Risk factors associated with hospitalisation for influenza-associated severe acute respiratory illness in South Africa: A case-population study

Effect of Pneumococcal Conjugate Vaccines on Viral Respiratory Infections: A Systematic Literature Review

BACKGROUND

In addition to preventing pneumococcal disease, emerging evidence indicates that pneumococcal conjugate vaccines (PCVs) might indirectly reduce viral respiratory tract infections (RTIs) by affecting pneumococcal-viral interactions.

METHODS

We performed a systematic review of interventional and observational studies published during 2000-2022 on vaccine efficacy/adjusted effectiveness (VE) and overall effect of PCV7, PCV9, PCV10, or PCV13 against viral RTIs.

RESULTS

Sixteen of 1671 records identified were included. Thirteen publications described effects of PCVs against viral RTIs in children. VE against influenza ranged between 41% and 86% (n = 4), except for the 2010-2011 influenza season. In a randomized controlled trial, PCV9 displayed efficacy against any viral RTI, human seasonal coronavirus, parainfluenza, and human metapneumovirus. Data in adults were limited (n = 3). PCV13 VE was 4%-25% against viral lower RTI, 32%-35% against coronavirus disease 2019 outcomes, 24%-51% against human seasonal coronavirus, and 13%-36% against influenza A lower RTI, with some 95% confidence intervals spanning zero. No protection was found against adenovirus or rhinovirus in children or adults.

CONCLUSIONS

PCVs were associated with protection against some viral RTI, with the strongest evidence for influenza in children. Limited evidence for adults was generally consistent with pediatric data. Restricting public health evaluations to confirmed pneumococcal outcomes may underestimate the full impact of PCVs.

Maternal immunization in women living with HIV

Thanks to widespread use of antiretroviral therapy worldwide, women living with HIV (WLWH) are becoming pregnant and giving birth to HIV-exposed but uninfected (HEU) newborns. Both pregnancy and HIV infection-related factors such as low CD4+ T-cell count or uncontrolled viral load increase the risk of severe infections such as influenza, COVID-19, and others, making maternal immunization a valuable tool to decrease maternal morbidity among WLWH. Vaccines administered during pregnancy may also benefit the health of HEU infants. Indeed, HEU infants suffer from higher risk of morbidity of infectious origin, including respiratory syncytial virus (RSV), group B streptococcus (GBS), pneumococcus and pertussis infections. Maternal pertussis immunization is recommended in various high-income countries but not in many low-middle income countries where HIV prevalence is higher. GBS and RSV vaccines to be administered during pregnancy are currently in late-phase clinical trials in HIV-uninfected women and could represent a valuable tool to decrease morbidity during infancy. Decreased transfer of vaccine-specific IgG, accelerated waning of vaccine-induced antibody responses, linked to persistent maternal immune activation, and blunting of infant immune response to vaccines could hamper vaccine effectiveness among WLWH and HEU infants. Vaccine hesitancy could limit benefits of maternal immunization and strategies to tackle vaccine hesitancy should be part of HIV routine care. The aim of this review is to summarize the current knowledge regarding the immunogenicity and efficacy of available and upcoming vaccines recommended during pregnancy of WLWH.

Relationship between molecular pathogen detection and clinical disease in febrile children across Europe: a multicentre, prospective observational study

BACKGROUND

The PERFORM study aimed to understand causes of febrile childhood illness by comparing molecular pathogen detection with current clinical practice.

METHODS

Febrile children and controls were recruited on presentation to hospital in 9 European countries 2016-2020. Each child was assigned a standardized diagnostic category based on retrospective review of local clinical and microbiological data. Subsequently, centralised molecular tests (CMTs) for 19 respiratory and 27 blood pathogens were performed.

FINDINGS

Of 4611 febrile children, 643 (14%) were classified as definite bacterial infection (DB), 491 (11%) as definite viral infection (DV), and 3477 (75%) had uncertain aetiology. 1061 controls without infection were recruited. CMTs detected blood bacteria more frequently in DB than DV cases for N. meningitidis (OR: 3.37, 95% CI: 1.92-5.99), S. pneumoniae (OR: 3.89, 95% CI: 2.07-7.59), Group A streptococcus (OR 2.73, 95% CI 1.13-6.09) and E. coli (OR 2.7, 95% CI 1.02-6.71). Respiratory viruses were more common in febrile children than controls, but only influenza A (OR 0.24, 95% CI 0.11-0.46), influenza B (OR 0.12, 95% CI 0.02-0.37) and RSV (OR 0.16, 95% CI: 0.06-0.36) were less common in DB than DV cases. Of 16 blood viruses, enterovirus (OR 0.43, 95% CI 0.23-0.72) and EBV (OR 0.71, 95% CI 0.56-0.90) were detected less often in DB than DV cases. Combined local diagnostics and CMTs respectively detected blood viruses and respiratory viruses in 360 (56%) and 161 (25%) of DB cases, and virus detection ruled-out bacterial infection poorly, with predictive values of 0.64 and 0.68 respectively.

INTERPRETATION

Most febrile children cannot be conclusively defined as having bacterial or viral infection when molecular tests supplement conventional approaches. Viruses are detected in most patients with bacterial infections, and the clinical value of individual pathogen detection in determining treatment is low. New approaches are needed to help determine which febrile children require antibiotics.

FUNDING

EU Horizon 2020 grant 668303.

Associations of Combustible Cigarette, Electronic Cigarette, and Dual Use With COVID Infection and Severity in the U.S.: A Cross-sectional Analysis of the 2021 National Health Information Survey

Given the potential respiratory health risks, the association of COVID infection and the use of combustible cigarettes, electronic nicotine delivery systems (ENDS), and concurrent dual use is a priority for public health. Many published reports have not accounted for known covarying factors. This study sought to calculate adjusted odds ratios for self-reported COVID infection and disease severity as a function of smoking and ENDS use, while accounting for factors known to influence COVID infection and disease severity (i.e., age, sex, race and ethnicity, socioeconomic status and educational attainment, rural or urban environment, self-reported diabetes, COPD, coronary heart disease, and obesity status). Data from the 2021 U.S. National Health Interview Survey, a cross-sectional questionnaire design, were used to calculate both unadjusted and adjusted odds ratios for self-reported COVID infection and severity of symptoms. Results indicate that combustible cigarette use is associated with a lower likelihood of self-reported COVID infection relative to non-use of tobacco products (AOR = .64; 95% CI [.55, .74]), whereas ENDS use is associated with a higher likelihood of self-reported COVID infection (AOR = 1.30; 95% CI [1.04, 1.63]). There was no significant difference in COVID infection among dual users (ENDS and combustible use) when compared with non-users. Adjusting for covarying factors did not substantially change the results. There were no significant differences in COVID disease severity between those of varying smoking status. Future research should examine the relationship between smoking status and COVID infection and disease severity utilizing longitudinal study designs and non-self-report measures of smoking status (e.g., the biomarker cotinine), COVID infection (e.g., positive tests), and disease severity (e.g., hospitalizations, ventilator assistance, mortality, and ongoing symptoms of long COVID).

