The 2017 plague outbreak in Madagascar: data descriptions and epidemic modelling

Abstract

From August to November 2017, Madagascar has endured an outbreak of plague.A total of 2119 cases of plague has been confirmed, causing until now a death toll of 195. Public health interventions have been introduced, preventing new cases and deaths. However, it is likely that the outbreak could reappear as plague is endemic in the region and typically only last until April annually. We collected real-time data from various official reports. We described the outbreak's characteristics and reported estimates of the key transmission parameters using statistical and mathematical modelling approaches. Plague's epidemic curve depicts a propagated outbreak with multiple peaks, caused by continuing exposure. Optimal climate conditions for rat flea to flourish were observed during the epidemic. Estimate of the Plague's reproduction number based on pneumonic data was 6.9. The main mode of transmission is human-to-human with a much higher transmission rate than that of flea-to-human mode. With a potential of continuing exposure to infected rat fleas until April 2018, current public health efforts should be maintained at the high level. While efforts in controlling vector to prevent the appearance of new index cases can be critical, maintaining interventions targeting reduce human-to-human transmission is key to prevent large-scale outbreaks.

Measurability of the epidemic reproduction number in data-driven contact networks

“…Fitting a linear regression model to the estimated growth rate over time in the ILI data results in an estimated coefficient of 0.064 (SE of 0.033), while the mean value obtained with a linear regression model of case incidence from all stochastic realizations is 0.064 (95% CI, −0.207–0.305). An increase in the initial growth rate of the epidemic has also been observed for other diseases and countries (57–59). Although alternative explanations may exist (60), our results provide a plausible explanation for these patterns based on the intrinsic structure of human contact networks.…”

Targeting of the Yersinia pestis F1 capsular antigen by innate-like B1b cells mediates a rapid protective response against bubonic plague

“…In addition, the rapid induction of protective immunity against bacterial infections could also be used for prophylaxis in combination with second-line antibiotics in cases of antibiotic resistance to the first-choice therapy. 7 , 8 The recent outbreak of pneumonic plague on the island of Madagascar 4 and the concern regarding the appearance of antibiotic-resistant Y. pestis strains further emphasize the benefits of the development of such countermeasures.…”

“…2 The island of Madagascar is the most active focus of plague and recently experienced a severe outbreak, WHO Plague-Madagascar. 3 , 4 The most prevalent form of this disease in nature is bubonic plague, which is acquired following a bite from an infected flea. 5 Without prompt effective antibiotic treatment bubonic plague may develop into the highly fatal pneumonic plague.…”

Vaccines for emerging pathogens: prospects for licensure

“…All the viruses listed by the WHO also occur on these lists, alongside bacterial pathogens of concern. One of these is Yersinia pestis , causative of bubonic and pneumonic plague, which is recognized by all three bodies (WHO, CDC, NIAID) as a current priority following the exceptionally large and serious outbreak between September 2017 to April 2018 in Madagascar , where the disease is endemic. In addition, NIAID recognizes the added threat to human health posed by the acquisition of AMR by pathogens and WHO has also published a priority list of bacterial species for which R&D is required to develop new antibiotics (Table ).…”