Examining the Association Between Household Enrollment in the Pantawid Pamilyang Pilipino Program (4Ps) and Wasting and Stunting Status Among Children Experiencing Poverty in the Philippines: A Cross-Sectional Study.

This study assessed whether enrollment in a national conditional cash transfer program was associated with wasting and stunting among children experiencing extreme poverty in the Philippines. Data were drawn from cross-sectional surveys collected from 10 regional areas in the Philippines between April 2018 and May 2019. A total of 2945 children aged between six months and 12 years comprised the analytical sample. Multilevel logistic regression was conducted to estimate the association between enrollment in Pantawid Pamilyang Pilipino Program (4Ps) and stunting and wasting, controlling for sociodemographic factors and clustering by region. There was no meaningful association between household enrollment in 4Ps and the wasting status of children, but enrollment in 4Ps was associated with lower odds of stunting and differed by geography type. Findings suggest that the current design of 4Ps may not address sudden shocks that contribute to wasting, but may address the underlying socioeconomic risk factors associated with stunting.

The contributions of religious leaders in addressing food insecurity during the COVID-19 pandemic in the Philippines: A realist evaluation of the Rapid Emergencies and Disasters Intervention (REDI).

To address the unintended consequences of public health measures during the COVID-19 pandemic (e.g., emergency food insecurity, income loss), non-governmental organizations (NGOs) have partnered with diverse actors, including religious leaders, to provide humanitarian relief in resource-constrained communities. One such example is the Rapid Emergencies and Disasters Intervention (REDI), which is an NGO-led program in the Philippines that leverages a network of volunteer religious leaders to identify and address emergency food insecurity among households experiencing poverty. Guided by a realist evaluation approach, the objectives of this study were to identify the facilitators and barriers to effective implementation of REDI by religious leaders during the COVID-19 pandemic and to explore the context and mechanisms that influenced REDI implementation. In total, we conducted 25 virtual semi-structured interviews with religious leaders actively engaged in REDI implementation across 17 communities in Negros Occidental, Philippines. Interviews were audio recorded, transcribed, and thematically analyzed. Three main context-mechanism configurations were identified in shaping effective food aid distribution by religious leaders, including program infrastructure (e.g., technical and relational support from partner NGO), social infrastructure (e.g., social networks), and community infrastructure (e.g., community assets as well as a broader enabling environment). Overall, this study contributes insight into how the unique positionality of religious leaders in combination with organizational structures and guidance from a partner NGO shapes the implementation of a disaster response initiative across resource-constrained communities. Further, this study describes how intersectoral collaboration (involving religious leaders, NGOs, and local governments) can be facilitated through an NGO-led disaster response network.

Extending health systems resilience into communities: a qualitative study with community-based actors providing health services during the COVID-19 pandemic in the Philippines.

BACKGROUND: Amidst ongoing calls for increased health systems resilience, gaps remain in our understanding of how health systems can reach further into communities to ensure resilient service delivery. Indeed, public health emergencies caused by infectious hazards reveal both the value and vulnerability of the workforce delivering health services in communities. This study explores ways in which a non-governmental organization (NGO) in the Philippines protected their frontline workforce during the first year of the COVID-19 pandemic. METHODS: Guided by a qualitative descriptive approach, 34 in-depth interviews were conducted with community-based health actors employed by the NGO between June 2020 and February 2021. Data analysis was guided by an iterative deductive and inductive approach. RESULTS: We identified four key activities that enabled the NGO and their staff to provide health and social services in communities in a safe and consistent manner as part of the organization's pandemic response. These include (1) ensuring adequate personal protective equipment (PPE) and hygiene supplies; (2) providing contextualized and role-specific infection prevention and control (IPC) training; (3) ensuring access to testing for all staff; and (4) providing support during quarantine or isolation. CONCLUSION: Learning from the implementation of these activities offers a way forward toward health emergency preparedness and response that is crucially needed for NGOs to safely leverage their workforce during pandemics. Further, we describe how community-based health actors employed by NGOs can contribute to broader health systems resilience in the context of health emergency preparedness and response.

