Risk for Invasive Streptococcal Infections among Adults Experiencing Homelessness, Anchorage, Alaska, USA, 2002-2015

Antibiotic chemoprophylaxis for close contacts of invasive group A streptococcus in community settings: Evidence review

OBJECTIVES

Revised UK guidelines for the management of contacts of invasive group A Streptococcus (iGAS) infection in community settings were published in December 2022. We present the findings of a narrative review which informed the public health recommendations around the provision of antibiotic chemoprophylaxis detailed in the updated guidelines.

METHODS

We conducted a literature review of studies reporting the risk of iGAS infection associated with specific risk factors.

RESULTS

There was strong epidemiological evidence for an increased risk of iGAS infection in contacts who are older individuals, post-partum women, neonates and individuals with chickenpox infection; evidence on the impact of influenza co-infection, injecting drug use or being homeless in increasing risk of iGAS infection was less robust.

CONCLUSIONS

The guidelines made recommendations to offer chemoprophylaxis to close contacts of iGAS cases who are aged ≥75 years, pregnant ≥37 weeks gestation, post-partum, neonates or those with a recent history of, or current chickenpox infection. Systematic data collection evaluating the use of chemoprophylaxis and other control measures is recommended.

Infectious Diseases Among People Experiencing Homelessness: A Systematic Review of the Literature in the United States and Canada, 2003-2022

Homelessness increases the risk of acquiring an infectious disease. We conducted a systematic review of the literature to identify quantitative data related to infectious diseases and homelessness. We searched Google Scholar, PubMed, and SCOPUS for quantitative literature published from January 2003 through December 2022 in English from the United States and Canada. We excluded literature on vaccine-preventable diseases and HIV because these diseases were recently reviewed. Of the 250 articles that met inclusion criteria, more than half were on hepatitis C virus or Mycobacterium tuberculosis. Other articles were on COVID-19, respiratory syncytial virus, Staphylococcus aureus, group A Streptococcus, mpox (formerly monkeypox), 5 sexually transmitted infections, and gastrointestinal or vectorborne pathogens. Most studies showed higher prevalence, incidence, or measures of risk for infectious diseases among people experiencing homelessness as compared with people who are housed or the general population. Although having increased published data that quantify the infectious disease risks of homelessness is encouraging, many pathogens that are known to affect people globally who are not housed have not been evaluated in the United States or Canada. Future studies should focus on additional pathogens and factors leading to a disproportionately high incidence and prevalence of infectious diseases among people experiencing homelessness.

Respiratory Syncytial Virus, Influenza and SARS-CoV-2 in Homeless People from Urban Shelters: A Systematic Review and Meta-Analysis (2023)

Homeless people (HP) are disproportionally affected by respiratory disorders, including pneumococcal and mycobacterial infections. On the contrary, more limited evidence has been previously gathered on influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and very little is known about the occurrence of human respiratory syncytial virus (RSV), a common cause of respiratory tract infections among children and the elderly. The present systematic review was designed to collect available evidence about RSV, influenza and SARS-CoV-2 infections in HP, focusing on those from urban homeless shelters. Three medical databases (PubMed, Embase and Scopus) and the preprint repository medRxiv.org were therefore searched for eligible observational studies published up to 30 December 2023, and the collected cases were pooled in a random-effects model. Heterogeneity was assessed using the I2 statistics. Reporting bias was assessed by funnel plots and a regression analysis. Overall, 31 studies were retrieved, and of them, 17 reported on the point prevalence of respiratory pathogens, with pooled estimates of 4.91 cases per 1000 HP (95%CI: 2.46 to 9.80) for RSV, 3.47 per 1000 HP for influenza and 40.21 cases per 1000 HP (95%CI: 14.66 to 105.55) for SARS-CoV-2. Incidence estimates were calculated from 12 studies, and SARS-CoV-2 was characterized by the highest occurrence (9.58 diagnoses per 1000 persons-months, 95%CI: 3.00 to 16.16), followed by influenza (6.07, 95%CI: 0.00 to 15.06) and RSV (1.71, 95%CI: 0.00 to 4.13). Only four studies reported on the outcome of viral infections in HP: the assessed pathogens were associated with a high likelihood of hospitalization, while high rates of recurrence and eventual deaths were reported in cases of RSV infections. In summary, RSV, influenza and SARS-CoV-2 infections were documented in HP from urban shelters, and their potential outcomes stress the importance of specifically tailored preventive strategies.

Invasive Pneumococcal Disease and Potential Impact of Pneumococcal Conjugate Vaccines Among Adults, Including Persons Experiencing Homelessness-Alaska, 2011-2020

BACKGROUND

Adults aged ≥65 years, adults with certain underlying medical conditions, and persons experiencing homelessness are at increased risk for invasive pneumococcal disease (IPD). Two new pneumococcal conjugate vaccines, 15-valent pneumococcal conjugate vaccine (PCV15) and 20-valent pneumococcal conjugate vaccine (PCV20), were recently approved for use in US adults. We describe the epidemiology of IPD among Alaska adults and estimate the proportion of IPD cases potentially preventable by new vaccines.

