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1.
Epigenomics ; 15(7): 453-473, 2023 04.
Article in English | MEDLINE | ID: covidwho-20238843

ABSTRACT

The rate of substance use is rising, especially among reproductive-age individuals. Emerging evidence suggests that paternal pre-conception and maternal prenatal substance use may alter offspring epigenetic regulation (changes to gene expression without modifying DNA) and outcomes later in life, including neurodevelopment and mental health. However, relatively little is known due to the complexities and limitations of existing studies, making causal interpretations challenging. This review examines the contributions and influence of parental substance use on the gametes and potential transmissibility to the offspring's epigenome as possible areas to target public health warnings and healthcare provider counseling of individuals or couples in the pre-conception and prenatal periods to ultimately mitigate short- and long-term offspring morbidity and mortality.


More people, especially those of reproductive age, are using substances, and there is growing evidence to suggest that parental substance use before and during pregnancy may adversely affect offspring and result in issues later in life, including mental health challenges. Such relationships have been demonstrated with nicotine, alcohol, cannabis, opioids and illegal drugs (e.g., heroin, cocaine, methamphetamines). Some of these adverse impacts on offspring can potentially be passed down in families even after parents have quit using the substance. Because more individuals are using drugs, especially during the COVID-19 pandemic, it is important that families learn more about the potential impact of substance use on their future offspring before they try to get pregnant.


Subject(s)
Epigenesis, Genetic , Substance-Related Disorders , Pregnancy , Female , Humans , DNA Methylation , Parents , Reproduction , Substance-Related Disorders/genetics
2.
Am J Reprod Immunol ; 89(6): e13705, 2023 06.
Article in English | MEDLINE | ID: covidwho-2324421
3.
Hum Fertil (Camb) ; 26(1): 169-181, 2023 Feb.
Article in English | MEDLINE | ID: covidwho-2317259

ABSTRACT

We explored whether coronavirus disease 2019 (COVID-19)-related distress was associated with voluntary suspension of medically-assisted reproduction (MAR) treatment from April to May 2020 in Japan. Data for 1,096 candidate respondents were collected from a Japanese nationwide cross-sectional internet survey distributed from August 25 to September 30, 2020. Multiple logistic regression was performed to clarify the association between voluntary suspension of MAR treatment and the Fear of COVID-19 Scale (FVC-19S) score. High FCV-19S score was inversely associated with voluntary suspension of MAR treatment compared to low FCV-19S score among women (OR = 0.28, 95% CI = 0.10-0.84). Age-stratified analyses revealed that low FVC-19S score was significantly associated with voluntary suspension of MAR treatment among women aged < 35 years (OR = 3.86, 95% CI = 1.35-11.0). In contrast, the association between FVC-19S score and voluntary suspension of MAR treatment was reversed and not significant among women aged ≥ 35 years (OR = 0.67, 95% CI = 0.24-1.84). COVID-19-related distress was significantly associated with voluntary suspension of MAR treatment among women aged < 35 years, and this association was reversed but not significant among women aged ≥ 35 years.


Subject(s)
COVID-19 , Pandemics , Humans , Female , Japan/epidemiology , COVID-19/epidemiology , Cross-Sectional Studies , Internet , Reproduction
4.
Bull Entomol Res ; 113(3): 396-401, 2023 Jun.
Article in English | MEDLINE | ID: covidwho-2299489