Effectiveness of Pneumococcal Conjugate Vaccination Against Virus-Associated Lower Respiratory Tract Infection Among Adults: A Case-Control Study

BACKGROUND

Interactions of Streptococcus pneumoniae with viruses feature in the pathogenesis of numerous respiratory illnesses.

METHODS

We undertook a case-control study among adults at Kaiser Permanente Southern California between 2015 and 2019. Case patients had diagnoses of lower respiratory tract infection (LRTI; including pneumonia or nonpneumonia LRTI diagnoses), with viral infections detected by multiplex polymerase chain reaction testing. Controls without LRTI diagnoses were matched to case patients by demographic and clinical attributes. We measured vaccine effectiveness (VE) for 13-valent (PCV13) against virus-associated LRTI by determining the adjusted odds ratio for PCV13 receipt, comparing case patients and controls.

RESULTS

Primary analyses included 13 856 case patients with virus-associated LRTI and 227 887 matched controls. Receipt of PCV13 was associated with a VE of 24.9% (95% confidence interval, 18.4%-30.9%) against virus-associated pneumonia and 21.5% (10.9%-30.9%) against other (nonpneumonia) virus-associated LRTIs. We estimated VEs of 26.8% (95% confidence interval, 19.9%-33.1%) and 18.6% (9.3%-27.0%) against all virus-associated LRTI episodes diagnosed in inpatient and outpatient settings, respectively. We identified statistically significant protection against LRTI episodes associated with influenza A and B viruses, endemic human coronaviruses, parainfluenza viruses, human metapneumovirus, and enteroviruses but not respiratory syncytial virus or adenoviruses.

CONCLUSIONS

Among adults, PCV13 conferred moderate protection against virus-associated LRTI. The impacts of pneumococcal conjugate vaccines may be mediated, in part, by effects on polymicrobial interactions between pneumococci and respiratory viruses.

A tale of three in symbiosis: TB-COVID-19-Bordetella coinfection

Coinfections/mixed infections are common in the respiratory tract. Many times existing organisms have similar risk factors and clinical features that make the diagnosis difficult. Coronavirus diagnosed in 2019 (COVID-19) and tuberculosis (TB) are two such diseases. Patients with TB have lower cellular immunity and impaired pulmonary function. In such environment, atypical organisms, can infect and make the outcome unfavorable. A 21-year-old malnourished (body mass index- 15 kg/m²) girl presented with fever and cough for 10 days. Sputum for Cartridge Based Nucleic Acid Amplification Test demonstrated Mycobacterium tuberculosis with no rifampin resistance. Fever persisted (100-101°F) and saturation was dropping even after 10 days of antitubercular treatment. A repeat reverse transcription-polymerase chain reaction was done and was positive. In view of persistent symptoms after 20 days, bronchoscopy was done, and cultures showed Bordetella bronchiseptica. Fever and symptoms resolved completely after initiation of the sensitive drug. Diagnostic delay in coinfections can lead to increased morbidity and mortality.

Adherence to COVID-19 Guidelines among Current, Former, and Never Smokers

Objectives: In this paper, we explore the adherence patterns to US Centers for Disease Control and Prevention (CDC) COVID-19 mitigation guidelines among current, former, and never smokers. Methods: We used an online cross-sectional survey of adults 18 years or older in 5 northeastern states of the US (N=1084). Results: Unadjusted analyses revealed that current smokers reported lower adherence to the CDC guidelines than former smokers (27.5 vs 29.4, p<.05). After accounting for sociodemographic covariates, this finding was no longer statistically significant. However, compared to former smokers, never smokers reported wearing their mask less often (OR=0.65; 95% CI=0.45-0.94) and current smokers were less likely to report always practicing illness-related hygiene skills (OR=0.60; 95% CI=0.39-0.93).Conclusions: Never smokers had poorer adherence to CDC guidelines than former smokers, namely wearing their masks, and current smokers were less likely to always follow the hygiene recommendations. Results should inform future public health efforts in targeting current smokers with lower adherence to CDC guidelines and learning from the ability of former smokers to demonstrate high adherence.

The intersecting pandemics of tuberculosis and COVID-19: population-level and patient-level impact, clinical presentation, and corrective interventions

The global tuberculosis burden remains substantial, with more than 10 million people newly ill per year. Nevertheless, tuberculosis incidence has slowly declined over the past decade, and mortality has decreased by almost a third in tandem. This positive trend was abruptly reversed by the COVID-19 pandemic, which in many parts of the world has resulted in a substantial reduction in tuberculosis testing and case notifications, with an associated increase in mortality, taking global tuberculosis control back by roughly 10 years. Here, we consider points of intersection between the tuberculosis and COVID-19 pandemics, identifying wide-ranging approaches that could be taken to reverse the devastating effects of COVID-19 on tuberculosis control. We review the impact of COVID-19 at the population level on tuberculosis case detection, morbidity and mortality, and the patient-level impact, including susceptibility to disease, clinical presentation, diagnosis, management, and prognosis. We propose strategies to reverse or mitigate the deleterious effects of COVID-19 and restore tuberculosis services. Finally, we highlight research priorities and major challenges and controversies that need to be addressed to restore and advance the global response to tuberculosis.

Durability of ChAdOx1 nCoV-19 vaccination in people living with HIV

Duration of protection from SARS-CoV-2 infection in people living with HIV (PWH) following vaccination is unclear. In a substudy of the phase II/III the COV002 trial (NCT04400838), 54 HIV+ male participants on antiretroviral therapy (undetectable viral loads, CD4+ T cells > 350 cells/μL) received 2 doses of ChAdOx1 nCoV-19 (AZD1222) 4-6 weeks apart and were followed for 6 months. Responses to vaccination were determined by serology (IgG ELISA and Meso Scale Discovery [MSD]), neutralization, ACE-2 inhibition, IFN-γ ELISpot, activation-induced marker (AIM) assay and T cell proliferation. We show that, 6 months after vaccination, the majority of measurable immune responses were greater than prevaccination baseline but with evidence of a decline in both humoral and cell-mediated immunity. There was, however, no significant difference compared with a cohort of HIV-uninfected individuals vaccinated with the same regimen. Responses to the variants of concern were detectable, although they were lower than WT. Preexisting cross-reactive T cell responses to SARS-CoV-2 spike were associated with greater postvaccine immunity and correlated with prior exposure to beta coronaviruses. These data support the ongoing policy to vaccinate PWH against SARS-CoV-2, and they underpin the need for long-term monitoring of responses after vaccination.

Severe acute respiratory illness surveillance for influenza in Kenya: Patient characteristics and lessons learnt

Background

We describe the epidemiology and clinical features of Kenyan patients hospitalized with laboratory‐confirmed influenza compared with those testing negative and discuss the potential contribution of severe acute respiratory illness (SARI) surveillance in monitoring a broader range of respiratory pathogens.

