scholarly journals Infection Fatality Rate and Infection Attack Rate of COVID-19 in South American Countries

2021 ◽  
Author(s):  
Salihu Sabiu Musa ◽  
Amna Tariq ◽  
Liu Yuan ◽  
Wei Haozhen ◽  
Daihai He
Keyword(s):  
South America ◽  
Attack Rate ◽  
Transmission Rate ◽  
Vaccination Rate ◽  
South American ◽  
Time Varying ◽  
Fatality Rate ◽  
Protective Behavior ◽  
Modelling Framework ◽  
Severe Infections

Abstract Background: The ongoing COVID-19 pandemic hit South America badly with two waves. Different COVID-19 variants have been storming across the region, leading to more severe infections and deaths even in places with high vaccination coverages.Methods: We use the start-of-the-art iterated filtering likelihood-based inference disease modelling framework. We modify the classical susceptible-exposed-infectious-recovered model with a time-varying transmission rate, and additional delayed class and vaccinations to reported COVID-19 deaths in 12 South American countries with the highest COVID-19 mortalities. Results: We yield biologically reasonable estimates for the infection fatality rate (IFR), the infection attack rate (IAR) and time-varying transmission rate. We observe that the severity, the dynamical patterns of the deaths and the time-varying transmission rates among the countries are highly heterogeneous. Further, our analysis of the model with vaccination highlights that increasing the vaccination rate could effectively suppress the pandemics in South America.Conclusion: This study reveals the possible mechanism behind the two waves of COVID-19 in South America. We observe reductions in the transmission rate corresponding to each wave plausibly due to improvement in nonpharmaceutical interventions (NPIs) measures and human protective behavior reaction to recent deaths. Thus, strategies coupling social distancing and vaccination could substantially suppress the mortality rate of COVID-19 in South America.

scholarly journals The global burden of yellow fever

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Katy AM Gaythorpe ◽  
Arran Hamlet ◽  
Kévin Jean ◽  
Daniel Garkauskas Ramos ◽  
Laurence Cibrelus ◽  
...  
Keyword(s):  
South America ◽  
Yellow Fever ◽  
Viral Vector ◽  
Credible Interval ◽  
Endemic Region ◽  
Tropical Regions ◽  
Modelling Framework ◽  
Severe Infections ◽  
Vector Borne ◽  
The Impact

Yellow fever (YF) is a viral, vector-borne, haemorrhagic fever endemic in tropical regions of Africa and South America. The vaccine for YF is considered safe and effective, but intervention strategies need to be optimised; one of the tools for this is mathematical modelling. We refine and expand an existing modelling framework for Africa to account for transmission in South America. We fit to YF occurrence and serology data. We then estimate the subnational forces of infection for the entire endemic region. Finally, using demographic and vaccination data, we examine the impact of vaccination activities. We estimate that there were 109,000 (95% credible interval [CrI] [67,000–173,000]) severe infections and 51,000 (95% CrI [31,000–82,000]) deaths due to YF in Africa and South America in 2018. We find that mass vaccination activities in Africa reduced deaths by 47% (95% CrI [10%–77%]). This methodology allows us to evaluate the effectiveness of vaccination and illustrates the need for continued vigilance and surveillance of YF.

scholarly journals The second wave of COVID-19 in South and Southeast Asia and vaccination effects

2021 ◽  
Author(s):  
Haitao Song ◽  
Guihong Fan ◽  
Yuan Liu ◽  
Xueying Wang ◽  
Daihai He
Keyword(s):  
Southeast Asia ◽  
Migrant Workers ◽  
Attack Rate ◽  
Transmission Rate ◽  
Time Varying ◽  
Pharmacological Interventions ◽  
Social Unrest ◽  
South And Southeast Asia ◽  
Second Wave ◽  
Death Data

