Increased transmissibility and global spread of SARS-CoV-2 variants of concern as at June 2021

We present a global analysis of the spread of recently emerged SARS-CoV-2 variants and estimate changes in effective reproduction numbers at country-specific level using sequence data from GISAID. Nearly all investigated countries demonstrated rapid replacement of previously circulating lineages by the World Health Organization-designated variants of concern, with estimated transmissibility increases of 29% (95% CI: 24-33), 25% (95% CI: 20-30), 38% (95% CI: 29-48) and 97% (95% CI: 76-117), respectively, for B.1.1.7, B.1.351, P.1 and B.1.617.2.

Ebola RNA Persistence in Semen of Ebola Virus Disease Survivors - Final Report

BACKGROUND

Ebola virus has been detected in the semen of men after their recovery from Ebola virus disease (EVD). We report the presence of Ebola virus RNA in semen in a cohort of survivors of EVD in Sierra Leone.

METHODS

We enrolled a convenience sample of 220 adult male survivors of EVD in Sierra Leone, at various times after discharge from an Ebola treatment unit (ETU), in two phases (100 participants were in phase 1, and 120 in phase 2). Semen specimens obtained at baseline were tested by means of a quantitative reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay with the use of the target sequences of NP and VP40 (in phase 1) or NP and GP (in phase 2). This study did not evaluate directly the risk of sexual transmission of EVD.

RESULTS

Of 210 participants who provided an initial semen specimen for analysis, 57 (27%) had positive results on quantitative RT-PCR. Ebola virus RNA was detected in the semen of all 7 men with a specimen obtained within 3 months after ETU discharge, in 26 of 42 (62%) with a specimen obtained at 4 to 6 months, in 15 of 60 (25%) with a specimen obtained at 7 to 9 months, in 4 of 26 (15%) with a specimen obtained at 10 to 12 months, in 4 of 38 (11%) with a specimen obtained at 13 to 15 months, in 1 of 25 (4%) with a specimen obtained at 16 to 18 months, and in no men with a specimen obtained at 19 months or later. Among the 46 participants with a positive result in phase 1, the median baseline cycle-threshold values (higher values indicate lower RNA values) for the NP and VP40 targets were lower within 3 months after ETU discharge (32.4 and 31.3, respectively; in 7 men) than at 4 to 6 months (34.3 and 33.1; in 25), at 7 to 9 months (37.4 and 36.6; in 13), and at 10 to 12 months (37.7 and 36.9; in 1). In phase 2, a total of 11 participants had positive results for NP and GP targets (samples obtained at 4.1 to 15.7 months after ETU discharge); cycle-threshold values ranged from 32.7 to 38.0 for NP and from 31.1 to 37.7 for GP.

CONCLUSIONS

These data showed the long-term presence of Ebola virus RNA in semen and declining persistence with increasing time after ETU discharge. (Funded by the World Health Organization and others.).

Impact of Ebola experiences and risk perceptions on mental health in Sierra Leone, July 2015

Background

The mental health impact of the 2014-2016 Ebola epidemic has been described among survivors, family members and healthcare workers, but little is known about its impact on the general population of affected countries. We assessed symptoms of anxiety, depression and post-traumatic stress disorder (PTSD) in the general population in Sierra Leone after over a year of outbreak response.

Methods

We administered a cross-sectional survey in July 2015 to a national sample of 3564 consenting participants selected through multistaged cluster sampling. Symptoms of anxiety and depression were measured by Patient Health Questionnaire-4. PTSD symptoms were measured by six items from the Impact of Events Scale-revised. Relationships among Ebola experience, perceived Ebola threat and mental health symptoms were examined through binary logistic regression.

Results

Prevalence of any anxiety-depression symptom was 48% (95% CI 46.8% to 50.0%), and of any PTSD symptom 76% (95% CI 75.0% to 77.8%). In addition, 6% (95% CI 5.4% to 7.0%) met the clinical cut-off for anxiety-depression, 27% (95% CI 25.8% to 28.8%) met levels of clinical concern for PTSD and 16% (95% CI 14.7% to 17.1%) met levels of probable PTSD diagnosis. Factors associated with higher reporting of any symptoms in bivariate analysis included region of residence, experiences with Ebola and perceived Ebola threat. Knowing someone quarantined for Ebola was independently associated with anxiety-depression (adjusted OR (AOR) 2.3, 95% CI 1.7 to 2.9) and PTSD (AOR 2.095% CI 1.5 to 2.8) symptoms. Perceiving Ebola as a threat was independently associated with anxiety-depression (AOR 1.69 95% CI 1.44 to 1.98) and PTSD (AOR 1.86 95% CI 1.56 to 2.21) symptoms.