Methods

We described demographic and clinical characteristics of SARI cases among children (<18 years) and adults, separately. We compared disease severity (clinical features and treatment) of hospitalized influenza positive versus negative cases and explored independent predictors of death among SARI cases using a multivariable logistic regression model.

Results

From January 2014 to December 2018, 11,166 persons were hospitalized with SARI and overall positivity for influenza was ~10%. There were 10,742 (96%) children (<18 years)—median age of 1 year, interquartile range (IQR = 6 months, 2 years). Only 424 (4%) of the SARI cases were adults (≥18 years), with median age of 38 years (IQR 28 years, 52 years). There was no difference in disease severity comparing influenza positive and negative cases among children. Children hospitalized with SARI who had an underlying illness had greater odds of in‐hospital death compared with those without (adjusted odds ratio 2.11 95% CI 1.09–4.07). No further analysis was done among adults due to the small sample size.

Conclusion

Kenya's sentinel surveillance for SARI mainly captures data on younger children. Hospital‐based platforms designed to monitor influenza viruses and associated disease burden may be adapted and expanded to other respiratory viruses to inform public health interventions. Efforts should be made to capture adults as part of routine respiratory surveillance.

Human respiratory syncytial virus diversity and epidemiology among patients hospitalized with severe respiratory illness in South Africa, 2012-2015

BACKGROUND

We aimed to describe the prevalence of human respiratory syncytial virus (HRSV) and evaluate associations between HRSV subgroups and/or genotypes and epidemiologic characteristics and clinical outcomes in patients hospitalized with severe respiratory illness (SRI).

METHODS

Between January 2012 and December 2015, we enrolled patients of all ages admitted to two South African hospitals with SRI in prospective hospital-based syndromic surveillance. We collected respiratory specimens and clinical and epidemiological data. Unconditional random effect multivariable logistic regression was used to assess factors associated with HRSV infection.

RESULTS

HRSV was detected in 11.2% (772/6908) of enrolled patients of which 47.0% (363/772) were under the age of 6 months. There were no differences in clinical outcomes of HRSV subgroup A-infected patients compared with HRSV subgroup B-infected patients but among patients aged <5 years, children with HRSV subgroup A were more likely be coinfected with Streptococcus pneumoniae (23/208, 11.0% vs. 2/90, 2.0%; adjusted odds ratio 5.7). No significant associations of HRSV A genotypes NA1 and ON1 with specific clinical outcomes were observed.

CONCLUSIONS

While HRSV subgroup and genotype dominance shifted between seasons, we showed similar genotype diversity as noted worldwide. We found no association between clinical outcomes and HRSV subgroups or genotypes.

COVID-19, smoking and inequalities: a study of 53 002 adults in the UK

BACKGROUND

This study aimed to examine associations between smoking and COVID-19 relevant outcomes, taking into account the influence of inequalities and adjusting for potential confounding variables.

METHODS

Cross-sectional data were used from an online study of adults in the UK (n=53 002). Main outcome measures were confirmed and suspected COVID-19, worry about catching or becoming seriously ill from COVID-19 and adherence to protective behaviours. Covariates included age, sex, ethnicity, education (post-16 qualifications: yes/no), key worker status and comorbid health conditions.

RESULTS

Compared with never smokers (0.26% (95% CI 0.21% to 0.33%)), prevalence of confirmed COVID-19 was higher among current (0.56% (0.41% to 0.75%)) but not ex-smokers (0.19% (0.13% to 0.28%)). Associations were similar before (current: OR=2.14 (1.49-3.08); ex-smokers: OR=0.73 (0.47-1.14)) and after (current: OR=1.79 (1.22-2.62); ex-smokers: OR=0.85 (0.54-1.33)) adjustment. For current smokers, this was moderated by socio-economic position, with higher rates only seen in those without post-16 qualifications (OR=3.53 (2.04-6.10)). After including suspected cases, prevalence was higher among current smokers (11.2% (10.6% to 11.9%), OR=1.11 (1.03-1.20)) and ex-smokers (10.9% (10.4% to 11.5%), OR=1.07 (1.01-1.15)) than never smokers (10.2% (9.9% to 10.6%)), but remained higher only among ex-smokers after adjustment (OR=1.21 (1.13-1.29)). Current and ex-smokers had higher odds than never smokers of reporting significant stress about becoming seriously ill from COVID-19 (current: OR=1.34 (1.27-1.43); ex-smokers: OR=1.22 (1.16-1.28)). Adherence to recommendations to prevent spread of COVID-19 was high (96.3% (96.1% to 96.4%)), but lower among current than never smokers (OR=0.70 (0.62-0.78)).

CONCLUSIONS

In a population sample, current smoking was independently associated with self-reported confirmed COVID-19 infection. There were socio-economic disparities, with the association only apparent among those without post-16 qualifications. Smokers reported lower adherence to guidelines despite being more worried than non-smokers about catching or becoming seriously ill from COVID-19.

The effect of smoking on COVID-19-linked biomarkers in hospitalized patients with COVID-19

Background

The coronavirus pandemic, an infection (coronavirus disease 2019—COVID‐19), caused by severe acute respiratory disease coronavirus 2 (SARS‐CoV‐2), continues to have a strong influence worldwide. Although smoking is a major known risk factor for respiratory infectious disease, the effects of smoking on COVID‐19 are unclear. In this study, we aimed to evaluate the relationship between smoking and important hematologic (lymphocyte count, neutrophil count, platelet count, neutrophil‐lymphocyte ratio [NLR], platelet‐lymphocyte ratio [PLR]), inflammatory, and biochemical biomarkers in the prognosis of hospitalized patients with COVID‐19.

Methods

In a COVID‐19 pandemic hospital between June and August 2020, 200 adult patients aged over 18 years were hospitalized with COVID‐19 inflammatory and hematologic biomarkers at their first admission and smoking data were selected for this study.

Results

The rate of smokers was much higher among men (91.5%) than in women (8.5%) (p = 0.001). Neutrophil counts were evaluated and was significantly higher in current smokers (p < 0.001) and ex‐smokers (p = 0.001), and NLR (p = 0.008) and ferritin (p = 0.004) levels were higher than in never smokers. The saturation of patients had a negative significant linear correlation of NLR, PLR, and pack years of smoking. Compared with never smokers, current smokers had higher neutrophil counts (OR = 0.828 [0.750–0.915]; p = 0.041), NLR values (OR = 0.948 [0.910–0.987]; p = 0.009), and CRP levels (OR = 0.994 [0.990–0.999]; p = 0.019).

Conclusion

Serum neutrophil, NLR, and ferritin levels, which are widely used in determining the prognosis of COVID‐19, were found higher in current smokers/ex‐smokers. These results support the view that a poor prognosis of COVID‐19 is associated with smoking.