ABSTRACT

Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), is a major global pest of fruits. Currently, the sequential male annihilation technique, followed by the sterile insect technique has been used to significantly reduce the population of feral males in this species. However, issues with sterile males being killed by going to male annihilation traps have reduced the efficacy of this approach. The availability of males that are non-methyl eugenol-responding would minimize this issue and increase the efficacy of both approaches. For this, we recently established two separate lines of non-methyl eugenol-responding males. These lines were reared for 10 generations and in this paper, we report on the assessment of males from these lines in terms of methyl eugenol response and mating ability. We saw a gradual decrease in non-responders from ca. 35 to 10% after the 7th generation. Despite that, there were still significant differences until the 10th generation in numbers of non-responders over controls using laboratory strain males. We did not attain pure isolines of non-methyl eugenol-responding males, so we used non-responders from the 10th generation of those lines as sires to initiate two reduced-responder lines. Using these reduced responder flies, we found that there was no significant difference in mating competitiveness when compared with control males. Overall, we suggest that it may be possible to establish lines of low or reduced responder males to be used for sterile release programs, that could be applied until the 10th generation of rearing. Our information will contribute to the further development of an increasingly successful management technique incorporating the use of SIT alongside MAT to contain wild populations of B. dorsalis.


Subject(s)
Tephritidae , Male , Animals , Tephritidae/physiology , Eugenol/pharmacology , Sexual Behavior, Animal , Reproduction
5.
J Womens Health (Larchmt) ; 32(6): 657-669, 2023 06.
Article in English | MEDLINE | ID: covidwho-2297606

ABSTRACT

Background: People's preferences regarding how they want to obtain contraception should be considered when building and refining high-quality contraceptive care programs, especially in light of recent shifts to incorporate more telehealth options into contraceptive care due to the coronavirus disease 2019 (COVID-19) pandemic. Methods: Our study is a cross-sectional analysis of population-representative surveys conducted between November 2019 and August 2020 among women aged 18-44 years in Arizona (N = 885), New Jersey (N = 952), and Wisconsin (N = 967). We use multivariable logistic regression to identify characteristics associated with each of five contraception source preference groups (in-person via health care provider, offsite with a provider via telemedicine, offsite without a provider via telehealth, at a pharmacy, or via innovative strategies), and we examine associations between contraceptive care experiences and perceptions and each preference group. Results: Across states, most respondents (73%) expressed preferences for obtaining contraception via more than one source. One quarter indicated a narrow preference for obtaining contraception in-person from a provider, 19% expressed interest in doing so offsite with a provider via telemedicine, 64% for doing so offsite without a provider via telehealth, 71% reported interest in pharmacy-based contraception, and 25% indicated interest in getting contraception through innovative strategies. Those who had experienced nonperson-centered contraceptive counseling reported higher levels of interest in telehealth and innovative sources, and those who expressed mistrust in the contraceptive care system had higher levels of preferring to obtain contraception offsite, via telemedicine, telehealth, and other innovative avenues. Conclusions: Policies that ensure access to a diversity of contraceptive sources, which acknowledge and address people's past experiences of contraceptive care, have the greatest likelihood of closing the gap between people's contraceptive access preferences and realities.


Subject(s)
COVID-19 , Female , Humans , Adult , Cross-Sectional Studies , Contraception , Contraceptive Agents , Reproduction , Family Planning Services , Contraception Behavior
6.
Hum Reprod ; 38(6): 1202-1212, 2023 06 01.
Article in English | MEDLINE | ID: covidwho-2290606