Dramatic increases in knowledge, attitudes and practices of COVID-19 observed among low-income households in the Philippines: A repeated cross-sectional study in 2020.

Background: The COVID-19 pandemic has severely impacted populations globally, and knowledge, attitudes and practices (KAPs) surrounding the virus have necessarily evolved. This study was conducted in partnership with International Care Ministries (ICM), a Philippine-based non-governmental organization that runs the "Transform" poverty alleviation program. The main objective of this study was to describe the changes in COVID-19 KAPs among households experiencing extreme poverty in the Philippines over an 8-month period. Methods: A KAP questionnaire was integrated into the household survey collected as part of ICM's regular monitoring and evaluation of "Transform". Data collection for the first survey was conducted between February 20 and March 13, 2020, and the second survey was conducted between November 12 and December 12, 2020. Frequencies and proportions were calculated to describe the respondents' responses and the Kruskal-Wallis test was used to assess if there were significant differences in KAP identification between the two time points. Results: We observed a distinct increase across all KAP domains. Over 90% of study participants were able to correctly identify COVID-19 transmission modes and preventive measures, and an even higher percentage reported adopting these measures. However, the intention to seek care from public hospitals for COVID-19 symptoms dropped from 43.6% to 28.4%, while reports of self-treatment using stored medicines or antibiotics increased. Trust in community members and local health authorities was correlated with higher knowledge and practice scores. Conclusions: Our study results reflect the extraordinary speed of information dissemination and behaviour change globally over the course of the pandemic, but they also highlight the changes in KAP that show the additional challenges faced by populations experiencing poverty in the Philippines. Prioritization of reducing inequities in the implementation and adoption of the evolving public health measures will be integral as the pandemic continues.

Exploring the Role of Social Networks in Facilitating Health Service Access Among Low-Income Women in the Philippines: A Qualitative Study.

Despite efforts to implement universal health care coverage (UHC) in the Philippines, income poor households continue to face barriers to health care access and use. In light of recent UHC legislation, the aim of this study was to explore how gender and social networks shape health care access and use among women experiencing poverty in Negros Occidental, Philippines. Semi-structured interviews were conducted with women (n = 35) and health care providers (n = 15). Descriptive statistical analyses were performed to report demographic information. Interview data were analyzed thematically using a hybrid deductive-inductive approach and guided by the Patient-Centred Access to Health Care framework. Women's decisions regarding health care access were influenced by their perceptions of illness severity, their trust in health care facilities, and their available financial resources. Experiences of health care use were shaped by interactions with health professionals, resource availability at facilities, health care costs, and health insurance acquisition. Women drew upon social networks throughout their lifespan for social and financial support to facilitate healthcare access and use. These findings indicate that social networks may be an important complement to formal supports (eg, UHC) in improving access to health care for women experiencing poverty in the Philippines.

Addressing tuberculosis through complex community-based socioeconomic interventions in low- and middle-income countries: A systematic realist review.

The established relationship between poverty and tuberculosis has led to the implementation of complex socioeconomic interventions to address poverty as both a risk factor for and consequence of tuberculosis. However, limited research to date has examined the conditions that facilitate the successful implementation of these interventions. We conducted a systematic realist review to examine how complex socioeconomic interventions for tuberculosis treatment and care were defined, implemented, and evaluated in low- and middle-income countries. We used a systematic search to identify published work that implemented complex socioeconomic interventions for tuberculosis, followed by a realist analysis informed by existing programme theories. From a total of 2825 collected records, 36 peer-reviewed articles and 17 grey literature reports were included in this review. The realist analysis identified three main contexts (sociopolitical and cultural; relational and interpersonal; operational and administrative) and ten mechanisms that facilitated successful implementation of interventions. Overall, this review highlights the importance of political commitment in shaping sustainable programme delivery, the role of healthcare and community-based provider training in creating patient-centred treatment environments, and the opportunity to leverage operational research for evidence-based decision making to address the socioeconomic needs of tuberculosis patients experiencing poverty.

Codevelopment of COVID-19 infection prevention and control guidelines in lower-middle-income countries: the 'SPRINT' principles.

