidemiologically linked cases and the rest 2485 (59.1%) were IgM negative for measles which makes total measles cases 1718 (40.9%). Median age was 5 years with 2-18 years interquartile-range. The annualized measles reporting rate was 5.9, which was 40.2 among > 1 year, 11.5 among 1-4 years, 6.0 among 5-14 years, 4.1 among 15-44 years and 0.01 among ≥ 45 years per 100,000 population. Among the total measles cases; 380 (22%) were received at least one dose of measles containing vaccine (MCV) while 415 (24%) cases were not vaccinated and the vaccination status of 923 (54%) cases were not known. CONCLUSION: Our analysis revealed that the reporting rate was higher among young children than older age group. Among all the patients 22% were received at least one dose of measles vaccine whereas 13% were not vaccinated against measles antigen. Routine immunization should be strengthened to reach all children through well monitored vaccine cold chain management.

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.

Epidemiology of intussusception among infants in Ethiopia, 2013-2016.

INTRODUCTION: intussusception is a condition in which one segment of the bowel prolapses into another causing obstruction. Information on the epidemiology of intussusception in sub-Saharan Africa is limited. We describe the sociodemographic and clinical characteristics of children with intussusception in Ethiopia. METHODS: active surveillance for children < 12 months of age with intussusception was conducted at six sentinel hospitals in Ethiopia. Limited socio-economic and clinical data were collected from enrolled children. Characteristics among children who died and children who survived were compared using the Wilcoxon rank sum test for continuous variables and Chi-square tests for categorical variables. RESULTS: total of 164 children < 12 months of age with intussusception were enrolled; 62% were male. The median age at symptom onset was 6 months with only 12 (7%) of cases occurring in the first 3 months of life. Intussusception was reduced by surgery in 90% of cases and 10% were reduced by enema; 13% of cases died. Compared to survivors, children who died had a significantly longer time to presentation to the first health care facility and to the treating health care facility (median 3 days versus 2 days, p = 0.02, respectively). CONCLUSION: the high mortality rate, late presentation of intussusception cases, and lack of modalities for non-surgical management at some facilities highlight the need for better management of intussusception cases in Ethiopia.

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.

Assessment of reporting sites for acute flaccid paralysis surveillance in Ethiopia: implications for planning of active case search visits.

INTRODUCTION: The World Health Organization acute flaccid paralysis (AFP) surveillance standards recommend documentation of the role of each potentially reporting site for evidence -based planning and tailoring support for active surveillance visits. This study assessed the contribution of various sites as source and quality of AFP cases reported over a five -year period in Ethiopia. METHODS: We conducted a retrospective analysis of AFP surveillance data collected from 2010-2014 in Ethiopia. Analyses were done using EPI-INFO version 7 for calculating frequencies and proportions, and testing possible associations between reporting sites and key dependent variables. RESULTS: Of the 5,274 AFP cases reported, hospitals and health centers reported 4627 (88%) of the cases. Hospitals in Addis Ababa (53%) and health posts in Benishangul Gumuz (48%) regions have contributed majority of the cases reported. Only 3% of cases were reported by private clinics nationally. The stool adequacy rate for health posts (81%) was lower than the overall national rate of 88% .Cases from health posts are more likely to be reported after 14 days of onset of paralysis, and 62% less likely to be investigated within two days of notification(OR: 1.82, 95% CI OR : 1.41-2.36, p-value <0.0001). Greater proportion (2.4%) of cases reported from health posts were either compatible, VDPV or WPV compared to cases reported by health centers (1.14%) or hospitals (1.4%). CONCLUSION: Though majority of the cases were reported by health centers followed by hospitals ,our findings suggest that all potentially reporting sites should be exhaustively identified, prioritized and regularly supported for quality case detection, investigation and reporting.

Status of surveillance and routine immunization performances in Amhara Region, Ethiopia: findings from in-depth peer review.

INTRODUCTION: Trend analyses of non-polio AFP and stool adequacy rates in Amhara Region showed optimal performance over the years. However, sub regional gaps continue to persist in certain zones where the reasons for low performance were not well documented. The objective of this study was to assess the performance of the disease surveillance and immunization system in Amhara Region, Ethiopia with emphasis on low performing woredas and zones. METHODS: A descriptive cross-sectional study was conducted from July 2-10, 2015 to assess the structure, core and support surveillance functions in five zones and two town administrations that were purposively sampled based on differing performances, geographic location, and history of vaccine preventable disease outbreaks among others. RESULTS: Of the 82 sites reviewed, 71 (87%) have a designated surveillance focal person. Less than half 36(44%) of these focal persons have written terms of reference. Twenty-six (93%) of the health offices had a written surveillance work plan for the fiscal year. Only 17 (81%) of woreda health offices and town administrations had prioritized active surveillance sites into high, medium and low during the last 12 months. Only 4(17%) had independent active case search visits to these sites as per the priority. Seventy-eight (95%) and seventy-seven (94%) sites have a designated immunization focal person and updated EPI performance monitoring charts, respectively. There had been vaccine stock out in the 3 months before assessment in 28 (34%) of the sites. CONCLUSION: Though there is an existence of well-organized surveillance network with adoption of the integrated disease surveillance and response, gaps exist in following the standard guidelines and operation procedures. Improvements needed in reporting site priority setting and regular visiting for active case search, outbreak investigation and management, vaccine supply and overall documentations.