Host variations in SARS-CoV-2 infection

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the zoonotic pathogen that causes the "Coronavirus Disease of 2019 (COVID-19)", and COVID-19 itself is yet to be thoroughly understood. Both the disease as well as the mechanisms by which the host interacts with the SARS-CoV-2 have not been fully enlightened. The epidemiological factors -e.g. age, sex, race-, the polymorphisms of the host proteins, the blood types and individual differences have all been in discussions about affecting the progression and the course of COVID-19 both individually and collectively, as their effects are mostly interwoven. We focused mainly on the effect of polymorphic variants of the host proteins that have been shown to take part in and/or affect the pathogenesis of COVID-19. Additionally, how the procedures of diagnosing and treating COVID-19 are affected by these variants and what possible changes can be implemented are the other questions, which are sought to be answered.

Microbial contamination in the communal-use Lao tobacco waterpipe

BACKGROUND

The use of the Asian tobacco waterpipe (TWP) in the Lao People's Democratic Republic represents a potential communal source of infectious disease. This practice of smoking can lead to weakened defences of a smoker's respiratory epithelium, making the smoker vulnerable to respiratory diseases such as coronavirus disease 2019, tuberculosis and others.

METHODS

This study evaluated the water quality and hygiene factors among 43 smokers of five villages in rural Luang Namtha Province. Water samples were collected from participant's TWPs and assessed for the presence of Escherichia coli, coliforms and aerobic plate count (APC) bacteria using the 3M Petrifilm.

RESULTS

The microbial indicator testing results were 95% positive for the APC, 38% positive for coliforms and 17% positive for the E. coli indicator. The concentrations were highest for the APC, with an average of 106 colony forming units (cfu)/ml, followed by coliforms with <100 cfu/ml and lowest for E. coli with <10 cfu/ml. Most TWPs were infrequently cleaned, heavily used and contained a warm, brown-coloured water.

CONCLUSIONS

The warm, dark and moist internal water container may facilitate microbial survival and growth. The use of a TWP adds several unstudied modes of transmission to a complex and common biobehavioural and environmental pathogen exposure. Future TWP cessation activities should be tailored to consider risks of infectious disease transmission.

The association of smoking status with SARS-CoV-2 infection, hospitalization and mortality from COVID-19: a living rapid evidence review with Bayesian meta-analyses (version 7)

AIMS

To estimate the association of smoking status with rates of (i) infection, (ii) hospitalization, (iii) disease severity and (iv) mortality from SARS-CoV-2/COVID-19 disease.

DESIGN

Living rapid review of observational and experimental studies with random-effects hierarchical Bayesian meta-analyses. Published articles and pre-prints were identified via MEDLINE and medRxiv.

SETTING

Community or hospital, no restrictions on location.

PARTICIPANTS

Adults who received a SARS-CoV-2 test or a COVID-19 diagnosis.

MEASUREMENTS

Outcomes were SARS-CoV-2 infection, hospitalization, disease severity and mortality stratified by smoking status. Study quality was assessed (i.e. 'good', 'fair' and 'poor').

FINDINGS

Version 7 (searches up to 25 August 2020) included 233 studies with 32 'good' and 'fair' quality studies included in meta-analyses. Fifty-seven studies (24.5%) reported current, former and never smoking status. Recorded smoking prevalence among people with COVID-19 was generally lower than national prevalence. Current compared with never smokers were at reduced risk of SARS-CoV-2 infection [relative risk (RR) = 0.74, 95% credible interval (CrI) = 0.58-0.93, τ = 0.41]. Data for former smokers were inconclusive (RR = 1.05, 95% CrI = 0.95-1.17, τ = 0.17), but favoured there being no important association (21% probability of RR ≥ 1.1). Former compared with never smokers were at somewhat increased risk of hospitalization (RR = 1.20, CrI = 1.03-1.44, τ = 0.17), greater disease severity (RR = 1.52, CrI = 1.13-2.07, τ = 0.29) and mortality (RR = 1.39, 95% CrI = 1.09-1.87, τ = 0.27). Data for current smokers were inconclusive (RR = 1.06, CrI = 0.82-1.35, τ = 0.27; RR = 1.25, CrI = 0.85-1.93, τ = 0.34; RR = 1.22, 95% CrI = 0.78-1.94, τ = 0.49, respectively), but favoured there being no important associations with hospitalization and mortality (35% and 70% probability of RR ≥ 1.1, respectively) and a small but important association with disease severity (79% probability of RR ≥ 1.1).

CONCLUSIONS

Compared with never smokers, current smokers appear to be at reduced risk of SARS-CoV-2 infection, while former smokers appear to be at increased risk of hospitalization, increased disease severity and mortality from COVID-19. However, it is uncertain whether these associations are causal.

Serologic evidence of seasonal influenza A and B in HIV patients on combined antiretroviral therapy in Lagos, Nigeria

Background

Influenza and HIV are endemic in Nigeria but there is no epidemiological data on the co-infection of influenza A and B among HIV patients.

Objective

We investigated seasonal influenza A and B, and co-infection among HIV patients on combined antiretroviral therapy (cART) in Lagos, Nigeria.

Methods

In a prospective cross-sectional study, clear sera collected from 174 HIV-positive patients between August and September 2018 were analysed for immunoglobulin M-specific antibodies to seasonal influenza A subtypes H1N1 and H3N2, and influenza B by enzyme immunoassay.

Results

A total of 39.7% (69/174) of HIV patients were seropositive for influenza A or B viruses with 84.1% (58/69) being positive for influenza A, 13.04% (9/69) seropositive for both influenza A and B, and only 2.9% (2/69) positive for influenza B mono-infection. Median age was 44 (mean 45, mode 40, range 18–74) years. The 41–50 years age group had the highest seroprevalence (39.1%; 27/69). Seropositivity was highest among women (65.2%; 45/69). A total of 88.4% (61/69) of HIV patients seropositive for influenza A or B were on fixed dose cART, while 73.9% (51/69) were virologically suppressed. Furthermore, 27.5% (19/69) were immunocompromised, of which 21.1% (4/19) were severely immunosuppressed (cluster of differentiation 4 < 200 cells/mm^>3).

Conclusion

Influenza A and B was prevalent among HIV patients on cART, which may predispose them to life-threatening complications. We recommend strong advocacy on the need to reduce the risk of exposure to influenza and for the provision of an influenza vaccine in Nigeria.

The epidemiology of seasonal influenza after the 2009 influenza pandemic in Africa: a systematic review

Background

Influenza infection is a serious public health problem that causes an estimated 3 to 5 million cases and 250,000 deaths worldwide every year. The epidemiology of influenza is well-documented in high- and middle-income countries, however minimal effort had been made to understand the epidemiology, burden and seasonality of influenza in Africa. This study aims to assess the state of knowledge of seasonal influenza epidemiology in Africa and identify potential data gaps for policy formulation following the 2009 pandemic.

Method

We reviewed articles from Africa published into four databases namely: MEDLINE (PubMed), Google Scholar, Cochrane Library and Scientific Research Publishing from 2010 to 2019.