INTRODUCTION: The COVID-19 pandemic has required the rapid development of comprehensive guidelines to direct health service organisation and delivery. However, most guidelines are based on resources found in high-income settings, with fewer examples that can be implemented in resource-constrained settings. This study describes the process of adapting and developing role-specific guidelines for comprehensive COVID-19 infection prevention and control in low-income and middle-income countries (LMICs). METHODS: We used a collaborative autoethnographic approach to explore the process of developing COVID-19 guidelines. In this approach, multiple researchers contributed their reflections, conducted joint analysis through dialogue, reflection and with consideration of experiential knowledge and multidisciplinary perspectives to identify and synthesise enablers, challenges and key lessons learnt. RESULTS: We describe the guideline development process in the Philippines and the adaptation process in Sri Lanka. We offer key enablers identified through this work, including flexible leadership that aimed to empower the team to bring their expertise to the process; shared responsibility through equitable ownership; an interdisciplinary team; and collaboration with local experts. We then elaborate on challenges including interpreting other guidelines to the country context; tensions between the ideal compared with the feasible and user-friendly; adapting and updating with evolving information; and coping with pandemic-related challenges. Based on key lessons learnt, we synthesise a novel set of principles for developing guidelines during a public health emergency. The SPRINT principles are grounded in situational awareness, prioritisation and balance, which are responsive to change, created by an interdisciplinary team navigating shared responsibility and transparency. CONCLUSIONS: Guideline development during a pandemic requires a robust and time sensitive paradigm. We summarise the learning in the 'SPRINT principles' for adapting guidelines in an epidemic context in LMICs. We emphasise that these principles must be grounded in a collaborative or codesign process and add value to existing national responses.

National primary care responses to COVID-19: a rapid review of the literature.

OBJECTIVE: The aim of this review, conducted in April 2020, is to examine available national primary care guidelines for COVID-19 and to explore the ways in which these guidelines support primary care facilities in responding to the demands of the COVID-19 pandemic. DESIGN: Rapid review and narrative synthesis. DATA SOURCES: PubMed, Embase and Google, as well as the websites of relevant national health departments, were searched from 1 January 2020 to 24 April 2020. ELIGIBILITY CRITERIA: Documents included must be issued by a national health authority, must be specific to COVID-19 care, directed at healthcare workers or managers, and must refer to the role of primary care in the COVID-19 response. RESULTS: We identified 17 documents from 14 countries. An adapted framework on primary care challenges and responses to pandemic influenza framed our analysis. Guidelines generally reported on COVID-19 service delivery and mostly made specific recommendations for ensuring continued delivery of essential primary care services through telehealth or other virtual care modalities. Few offered guidance to support surveillance as a public health function. All offered guidance on implementing outbreak control measures, largely through flexible and coordinated organisational models with partners from various sectors. There was a lack of guidance to support supply chain management and practice resilience in primary care, and lack of personal protective equipment represents a serious threat to the provision of quality care during the pandemic. CONCLUSIONS: Current national primary care guidelines for COVID-19 provide guidance on infection control and minimising the risk of spread in primary care practices, while supporting the use of new technology and coordinated partnerships. However, to ensure primary care practice resilience and quality of care are upheld, guidelines must offer recommendations on supply chain management and operational continuity, supported by adequate resources.

Social trust and health seeking behaviours: A longitudinal study of a community-based active tuberculosis case finding program in the Philippines.