Conclusion

Symptoms of PTSD and anxiety-depression were common after one year of Ebola response; psychosocial support may be needed for people with Ebola-related experiences. Preventing, detecting, and responding to mental health conditions should be an important component of global health security efforts.

Community screening interview for dementia (CSI 'D'); performance in five disparate study sites

The Community Screening Interview for Dementia (CSI 'D') was developed as a screening instrument for dementia for use in cross-cultural studies. It consists of two components, a cognitive test for non-literate and literate populations and an informant interview regarding performance in everyday living. The development of the CSI 'D', involving harmonization, translation, back translation and pilot testing, for use in five sites is described. The results demonstrate the adaptability and utility of the CSI 'D' in populations from very different socioeconomic backgrounds. The inclusion of informant data adds significantly to the performance of the CSI 'D' as a dementia screen. The combination of informant and cognitive scores in a discriminant score produces better sensitivity and specificity for dementia than cognitive scores alone. The informant score has a significant independent effect in predicting dementia.

Transactivation of interleukin 2 and its receptor induces immune activation in human T-cell lymphotropic virus type I-associated myelopathy: pathogenic implications and a rationale for immunotherapy

A state of T-cell activation, reflected by a marked degree of spontaneous proliferation in vitro, exists among patients with human T-cell lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) but not in those with retroviral-induced adult T-cell leukemia (ATL). We wished to define the mechanism by which the immune activation of circulating cells from HAM/TSP is driven, thus gaining insight into the pathogenesis of this HTLV-I-associated disease. By using a modification of the polymerase chain reaction, we compared the levels of interleukin 2 (IL-2) and IL-2 receptor alpha chain (IL-2R alpha) mRNA expression to the transcription of the HTLV-I transactivator gene, pX, in peripheral blood mononuclear cells of HAM/TSP and ATL patients as well as seropositive carriers. Up-regulation of IL-2 and IL-2R alpha transcripts was detected in HAM/TSP and seropositive carriers that paralleled the coordinate mRNA expression of the pX transactivator. In addition, IL-2 and soluble IL-2R alpha serum levels in HAM/TSP and seropositive carriers were elevated. Despite markedly elevated levels of soluble IL-2R alpha in ATL, transcripts for IL-2 and pX were not demonstrable in the circulating cells. Finally, the marked degree of in vitro spontaneous proliferation present in HAM/TSP was profoundly inhibited by specific anti-IL-2R or anti-IL-2 blocking antibodies. Collectively, these results suggest that immune activation in HAM/TSP, in contrast to ATL, is virally driven by the transactivation and coordinate expression of IL-2 and IL-2R alpha. This deregulated autocrine process may contribute to the evolution of inflammatory nervous system damage in HAM/TSP.

Policy implications for implementing evidence-based practices

The authors describe the policy and administrative-practice implications of implementing evidence-based services, particularly in public-sector settings. They review the observations of the contributors to the evidence-based practices series published throughout 2001 in Psychiatric Services. Quality and accountability have become the watchwords of health and mental health services; evidence-based practices are a means to both ends. If the objective of accountable, high-quality services is to be achieved by implementing evidence-based practices, the right incentives must be put in place, and systemic barriers must be overcome. The authors use the framework from the U.S. Surgeon General's 1999 report on mental health to describe eight courses of action for addressing the gap between science and practice: continue to build the science base; overcome stigma; improve public awareness of effective treatments; ensure the supply of mental health services and providers; ensure delivery of state-of-the-art treatments; tailor treatment to age, sex, race, and culture; facilitate entry into treatment; and reduce financial barriers to treatment.