Results

We screened titles and abstracts of 2070 studies of which 311 were selected for full content evaluation and 199 studies were considered. Selected articles varied substantially on the basis of the topics they addressed covering the field of influenza surveillance (n=80); influenza risk factors and co-morbidities (n=15); influenza burden (n=37); influenza vaccination (n=40); influenza and other respiratory pathogens (n=22) and influenza diagnosis (n=5).

Conclusion

Significant progress has been made since the last pandemic in understanding the influenza epidemiology in Africa. However, efforts still remain for most countries to have sufficient data to allow countries to prioritize strategies for influenza prevention and control.

Impact of Vaccines; Health, Economic and Social Perspectives

In the 20th century, the development, licensing and implementation of vaccines as part of large, systematic immunization programs started to address health inequities that existed globally. However, at the time of writing, access to vaccines that prevent life-threatening infectious diseases remains unequal to all infants, children and adults in the world. This is a problem that many individuals and agencies are working hard to address globally. As clinicians and biomedical scientists we often focus on the health benefits that vaccines provide, in the prevention of ill-health and death from infectious pathogens. Here we discuss the health, economic and social benefits of vaccines that have been identified and studied in recent years, impacting all regions and all age groups. After learning of the emergence of SARS-CoV-2 virus in December 2019, and its potential for global dissemination to cause COVID-19 disease was realized, there was an urgent need to develop vaccines at an unprecedented rate and scale. As we appreciate and quantify the health, economic and social benefits of vaccines and immunization programs to individuals and society, we should endeavor to communicate this to the public and policy makers, for the benefit of endemic, epidemic, and pandemic diseases.

Influenza epidemiology and risk factors for severe acute respiratory infection in Morocco during the 2016/2017 and 2017/2018 seasons

Introduction

in order to implement an influenza vaccination program for high-risk-groups in Morocco, as recommended by the World Health Organization, an epidemiological study indicating the influenza virus effect in the development of complicated influenza for subjects with co-morbidity was required. The present study aims to evaluate the risk factors for severe acute respiratory infections caused by influenza in risk groups.

Methods

this research is based on the epidemiological and virological surveillance data of severe acute respiratory infections and influenza-like illness during the 2016/2017 and 2017/2018 seasons. It was realized using a retrospective series study with a descriptive and analytical purpose.

Results

the over-recruitment of pediatric cases with a severe acute respiratory infection has been significantly rectified because cases of severe acute respiratory infections under 15 years old in the 2017/2018 season represent only 57.9%, whereas they represented 75.9% of the total cases of severe acute respiratory infections during the 2016/2017 season. The influenza positivity rate has increased globally and specifically by age group, clinical service and co-morbidity. The risk factors considered were significantly associated with hospitalization for influenza-associated severe acute respiratory infections. The multivariate logistic regression analysis considers male sex (OR=2.1), age ≥65 years (OR=5.4), presence of influenza cases in the surroundings (OR=0.1), diabetes (OR=7.5) and chronic respiratory disease (OR=10.9) as risk factors influenza-associated severe acute respiratory infections.

Conclusion

the risk assessment of influenza-associated severe acute respiratory infections in high-risk groups revealed national epidemiological findings, particularly for diabetics and the elderly. An influenza vaccination program for these high-risk-groups becomes much recommended in Morocco.

COVID-19 and Tuberculosis

On March 11, 2020, the WHO declared that coronavirus disease 2019 (COVID-19) can be characterized as a pandemic based on the alarming levels of spread and severity and on the alarming levels of inaction. COVID-19 has received worldwide attention as emergency, endangering international public health and economic development. There is a growing body of literatures regarding severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as well as COVID-19. This review will focus on the latest advance of epidemiology, pathogenesis, and clinical characteristics about COVID-19. Meanwhile, tuberculosis (TB) remains the leading representative respiratory tract communicable disease threatening public health. There are limited data on the risk of severe disease or outcomes in patients with concurrence of TB and COVID-19. Nevertheless, co-infection of some virus would aggravate TB, such as measles. And tuberculosis and influenza co-infection compared with tuberculosis single infection was associated with increased risk of death in individuals. This review will also introduce the characteristics about the concurrence of TB and emerging infectious diseases to provide a hint to manage current epidemic.

Influenza disease burden among potential target risk groups for immunization in South Africa, 2013-2015

BACKGROUND

Data on influenza burden in risk groups for severe influenza are important to guide targeted influenza immunization, especially in resource limited settings. However, this information is limited overall and in particular in low- and middle-income countries. We sought to assess the mean annual national burden of medically and non-medically attended influenza-associated mild, severe-non-fatal and fatal illness among potential target groups for influenza immunization in South Africa during 2013-2015.

METHODS

We used published mean national annual estimates of mild, severe-non-fatal, and fatal influenza-associated illness in South Africa during 2013-2015 and estimated the number of such illnesses occurring among the following risk groups: (i) children aged 6-59 months; (ii) individuals aged 5-64 years with HIV, and/or pulmonary tuberculosis (PTB), and/or selected underlying medical conditions (UMC); (iii) pregnant women; and (iv) individuals aged ≥65 years. We also estimated the number of individuals among the same risk groups in the population.

RESULTS

During 2013-2015, individuals in the selected risk groups accounted for 45.3% (24,569,328/54,086,144) of the population and 43.5% (4,614,763/10,598,138), 86.8% (111,245/128,173) and 94.5% (10,903/11,536) of the mean annual estimated number of influenza-associated mild, severe-non-fatal and fatal illness episodes, respectively. The rates of influenza-associated illness were highest in children aged 6-59 months (23,983 per 100,000 population) for mild illness, in pregnant women (930 per 100,000 population) for severe-non-fatal illness and in individuals aged ≥65 years (138 per 100,000 population) for fatal illness.

CONCLUSION

Influenza immunization of the selected risk groups has the potential to prevent a substantial number of influenza-associated severe illness. Nonetheless, because of the high number of individuals at risk, South Africa, due to financial resources constrains, may need to further prioritize interventions among risk populations. Cost-burden and cost-effectiveness estimates may assist with further prioritization.

An evaluation of the Zambia influenza sentinel surveillance system, 2011-2017

Background

Over the past decade, influenza surveillance has been established in several African countries including Zambia. However, information on the on data quality and reliability of established influenza surveillance systems in Africa are limited. Such information would enable countries to assess the performance of their surveillance systems, identify shortfalls for improvement and provide evidence of data reliability for policy making and public health interventions.

Methods

We used the Centers for Disease Control and Prevention guidelines to evaluate the performance of the influenza surveillance system (ISS) in Zambia during 2011–2017 using 9 attributes: (i) data quality and completeness, (ii) timeliness, (iii) representativeness, (iv) flexibility, (v) simplicity, (vi) acceptability, (vii) stability, (viii) utility, and (ix) sustainability. Each attribute was evaluated using pre-defined indicators. For each indicator we obtained the proportion (expressed as percentage) of the outcome of interest over the total. A scale from 1 to 3 was used to provide a score for each attribute as follows: < 60% (as obtained in the calculation above) scored 1 (weak performance); 60–79% scored 2 (moderate performance); ≥80% scored 3 (good performance). An overall score for each attribute and the ISS was obtained by averaging the scores of all evaluated attributes.