ABSTRACT

STUDY QUESTION: How did the first two coronavirus disease 2019 (COVID-19) waves affect fertility rates in the USA? SUMMARY ANSWER: States differed widely in how their fertility rates changed following the COVID-19 outbreak and these changes were influenced more by state-level economic, racial, political, and social factors than by COVID-19 wave severity. WHAT IS KNOWN ALREADY: The outbreak of the COVID-19 pandemic contributed to already declining fertility rates in the USA, but not equally across states. Identifying drivers of differential changes in fertility rates can help explain variations in demographic shifts across states in the USA and motivate policies that support families in general, not only during crises. STUDY DESIGN, SIZE, DURATION: This is an ecological study using state-level data from 50 US states and the District of Columbia (n = 51). The study period extends from 2020 to 2021 with historical data from 2016 to 2019. We identified Wave 1 as the first apex for each state after February 2020 and Wave 2 as the second apex, during Fall/Winter 2020-2021. PARTICIPANTS/MATERIALS, SETTING, METHODS: State-level COVID-19 wave severity, defined as case acceleration during each 3-month COVID-19 wave (cases/100 000 population/month), was derived from 7-day weekly moving average COVID-19 case rates from the US Centers for Disease Control and Prevention (CDC). State-level fertility rate changes (change in average monthly fertility rate/100 000 women of reproductive age (WRA)/year) were derived from the CDC Bureau of Vital Statistics and from 2020 US Census and University of Virginia 2021 population estimates 9 months after each COVID-19 wave. We performed univariate analyses to describe national and state-level fertility rate changes following each wave, and simple and multivariable linear regression analyses to assess the relation of COVID-19 wave severity and other state-level characteristics with fertility rate changes. MAIN RESULTS AND THE ROLE OF CHANCE: Nationwide, fertility dropped by 17.5 births/month/100 000 WRA/year following Wave 1 and 9.2 births/month/100 000 WRA/year following Wave 2. The declines following Wave 1 were largest among majority-Democrat, more non-White states where people practiced greater social distancing. Greater COVID-19 wave severity was associated with steeper fertility rate decline post-Wave 1 in simple regression, but the association was attenuated when adjusted for other covariates. Adjusting for the economic impact of the pandemic (hypothesized mediator) also attenuated the effect. There was no relation between COVID-19 wave severity and fertility rate change following Wave 2. LIMITATIONS, REASONS FOR CAUTION: Our study harnesses state-level data so individual-level conclusions cannot be inferred. There may be residual confounding in our multivariable regression and we were underpowered to detect some effects. WIDER IMPLICATIONS OF THE FINDINGS: The COVID-19 pandemic initially impacted the national fertility rate but, overall, the fertility rate rebounded to the pre-pandemic level following Wave 2. Consistent with prior literature, COVID-19 wave severity did not appear to predict fertility rate change. Economic, racial, political, and social factors influenced state-specific fertility rates during the pandemic more than the severity of the outbreak alone. Future studies in other countries should also consider whether these factors account for internal heterogeneity when examining the impact of the COVID-19 pandemic and other crises on fertility. STUDY FUNDING/COMPETING INTEREST(S): L.G.K. received funding from the National Institute of Environmental Health Sciences (R00ES030403), M.C. from the National Science Foundation Graduate Research Fellowship Program (20-A0-00-1005789), and M.L. and E.S. from the National Institute of Environmental Health Sciences (R01ES032808). None of the authors have competing interests. TRIAL REGISTRATION NUMBER: N/A.


Subject(s)
Birth Rate , COVID-19 , Humans , Female , COVID-19/epidemiology , Pandemics , Fertility , Reproduction
8.
Eur J Med Res ; 28(1): 94, 2023 Feb 24.
Article in English | MEDLINE | ID: covidwho-2265598

ABSTRACT

SARS-COV-2 is responsible for the current worldwide pandemic, which started on December 2019 in Wuhan, China. On March 2020 World Health Organization announced COVID-19 as the new pandemic. Some SARS-COV-2 variants have increased transmissibility, cause more severe disease (e.g., increased hospitalizations or deaths), are resistant to antibodies produced by the previous infection or vaccination, and there is more difficulty in treatment and diagnosis of them. World Health Organization considered them as SARS-CoV-2 variants of concern. The introductory reproduction rate (R0) is an epidemiologic index of the transmissibility of the virus, defined as the average number of persons infected by the virus after known contact with an infectious person in a susceptible population. An R0 > 1 means that the virus is spreading exponentially, and R0 < 1, means that the outbreak is subsiding. In various studies, the estimated R and VOC growth rates were reported to be greater than the ancestral strains. However, it was also a low level of concordance between the estimated Rt of the same variant in different studies. It is because the R of a variant not only dependent on the biological and intrinsic factors of the virus but also several parameters can affect the R0, including the duration of contagiousness and the likelihood of infection per contact. Evaluation of changes in SARS-CoV-2 has shown that the rate of human-to-human transmission of this virus has increased. Like other viruses with non-human sources which succeeded in surviving in the human population, SARS-CoV-2 has gradually adapted to the human population, and its ability to transmit from human to human has increased. Of course, due to the continuous changes in this virus, it is crucial to survey the rate of transmission of the virus over time.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , COVID-19/epidemiology , Pandemics , Reproduction
9.
Front Immunol ; 14: 1120328, 2023.
Article in English | MEDLINE | ID: covidwho-2254864