Abstract Background By February 2021, the overall impact of the coronavirus disease 2019 (COVID-19) in South and Southeast Asia had been relatively mild. Surprisingly, the second wave in early April 2021 in this region becomes devastating and attracts worldwide attention. Methods We focus on the nine countries with the highest accumulative deaths due to the disease by July 30, 2021. We study the transmission dynamics of the COVID-19 in South and Southeast Asia using the reported death data and fit into a mathematical model with time varying transmission rate. Results We estimated the transmission rate, the infection fatality rate, and the infection attack rate, the effects of vaccination in the nine countries in South and Southeast Asia. Our study suggests that the infection attack rate is still low in most of the countries and vaccination is needed to prevent further waves. Conclusion The implementation of the non-pharmacological interventions (NPIs) could have helped South and Southeast Asia to keep the COVID-19 under control in 2020 as reflected in our estimated low transmission rate. Factors like the emergence of the new Delta variant, social unrest, and migrant workers could have been the trigger of the second wave of COVID-19. Trial registration. NA

scholarly journals Forecast of the COVID-19 trend in India: A simple modelling approach

2021 ◽  
Vol 18 (6) ◽  
pp. 9775-9786
Author(s):  
Haitao Song ◽  
◽  
Guihong Fan ◽  
Shi Zhao ◽  
Huaichen Li ◽  
...  
Keyword(s):  
Attack Rate ◽  
Model Simulation ◽  
Transmission Rate ◽  
Current Trend ◽  
Mortality Data ◽  
Fatality Rate ◽  
Epidemic Size ◽  
Short Period ◽  
Second Wave ◽  
Modelling Approach

<abstract> <p>By February 2021, the overall impact of the COVID-19 pandemic in India had been relatively mild in terms of total reported cases and deaths. Surprisingly, the second wave in early April becomes devastating and attracts worldwide attention. Multiple factors (e.g., Delta variants with increased transmissibility) could have driven the rapid growth of the epidemic in India and led to a large number of deaths within a short period. We aim to reconstruct the transmission rate, estimate the infection fatality rate and forecast the epidemic size. We download the reported COVID-19 mortality data in India and formulate a simple mathematical model with a flexible transmission rate. We use iterated filtering to fit our model to deaths data. We forecast the infection attack rate in a month ahead. Our model simulation matched the reported deaths well and is reasonably close to the results of the serological study. We forecast that the infection attack rate (IAR) could have reached 43% by July 24, 2021, under the current trend. Our estimated infection fatality rate is about 0.07%. Under the current trend, the IAR will likely reach a level of 43% by July 24, 2021. Our estimated infection fatality rate appears unusually low, which could be due to a low case to infection ratio reported in previous study. Our approach is readily applicable in other countries and with other types of data (e.g., excess deaths).</p> </abstract>

scholarly journals Pleistocene Mammals from Pampean Region (Argentina). Biostratigraphic, Biogeographic, and Environmental Implications

Quaternary ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 15
Author(s):  
José Luis Prado ◽  
María Teresa Alberdi ◽  
Jonathan Bellinzoni
Keyword(s):  
South America ◽  
The State ◽  
Historical Study ◽  
South American ◽  
Environmental Implications ◽  
Sedimentary Sequences ◽  
Pampean Region ◽  
Mammalian Faunas ◽  
Pleistocene Mammals ◽  
Fossil Records

The Pampean Region contains sedimentary sequences with abundant mammal fossil records, which constitute the chronological outline of the Plio–Pleistocene of South America. These classic localities have been used for more than a century to correlate with other South American regions. Throughout this time, a series of misinterpretations have appeared. To understand the stratigraphic significance of these localities and the geochronological situation of each unit referring to the Pleistocene, a critical historical study of the antecedents was carried out, evaluating the state of each unit. The biostratigraphic studies of the Pampean Region’s mammalian faunas improved the understanding of biogeographic changes taking into account the environmental fluctuations of the Pleistocene.

scholarly journals An Overview of Equine Influenza in South America

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 888
Author(s):  
Cecilia Olguin-Perglione ◽  
María Edith Barrandeguy
Keyword(s):  
South America ◽  
Disease Surveillance ◽  
Economic Losses ◽  
South American ◽  
Respiratory Pathogens ◽  
Equine Influenza Virus ◽  
Equine Influenza ◽  
Vaccine Manufacturer ◽  
Gene Level ◽  
Control Procedures

