Global Health Crisis: COVID-19

Photo by :   Spencer Davis (Unsplash)


Socioeconomic status determines COVID-19 incidence and related mortality in Santiago, Chile

Structured Abstract


The COVID-19 crisis has exposed major inequalities between communities. Understanding the societal risk factors that make some groups particularly vulnerable is essential to ensure more effective interventions for this and future pandemics. Here, we focus on socioeconomic status as a risk factor. Although it is broadly understood that social and economic inequality has a negative impact on health outcomes, the mechanisms by which socioeconomic status affects disease outcomes remain unclear. These mechanisms can be mediated by a range of systemic structural factors, such as access to health care and economic safety nets. We address this gap by providing an in-depth characterization of disease incidence and mortality and their dependence on demographic and socioeconomic strata in Santiago, a highly segregated city and the capital of Chile.


Combining publicly available data sources, we conducted a comprehensive analysis of case incidence and mortality during the first wave of the pandemic. We correlated COVID-19 outcomes with behavioral and health care system factors while studying their interaction with age and socioeconomic status. To overcome the intrinsic biases of incomplete case count data, we used detailed mortality data. We developed a parsimonious Gaussian process model to study excess deaths and their uncertainty and reconstructed true incidence from the time series of deaths with a new regularized maximum likelihood deconvolution method. To estimate infection fatality rates by age and socioeconomic status, we implemented a hierarchical Bayesian model that adjusts for reporting biases while accounting for incompleteness in case information.


We find robust associations between COVID-19 outcomes and socioeconomic status, based on health and behavioral indicators. Specifically, we show in lower–socioeconomic status municipalities that testing was almost absent early in the pandemic and that human mobility was not reduced by lockdowns as much as it was in more affluent locations. Test positivity and testing delays were much higher in these locations, indicating an impaired capacity of the health care system to contain the spread of the epidemic. We also find that 73% more deaths than in a normal year were observed between May and July 2020, and municipalities at the lower end of the socioeconomic spectrum were hit the hardest, both in relation to COVID-19–attributed deaths and excess deaths. Finally, the socioeconomic gradient of the infection fatality rate appeared particularly steep for younger age groups, reflecting worse baseline health status and limited access to health care in municipalities with low socioeconomic status.


Together, these findings highlight the substantial consequences of socioeconomic and health care disparities in a highly segregated city and provide practical methodological approaches useful for characterizing the COVID-19 burden and mortality in other urban centers based on public data, even if reports are incomplete and biased.


By             :            Gonzalo E. Mena, Pamela P. Martinez, Ayesha S. Mahmud, Pablo A. Marquet,  Caroline O. Buckee,                                                           Mauricio Santillana

Date          :            May 28, 2021 

Source      :            Science  



Demand for longer quarantine period among common and uncommon COVID-19 infections: a scoping review



As one of the non-pharmacological interventions to control the transmission of COVID-19, determining the quarantine duration is mainly based on the accurate estimates of the incubation period. However, patients with coarse information of the exposure date, as well as infections other than the symptomatic, were not taken into account in previously published studies. Thus, by using the statistical method dealing with the interval-censored data, we assessed the quarantine duration for both common and uncommon infections. The latter type includes the presymptomatic, the asymptomatic and the recurrent test positive patients.


As of 10 December 2020, information on cases have been collected from the English and Chinese databases, including Pubmed, Google scholar, CNKI (China National Knowledge Infrastructure) and Wanfang. Official websites and medias were also searched as data sources. All data were transformed into doubly interval-censored and the accelerated failure time model was applied. By estimating the incubation period and the time-to-event distribution of worldwide COVID-19 patients, we obtain the large percentiles for determining and suggesting the quarantine policies. For symptomatic and presymptomatic COVID-19 patients, the incubation time is the duration from exposure to symptom onset. For the asymptomatic, we substitute the date of first positive result of nucleic acid testing for that of symptom onset. Furthermore, the time from hospital discharge or getting negative test result to the positive recurrence has been calculated for recurrent positive patients.