INTRODUCTION: Social trust is an important driver of health seeking behaviours and plays a particularly important role for diseases that have a high degree of stigma associated with them, such as tuberculosis (TB). Individuals experiencing poverty also face additional social and financial barriers in accessing care for TB. We examined an active case finding (ACF) initiative embedded in a program targeting those living in poverty (Transform) implemented by International Care Ministries (ICM), a Philippine-based non-governmental organization (NGO), and analyzed how different forms of social trust may affect the initial uptake of ACF. METHODS: Program monitoring data and a cross-sectional survey conducted at the beginning of Transform included six dimensions of social trust: satisfaction with family life, satisfaction with friendships, and level of trust in relatives, neighbours, pastor or religious leader, and local government officials. Amongst individuals suspected of having TB who received referrals post-screening, multilevel modelling examined the effects of social trust on rural health unit (RHU) attendance. RESULTS: Among the subset of 3350 individuals who received TB screening in 51 communities, 889 (26.5%) were symptom positive and required referral to the RHU, but only 24.1% of those who received referrals successfully attended the RHU. Multilevel regression analysis showed that for each unit increase on the Likert scale in baseline level of family satisfaction and level of trust in relatives, the odds of attending an RHU was 1.03 times (95% CI: 0.99, 1.07) and 1.06 times greater (95% CI: 1.00, 1.11), respectively, independent of other factors. CONCLUSION: These results suggest that social trust in family members could play a valuable role in addressing stigma and rejection, both cited as barriers to higher screening rates. It is recommended that ACF programs that target TB, or other diseases that are stigmatized, prioritize trust-building as an important component of their intervention.

Viral Shedding and Transmission Potential of Asymptomatic and Paucisymptomatic Influenza Virus Infections in the Community.

Background: Influenza virus infections are associated with a wide spectrum of disease. However, few studies have investigated in detail the epidemiological and virological characteristics of asymptomatic and mild illness with influenza virus infections. Methods: In a community-based study in Hong Kong from 2008 to 2014, we followed up initially healthy individuals who were household contacts of symptomatic persons with laboratory-confirmed influenza, to identify secondary infections. Information from daily symptom diaries was used to classify infections as symptomatic (≥2 signs/symptoms, including fever ≥37.8°C, headache, myalgia, cough, sore throat, runny nose and sputum), paucisymptomatic (1 symptom only), or asymptomatic (none of these symptoms). We compared the patterns of influenza viral shedding between these groups. Results: We identified 235 virologically confirmed secondary cases of influenza virus infection in the household setting, including 31 (13%) paucisymptomatic and 25 (11%) asymptomatic cases. The duration of viral RNA shedding was shorter and declined more rapidly in paucisymptomatic and asymptomatic than in symptomatic cases. The mean levels of influenza viral RNA shedding in asymptomatic and paucisymptomatic cases were approximately 1-2 log10 copies lower than in symptomatic cases. Conclusions: The presence of influenza viral shedding in patients with influenza who have very few or no symptoms reflects their potential for transmitting the virus to close contacts. These findings suggest that further research is needed to investigate the contribution of persons with asymptomatic or clinically mild influenza virus infections to influenza virus transmission in household, institutional, and community settings.

The Dynamic Relationship Between Clinical Symptomatology and Viral Shedding in Naturally Acquired Seasonal and Pandemic Influenza Virus Infections.

BACKGROUND: Although the pattern of viral shedding over time has been documented in volunteer challenge studies, understanding of the relationship between clinical symptomatology and viral shedding in naturally acquired influenza infections in humans remains limited. METHODS: In a community-based study in Hong Kong from 2008 to 2014, we followed up initially healthy individuals and identified 224 secondary cases of natural influenza virus infection in the household setting. We examined the dynamic relationship between patterns of clinical symptomatology and viral shedding as quantified using reverse transcription polymerase chain reaction and viral culture in 127 cases with a clinical picture of acute respiratory infection. RESULTS: Viral shedding in influenza A virus infections peaked on the first 1-2 days of clinical illness, and decreased gradually to undetectable levels by day 6-7, matching closely with the dynamics of clinical illness. Viral shedding in influenza B virus infections rose up to 2 days prior to symptom onset and persisted for 6-7 days after onset with a bimodal pattern. CONCLUSIONS: Our results suggest that while clinical illness profiles may serve as a proxy for clinical infectiousness in influenza A virus infections, patients may potentially be infectious even before symptom onset or after clinical improvement in influenza B virus infections.

Household Transmission of Influenza Virus.