Results

The overall mean score for the ISS in Zambia was 2.6. Key strengths of the system were the quality of data generated (score: 2.9), its flexibility (score: 3.0) especially to monitor viral pathogens other than influenza viruses, its simplicity (score: 2.8), acceptability (score: 3.0) and stability (score: 2.6) over the review period and its relatively low cost ($310,000 per annum). Identified weaknesses related mainly to geographic representativeness (score: 2.0), timeliness (score: 2.5), especially in shipment of samples from remote sites, and sustainability (score: 1.0) in the absence of external funds.

Conclusions

The system performed moderately well in our evaluation. Key improvements would include improvements in the timeliness of samples shipments and geographical coverage. However, these improvements would result in increased cost and logistical complexity. The ISSS in Zambia is largely reliant on external funds and the acceptability of maintaining the surveillance system through national funds would require evaluation.

Evaluation of the influenza sentinel surveillance system in the Democratic Republic of Congo, 2012-2015

BACKGROUND

The World Health Organization recommends periodic evaluations of influenza surveillance systems to identify areas for improvement and provide evidence of data reliability for policymaking. However, data about the performance of established influenza surveillance systems are limited in Africa, including in the Democratic Republic of Congo (DRC).

METHODS

We used the Centers for Disease Control and Prevention guidelines to evaluate the performance of the influenza sentinel surveillance system (ISSS) in DRC during 2012-2015. The performance of the system was evaluated using eight surveillance attributes: (i) data quality and completeness for key variables, (ii) timeliness, (iii) representativeness, (iv) flexibility, (v) simplicity, (vi) acceptability, (vii) stability and (viii) utility. For each attribute, specific indicators were developed and described using quantitative and qualitative methods. Scores for each indicator were as follows: < 60% weak performance; 60-79% moderate performance; ≥80% good performance.

RESULTS

During 2012-2015, we enrolled and tested 4339 patients with influenza-like illness (ILI) and 2869 patients with severe acute respiratory illness (SARI) from 11 sentinel sites situated in 5 of 11 provinces. Influenza viruses were detected in 446 (10.3%) samples from patients with ILI and in 151 (5.5%) samples from patients with SARI with higher detection during December-May. Data quality and completeness was > 90% for all evaluated indicators. Other strengths of the system were timeliness, simplicity, stability and utility that scored > 70% each. Representativeness, flexibility and acceptability had moderate performance. It was reported that the ISSS contributed to: (i) a better understanding of the epidemiology, circulating patterns and proportional contribution of influenza virus among patients with ILI or SARI; (ii) acquisition of new key competences related to influenza surveillance and diagnosis; and (iii) continuous education of surveillance staff and clinicians at sentinel sites about influenza. However, due to limited resources no actions were undertaken to mitigate the impact of seasonal influenza epidemics.

CONCLUSIONS

The system performed overall satisfactorily and provided reliable and timely data about influenza circulation in DRC. The simplicity of the system contributed to its stability. A better use of the available data could be made to inform and promote prevention interventions especially among the most vulnerable groups.

Responses to Quadrivalent Influenza Vaccine Reveal Distinct Circulating CD4+CXCR5+ T Cell Subsets in Men Living with HIV

T cell help for B cells may be perturbed in people living with HIV (PLWH), even when HIV is suppressed, as evidenced by reports of suboptimal responses to influenza vaccination. We investigated cT_FH responses to the 2017-18 inactivated quadrivalent influenza vaccine (QIV) in men living with antiretroviral therapy (ART)-suppressed HIV infection who were treated in the early or chronic phase of infection, and control subjects. Here we show that seroprotective antibody responses in serum and oral fluid correlated with cT_FH activation and were equivalent in all three groups, irrespective of when ART was started. These responses were attenuated in those reporting immunisation with influenza vaccine in the preceding three years, independent of HIV infection. Measurement of influenza-specific IgG in oral fluid was closely correlated with haemagglutination inhibition titre. T-SNE and two-dimensional analysis revealed a subset of CD4⁺CXCR3⁺CXCR5⁺ cT_FH activated at one week after vaccination. This was distinguishable from cTFH not activated by vaccination, and a rare, effector memory CD4⁺CXCR5^hiCD32^hi T cell subset. The data support the use of QIV for immunisation of PLWH, reveal distinct circulating CD4⁺CXCR5⁺ T cell subsets and demonstrate oral fluid sampling for influenza-specific IgG is an alternative to phlebotomy.

Impact of Human Immunodeficiency Virus on the Burden and Severity of Influenza Illness in Malawian Adults: A Prospective Cohort and Parallel Case-Control Study

Background

The impact of human immunodeficiency virus (HIV) infection on influenza incidence and severity in adults in sub-Saharan Africa is unclear. Seasonal influenza vaccination is recommended for HIV-infected persons in developed settings but is rarely implemented in Africa.

Methods

We conducted a prospective cohort study to compare the incidence of laboratory-confirmed influenza illness between HIV-infected and HIV-uninfected adults in Blantyre, Malawi. In a parallel case-control study, we explored risk factors for severe influenza presentation of severe (hospitalized) lower respiratory tract infection, and mild influenza (influenza-like illness [ILI]).

Results

The cohort study enrolled 608 adults, of whom 360 (59%) were HIV infected. Between April 2013 and March 2015, 24 of 229 ILI episodes (10.5%) in HIV-infected and 5 of 119 (4.2%) in HIV-uninfected adults were positive for influenza by means of polymerase chain reaction (incidence rate, 46.0 vs 14.5 per 1000 person-years; incidence rate ratio, 2.75; 95% confidence interval, 1.02-7.44; P = .03; adjusted for age, sex, household crowding, and food security). In the case-control study, influenza was identified in 56 of 518 patients (10.8%) with hospitalized lower respiratory tract infection, and 88 or 642 (13.7%) with ILI. The HIV prevalence was 69.6% and 29.6%, respectively, among influenza-positive case patients and controls. HIV was a significant risk factor for severe influenza (odds ratio, 4.98; 95% confidence interval, 2.09-11.88; P < .001; population-attributable fraction, 57%; adjusted for season, sanitation facility, and food security).

Conclusions

HIV is an important risk factor for influenza-associated ILI and severe presentation in this high-HIV prevalence African setting. Targeted influenza vaccination of HIV-infected African adults should be reevaluated, and the optimal mechanism for vaccine introduction in overstretched health systems needs to be determined.

Economic Cost of Severe Acute Respiratory Infection Associated to Influenza in Colombian Children: A Single Setting Analysis

BACKGROUND

Influenza is considered a leading public health problem because its large economic burden of disease worldwide, especially in low-and middle-income countries, such as Colombia.

OBJECTIVE

We aimed to estimate the economic costs of influenza-confirmed patients in a pediatric hospital in Cartagena, Colombia.