ABSTRACT

Introduction: Every second woman suffering from infertility asks for medical help. There is public concern that vaccination-induced antibodies (Ab) are negatively associated with fertility. A recent study has demonstrated an association between SARS-CoV-2 vaccination and a lower pregnancy rate in the subsequent 60 days. Consequently, Ab could affect fertility success in assisted reproduction. Methods: To address this question, we compared fertilization outcomes of vaccinated (n=35) and nonvaccinated (n=34) women. Paired serum samples and multiple follicular fluids (FF) (up to 10 from the same donor) were collected during the course of assisted reproduction and characterized for oocyte quality, the presence of Ab and trace element concentrations. Results: The results showed a positive correlation of vaccination-induced neutralizing activity of SARS-CoV-2-Ab in serum and FF. On average, Ab concentrations in serum were higher than in the corresponding FF. However, wide variations in SARS-CoV-2 Ab titers were observed between different FF, correlating to trace element levels, even when retrieved from the same donor. Discussion: Overall, FF contents are highly variable, but no negative association was observed between Ab in serum or FF and fertilization success and oocyte development, supporting the safety of SARS-CoV-2 vaccination during assisted reproduction.


Subject(s)
COVID-19 , Trace Elements , Pregnancy , Humans , Female , Follicular Fluid , SARS-CoV-2 , Fertilization in Vitro/methods , COVID-19 Vaccines , Antibodies, Viral , Reproduction
10.
Nat Commun ; 14(1): 956, 2023 02 22.
Article in English | MEDLINE | ID: covidwho-2270284

ABSTRACT

Women of reproductive age are a group of particular concern with regards to vaccine uptake, related to their unique considerations of menstruation, fertility, and pregnancy. To obtain vaccine uptake data specific to this group, we obtained vaccine surveillance data from the Office for National Statistics, linked with COVID-19 vaccination status from the National Immunisation Management Service, England, from 8 Dec 2020 to 15 Feb 2021; data from 13,128,525 such women at population-level, were clustered by age (18-29, 30-39, and 40-49 years), self-defined ethnicity (19 UK government categories), and index of multiple deprivation (IMD, geographically-defined IMD quintiles). Here we show that among women of reproductive age, older age, White ethnicity and being in the least-deprived index of multiple deprivation are each independently associated with higher vaccine uptake, for first and second doses; however, ethnicity exerts the strongest influence (and IMD the weakest). These findings should inform future vaccination public messaging and policy.


Subject(s)
COVID-19 Vaccines , COVID-19 , Pregnancy , Humans , Female , Adolescent , England/epidemiology , Ethnicity , Reproduction , Vaccination
11.
J Assist Reprod Genet ; 40(2): 259-263, 2023 Feb.
Article in English | MEDLINE | ID: covidwho-2252950

ABSTRACT

The emergence of telehealth including telemedicine, at-home testing, and mobile health applications has enabled patients to self-manage their reproductive care, especially during the COVID-19 pandemic. Reproduction is rapidly changing and embracing deeptech initiatives that can improve outcomes and facilitate personalized fertility solutions in the near future. This so-called DIY IVF informed by deeptech and moderated by femtech not only holds a tremendous amount of promise, but also challenges and possible pitfalls. This review discusses the current status of deeptech and femtech for IVF care in a post-Roe v. Wade environment.