A total of 1920 laboratory confirmed COVID-19 cases were included. Among all uncommon infections, 34.1% (n = 55) of them developed symptoms or were identified beyond fourteen days. Based on all collected cases, the 95th and 99th percentiles were estimated to be 16.2 days (95% CI 15.5–17.0) and 22.9 days (21.7?24.3) respectively. Besides, we got similar estimates based on merely symptomatic and presymptomatic infections as 15.1 days (14.4?15.7) and 21.1 days (20.0?22.2).


There are a certain number of infected people who require longer quarantine duration. Our findings well support the current practice of the extended active monitoring. To further prevent possible transmissions induced and facilitated by such infectious outliers after the 14-days quarantine, properly prolonging the quarantine duration could be prudent for high-risk scenarios and in regions with insufficient test resources.


By                  :        Zhi-Yao Li, Yu Zhang, Liu-Qing Peng, Rong-Rong Gao, Jia-Rui Jing, Jia-Le Wang, Bin-Zhi Ren,                                                                     Jian-Guo Xu & Tong Wang

Published by :       April 26, 2021

Source          :       Infectious Diseases of Poverty 




Why health experts say you need vaccinated even if you’ve had COVID-19

While some who have had COVID-19 might not have an interest in getting vaccinated, a growing body of evidence and cautionary tales from other countries indicate that natural immunity won’t be the answer to beating the pandemic.

The most vulnerable people are those with no previous infection or vaccine, but new studies on vaccines and variants show that people who have had the virus but no vaccine are at more risk than those who are fully vaccinated.

“The notion that you’ve had the virus before and you’re protected: we’re seeing time and again now that that’s untrue,” said Dr. Vin Gupta, a physician and professor at the Institute for Health Metrics and Evaluation at the University of Washington. “We don’t have robust protection because of prior infection particularly because of transmission of these variants.”

The variant that originated in the United Kingdom, the B.1.1.7 variant, is the most common circulating in Washington state, and it has thus far been associated with more transmission and in some cases, more severe disease.

The U.K. variant is also associated with the highest number of breakthrough cases in the state so far, with 98 recorded cases of people who’ve been fully vaccinated testing positive with the variant.

People testing positive for the virus in recent months are, in essence, experiencing a different COVID-19 infection than those who were infected a year ago. Viruses mutate, and the more people don’t get vaccinated, the more opportunities the virus has to change its form, getting better in some mutations at evading antibody treatments or spreading faster.

Currently, the available vaccines in the United States are performing well against the variants, so much so that immune responses seen in fully vaccinated people are stronger than those who have had previous COVID-19 infection, experts say.

Gupta said he has been explaining this to his patients, especially those who have had COVID-19 and think they are immune. If the coronavirus hadn’t changed or evolved, their immunity might be stronger, but that’s not the reality.

“The antibodies you develop from infection from the original virus aren’t as useful,” Gupta said.

Vaccines are producing a more robust response at the biological level, he added.

Studies that measure antibodies in people who have had previous COVID infection have varied results, and scientists don’t yet know how long natural immunity lasts. Furthermore, some research has shown that antibody responses might be correlated with how severe a person’s disease was.

While some studies say a person who had the virus will have antibodies for months following infection, other studies show that variants can change that trajectory.

A May 2020 study from a placebo-controlled vaccine trial found that people who had had an older strain of COVID-19, before the South African variant was circulating, did not have reduced risk for getting infected again with the South African variant.

“The weakest form of protection looks like natural immunity,” Mike Famulare, a modeler with the Institute for Disease Modeling, said. “So the vaccines look as effective or better in terms of protecting you over a six-month time horizon of getting infected.”

On the opposite end of the spectrum, a person who has had COVID-19 and is fully vaccinated is likely the most protected a person can be against the virus.