Outbreak analytics: a developing data science for informing the response to emerging pathogens

Despite continued efforts to improve health systems worldwide, emerging pathogen epidemics remain a major public health concern. Effective response to such outbreaks relies on timely intervention, ideally informed by all available sources of data. The collection, visualization and analysis of outbreak data are becoming increasingly complex, owing to the diversity in types of data, questions and available methods to address them. Recent advances have led to the rise of outbreak analytics, an emerging data science focused on the technological and methodological aspects of the outbreak data pipeline, from collection to analysis, modelling and reporting to inform outbreak response. In this article, we assess the current state of the field. After laying out the context of outbreak response, we critically review the most common analytics components, their inter-dependencies, data requirements and the type of information they can provide to inform operations in real time. We discuss some challenges and opportunities and conclude on the potential role of outbreak analytics for improving our understanding of, and response to outbreaks of emerging pathogens. This article is part of the theme issue 'Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control'. This theme issue is linked with the earlier issue 'Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes'.

Infectious disease risks from dead bodies following natural disasters

OBJECTIVE

To review existing literature to assess the risks of infection from dead bodies after a natural disaster occurs, including who is most at risk, what precautions should be taken, and how to safely dispose of the bodies.

METHODS

Disease transmission requires the presence of an infectious agent, exposure to that agent, and a susceptible host. These elements were considered to characterize the infectious disease risk from dead bodies. Using the PubMed on-line databases of the National Library of Medicine of the United States of America, searching was done for relevant literature on the infection risks for public safety workers and funeral workers as well as for guidelines for the management of the dead and prevention of infection. A small but significant literature was also reviewed regarding the disposal of the dead and the contamination of groundwater by cemeteries.

RESULTS

Victims of natural disasters usually die from trauma and are unlikely to have acute or "epidemic-causing" infections. This indicates that the risk that dead bodies pose for the public is extremely small. However, persons who are involved in close contact with the dead-such as military personnel, rescue workers, volunteers, and others-may be exposed to chronic infectious hazards, including hepatitis B virus, hepatitis C virus, HIV, enteric pathogens, and Mycobacterium tuberculosis. Suitable precautions for these persons include training, use of body bags and disposable gloves, good hygiene practice, and vaccination for hepatitis B and tuberculosis. Disposal of bodies should respect local custom and practice where possible. When there are large numbers of victims, burial is likely to be the most appropriate method of disposal. There is little evidence of microbiological contamination of groundwater from burial.

CONCLUSIONS

Concern that dead bodies are infectious can be considered a "natural" reaction by persons wanting to protect themselves from disease. However, clear information about the risks is needed so that responsible local authorities ensure that the bodies of disaster victims are handled appropriately and with due respect. This paper provides a source of information for those who are in the unfortunate position of managing those bodies.

Approaches to increase physical activity: reviewing the evidence for exercise-referral schemes

OBJECTIVE

To review current evidence of effectiveness for exercise-referral schemes.

METHODS

Studies were identified from MEDLINE 1966-2002, EMBASE 1980-2002 and CINHAL 1982-2002 and bibliographies of relevant papers.

INCLUSION CRITERIA

Interventions providing access to exercise activities and/or facilities, experimental or quasi-experimental studies, studies with a control group, interventions based in a primary care setting, and interventions including an exercise component with measures of physical activity levels.

CONCLUSIONS

Exercise-referral schemes appear to increase physical activity levels in certain populations, namely individuals who are not sedentary but already slightly active, older adults and those who are overweight (but not obese). However, increases in the level of physical activity may not be sustained over time. Further studies are required to assess effectiveness in a range of populations and for different activities, and to find strategies to increase long-term adherence.

Outbreak of Ebola virus disease in the Democratic Republic of the Congo, April-May, 2018: an epidemiological study

BACKGROUND

On May 8, 2018, the Government of the Democratic Republic of the Congo reported an outbreak of Ebola virus disease in Équateur Province in the northwest of the country. The remoteness of most affected communities and the involvement of an urban centre connected to the capital city and neighbouring countries makes this outbreak the most complex and high risk ever experienced by the Democratic Republic of the Congo. We provide early epidemiological information arising from the ongoing investigation of this outbreak.

METHODS

We classified cases as suspected, probable, or confirmed using national case definitions of the Democratic Republic of the Congo Ministère de la Santé Publique. We investigated all cases to obtain demographic characteristics, determine possible exposures, describe signs and symptoms, and identify contacts to be followed up for 21 days. We also estimated the reproduction number and projected number of cases for the 4-week period from May 25, to June 21, 2018.