Subject(s)
COVID-19 , Telemedicine , Humans , COVID-19/epidemiology , Pandemics , Reproduction , Fertilization in Vitro
12.
PLoS One ; 18(2): e0281943, 2023.
Article in English | MEDLINE | ID: covidwho-2251513

ABSTRACT

We provide a novel way to correct the effective reproduction number for the time-varying amount of tests, using the acceleration index (Baunez et al., 2021) as a simple measure of viral spread dynamics. Not correcting results in the reproduction number being a biased estimate of viral acceleration and we provide a formal decomposition of the resulting bias, involving the useful notions of test and infectivity intensities. When applied to French data for the COVID-19 pandemic (May 13, 2020-October 26, 2022), our decomposition shows that the reproduction number, when considered alone, characteristically underestimates the resurgence of the pandemic, compared to the acceleration index which accounts for the time-varying volume of tests. Because the acceleration index aggregates all relevant information and captures in real time the sizable time variation featured by viral circulation, it is a more parsimonious indicator to track the dynamics of an infectious disease outbreak in real time, compared to the equivalent alternative which would combine the reproduction number with the test and infectivity intensities.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , Pandemics , France/epidemiology , Acceleration , Reproduction
13.
Am J Mens Health ; 16(1): 15579883221074816, 2022.
Article in English | MEDLINE | ID: covidwho-2268849

ABSTRACT

With the global epidemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the increasing number of infections, little is known about how SARS-CoV-2 affects the male reproductive system during infection or after recovery. Based on the existing research data, we reviewed the effects of SARS-CoV-2 on the male reproductive system and discussed its possible mechanism of action. SARS-CoV-2 enters host cells through the angiotensin-converting enzyme 2 (ACE2)/transmembrane serine protease 2 (TMPRSS2) pathway, and males are more susceptible than females. After infection, immunopathological damage is noticed in the testicles, and the semen index is significantly reduced. Second, abnormalities of serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone (T) levels were also observed, suggesting that there may be dysfunction of the hypothalamic-pituitary-gonadal (HPG) axis. Even after recovery, the effect of SARS-CoV-2 on the male reproductive system can last for at least a period. There are still many unresolved questions about the effect of SARS-CoV-2 infection on the male reproductive tract. Other receptors involved during the invasion of human cells by SARS-CoV-2 remain to be identified. Will the mutation of SARS-CoV-2 increase the diversity of receptors? How does SARS-CoV-2 affect the HPG axis? The long-term effects of SARS-CoV-2 on the male reproductive system remain to be evaluated. SARS-CoV-2 infection can affect male reproductive function. Standard treatment strategies should be developed in time to protect the fertility of infected patients. For recovered patients with fertility requirements, fertility assessments should be performed and professional fertility guidance should be provided at the same time.


Subject(s)
COVID-19 , Female , Genitalia, Male , Humans , Male , Reproduction , SARS-CoV-2 , Testis
14.
Fertil Steril ; 119(4): 618-623, 2023 04.
Article in English | MEDLINE | ID: covidwho-2244586

ABSTRACT

OBJECTIVE: To assess whether vaccination or the type of vaccine against SARS-CoV-2 affects ovarian function in an assisted reproduction treatment. DESIGN: A retrospective and observational study. SETTING: University-affiliated private in vitro fertilization (IVF) center. PATIENT(S): Five hundred one patients who had received the complete vaccination schedule. INTERVENTION(S): Treatment before and after vaccination. MAIN OUTCOME MEASURE(S): Parameters for both reproductive outcomes and IVF results in patients vaccinated RESULT(S): We included 510 patients, distributed as follows: 13.5% (n = 69) received a viral vector vaccine, either the adenovirus serotype 26 vector vaccine (Ad26.CoV2.S; Janssen; n = 31) or the chimpanzee adenovirus vector vaccine (ChAdOx; AstraZeneca; n = 38). The remaining 86.5% (n = 441) received an messenger RNA vaccine from either Pfizer-BioNTech (n = 336) or Moderna (n = 105). Sample size for the unexposed women was n = 1190. No differences were found in any of the evaluated parameters for both reproductive outcomes and IVF results in patients vaccinated with any adenovirus or messenger RNA vaccine. When we compared the results after vaccination with different types of vaccines between the exposed and unexposed groups, and similar results were obtained in the days of stimulation or the doses of administered follicle stimulating hormone. Finally, the numbers of oocytes were as follows: Johnson & Johnson (9.2 ± 2.6), AstraZeneca (7.7 ± 1.2), Moderna (11.3 ± 1.8), Pfizer (12.6 ± 1.0), and the unvaccinated group (10.2 ± 1.5), P=0.057. CONCLUSION(S): These early results suggest no measurable detrimental effect on reproductive outcomes, regardless of the type of vaccine received.