METHODS

We conducted a retrospective costing analysis. We estimated the direct (direct medical and out-of-pocket expenditures) and indirect costs for influenza-confirmed severe acute respiratory infection cases from a societal perspective. Total economic costs were calculated adding direct medical costs, out-of-pocket expenditures, and indirect costs owing to loss of productivity of caregivers. Mean, median, 95% confidence interval (95% CI) and interquartile range (IQR) of costs were measured. All costs are reported in USD ($1.00 = COP$2000.7) RESULTS: Forty-four cases were included in the analysis: 30 had influenza B, 10 influenza A and B, and 4 influenza AH1N1. Thirty patients were hospitalized in the general ward, 14 went to the intensive care unit. The average duration of stay was ∼9 days (95% CI, 6.3-11.5). The median direct medical cost for hospitalized case in general ward was $743.50 (IQR $590.20-$1404.60) and in intensive care unit $4669.80 (IQR $1614.60-$7801.50). The economic cost per hospitalized case was $1826.10 (IQR $1343.30-$2376.50); direct medical costs represented 93.8% of this cost. The median indirect cost was $82.10 (IQR $41.10-$133.40) and the median out-of-pocket expenditure per case was $45.70 (IQR $29.50-$64.90).

CONCLUSIONS

Severe acute respiratory infection is an important source of economic burden for the health system, families, and society in Colombia. Seasonal influenza vaccination should be strengthened to prevent more cases and save economic resources.

Influenza and tuberculosis co-infection: A systematic review

Introduction

There are limited data on risk of severe disease or outcomes in patients with influenza and pulmonary tuberculosis (PTB) co‐infection compared to those with single infection.

Methods

We conducted a systematic review of published literature on the interaction of influenza viruses and PTB. Studies were eligible for inclusion if they presented data on prevalence, disease association, presentation or severity of laboratory‐confirmed influenza among clinically diagnosed or laboratory‐confirmed PTB cases. We searched eight databases from inception until December 2018. Summary characteristics of each study were extracted, and a narrative summary was presented. Cohort or case‐control studies were assessed for potential bias using the Newcastle‐Ottawa scale.

Results

We assessed 5154 abstracts, reviewed 146 manuscripts and included 19 studies fulfilling selection criteria (13 human and six animal). Of seven studies reporting on the possible effect of the underlying PTB disease in patients with influenza, three of four analytical studies reported no association with disease severity of influenza infection in those with PTB, whilst one study reported PTB as a risk factor for influenza‐associated hospitalization.

An association between influenza infection and PTB disease was found in three of five analytical studies; whereas the two other studies reported a high frequency of PTB disease progression and complications among patients with seasonal influenza co‐infection.

Conclusion

Human analytical studies of an association between co‐infection and severe influenza‐ or PTB‐associated disease or increased prevalence of influenza co‐infection in individuals' hospitalized for PTB were not conclusive. Data are limited from large, high‐quality, analytical epidemiological studies with laboratory‐confirmed endpoints.

Respiratory viral infections and the risk of rheumatoid arthritis

Background

We aimed to investigate the effects of ambient respiratory viral infections in the general population on rheumatoid arthritis (RA) development.

Methods

Data of weekly incident RA (2012–2013) were obtained from the Korean National Health Insurance claims database, and those of weekly observations on eight respiratory viral infections were obtained from the Korea Centers for Disease Control and Prevention database. We estimated the percentage change in incident RA associated with ambient mean respiratory viral infections using a generalized linear model, after adjusting for time trend, air pollution, and meteorological data.

Results

A total of 24,117 cases of incident RA (mean age 54.7 years, 18,688 [77.5%] women) were analyzed. Ambient respiratory viral infections in the population were associated with a higher number of incident RA over time, and its effect peaked 6 or 7 weeks after exposure. Among the 8 viruses, parainfluenza virus (4.8% for 1% respiratory viral infection increase, 95% CI 1.6 to 8.1, P = .003), coronavirus (9.2%, 3.9 to 14.8, P < .001), and metapneumovirus (44%, 2.0 to 103.4, P = .038) were associated with increased number of incident RA. The impact of these respiratory viral infections remained significant in women (3.8%, 12.1%, and 67.4%, respectively, P < .05) and in older patients (10.7%, 14.6%, and 118.2%, respectively, P < .05).

Conclusions

Ambient respiratory viral infections in the population were associated with an increased number of incident RA, especially in women and older patients, suggesting that respiratory viral infections can be a novel environmental risk factor for the development of RA.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1977-9) contains supplementary material, which is available to authorized users.

Prioritization of risk groups for influenza vaccination in resource limited settings - A case study from South Africa

BACKGROUND

Due to competing health priorities, low- and middle-income countries (LMIC) may need to prioritize between different influenza vaccine risk groups. Risk group prioritization may differ in LMIC based upon programmatic feasibility, country-specific prevalence of risk conditions and influenza-associated morbidity and mortality.

METHODS

In South Africa, we collected local disease burden data (both published and unpublished) and published vaccine efficacy data in risk groups and healthy adults. We used these data to aid policy makers with risk group prioritization for influenza vaccination. We used the following formula to assess potential vaccine averted disease in each risk group: rate of influenza-associated hospitalization (or death) per 100,000 population * influenza vaccine efficacy (VE). We further estimated the cost per hospital day averted and the cost per year of life saved by influenza vaccination.

RESULTS

Pregnant women, HIV-infected adults, and adults and children with tuberculosis disease had among the highest estimates of hospitalizations averted per 100,000 vaccinated and adults aged 65 years and older had the highest estimated deaths averted per 100,000 vaccinated. However, when assessing both the cost per hospital day averted (range: USD148-1,344) and the cost per year of life saved (range: USD112-1,230); adults and children with TB disease, HIV-infected adults and pregnant women had the lowest cost per outcome averted.

DISCUSSION

An assessment of the potential disease outcomes averted and associated costs may aid policymakers in risk group prioritization for influenza vaccination.

Prevalence and seasonality of common viral respiratory pathogens, including Cytomegalovirus in children, between 0-5 years of age in KwaZulu-Natal, an HIV endemic province in South Africa

Background

Acute respiratory tract infections contribute significantly to morbidity and mortality among young children in resource-poor countries. However, studies on the viral aetiology of acute respiratory infections, seasonality and the relative contributions of comorbidities such as immune deficiency states to viral respiratory tract infections in children in these countries are limited.

Methods

A retrospective analysis of laboratory test results of upper or lower respiratory specimens of children between 0 and 5 years of age collected between 1st January 2011 and 31st July 2015 from hospitals in KwaZulu-Natal, South Africa. Respiratory specimens were tested for viral respiratory pathogens using multiplex polymerase chain reaction (PCR), HIV testing was performed either by serological or PCR methods. Cytomegalovirus (CMV) respiratory infection was determined using the CMV R-gene PCR kit.