“Having COVID plus vaccine is the most protected you can be,” Famulare said.

The Centers for Disease Control and Prevention changed its guidance for when people who tested positive for COVID-19 can be vaccinated in recent months. As soon as a patient with COVID-19 has resolved their symptoms and finished their isolation period, they can get vaccinated. The one exception to this rule is if a patient was treated in a hospital with monoclonal antibodies or convalescent plasma, the CDC recommends those patients wait 90 days before getting a vaccine.

Addressing ‘herd immunity’

To get to a level of immunity that will drive down the reproductive rate of the virus, health experts add together the number of people who have naturally acquired immunity to COVID-19 and the immunity gained by those who get vaccines.

In Washington, natural immunity is quite a bit lower than other parts of the country because residents here adhered to guidance so well. Lives were saved as a result, and now that means the state likely has more people vulnerable to the virus than other states with larger outbreaks or higher infection rates.

The Institute for Disease Modeling estimates that between 10% and 15% of Washington residents have natural immunity to COVID-19 from prior infection, according to Famulare.

If this is correct, combined with the 41% of Washington residents who have been fully vaccinated, a little more than 50% of the total state population has reached immunity status. This isn’t good enough for herd immunity levels, and health officials are now aiming for adequate vaccine coverage instead, with a goal of getting more than 70% of Washington residents the ages of 16 and over vaccinated in order to really keep the virus at bay.

The actual herd immunity threshold, Famulare said, is difficult to calculate due to the ever-changing nature of the virus, and even if we hit that magical threshold, COVID-19 won’t disappear immediately.

“What is herd immunity today may not be herd immunity tomorrow, so there will be a cat and mouse game we’ll play with this virus for many months,” he said.

What the future holds

COVID-19 won’t disappear when vaccination rates are higher, particularly in communities with low vaccination rates. There’s also the likelihood that we haven’t seen the end of the vaccine campaign either.

The idea of an annual vaccination or booster shot is definitely still on the table, Dr. John Lynch, infectious disease specialist at the University of Washington, said this month.

The danger remains for people and communities who do not get vaccinated, however, and in these nonimmune environments, variants will continue to mutate. So far, the vaccines have held up against variants, but if that is to change in the coming months or year, things could get a lot more challenging.

“Is it theoretically possible that a variant can get past vaccine immunity? I think it’s a theoretical concern,” Lynch said.

Gupta thinks it is possible that this coming fall and winter could be a “dangerous scenario” especially with seasonal changes, people gathering indoors and the lack of herd immunity. Hospitalizations could surge again.

“There’s a clear worry that that’s going to happen,” Gupta said.

The future Gupta is worried about is already happening on a smaller scale in some places with low vaccination rates today. Just ask health officials in northeastern Washington where an outbreak overwhelmed Republic’s critical access hospital after a superspreader event.

Roughly 30% of each county in northeastern Washington is fully vaccinated, leaving the majority of people vulnerable to the virus. And while local health officials don’t have a good indicator of how many people might have had the virus and now have some level of immunity, it likely isn’t so many people that there is more than 50% immunity in the region.

“In Eastern Washington we’re in this funny position where I think we’re going to deal with this longer than the West Side that has more people vaccinated, and our situation is reflected right now in our numbers,” Dr. Sam Artzis, health officer of the Northeast Tri County Health District, said earlier this month.

Ultimately, there is not going to be a hard stop to the pandemic where the virus just disappears, and Famulare thinks this coming year will likely bring a sort of adjustment to the virus in our lives instead of the pandemic suddenly being over. What that looks like depends a lot on vaccination rates.

“(Either) the way we live with the virus is different and better because everyone has gotten vaccinated or ugly because more people will die because they aren’t vaccinated,” he said.



Arielle Dreher's reporting for The Spokesman-Review is funded in part by Report for America and by members of the Spokane community. 