Subject(s)
COVID-19 Vaccines , COVID-19 , Fertilization in Vitro , Ovary , Female , Humans , Ad26COVS1 , COVID-19/prevention & control , COVID-19 Vaccines/adverse effects , Reproduction , Retrospective Studies , RNA, Messenger , SARS-CoV-2 , Vaccination/adverse effects , Ovary/drug effects , ChAdOx1 nCoV-19
15.
Sci Rep ; 13(1): 2435, 2023 02 10.
Article in English | MEDLINE | ID: covidwho-2239956

ABSTRACT

One clear aspect of behaviour in the COVID-19 pandemic has been people's focus on, and response to, reported or observed infection numbers in their community. We describe a simple model of infectious disease spread in a pandemic situation where people's behaviour is influenced by the current risk of infection and where this behavioural response acts homeostatically to return infection risk to a certain preferred level. This homeostatic response is active until approximate herd immunity is reached: in this domain the model predicts that the reproduction rate R will be centred around a median of 1, that proportional change in infection numbers will follow the standard Cauchy distribution with location and scale parameters 0 and 1, and that high infection numbers will follow a power-law frequency distribution with exponent 2. To test these predictions we used worldwide COVID-19 data from 1st February 2020 to 30th June 2022 to calculate [Formula: see text] confidence interval estimates across countries for these R, location, scale and exponent parameters. The resulting median R estimate was [Formula: see text] (predicted value 1) the proportional change location estimate was [Formula: see text] (predicted value 0), the proportional change scale estimate was [Formula: see text] (predicted value 1), and the frequency distribution exponent estimate was [Formula: see text] (predicted value 2); in each case the observed estimate agreed with model predictions.


Subject(s)
COVID-19 , Humans , COVID-19/epidemiology , Pandemics , Reproduction , Statistical Distributions
16.
Genes (Basel) ; 13(9)2022 09 10.
Article in English | MEDLINE | ID: covidwho-2236662

ABSTRACT

Genetic variation has been widely covered in literature, however, not from the perspective of an individual in any species. Here, a synthesis of genetic concepts and variations relevant for individual genetic constitution is provided. All the different levels of genetic information and variation are covered, ranging from whether an organism is unmixed or hybrid, has variations in genome, chromosomes, and more locally in DNA regions, to epigenetic variants or alterations in selfish genetic elements. Genetic constitution and heterogeneity of microbiota are highly relevant for health and wellbeing of an individual. Mutation rates vary widely for variation types, e.g., due to the sequence context. Genetic information guides numerous aspects in organisms. Types of inheritance, whether Mendelian or non-Mendelian, zygosity, sexual reproduction, and sex determination are covered. Functions of DNA and functional effects of variations are introduced, along with mechanism that reduce and modulate functional effects, including TARAR countermeasures and intraindividual genetic conflict. TARAR countermeasures for tolerance, avoidance, repair, attenuation, and resistance are essential for life, integrity of genetic information, and gene expression. The genetic composition, effects of variations, and their expression are considered also in diseases and personalized medicine. The text synthesizes knowledge and insight on individual genetic heterogeneity and organizes and systematizes the central concepts.