Equine influenza virus (EIV) is one of the most important respiratory pathogens of horses as outbreaks of the disease lead to significant economic losses worldwide. In this review, we summarize the information available on equine influenza (EI) in South America. In the region, the major events of EI occurred almost in the same period in the different countries, and the EIV isolated showed high genetic identity at the hemagglutinin gene level. It is highly likely that the continuous movement of horses, some of them subclinically infected, among South American countries, facilitated the spread of the virus. Although EI vaccination is mandatory for mobile or congregates equine populations in the region, EI outbreaks continuously threaten the equine industry. Vaccine breakdown could be related to the fact that many of the commercial vaccines available in the region contain out-of-date EIV strains, and some of them even lack reliable information about immunogenicity and efficacy. This review highlights the importance of disease surveillance and reinforces the need to harmonize quarantine and biosecurity protocols, and encourage vaccine manufacturer companies to carry out quality control procedures and update the EIV strains in their products.

scholarly journals Comparison of <i>H</i> component geomagnetic field time series obtained at different sites over South America

2018 ◽  
Vol 36 (3) ◽  
pp. 937-943 ◽  
Author(s):  
Maurício J. A. Bolzan ◽  
Clezio M. Denardini ◽  
Alexandre Tardelli
Keyword(s):  
South America ◽  
Geomagnetic Field ◽  
Phase Coherence ◽  
South American ◽  
Data Set ◽  
Geomagnetism And Paleomagnetism ◽  
Strong Phase ◽  
Geomagnetic Fields ◽  
Time Variations ◽  
Physical Phenomena

Abstract. The geomagnetic field in the Brazilian sector is influenced by the South American Magnetic Anomaly (SAMA) that causes a decrease in the magnitude of the local geomagnetic field when compared to other regions in the world. Thus, the magnetometer network and data set of space weather over Brazil led by Embrace are important tools for promoting the understanding of geomagnetic fields over Brazil. In this sense, in this work we used the H component of geomagnetic fields obtained at different sites in South America in order to compare results from the phase coherence obtained from wavelet transform (WT). Results from comparison between Cachoeira Paulista (CXP) and Eusébio (EUS), and Cachoeira Paulista and São Luis (SLZ), indicated that there exist some phenomena that occur simultaneously in both locations, putting them in the same phase coherence. However, there are other phenomena putting both locations in a strong phase difference as observed between CXP and Rio Grande, Argentina (RGA). This study was done for a specific moderate geomagnetic storm that occurred in March 2003. The results are explained in terms of nonlinear interaction between physical phenomena acting in distinct geographic locations and at different times and scales. Keywords. Geomagnetism and paleomagnetism (time variations – diurnal to secular)

Reflections on Contemporary South American Democracies

2001 ◽  
Vol 33 (3) ◽  
pp. 599-609 ◽  
Author(s):  
GUILLERMO O'DONNELL
Keyword(s):  
Latin America ◽  
South America ◽  
National Level ◽  
South American ◽  
Science Literature ◽  
Political Rights ◽  
Opinion Expression ◽  
Definition Of ◽  
The Third World ◽  
Indefinite Future

The occasion of honouring the memory of John Brooks, a great friend of Latin America, has helped me vanquish my initial reluctance to tackle a topic that is as broad, varied and still open-ended as the present situation of democracy in South America. As a first measure of my limitations, with the exception of some references to Costa Rica and Mexico, I will not discuss Central America and the Caribbean, not because I feel these regions are unimportant but because, simply, I do not know enough about them. However, when I feel that I am on sufficiently solid ground so as to refer to Latin America as a whole, I will do so.I begin by noting that in contemporary South America some countries satisfy the definition of political democracy. Those countries share two main characteristics. One is that they hold elections under universal adult franchise that, at least at the national level, are reasonably fair and competitive. These are standard criteria in the political science literature. However, having in mind the experience of Latin America and elsewhere in the third world, I believe that we should add that such elections must be institutionalised. By this I mean that all relevant actors expect that elections of this kind will continue being held in the indefinite future so, whether they like or not, it is rational for them to play democracy, not coup-making or insurrection. We should also stipulate that these elections are decisive, in the sense that those who are elected do occupy the respective offices and end their terms in the constitutionally prescribed way; they are not, as it has happened too often in Latin America, prevented from occupying office or thrown out of it because some supra-constitutional power feels that they are the ‘wrong people’.The second characteristic is the enjoyment of certain political rights, especially of opinion, expression, association, movement and access to a reasonably free and pluralist media. Of course, these and other rights are important per se; in addition, they are instrumental – necessary conditions – for the effectuation of the kind of elections I have just specified.