By               :             Arielle Dreher 

Date           :             May 27, 2021

Source       :             The Spokesman Review 



The use of medicinal plants to prevent COVID-19 in Nepal



Medicinal plants are the fundamental unit of traditional medicine system in Nepal. Nepalese people are rich in traditional medicine especially in folk medicine (ethnomedicine), and this system is gaining much attention after 1995. The use of medicinal plants has increased during the COVID-19 pandemic as a private behavior (not under the control of government). A lot of misinterpretations of the use of medicinal plants to treat or prevent COVID-19 have been spreading throughout Nepal which need to be managed proactively. In this context, a research was needed to document medicinal plants used, their priority of use in society, their cultivation status, and the source of information people follow to use them. This study aimed to document the present status of medicinal plant use and make important suggestion to the concerned authorities.


This study used a web-based survey to collect primary data related to medicinal plants used during COVID-19. A total of 774 respondents took part in the survey. The study calculated the relative frequencies of citation (RFC) for the recorded medicinal plants. The relationship between plants recorded and different covariates (age, gender education, occupation, living place, and treatment methods) was assessed using Kruskal-Wallis test and Wilcoxon test. The relationship between the information sources people follow and the respondent characteristics was assessed using chi-square test.


The study found that the use of medicinal plants has increased during COVID-19 and most of the respondents recommended medicinal plants to prevent COVID-19. This study recorded a total of 60 plants belonging to 36 families. The leaves of the plants were the most frequently used. The Zingiber officinale was the most cited species with the frequency of citation 0.398. Most of the people (45.61%) were getting medicinal plants from their home garden. The medicinal plants recorded were significantly associated with the education level, location of home, primary treatment mode, gender, and age class. The information source of plants was significantly associated with the education, gender, method of treatment, occupation, living with family, and location of home during the lockdown caused by COVID-19.


People were using more medicinal plants during COVID-19 claiming that they can prevent or cure COVID-19. This should be taken seriously by concerned authorities. The authorities should test the validity of these medicinal plants and control the flow of false information spread through research and awareness programs.


By                  :                Dipak Khadka, Man Kumar Dhamala, Feifei Li, Prakash Chandra Aryal, Pappu Rana Magar,                                                                                  Sijar Bhatta, Manju Shree Thakur, Anup Basnet, Dafang Cui & Shi Shi  

Published by  :               April 8, 2021

Source           :               Journal of Ethnobiology and Ethnomedicine 




COVID-19: which countries will be the next to see a big spike in cases?

Beneath the many complexities of the marathon that is the COVID-19 pandemic, there is a simple hypothesis: if the coronavirus is introduced into a susceptible population, and those people are able to mix, then there will be significant community transmission. Across 2020 and 2021, we have seen this happen around the world, including, recently, in India.

Could we see further situations like those in India, with cases rapidly spiking and health systems being overwhelmed? The short answer, sadly, is yes.

Globally, there’s been an encouraging downturn in daily new cases in May 2021, but despite this, cases are still at a very high level overall, with worldwide statistics masking huge differences across countries and areas. The global vaccine rollout is also progressing slowly, with most of the world still susceptible to COVID-19. These factors mean there’s potential for further spikes like those seen in India.

We only need look to Nepal to see a similar situation unfolding. Other countries have rising caseloads too, with many eyes looking nervously at Latin America, south-east Asia and some of the smaller island nations.

Who else is at risk?

In terms of where cases are increasing most quickly (at time of publication), the website Our World in Data highlights Laos, Timor, Thailand, Cambodia, Fiji and Mongolia as the countries where numbers have recently doubled in the shortest period of time (ranging from 16 to 23 days for these countries; for comparison, the doubling rate for India ahead of its second wave was 43 days). When looking at the countries whose reported deaths are currently doubling most quickly, it’s Timor, Thailand, Mongolia, Cambodia and Uruguay (range: four to 31 days).