FINDINGS

As of May 30, 2018, 50 cases (37 confirmed, 13 probable) of Zaire ebolavirus were reported in the Democratic Republic of the Congo. 21 (42%) were reported in Bikoro, 25 (50%) in Iboko, and four (8%) in Wangata health zones. Wangata is part of Mbandaka, the urban capital of Équateur Province, which is connected to major national and international transport routes. By May 30, 2018, 25 deaths from Ebola virus disease had been reported, with a case fatality ratio of 56% (95% CI 39-72) after adjustment for censoring. This case fatality ratio is consistent with estimates for the 2014-16 west African Ebola virus disease epidemic (p=0·427). The median age of people with confirmed or probable infection was 40 years (range 8-80) and 30 (60%) were male. The most commonly reported signs and symptoms in people with confirmed or probable Ebola virus disease were fever (40 [95%] of 42 cases), intense general fatigue (37 [90%] of 41 cases), and loss of appetite (37 [90%] of 41 cases). Gastrointestinal symptoms were frequently reported, and 14 (33%) of 43 people reported haemorrhagic signs. Time from illness onset and hospitalisation to sample testing decreased over time. By May 30, 2018, 1458 contacts had been identified, of which 746 (51%) remained under active follow-up. The estimated reproduction number was 1·03 (95% credible interval 0·83-1·37) and the cumulative case incidence for the outbreak by June 21, 2018, is projected to be 78 confirmed cases (37-281), assuming heterogeneous transmissibility.

INTERPRETATION

The ongoing Ebola virus outbreak in the Democratic Republic of the Congo has similar epidemiological features to previous Ebola virus disease outbreaks. Early detection, rapid patient isolation, contact tracing, and the ongoing vaccination programme should sufficiently control the outbreak. The forecast of the number of cases does not exceed the current capacity to respond if the epidemiological situation does not change. The information presented, although preliminary, has been essential in guiding the ongoing investigation and response to this outbreak.

FUNDING

None.

Exposure Patterns Driving Ebola Transmission in West Africa: A Retrospective Observational Study

BACKGROUND

The ongoing West African Ebola epidemic began in December 2013 in Guinea, probably from a single zoonotic introduction. As a result of ineffective initial control efforts, an Ebola outbreak of unprecedented scale emerged. As of 4 May 2015, it had resulted in more than 19,000 probable and confirmed Ebola cases, mainly in Guinea (3,529), Liberia (5,343), and Sierra Leone (10,746). Here, we present analyses of data collected during the outbreak identifying drivers of transmission and highlighting areas where control could be improved.

METHODS AND FINDINGS

Over 19,000 confirmed and probable Ebola cases were reported in West Africa by 4 May 2015. Individuals with confirmed or probable Ebola ("cases") were asked if they had exposure to other potential Ebola cases ("potential source contacts") in a funeral or non-funeral context prior to becoming ill. We performed retrospective analyses of a case line-list, collated from national databases of case investigation forms that have been reported to WHO. These analyses were initially performed to assist WHO's response during the epidemic, and have been updated for publication. We analysed data from 3,529 cases in Guinea, 5,343 in Liberia, and 10,746 in Sierra Leone; exposures were reported by 33% of cases. The proportion of cases reporting a funeral exposure decreased over time. We found a positive correlation (r = 0.35, p < 0.001) between this proportion in a given district for a given month and the within-district transmission intensity, quantified by the estimated reproduction number (R). We also found a negative correlation (r = -0.37, p < 0.001) between R and the district proportion of hospitalised cases admitted within ≤4 days of symptom onset. These two proportions were not correlated, suggesting that reduced funeral attendance and faster hospitalisation independently influenced local transmission intensity. We were able to identify 14% of potential source contacts as cases in the case line-list. Linking cases to the contacts who potentially infected them provided information on the transmission network. This revealed a high degree of heterogeneity in inferred transmissions, with only 20% of cases accounting for at least 73% of new infections, a phenomenon often called super-spreading. Multivariable regression models allowed us to identify predictors of being named as a potential source contact. These were similar for funeral and non-funeral contacts: severe symptoms, death, non-hospitalisation, older age, and travelling prior to symptom onset. Non-funeral exposures were strongly peaked around the death of the contact. There was evidence that hospitalisation reduced but did not eliminate onward exposures. We found that Ebola treatment units were better than other health care facilities at preventing exposure from hospitalised and deceased individuals. The principal limitation of our analysis is limited data quality, with cases not being entered into the database, cases not reporting exposures, or data being entered incorrectly (especially dates, and possible misclassifications).