Subject(s)
Genetic Heterogeneity , Genome , Chromosomes , DNA , Reproduction/genetics
17.
Stat Methods Med Res ; 31(9): 1675-1685, 2022 09.
Article in English | MEDLINE | ID: covidwho-2236610

ABSTRACT

Since the beginning of the COVID-19 pandemic, the reproduction number [Formula: see text] has become a popular epidemiological metric used to communicate the state of the epidemic. At its most basic, [Formula: see text] is defined as the average number of secondary infections caused by one primary infected individual. [Formula: see text] seems convenient, because the epidemic is expanding if [Formula: see text] and contracting if [Formula: see text]. The magnitude of [Formula: see text] indicates by how much transmission needs to be reduced to control the epidemic. Using [Formula: see text] in a naïve way can cause new problems. The reasons for this are threefold: (1) There is not just one definition of [Formula: see text] but many, and the precise definition of [Formula: see text] affects both its estimated value and how it should be interpreted. (2) Even with a particular clearly defined [Formula: see text], there may be different statistical methods used to estimate its value, and the choice of method will affect the estimate. (3) The availability and type of data used to estimate [Formula: see text] vary, and it is not always clear what data should be included in the estimation. In this review, we discuss when [Formula: see text] is useful, when it may be of use but needs to be interpreted with care, and when it may be an inappropriate indicator of the progress of the epidemic. We also argue that careful definition of [Formula: see text], and the data and methods used to estimate it, can make [Formula: see text] a more useful metric for future management of the epidemic.


Subject(s)
COVID-19 , Basic Reproduction Number , COVID-19/epidemiology , Forecasting , Humans , Pandemics/prevention & control , Reproduction
18.
Epidemiology ; 34(2): 201-205, 2023 03 01.
Article in English | MEDLINE | ID: covidwho-2222829

ABSTRACT

BACKGROUND: The time-varying reproduction number, Rt, is commonly used to monitor the transmissibility of an infectious disease during an epidemic, but standard methods for estimating Rt seldom account for the impact of overdispersion on transmission. METHODS: We developed a negative binomial framework to estimate Rt and a time-varying dispersion parameter (kt). We applied the framework to COVID-19 incidence data in Hong Kong in 2020 and 2021. We conducted a simulation study to compare the performance of our model with the conventional Poisson-based approach. RESULTS: Our framework estimated an Rt peaking around 4 (95% credible interval = 3.13, 4.30), similar to that from the Poisson approach but with a better model fit. Our approach further estimated kt <0.5 at the start of both waves, indicating appreciable heterogeneity in transmission. We also found that kt decreased sharply to around 0.4 when a large cluster of infections occurred. CONCLUSIONS: Our proposed approach can contribute to the estimation of Rt and monitoring of the time-varying dispersion parameters to quantify the role of superspreading.


Subject(s)
COVID-19 , Epidemics , Humans , COVID-19/epidemiology , Computer Simulation , Hong Kong/epidemiology , Reproduction
20.
Sci Rep ; 13(1): 1052, 2023 01 19.
Article in English | MEDLINE | ID: covidwho-2186064

ABSTRACT

Early detection of the emergence of a new variant of concern (VoC) is essential to develop strategies that contain epidemic outbreaks. For example, knowing in which region a VoC starts spreading enables prompt actions to circumscribe the geographical area where the new variant can spread, by containing it locally. This paper presents 'funnel plots' as a statistical process control method that, unlike tools whose purpose is to identify rises of the reproduction number ([Formula: see text]), detects when a regional [Formula: see text] departs from the national average and thus represents an anomaly. The name of the method refers to the funnel-like shape of the scatter plot that the data take on. Control limits with prescribed false alarm rate are derived from the observation that regional [Formula: see text]'s are normally distributed with variance inversely proportional to the number of infectious cases. The method is validated on public COVID-19 data demonstrating its efficacy in the early detection of SARS-CoV-2 variants in India, South Africa, England, and Italy, as well as of a malfunctioning episode of the diagnostic infrastructure in England, during which the Immensa lab in Wolverhampton gave 43,000 incorrect negative tests relative to South West and West Midlands territories.


Subject(s)
COVID-19 , Communicable Diseases , Humans , SARS-CoV-2 , COVID-19/diagnosis , COVID-19/epidemiology , Communicable Diseases/epidemiology , Reproduction
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