Measles outbreak reveals measles susceptibility among adults in Namibia, 2009 - 2011

Background. The World Health Organization, African Region, set the goal of  achieving measles elimination by 2020. Namibia was one of seven African countries to implement an accelerated measles control strategy beginning in 1996. Following implementation of this strategy, measles incidence decreased; however, between 2009 and 2011 a major outbreak occurred in Namibia.Methods. Measles vaccination coverage data were analysed and a descriptive  epidemiological analysis of the measles outbreak was conducted using measles case-based surveillance and laboratory data.Results. During 1989 - 2008, MCV1 (the first routine dose of measles vaccine) coverage increased from 56% to 73% and five supplementary immunisation activities were implemented. During the outbreak (August 2009 - February 2011), 4 605 suspected measles cases were reported; of these, 3 256 were confirmed by laboratory testing or epidemiological linkage. Opuwo, a largely rural district in north-western Namibia with nomadic populations, had the highest confirmed measles incidence (16 427 cases per million). Infants aged ≤11 months had the highest cumulative age-specific incidence (9 252 cases per million) and comprised 22% of all confirmed cases; however, cases occurred across a wide age range, including adults aged ≥30 years. Among confirmed cases, 85% were unvaccinated or had unknown vaccination history. The predominantly detected measles virus genotype was B3, circulating in concurrent outbreaks in southern Africa, and B2, previously detected in Angola.Conclusion. A large-scale measles outbreak with sustained transmission over 18 months occurred in Namibia, probably caused by importation. The wide age distribution of cases indicated measles-susceptible individuals accumulated over several decades prior to the start of the outbreak

Searching for gamma-ray counterparts of FRBs with H.E.S.S.

International audienceFast Radio Bursts (FRBs) are highly energetic, extremely short-lived bursts of radio flashes.Despite extensive research, the exact cause of these outbursts remains a mystery. One of themost accredited models suggests that they originate from highly magnetized and rapidly spinningneutron stars known as magnetars. The high luminosity, short duration, and high dispersionmeasure of these events suggest they result from extreme, high-energy astrophysical processesof extragalactic origin. The number of detected FRBs, including repeating ones, has grownrapidly in recent years. Except for FRB20200428, that is associated to the galactic magnetarSGR1925+2154, no multi-wavelength counterparts to any FRB has been detected yet. The HighEnergy Stereoscopic System (H.E.S.S.) telescope has developed a program to uncover the natureof these mysterious events by searching for their gamma-ray counterparts. This contributionprovides an overview of the searches for FRB sources conducted by H.E.S.S., including follow-upobservations and simultaneous multi-wavelength campaigns with radio and X-ray observatorie