METHODS

We used statewide, laboratory-based surveillance data to calculate and compare IPD incidence rates and 95% confidence intervals (CIs) among Alaska adults aged ≥18 years during 2011-2020 and estimate the proportion of IPD cases that were caused by serotypes in PCV15 and PCV20.

RESULTS

During 2011-2020, 1164 IPD cases were reported among Alaska adults for an average annual incidence of 21.3 cases per 100 000 adults per year (95% CI, 20.1-22.5). Incidence increased significantly during the study period (P < .01). IPD incidence among Alaska Native adults was 4.7 times higher than among non-Alaska Native adults (95% CI, 4.2-5.2). Among adults experiencing homelessness in Anchorage, IPD incidence was 72 times higher than in the general adult population (95% CI, 59-89). Overall, 1032 (89%) Alaska adults with IPD had an indication for pneumococcal vaccine according to updated vaccination guidelines; 456 (39%) and 700 (60%) cases were caused by serotypes in PCV15 and PCV20, respectively.

CONCLUSIONS

Use of PCV15 and PCV20 could substantially reduce IPD among adults in Alaska, including Alaska Native adults and adults experiencing homelessness.

Differences in meningococcal disease incidence by health insurance type and among persons experiencing homelessness-United States, 2016-2019

Meningococcal disease is a serious but rare disease in the United States. Prior publications suggest incidence differs among privately vs publicly-insured persons, and that incidence is higher among persons experiencing homelessness (PEH) than persons not known to be experiencing homelessness (non-PEH). Using insurance claims data for persons aged <1 to 64 years, we calculated meningococcal disease incidence among a population with employer-sponsored commercial insurance and persons enrolled in state Medicaid programs nationwide. We also examined meningococcal disease incidence by PEH status in Medicaid data. From 2016 through 2019, persons who met our study inclusion criteria contributed a total of 84,460,548 person-years (PYs) to our analysis of commercial insurance data and 253,496,622 PYs to our analysis of Medicaid data. Incidence was higher among persons enrolled in Medicaid (0.12 cases per 100,000 PYs) than persons with commercial insurance (0.06 cases per 100,000 PYs). Incidence was 3.17 cases per 100,000 PYs among PEH in Medicaid, 27 times higher than among non-PEH in Medicaid. Understanding the underlying drivers of the higher meningococcal disease incidence among PEH and persons enrolled in Medicaid may inform prevention strategies for populations experiencing a higher burden of disease.

Pneumococcal Vaccine for Adults Aged ≥19 Years: Recommendations of the Advisory Committee on Immunization Practices, United States, 2023

This report compiles and summarizes all published recommendations from CDC’s Advisory Committee on Immunization Practices (ACIP) for use of pneumococcal vaccines in adults aged ≥19 years in the United States. This report also includes updated and new clinical guidance for implementation from CDC

Before 2021, ACIP recommended 23-valent pneumococcal polysaccharide vaccine (PPSV23) alone (up to 2 doses), or both a single dose of 13-valent pneumococcal conjugate vaccine (PCV13) in combination with 1–3 doses of PPSV23 in series (PCV13 followed by PPSV23), for use in U.S. adults depending on age and underlying risk for pneumococcal disease. In 2021, two new pneumococcal conjugate vaccines (PCVs), a 15-valent and a 20-valent PCV (PCV15 and PCV20), were licensed for use in U.S. adults aged ≥18 years by the Food and Drug Administration

ACIP recommendations specify the use of either PCV20 alone or PCV15 in series with PPSV23 for all adults aged ≥65 years and for adults aged 19–64 years with certain underlying medical conditions or other risk factors who have not received a PCV or whose vaccination history is unknown. In addition, ACIP recommends use of either a single dose of PCV20 or ≥1 dose of PPSV23 for adults who have started their pneumococcal vaccine series with PCV13 but have not received all recommended PPSV23 doses. Shared clinical decision-making is recommended regarding use of a supplemental PCV20 dose for adults aged ≥65 years who have completed their recommended vaccine series with both PCV13 and PPSV23

Updated and new clinical guidance for implementation from CDC includes the recommendation for use of PCV15 or PCV20 for adults who have received PPSV23 but have not received any PCV dose. The report also includes clinical guidance for adults who have received 7-valent PCV (PCV7) only and adults who are hematopoietic stem cell transplant recipients

Temporally Associated Invasive Pneumococcal Disease and SARS-CoV-2 Infection, Alaska, USA, 2020-2021