Human influenza viruses cause regular epidemics and occasional pandemics with a substantial public health burden. Household transmission studies have provided valuable information on the dynamics of influenza transmission. We reviewed published studies and found that once one household member is infected with influenza, the risk of infection in a household contact can be up to 38%, and the delay between onset in index and secondary cases is around 3 days. Younger age was associated with higher susceptibility. In the future, household transmission studies will provide information on transmission dynamics, including the correlation of virus shedding and symptoms with transmission, and the correlation of new measures of immunity with protection against infection.

A systematic review and meta-analysis of prophylactic central neck dissection on short-term locoregional recurrence in papillary thyroid carcinoma after total thyroidectomy.

BACKGROUND: Prophylactic central neck dissection (pCND) at the time of total thyroidectomy (TT) remains controversial in clinically node-negative (cN0) papillary thyroid carcinoma (PTC). Despite occult central lymph node metastases being common, it is unclear if removing these metastases initially would reduce future locoregional recurrence (LRR). This systematic review and meta-analysis aimed at comparing the short-term LRR between patients who underwent TT with pCND and those who underwent TT alone. METHODS: A systematic review of the literature was performed to identify studies comparing LRR between patients with PTC who underwent TT + pCND (group A) and those who underwent TT alone (group B). Inclusion criteria were cN0 patients, with each comparative group containing > 10 patients, and with the number of LRR and mean follow-up duration available. The pooled incidence rate ratio (IRR) was used for calculating the LRR rate between the two groups. Other parameters evaluated included postoperative radioiodine (RAI) ablation, surgically related complications, and overall morbidity. Meta-analysis was performed using a fixed-effects model. RESULTS: Fourteen studies matched the selection criteria. Of the 3331 patients, 1592 (47.8%) belonged to group A, while 1739 (52.2%) belonged to group B. Relative to group B, group A was significantly more likely to have postoperative RAI ablation (71.7% vs. 53.1%; odds ratio [OR] = 2.60 [95% confidence interval (CI) = 2.12-3.18]), temporary hypocalcemia (26.0% vs. 10.8%; OR = 2.56 [CI = 2.04-3.21]), and overall morbidity (33.2% vs. 17.7%; OR = 2.12 [CI = 1.75-2.57]). When temporary hypocalcemia was excluded, overall morbidity was similar between the two groups (7.3% vs. 6.8%; OR = 1.07 [CI = 0.78-1.47]). Group A had a significantly lower risk of LRR than group B (4.7% vs. 8.6%; IRR = 0.65 [CI = 0.48-0.86]). CONCLUSIONS: Group A was more likely to have postoperative RAI ablation, temporary hypocalcemia, and overall morbidity than group B. Temporary hypocalcemia was the major surgical morbidity in pCND and, when excluded, the overall morbidity appeared similar between the two groups. Although our meta-analysis would suggest that those who undergo TT + pCND may have a 35% reduction in risk of LRR than those who undergo TT alone in the short term (< 5 years), it remains unclear how much of this risk reduction is related to increased use of RAI ablation and potential selection bias in some of the studies examined.

Heterogeneity in viral shedding among individuals with medically attended influenza A virus infection.

Compared with the average transmissibility of human influenza A virus, much less attention has been paid to the potential variability in its transmissibility. We considered viral shedding as a proxy for infectiousness and explored the heterogeneity of infectiousness among patients with medically attended seasonal influenza A virus infection. The analysis revealed that viral shedding is more heterogeneous in children than in adults. The top 20% most infectious children and adults were estimated to be responsible for 89%-96% and 78%-82%, respectively, of the total infectiousness in each age group. Further investigation is required to correlate the substantial variations in viral shedding with heterogeneity in actual transmissibility.

A systematic review and meta-analysis comparing the efficacy and surgical outcomes of total thyroidectomy between harmonic scalpel versus ligasure.