For countries such as Laos, Thailand, Cambodia and also Vietnam (highly praised so far), it’s high susceptibility to COVID-19 that’s the problem. They’ve had few cases in the past, so there’s little natural immunity, and they’re now experiencing outbreaks amid an inability to procure a large vaccine supply. Vaccine coverage therefore is low. Thailand and Vietnam have given a first dose to just 2% and 1% of their populations respectively.

Elsewhere, it’s the mixing part of the equation that’s more of a concern. Japan, for example, is soon to host the Olympics, attracting athletes, dignitaries, coaches and media from every corner of the globe. Despite a ramping up of vaccine distribution over the past month, the programme has been sluggish, with less than 4% of the population having received a first dose. In this author’s view, the Olympics should not go ahead this year.

Latin America continues to experience a huge burden of COVID-19 disease and so is also at risk. Argentina, Uruguay, Costa Rica and Colombia are all still in the top ten countries in terms of daily new confirmed cases per million people. On the other hand, sub-Saharan Africa has on the face of it – with some exceptions – handled the pandemic relatively well, with countries praised for an early and decisive response, having learned lessons from the west African Ebola outbreak of 2013-16.

Working with uncertain data

Of course, our conclusions must be cautious. Creating high-quality real-time data during a public health emergency is complicated, and data is patchy and slow in most parts of the world. The extent of transmission within refugee camps and in conflict settings, for instance, is very much unknown. Some vulnerable areas may slip under the radar.

The reporting of data may also be influenced by local politics. Some countries, such as Tanzania, have chosen to downplay the severity of COVID-19. The former Tanzanian president, John Magufuli, died in March 2021 – and news coverage suggested he may have died of COVID-19 amid reports of uncontrolled outbreaks around the country and sharp increases in deaths. However, officially the impact of COVID-19 in Tanzania has been low.

Similarly, Belarus is reporting low death rates (27.8 per 100,000), having refused to consider COVID-19 a serious threat. But the Institute for Health Metrics and Evaluation (IMHE) has modelled the country’s actual death rate to be one of the highest in the world, at 472.2 per 100,000 people. IHME modelling puts Azerbaijan at the top of that list, with a death rate of 672.7 compared with official numbers of 46.3 per 100,000.

Politics and mixing

The timing of elections and volatility of political governance may be interesting factors to observe when trying to predict future spikes in cases. Political mass gatherings in India are likely to have contributed to the extensive recent transmission. The prime minister and health minister encouraged people to attend, wrongly believing earlier in the spring that India had reached the end stages of the pandemic.

Elsewhere, Donald Trump’s campaigning events caused numerous super-spreading events in the US, while in Myanmar there were reported breaches of COVID-19 protocols due to electioneering and mass gatherings. Myanmar’s elections in October 2020 were preceded by the highest spike in cases the country had experienced. Soon after the election, stricter policies were put in place and case rates lowered. Countries that engage in similar behaviour – or, like India, declare success too early – could well be the next hotspots.

Of course, the next outbreak may prove difficult to spot. Few of us could easily point to Timor on a map. This lack of knowledge influences our perception over local situations and also the news coverage that countries get. Compare Nepal and Timor to Brazil and India, on which public reporting has been extensive. Plus, some countries might not be reporting good-quality data – Belarus, Azerbaijan or indeed Russia may have much bigger burdens of COVID-19 than appears to be the case.

The “next big outbreak” will be reliant on a perfect storm of a few variables coming together. At the core of this storm will be a slow vaccine rollout and susceptible populations mixing freely. Political rallies, large-scale festivals and protests are examples of mass gatherings that can seed new outbreaks and facilitate sufficient spread to rapidly overwhelm a health system. But depending on where this happens, we may not even notice.


By                       :                    Michael Head (Senior Research Fellow in Global Health, University of Southampton)

Date                    :                    May 20, 2021

Source                :                    The Conversation