Assessment of the yellow fever outbreak in Angola from December 2015 through December 2016: A retrospective study.

Background and Aims: The acute tropical infectious disease known as yellow fever (YF) is caused by an arbovirus and is characterized by fever, jaundice, hemorrhage, headache, muscle pain, nausea, vomiting, and fatigue. Angola experienced a yellow fever virus (YFV) outbreak that was documented in December 2015. However, little is known about the outcome of this outbreak. We aimed to demonstrate epidemic features and lessons learned during the YF epidemic in Angola. Methods: A total of 4618 blood samples from suspected YF cases were sent to the Instituto Nacional de Investigação em Saúde (INIS), a national referral and public health laboratory, between December 5, 2015, and December 23, 2016. Sample analyses were conducted using enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR) assays. Blood samples were sent from 16 out of the 18 provinces of Angola. Results: We detected 884 (19.1%) cases that were positive for ELISA, which were confirmed by RT-PCR assay. Considering the positive cases, the incidence among male patients was around three times higher (n = 223; 10.9%) than in female patients (n = 59; 2.6%) in the 20-29 age group, followed by the age group 10-19 with n = 211 (6.8%) in males versus n = 108 (3.3%) in females; and the age group 30-39 had n = 68 (4.8%) in males versus n = 28 (1.8%) in females. The other groups had an incidence below 3.0%. The case fatality ratio for YF was in young adults in the age group 20-29 with n = 39 cases, followed by the age group 10-19 with n = 16 cases, and finally the age group 0-9 with n = 13 cases. The other age groups had several deaths by YF below 10 cases. Conclusions: This study demonstrates features of the YF epidemic that occurred in Angola. Also, it demonstrates that YF causes deaths in young people but is preventable by high vaccine coverage. Thus, public health laboratory surveillance must be strengthened to reduce the possibility of emerging and re-emerging human infections.

Epidemiology of measles in Angola: Results from routine surveillance from 2015 to 2021.

Background: Measles, an acute infectious disease of extremely contagious viral aetiology, has been eliminated in some parts of the world. To the best of the authors' knowledge, this is the first study on the epidemiological pattern of the measles virus in Angola, and it was carried out through a review of 7 years of observational retrospective data from the national measles laboratory surveillance programme. Methods: A retrospective study using national databases on the laboratory surveillance of measles was performed. Patients of all ages with suspected measles from all provinces of Angola were included. Serum samples were used to detect IgM-type measles-virus-specific antibodies by enzyme-linked immunosorbent assay. Findings: In total, 3690 suspected measles samples were sent to the Instituto Nacional de Investigação em Saúde. There were 962 (26.1%) laboratory-confirmed cases, and the most affected age group was children aged 1-4 years. The highest incidence rate per 100,000 population was found in Benguela (17.9%), followed by Huambo (16.7%) and Cuanza Sul (13.6%). Of the study years, the incidence rate per 1,000,000 population was highest in 2020 (11.9%). The most common complication was diarrhoea (n=406, 42.2%). Of the confirmed cases, 209 (21.7%) were vaccinated, 633 (65.8%) were unvaccinated, and 120 (12.5%) had unknown vaccination status. For all study years, vaccination coverage was <70%. Interpretation: Measles continues to be a serious problem in Angola, and more efforts are needed to increase measles surveillance and achieve a high percentage of vaccination coverage.

Comparison of COVID-19 Pandemic Waves in 10 Countries in Southern Africa, 2020-2021.

We used publicly available data to describe epidemiology, genomic surveillance, and public health and social measures from the first 3 COVID-19 pandemic waves in southern Africa during April 6, 2020-September 19, 2021. South Africa detected regional waves on average 7.2 weeks before other countries. Average testing volume 244 tests/million/day) increased across waves and was highest in upper-middle-income countries. Across the 3 waves, average reported regional incidence increased (17.4, 51.9, 123.3 cases/1 million population/day), as did positivity of diagnostic tests (8.8%, 12.2%, 14.5%); mortality (0.3, 1.5, 2.7 deaths/1 million populaiton/day); and case-fatality ratios (1.9%, 2.1%, 2.5%). Beta variant (B.1.351) drove the second wave and Delta (B.1.617.2) the third. Stringent implementation of safety measures declined across waves. As of September 19, 2021, completed vaccination coverage remained low (8.1% of total population). Our findings highlight opportunities for strengthening surveillance, health systems, and access to realistically available therapeutics, and scaling up risk-based vaccination.

The control of an epidemic outbreak of Marburg hemorrhagic fever in Angola, 2004-2005 / No disponible

Entre Octubre del 2004 y Septiembre del 2005 Angola vivió un brote epidémico de fiebre hemorrágica debida al virus Marburg. La epidemia se dio por oficialmente por concluida el 7 de Noviembre del 2005, y se consideró la más grave de las ocurridas en todo el mundo, con 252 casos y 227 muertes, lo que suponía una tasa de mortalidad del 90%. Considerando que es un agente patógeno de gran virulencia para el cual no hay vacunas o tratamiento específico, estas epidemias precisan de una enorme cantidad de recursos humanos, financieros y técnicos tanto nacionales como internacionales Es importante poner de manifiesto que el laboratorio del Center for Diseases Control de Atlanta fue el responsable del primer aislamiento del virus y de su identificación como causante de la epidemia. Posteriormente fue el encargado de monitorizar la epidemia y estudiar todas las muestras biológicas recogidas de los casos sospechosos. Hasta este momento ha sido imposible identificar el foco primario de la enfermedad, aunque existen sugerencias a nivel local sobre la posibilidad de que el hospital provincial de UIge haya sido el sitio inicial y responsable de la diseminación de la epidemia a través de la infección nosocomial. En una segunda fase la ausencia de una adecuada educación para la salud, el pánico y las tradiciones culturales locales fueron los elementos cruciales para la diseminación de la enfermedad a otras provincias del país. En este contexto, la participación de sociólogos y antropólogos fue un factor clave para el control de las epidemias, en paralelo a las medidas de bioseguridad y detección activa emprendidas (AU)

Angola has lived an epidemic outbreak of hemorrhagic fever caused by Marburg virus between October 2004 and September 2005. The epidemic was officially terminated in November 7th 2005, and considered the most severe ever occurred in the world, with 252 cases and 227 deaths, with a lethality rate of 90%. Considering that it is a pathogenic agent of great virulence for which there are no vaccines or specific treatment, these epidemics caused a huge recruitment of national and international human, financial and technical resources despite some local constraints. It must be outlined that CDC-Atlanta laboratory was the responsible for the first isolation of the virus as the cause of the epidemics, and later on, for monitoring the epidemics and manipulating all biological samples collected from suspected patients. Until now it was impossible to identify the primary focus of the disease, though there are suggestions from local oral comments that Uige provincial hospital may have been the initial site and responsible for the dissemination of the epidemics through nosocomial infection. In a second phase, lack of proper health education, panic and local cultural traditions were the crucial elements for disease spread to other provinces of the country. In this context, the participation of sociologist and anthropologists was a key factor for the epidemics control, in parallel with the biosafety and active survey measures undertaken (AU)