BACKGROUND: Both ultrasonic coagulation (Harmonic Scalpel) (HS) and bipolar coagulation (Ligasure) (LS) are new energy devices commonly used in open thyroidectomy. This systematic review aimed at comparing the efficacy and surgical outcomes of total thyroidectomy (TT) between HS and. LS. METHODS: A systematic review of the literature was performed to identify studies comparing HS and LS. Intraoperative outcomes, surgically related complications, overall morbidity, and hospital stay were evaluated. Meta-analysis was performed using a fixed-effects model. RESULTS: There were 8 studies that matched the selection criteria. Of the 963 patients who underwent TT, 433 (45.0 %) used HS (HS group) while 530 (55.0 %) used LS (LS group). Compared with LS, the HS group had significantly less volume of blood loss by 2.22 ml (95 % CI = 0.26-4.23 ml) (standardized mean difference [SMD] = -0.2, 95 % CI = -0.38 to -0.02) and reduced total operating time by 3.32 minutes (95 % CI = 1.62-5.03 minutes) (SMD = -0.28, 95 % CI = -0.42 to -0.15). There was no significant difference in temporary postoperative hypocalcemia (OR = 1.29, 95 % CI = 0.88-1.90), permanent postoperative hypocalcemia (OR = 1.45, 95 % CI = 0.23-9.26), temporary recurrent laryngeal nerve (RLN) injury (OR = 1.34; 95 % CI = 0.66-2.71), permanent RLN injury (OR = 1.00; 95 % CI = 0.25-4.03), hematoma (OR = 1.00; 95 % CI = 0.3-3.31), overall morbidity (OR = 1.21, 95 % CI = 0.87-1.69), and hospital stay (SMD = -0.03; 95 % CI = -0.07 to 0.01). CONCLUSIONS: Compared with LS, using HS in TT significantly reduced the volume of blood loss and operating time. However, the clinical significance of these findings remained questionable because the overall mean difference appeared small. There was no significant difference in the rate of complications, overall morbidity, and hospital stay between the two devices.

Household transmission of 2009 pandemic influenza A (H1N1): a systematic review and meta-analysis.

BACKGROUND: During the 2009 influenza A (H1N1) pandemic, household transmission studies were implemented to better understand the characteristics of the transmission of the novel virus in a confined setting. METHODS: We conducted a systematic review and meta-analysis to assess and summarize the findings of these studies. We identified 27 articles, around half of which reported studies conducted in May and June 2009. RESULTS: In 13 of the 27 studies (48%) that collected respiratory specimens from household contacts, point estimates of the risk of secondary infection ranged from 3% to 38%, with substantial heterogeneity. Meta-regression analyses revealed that a part of the heterogeneity reflected varying case ascertainment and study designs. The estimates of symptomatic secondary infection risk, based on 20 studies identifying febrile acute respiratory illness among household contacts, also showed substantial variability, with point estimates ranging from 4% to 37%. CONCLUSIONS: Transmission of the 2009 pandemic virus in households appeared to vary among countries and settings, with differences in estimates of the secondary infection risk also partly due to differences in study designs.

Seroprevalence of pandemic H1N1 antibody among health care workers in Hong Kong following receipt of monovalent 2009 H1N1 influenza vaccine.

BACKGROUND: Healthcare workers in many countries are recommended to receive influenza vaccine to protect themselves as well as patients. A monovalent H1N1 vaccine became available in Hong Kong in December 2009 and around 10% of local healthcare workers had received the vaccine by February 2010. METHODS: We conducted a cross-sectional study of the prevalence of antibody to pandemic (H1N1) 2009 among HCWs in Hong Kong in February-March 2010 following the first pandemic wave and the pH1N1 vaccination campaign. In this study we focus on the subset of healthcare workers who reported receipt of non-adjuvanted monovalent 2009 H1N1 vaccine (Panenza, Sanofi Pasteur). Sera collected from HCWs were tested for antibody against the pH1N1 virus by hemagglutination inhibition (HI) and viral neutralization (VN) assays. RESULTS: We enrolled 703 HCWs. Among 104 HCWs who reported receipt of pH1N1 vaccine, 54% (95% confidence interval (CI): 44%-63%) had antibody titer ≥1∶40 by HI and 42% (95% CI: 33%-52%) had antibody titer ≥1∶40 by VN. The proportion of HCWs with antibody titer ≥1∶40 by HI and VN significantly decreased with age, and the proportion with antibody titer ≥1∶40 by VN was marginally significantly lower among HCWs who reported prior receipt of 2007-08 seasonal influenza vaccine (odds ratio: 0.43; 95% CI: 0.19-1.00). After adjustment for age, the effect of prior seasonal vaccine receipt was not statistically significant. CONCLUSIONS: Our findings suggest that monovalent H1N1 vaccine may have had suboptimal immunogenicity in HCWs in Hong Kong. Larger studies are required to confirm whether influenza vaccine maintains high efficacy and effectiveness in HCWs.