scholarly journals An epidemiological investigation of the 2019 suspected pertussis outbreak in northwestern Nigeria

2021 ◽  
Vol 9 ◽  
pp. 205031212110083
Author(s):  
Omoleke Semeeh ◽  
Biniam Getachew ◽  
Yusuf Taofik ◽  
Lukman Surajudeen ◽  
Assad Hassan ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Disease Transmission ◽  
Attack Rate ◽  
Odds Ratio ◽  
Case Fatality Rate ◽  
Adjusted Odds Ratio ◽  
Case Fatality ◽  
Immunization Coverage ◽  
Fatality Rate ◽  
Vaccine Preventable Diseases

Introduction: In 2019, we investigated the profile of the cases and controls and the determinants of pertussis transmission in Kebbi State, Northwestern Nigeria, to inform better immunization and surveillance strategies. Methods: Community-based unmatched case–control study and review of the 2019 pertussis routine surveillance data in the affected settlements in the state were conducted. A total of 52 suspected cases of pertussis and 107 control from two local government areas in Kebbi State were recruited. Data were analyzed using descriptive and inferential statistics. Results: The highest attack rate was observed among between 1- and 4-year age group followed by children less than 1-year old, and the least attack rate was among those above 15 years. The overall attack rate and the case fatality rate were 2.10% and 0.10%, respectively. A higher attack rate was observed among women, whereas the case fatality rate was more among males. From the community survey, we observed that the cases were less likely to have pertussis vaccination history (adjusted odds ratio = 0.28, 95% confidence interval = 0.11–0.74) compared with the controls. Knowing pertussis prevention methods were found protective for pertussis transmission (adjusted odds ratio = 0.14, 95% confidence interval = 0.04–0.45). Conclusion: This study showed the vulnerability of children under 5 years, especially under 1 year, to vaccine-preventable diseases in rural populations, where “real” immunization coverage is sub-optimal, and the dominant socio-demographic factors are supportive of disease transmission. We found immunization and knowledge of the preventive measures to be protective against pertussis outbreaks. Therefore, routine immunization services must be intensified to improve coverage and prevent future pertussis outbreak(s).

Salicornia cuscoensis (Amaranthaceae/Chenopodiaceae), a new species from Peru (South America)

Phytotaxa ◽  
2017 ◽  
Vol 319 (3) ◽  
pp. 254 ◽  
Author(s):  
M. ÁNGELES ALONSO ◽  
MANUEL B. CRESPO ◽  
HELMUT FREITAG
Keyword(s):  
New Species ◽  
South America ◽  
Morphological Characters ◽  
Tierra Del Fuego ◽  
South American ◽  
Habitat Distribution ◽  
Closely Related Species ◽  
Molecular Analyses ◽  
Southern Patagonia ◽  
A New Species

The name Salicornia cuscoensis given to a plant from high Andean saltmarshes near Cusco [Cuzco] and Ayacucho, Peru (South America) is validated by a diagnosis and description. The main morphological characters that separate S. cuscoensis from other closely related species are creeping habit, delicate branches, inflorescence of short and thin spikes, and seed indumentum. The new species clearly differs from other perennial Salicornia taxa growing in high Andean saltmarshes such as S. pulvinata and S. andina. The former forms small compact cushions producing very short, few-flowered inflorescences. The latter shows woody stems and forms larger rounded carpets. Morphologically, S. cuscoensis is also similar to S. magellanica, a species growing along the seashore in southern Patagonia and Tierra del Fuego, but the latter has shorter and wider inflorescences and larger seeds with a different type and arrangement of indumentum. Molecular analyses also supported the separation of S. cuscoensis. Data on habitat, distribution and phylogenetic relationships are presented for the new species and its relatives, and an identification key is given for the South American taxa of the genus Salicornia.

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