Results

In total 2172 specimens were analysed, of which 1175 (54.1%) were from males. The median age was 3.0 months (interquartile range [IQR] 1–7). Samples from the lower respiratory tract accounted for 1949 (89.7%) of all specimens. Respiratory multiplex PCR results were positive in 834 (45.7%) specimens. Respiratory syncytial virus (RSV) was the most commonly detected virus in 316 (32.1%) patients, followed by adenovirus (ADV) in 215 (21.8%), human rhinovirus (Hrhino) in 152 (15.4%) and influenza A (FluA) in 50 (5.1%). A seasonal time series pattern was observed for ADV (winter peak), enterovirus (EV) (autumn), human bocavirus (HBoV) (summer), and parainfluenza viruses 1 and 3 (PIV1 and 3) (spring). Stationary or untrended seasonal variation was observed for FluA (winter peak) and RSV (summer). HIV results were available for 1475 (67.9%) specimens; of these 348 (23.6%) were positive. CMV results were available for 714 (32.9%) specimens, of which 416 (58.3%) were positive. There was a statistically significant association between the coinfection of HIV and CMV with ADV.

Conclusions

In this study, we identified the most common respiratory viral pathogens detected among hospitalized children in KwaZulu-Natal. The coinfection between HIV and CMV was found to be associated with an increased risk of only adenovirus infection. Most viral pathogens showed a seasonal trend of occurrence. Our data has implications for the rational design of public health programmes.

Intra-host and intra-household diversity of influenza A viruses during household transmissions in the 2013 season in 2 peri-urban communities of South Africa

Limited information is available on influenza virus sequence drift between transmission events. In countries with high HIV burdens, like South Africa, the direct and indirect effect of HIV on influenza sequence drift between transmission events may be of public health concern. To this end, we measured hemagglutinin sequence diversity between influenza transmission events using data and specimens from a study investigating household transmission dynamics of seasonal influenza viruses in 2 peri-urban communities in South Africa during the 2013 influenza season. Thirty index cases and 107 of 110 eligible household contacts were enrolled into the study, 47% (14/30) demonstrating intra-household laboratory-confirmed influenza transmission. In this study 35 partial hemagglutinin gene sequences were obtained by Sanger sequencing from 11 index cases (sampled at enrolment only) and 16 secondary cases (8 cases sampled at 1 and 8 cases sampled at 2 time-points). Viral sequence identities confirmed matched influenza transmission pairs within the 11 households with corresponding sequenced index and secondary cases. Phylogenetic analysis revealed 10 different influenza viral lineages in the 14 households. Influenza A(H1N1)pdm09 strains were shown to be genetically distinct between the 2 communities (from distinct geographic regions), which was not observed for the influenza A(H3N2) strains. Intra-host/intra-household influenza A(H3N2) sequence drift was identified in 2 households. The first was a synonymous mutation between the index case and a household contact, and the second a non-synonymous mutation between 2 serial samples taken at days 0 and 4 post enrolment from an HIV-infected secondary case. Limited inter-household sequence diversity was observed as highlighted by sharing of the same influenza strain between different households within each community. The limited intra-household sequence drift is in line with previous studies also using Sanger sequencing, corroborating the presence of strict selective bottlenecks that limit sequence variance. We were not able to directly ascertain the effect of HIV on influenza sequence drift between transmission events.

Influenza immunization of pregnant women in resource-constrained countries: an update for funding and implementation decisions

PURPOSE OF REVIEW

In 2018, Gavi, the Vaccine Alliance, is expected to review the strategy of maternal influenza immunization for potential investment in low-income countries.

RECENT FINDINGS

Clinical trial data confirm the efficacy of maternal influenza immunization to prevent influenza disease in both mothers and their infants during the first months of life. Trial and observational data indicate no significant adverse events in mothers or newborns. High-quality disease burden data, particularly for seasonal influenza in low-income and middle-income countries, are limited. Thus, the anticipated impact of maternal influenza immunization programs on severe illness is unclear. However, assessments of the public health value of investment in maternal influenza immunization should extend beyond calculations of disease prevention and include broader effects such as improving health systems for antenatal care delivery, preventing inappropriate antibacterial prescribing, building a platform for other vaccines to be used during pregnancy, and strengthening systems to regulate, procure, and distribute influenza vaccines in response to a future pandemic.

SUMMARY

A global investment in a maternal influenza immunization strategy would prevent influenza disease in pregnant women and their infants. It would also provide additional public health value by strengthening antenatal care systems and improving country pandemic preparedness.

In- and Out-of-hospital Mortality Associated with Seasonal and Pandemic Influenza and Respiratory Syncytial Virus in South Africa, 2009-2013

Background

Estimates of influenza- and respiratory syncytial virus (RSV)-associated mortality burden are important to guide policy for control. Data are limited on the contribution of out-of-hospital deaths to this mortality.

Methods

We modeled excess mortality attributable to influenza and RSV infection by applying regression models to weekly deaths from national vital statistics from 2009 through 2013, using influenza and RSV laboratory surveillance data as covariates. We fitted separate models for in- and out-of-hospital deaths.

Results

There were 509791 average annual deaths in South Africa, of which 44% (95% confidence interval [CI] 43%-45%) occurred out-of-hospital. Seasonal influenza and RSV all-cause mortality rates were 23.0 (95% CI 11.0-30.6) and 13.2 (95% CI 6.4-33.8) per 100000 population annually (2.3% [95%CI 2.3%-2.4%] and 1.3% [95% CI 1.2%-1.4%] of all deaths respectively). The peak mortality rate was in individuals aged ≥75 years (386.0; 95% CI 176.5-466.3) for influenza and in infants (143.4; 95% CI 0-194.8) for RSV. Overall, 63% (95% CI 62%--65%) of seasonal influenza and 48% (95% CI 47%-49%) of RSV-associated deaths occurred out-of-hospital. Among children aged <5 years, RSV-associated deaths were more likely to occur in-hospital, whereas influenza-associated deaths were more likely to occur out-of-hospital. The mortality rate was 6.7 (95% CI 6.4-33.8) in the first influenza A(H1N1)pdm09 wave in 2009 and 20.9 (95% CI 6.4-33.8) in the second wave in 2011, with 30% (95% CI 29%-32%) of A(H1N1)pdm09-associated deaths in 2009 occurring out-of-hospital.

Discussion

More than 45% of seasonal influenza- and RSV-associated deaths occur out-of-hospital in South Africa. These data suggest that hospital-based studies may substantially underestimate mortality burden.

Vaccinations for the HIV-Infected Adult: A Review of the Current Recommendations, Part I

Vaccination is a critical component for ensuring the health of those living with the human immunodeficiency virus (HIV) by protection against vaccine-preventable diseases. Since HIV-infected persons may have reduced immune responses and shorter durations of protection post-vaccination, HIV-specific guidelines have been published by global and national advisory organizations to address these potential concerns. This article provides a comprehensive review of the current guidelines and evidence-based data for vaccinating HIV-infected adults, including guidance on modified vaccine dosing and testing strategies, as well as safety considerations, to enhance protection among this vulnerable population. In the current article, part I of the two-part series, inactivated vaccines with broad indications as well as vaccines for specific risk and age groups will be discussed.