CONCLUSIONS

Achieving elimination of Ebola is challenging, partly because of super-spreading. Safe funeral practices and fast hospitalisation contributed to the containment of this Ebola epidemic. Continued real-time data capture, reporting, and analysis are vital to track transmission patterns, inform resource deployment, and thus hasten and maintain elimination of the virus from the human population.

Trust, fear, stigma and disruptions: community perceptions and experiences during periods of low but ongoing transmission of Ebola virus disease in Sierra Leone, 2015

Social mobilisation and risk communication were essential to the 2014–2015 West African Ebola response. By March 2015, >8500 Ebola cases and 3370 Ebola deaths were confirmed in Sierra Leone. Response efforts were focused on ‘getting to zero and staying at zero’. A critical component of this plan was to deepen and sustain community engagement. Several national quantitative studies conducted during this time revealed Ebola knowledge, personal prevention practices and traditional burial procedures improved as the outbreak waned, but healthcare system challenges were also noted. Few qualitative studies have examined these combined factors, along with survivor stigma during periods of ongoing transmission. To obtain an in-depth understanding of people’s perceptions, attitudes and behaviours associated with Ebola transmission risks, 27 focus groups were conducted between April and May 2015 with adult Sierra Leonean community members on: trust in the healthcare system, interactions with Ebola survivors, impact of Ebola on lives and livelihood, and barriers and facilitators to ending the outbreak. Participants perceived that as healthcare practices and facilities improved, so did community trust. Resource management remained a noted concern. Perceptions of survivors ranged from sympathy and empathy to fear and stigmatisation. Barriers included persistent denial of ongoing Ebola transmission, secret burials and movement across porous borders. Facilitators included personal protective actions, consistent messaging and the inclusion of women and survivors in the response. Understanding community experiences during the devastating Ebola epidemic provides practical lessons for engaging similar communities in risk communication and social mobilisation during future outbreaks and public health emergencies.

Impact of paracetamol pack size restrictions on poisoning from paracetamol in England and Wales: an observational study

BACKGROUND

About 500 drug poisoning deaths involving paracetamol (acetaminophen) occur every year in England and Wales. To reduce the number of deaths, regulations were introduced in 1998 to restrict the sale of paracetamol. In this paper, we evaluate the impact of these regulations.

METHODS

Mortality data for England and Wales were provided by the Office for National Statistics. Deaths were defined as due to compound paracetamol (paracetamol in combination with another analgesic, a low dose opioid or other ingredients) or paracetamol only, with or without alcohol or other drugs. The Department of Health provided data on all hospital admissions with a primary diagnosis of paracetamol poisoning.

RESULTS

Mortality rates for paracetamol only were similar for males and females, and decreased from about 4.5 to 2.8 per million between 1997 and 1999 and again from about 3.1 to 2.2 per million between 2001 and 2002. These falls may be attributable to random variation in the rates. Deaths involving compound paracetamol, which were not subject to the 1998 regulations, remained relatively constant over the study period. There was evidence of a decreasing trend in paracetamol only mortality rates and this followed overall trends for other drug poisoning excluding opioids and drugs of misuse. Hospital admissions due to paracetamol poisoning increased from about 27 000 to 33 000 between 1995/1996 and 1997/1998 and then decreased to 25 000 in 2001/2002. There were almost 50 per cent more admissions for females than males, with the highest admission rates amongst females aged 15-24 years old.

CONCLUSIONS

Between 1993 and 2002, mortality rates and hospital admissions due to paracetamol poisoning declined. However, the contribution of the 1998 regulations to this decline is not clear. Paracetamol poisoning continues to be an important public health issue in England and Wales and represents significant workload for the NHS in England.

Association between availability of heroin and methadone and fatal poisoning in England and Wales 1993–2004

BACKGROUND

The UK heroin market is the biggest in Europe and approximately 70% of heroin deaths are due to fatal poisoning. Methadone treatment for heroin addiction in the UK, the 'British system', is unique as it is largely provided by General Practitioners.