Comparative epidemiology of pandemic and seasonal influenza A in households.

BACKGROUND: There are few data on the comparative epidemiology and virology of the pandemic 2009 influenza A (H1N1) virus and cocirculating seasonal influenza A viruses in community settings. METHODS: We recruited 348 index patients with acute respiratory illness from 14 outpatient clinics in Hong Kong in July and August 2009. We then prospectively followed household members of 99 patients who tested positive for influenza A virus on rapid diagnostic testing. We collected nasal and throat swabs from all household members at three home visits within 7 days for testing by means of quantitative reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay and viral culture. Using hemagglutination-inhibition and viral-neutralization assays, we tested baseline and convalescent serum samples from a subgroup of patients for antibody responses to the pandemic and seasonal influenza A viruses. RESULTS: Secondary attack rates (as confirmed on RT-PCR assay) among household contacts of index patients were similar for the pandemic influenza virus (8%; 95% confidence interval [CI], 3 to 14) and seasonal influenza viruses (9%; 95% CI, 5 to 15). The patterns of viral shedding and the course of illness among index patients were also similar for the pandemic and seasonal influenza viruses. In a subgroup of patients for whom baseline and convalescent serum samples were available, 36% of household contacts who had serologic evidence of pandemic influenza virus infection did not shed detectable virus or report illness. CONCLUSIONS: Pandemic 2009 H1N1 virus has characteristics that are broadly similar to those of seasonal influenza A viruses in terms of rates of viral shedding, clinical illness, and transmissibility in the household setting.

Viral shedding and clinical illness in naturally acquired influenza virus infections.

BACKGROUND: Volunteer challenge studies have provided detailed data on viral shedding from the respiratory tract before and through the course of experimental influenza virus infection. There are no comparable quantitative data to our knowledge on naturally acquired infections. METHODS: In a community-based study in Hong Kong in 2008, we followed up initially healthy individuals to quantify trends in viral shedding on the basis of cultures and reverse-transcription polymerase chain reaction (RT-PCR) through the course of illness associated with seasonal influenza A and B virus infection. RESULTS: Trends in symptom scores more closely matched changes in molecular viral loads measured with RT-PCR for influenza A than for influenza B. For influenza A virus infections, the replicating viral loads determined with cultures decreased to undetectable levels earlier after illness onset than did molecular viral loads. Most viral shedding occurred during the first 2-3 days after illness onset, and we estimated that 1%-8% of infectiousness occurs prior to illness onset. Only 14% of infections with detectable shedding at RT-PCR were asymptomatic, and viral shedding was low in these cases. CONCLUSIONS: Our results suggest that "silent spreaders" (ie, individuals who are infectious while asymptomatic or presymptomatic) may be less important in the spread of influenza epidemics than previously thought.

Entry screening to delay local transmission of 2009 pandemic influenza A (H1N1).

BACKGROUND: After the WHO issued the global alert for 2009 pandemic influenza A (H1N1), many national health agencies began to screen travelers on entry in airports, ports and border crossings to try to delay local transmission. METHODS: We reviewed entry screening policies adopted by different nations and ascertained dates of official report of the first laboratory-confirmed imported H1N1 case and the first laboratory-confirmed untraceable or 'local' H1N1 case. RESULTS: Implementation of entry screening policies was associated with on average additional 7-12 day delays in local transmission compared to nations that did not implement entry screening, with lower bounds of 95% confidence intervals consistent with no additional delays and upper bounds extending to 20-30 day additional delays. CONCLUSIONS: Entry screening may lead to short-term delays in local transmission of a novel strain of influenza virus. The resources required for implementation should be balanced against the expected benefits of entry screening.