METHODS

The Office for National Statistics provided data on deaths, the Home Office provided law enforcement data on drug seizures and the Department of Health data on prescriptions. For methadone treatment we calculated the death rate per 1000 patient years. We used Spearman's rank correlation to assess the association between illicit drug seizures for heroin and methadone and deaths.

RESULTS

Between 1993 and 2004 there were 7072 deaths involving heroin/morphine (86% males) and 3298 deaths involving methadone (83% male). From 1993-1997, directly age-standardized mortality rates for males were similar for both drugs, increasing from approximately 5 to 15 per million. Mortality rates for heroin continued to increase until 2000, subsequently decreasing from 30 to 20 per million by 2003, and rising again to 24 per million in 2004. In contrast, mortality rates for methadone decreased between 1997 and 2004 to just above 1993 levels. Among females the mortality rate for both drugs was lower than for males throughout the study period, remaining relatively stable. Methadone deaths per 1000 patient years remained similar between 1993 and 1997, after which they fell by three quarters. For both heroin/morphine and methadone, deaths were strongly associated with seizures (Spearmans' coefficient for males: heroin, P = 0.95, P < 0.001 and methadone, P = 0.83, P = 0.0013).

CONCLUSIONS

Our study suggests the 'British System' can deliver substantial expansion of treatment without increased mortality risk. The fall in heroin/morphine deaths since 2000 may also be an indication of success of increasing methadone treatment. Data on mortality risk is needed to determine whether increased methadone treatment has reduced drug-related deaths.

Restricting paracetamol in the United Kingdom to reduce poisoning: a systematic review

BACKGROUND

Paracetamol poisoning is implicated in about 150-200 poisoning deaths per year in England and Wales. We review previous studies assessing the effectiveness of regulations introduced in 1998 to restrict sales of paracetamol and reduce paracetamol poisoning.

METHODS

We searched the following electronic databases: MEDLINE, EMBASE, CINHAL, HIMIC, COCH, APC, CENTRAL and DARE. English language publications between 1998 and 2003 were included. Studies were included if they took place in the United Kingdom and assessed changes in any aspect of paracetamol poisoning following the introduction of the 1998 regulations.

RESULTS

Twelve studies were identified, which examined several different outcomes. Three studies examined admissions to liver transplant units; all reported reductions. Eight studies evaluated severity of paracetamol poisoning; three reported reductions but five did not. Five out of six studies reported reductions in hospital admissions. One study reported reduced mortality in England and Wales after 1 year while another found no difference in Scotland 2 years after the regulations were introduced. Two studies observed a significant reduction in over-the-counter sales. Studies suffered from several limitations including short follow-up periods, no case definition for paracetamol poisoning and lack of comparison groups.

CONCLUSIONS

The limitations of these studies makes it difficult to draw firm conclusions. They do, however, suggest that the 1998 regulations may have been associated with reduced admissions to liver units and liver transplants, reduced hospital attendance due to paracetamol poisoning and reduced sales of paracetamol. Further research is needed to fully evaluate the impact of the 1998 regulations. In the future, formal evaluation of the impact of similar interventions should be an integral part of policy formation.

The risk of Guillain-Barré syndrome associated with influenza A (H1N1) 2009 monovalent vaccine and 2009-2010 seasonal influenza vaccines: results from self-controlled analyses

PURPOSE

The Centers for Disease Control and Prevention Emerging Infections Program implemented active, population-based surveillance for Guillain-Barré syndrome (GBS) following H1N1 vaccines in 10 states/metropolitan areas. We report additional analyses of these data using self-controlled methods, which avoid potential confounding from person-level factors and co-morbidities.

METHODS

Surveillance officers identified GBS cases with symptom onset during October 2009-April 2010 and ascertained receipt of H1N1 vaccines. We calculated self-controlled relative risks by comparing the number of cases with onset during a risk interval 1-42 days after vaccination with cases with onset during fixed (days 43-84) or variable (days 43-end of study period) control intervals. We calculated attributable risks by applying statistically significant relative risks to an independent estimate of GBS incidence.

RESULTS

Fifty-nine GBS cases received H1N1 vaccine with or without seasonal vaccine. The relative risk was 2.1 (95%CI 1.2, 3.5) by the variable-window and 3.0 (95%CI 1.4, 6.4) by the fixed-window analyses. The corresponding attributable risks per million doses administered were 1.5 (95%CI 0.3, 3.4) and 2.8 (95%CI 0.6, 7.4).

CONCLUSIONS

These attributable risks are similar to those of some previous formulations of seasonal influenza vaccine (about one to two cases per million doses administered), suggesting a low risk of GBS following the H1N1 vaccine that is not clearly higher than that of seasonal influenza vaccines.

Ebola Surveillance - Guinea, Liberia, and Sierra Leone

Developing a surveillance system during a public health emergency is always challenging but is especially so in countries with limited public health infrastructure. Surveillance for Ebola virus disease (Ebola) in the West African countries heavily affected by Ebola (Guinea, Liberia, and Sierra Leone) faced numerous impediments, including insufficient numbers of trained staff, community reticence to report cases and contacts, limited information technology resources, limited telephone and Internet service, and overwhelming numbers of infected persons. Through the work of CDC and numerous partners, including the countries' ministries of health, the World Health Organization, and other government and nongovernment organizations, functional Ebola surveillance was established and maintained in these countries. CDC staff were heavily involved in implementing case-based surveillance systems, sustaining case surveillance and contact tracing, and interpreting surveillance data. In addition to helping the ministries of health and other partners understand and manage the epidemic, CDC's activities strengthened epidemiologic and data management capacity to improve routine surveillance in the countries affected, even after the Ebola epidemic ended, and enhanced local capacity to respond quickly to future public health emergencies. However, the many obstacles overcome during development of these Ebola surveillance systems highlight the need to have strong public health, surveillance, and information technology infrastructure in place before a public health emergency occurs. Intense, long-term focus on strengthening public health surveillance systems in developing countries, as described in the Global Health Security Agenda, is needed.The activities summarized in this report would not have been possible without collaboration with many U.S and international partners (http://www.cdc.gov/vhf/ebola/outbreaks/2014-west-africa/partners.html).

Early Insights from Statistical and Mathematical Modeling of Key Epidemiologic Parameters of COVID-19

We report key epidemiologic parameter estimates for coronavirus disease identified in peer-reviewed publications, preprint articles, and online reports. Range estimates for incubation period were 1.8–6.9 days, serial interval 4.0–7.5 days, and doubling time 2.3–7.4 days. The effective reproductive number varied widely, with reductions attributable to interventions. Case burden and infection fatality ratios increased with patient age. Implementation of combined interventions could reduce cases and delay epidemic peak up to 1 month. These parameters for transmission, disease severity, and intervention effectiveness are critical for guiding policy decisions. Estimates will likely change as new information becomes available.

How decision makers can use quantitative approaches to guide outbreak responses

Decision makers are responsible for directing staffing, logistics, selecting public health interventions, communicating to professionals and the public, planning future response needs, and establishing strategic and tactical priorities along with their funding requirements. Decision makers need to rapidly synthesize data from different experts across multiple disciplines, bridge data gaps and translate epidemiological analysis into an operational set of decisions for disease control. Analytic approaches can be defined for specific response phases: investigation, scale-up and control. These approaches include: improved applications of quantitative methods to generate insightful epidemiological descriptions of outbreaks; robust investigations of causal agents and risk factors; tools to assess response needs; identifying and monitoring optimal interventions or combinations of interventions; and forecasting for response planning. Data science and quantitative approaches can improve decision-making in outbreak response. To realize these benefits, we need to develop a structured approach that will improve the quality and timeliness of data collected during outbreaks, establish analytic teams within the response structure and define a research agenda for data analytics in outbreak response.

This article is part of the theme issue ‘Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control’. This theme issue is linked with the earlier issue ‘Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes’.

Public information needs after the poisoning of Alexander Litvinenko with polonium-210 in London: cross sectional telephone survey and qualitative analysis

OBJECTIVES

To identify public perceptions of the risk to health after the poisoning of Alexander Litvinenko with polonium-210 (210Po) in London and to assess the impact of public health communications.

DESIGN

Cross sectional telephone survey and qualitative interviews.

SETTING

London, United Kingdom.

PARTICIPANTS

1000 people completed the cross sectional survey and 86 potentially exposed people completed the qualitative interviews.

MAIN OUTCOME MEASURES

Perception of risk to personal health after the 210Po incident. Qualitative interviews were analysed with an emphasis on information needs.

RESULTS

11.7% of the survey sample (n=117) perceived their health to be at risk. Aside from personal variables the main predictors of perceived risk to health were believing that the incident was related to terrorism (odds ratio 2.7, 95% confidence interval 1.5 to 4.6) rather than to espionage, that it was targeted at the wider public rather than one person (5.9, 3.2 to 10.9), and that it could affect people who had not been in the contaminated area (3.2, 2.1 to 5.1). Participants in the qualitative interviews were generally satisfied with the information they had received, although they would have preferred more information about their individual risk of exposure, the results of their urine tests, and the health implications of the incident.

CONCLUSIONS

Perceptions of the public that the 210Po incident in London in 2006 was related to espionage helped to reassure them that the risks to personal health were low. In the event of future incidents it is important to ensure that detailed, comprehensible information about the risks of any exposure is available.

HTLV-1 associated polymyositis in Jamaica

The clinical, laboratory and epidemiological characteristics of 38 adult Jamaican patients with polymyositis were evaluated. Twenty-four patients (63%) were human T-lymphotropic virus 1 (HTLV-1) seropositive and 14 patients (37%) were HTLV-1 seronegative. Polymyositis runs a more protracted course in seropositive patients who had more frequent hospital admissions and a significantly longer duration of symptoms prior to presentation. Joint swelling, chest pain and dyspnoea were more frequent complaints among the seronegative patients. There was no significant difference between the two serological groups in muscle enzyme levels, antinuclear antibody positivity or frequency of Jo-1 antibodies. HTLV-1 infection may define a subgroup of polymyositis patients with a more insidious presentation and poorer response to corticosteroid therapy.

Assessment of Community Event-Based Surveillance for Ebola Virus Disease, Sierra Leone, 2015

Case detection improved, but many false alerts were generated, suggesting a need for additional staff training.

In 2015, community event–based surveillance (CEBS) was implemented in Sierra Leone to assist with the detection of Ebola virus disease (EVD) cases. We assessed the sensitivity of CEBS for finding EVD cases during a 7-month period, and in a 6-week subanalysis, we assessed the timeliness of reporting cases with no known epidemiologic links at time of detection. Of the 12,126 CEBS reports, 287 (2%) met the suspected case definition, and 16 were confirmed positive. CEBS detected 30% (16/53) of the EVD cases identified during the study period. During the subanalysis, CEBS staff identified 4 of 6 cases with no epidemiologic links. These CEBS-detected cases were identified more rapidly than those detected by the national surveillance system; however, too few cases were detected to determine system timeliness. Although CEBS detected EVD cases, it largely generated false alerts. Future versions of community-based surveillance could improve case detection through increased staff training and community engagement.

Hyperinfection syndrome with Strongyloides stercoralis in malignant lymphoma

Hyperinfection with Strongyloides stercoralis occurred in three patients with malignant lymphoma. The probable cause in each case was alteration of the immune responses either as a result of the malignant lymphoma or by the treatment given. Though thiabendazole (Mintezol) has produced reasonable results in the treatment of the hyperinfection syndrome, preliminary data suggest that the new broad-spectrum anthelmintic levamisole (Ketrax) is more effective. All patients who live or have lived in an area where strongyloidiasis is endemic should be investigated to detect the presence of the nematode before and during treatment with drugs with immunosuppressive properties. In view of the high mortality with S. stercoralis hyperinfection, vigorous therapy should be instituted before the use of immunosuppressive drugs.

Ebola Virus Infection Associated with Transmission from Survivors

Ebola virus (EBOV) can persist in immunologically protected body sites in survivors of Ebola virus disease, creating the potential to initiate new chains of transmission. From the outbreak in West Africa during 2014-2016, we identified 13 possible events of viral persistence-derived transmission of EBOV (VPDTe) and applied predefined criteria to classify transmission events based on the strength of evidence for VPDTe and source and route of transmission. For 8 events, a recipient case was identified; possible source cases were identified for 5 of these 8. For 5 events, a recipient case or chain of transmission could not be confidently determined. Five events met our criteria for sexual transmission (male-to-female). One VPDTe event led to at least 4 generations of cases; transmission was limited after the other events. VPDTe has increased the importance of Ebola survivor services and sustained surveillance and response capacity in regions with previously widespread transmission.