Streptococcus pneumoniae can co-infect persons who have viral respiratory tract infections. However, research on S. pneumoniae infections that are temporally associated with SARS-CoV-2 infections is limited. We described the epidemiology and clinical course of patients who had invasive pneumococcal disease (IPD) and temporally associated SARS-CoV-2 infections in Alaska, USA, during January 1, 2020-December 23, 2021. Of 271 patients who had laboratory-confirmed IPD, 55 (20%) had a positive SARS-CoV-2 test result. We observed no major differences in age, race, sex, or underlying medical conditions among IPD patients with and without SARS-CoV-2. However, a larger proportion of IPD patients with SARS-CoV-2 died (16%, n = 9) than for those with IPD alone (4%, n = 9) (p<0.01). IPD patients with SARS-CoV-2 were also more likely to be experiencing homelessness (adjusted OR 3.5; 95% CI 1.7-7.5). Our study highlights the risk for dual infection and ongoing benefits of pneumococcal and COVID-19 vaccination, especially among vulnerable populations.

Communicating Effectively With People Experiencing Homelessness to Prevent Infectious Diseases

Background

People experiencing homelessness (PEH) are disproportionately affected by many infectious diseases, including coronavirus disease 2019 (COVID-19). However, communication efforts during public health emergencies like the COVID-19 pandemic often do not consider the unique needs of PEH. We examined how PEH seek and receive health information and how traditional health communication methods resonate with them.

Methods

We conducted in-person focus groups with PEH in 4 jurisdictions (Cincinnati, Ohio; Denver, Colorado; Sacramento, California; and the Bronx, New York) during July 2021.

Results

Findings from 15 focus groups with PEH (n = 53) revealed the need for trusted messengers and consistent messaging across local organizations, as PEH seek to verify information they receive from multiple sources. PEH overwhelmingly preferred to receive health information through face-to-face conversations, especially with healthcare providers with whom they had an established relationship, but they also cited news media, the internet, and social media as their main sources for obtaining health information. PEH reported that effective communication products pair a recommended action with instructions and resources about how to take that action within their community.

Conclusions

These findings support healthcare providers collaborating with public health agencies to ensure that infectious disease prevention messages for PEH are provided by trusted messengers, multimodal, paired with resources, and consistent.

Invasive Meningococcal Disease Among People Experiencing Homelessness-United States, 2016-2019

BACKGROUND

Recently, several invasive meningococcal disease (IMD) outbreaks caused by Neisseria meningitidis have occurred among people experiencing homelessness (PEH). However, overall IMD risk among PEH is not well described. We compared incidence and characteristics of IMD among PEH and persons not known to be experiencing homelessness (non-PEH) in the United States.

METHODS

We analyzed 2016-2019 IMD data from the National Notifiable Diseases Surveillance System and enhanced meningococcal disease surveillance. Incidence was calculated using US census data and point-in-time counts from the US Department of Housing and Urban Development.

RESULTS

Of cases from states participating in enhanced surveillance during 2016-2019 (n = 1409), 45 cases (3.2%) occurred among PEH. Annual incidence was higher among PEH (2.12 cases/100 000) than non-PEH (0.11 cases/100 000; relative risk, 19.8; 95% confidence interval [CI], 14.8-26.7). Excluding outbreak-associated cases (PEH n = 18, 40%; non-PEH n = 98, 7.2%), incidence among PEH remained elevated compared to incidence in non-PEH (relative risk, 12.8; 95% CI, 8.8-18.8). Serogroup C was identified in 68.2% of PEH cases compared to 26.4% in non-PEH (P < .0001).

CONCLUSIONS

PEH are at increased risk for IMD. Further assessment is needed to determine the feasibility and potential impact of meningococcal vaccination for PEH in the United States.

Strategies to improve vaccination rates in people who are homeless: A systematic review

People who are homeless experience higher rates of vaccine-preventable disease, including COVID-19, than the general population, and poorer associated health outcomes. However, delivering vaccinations to people who are homeless is complex, and there is a lack of evidence to inform practice in this area. The aim of this systematic review is to: (a) identify, (b) analyse the characteristics of, and (c) evaluate the outcomes of, strategies to improve vaccination rates in people who are homeless. Literature was retrieved from eight electronic databases. Studies undertaken in high-income countries, published in English, in a peer-reviewed journal, and in full-text were considered. No limits were placed on study design or date. A total of 1,508 articles were retrieved and, after the removal of duplicates, 637 were screened. Twenty-three articles, reporting on nineteen separate vaccination strategies for hepatitis A/B, influenza, herpes zoster, invasive pneumococcal disease, and diphtheria in people who are homeless, were selected for inclusion. All the strategies were effective at improving vaccination rates in, people who are homeless. Most strategies involved vaccination clinics and most were delivered, at least in part, by nurses. Other characteristics of successful strategies included: delivering vaccinations at convenient locations; using accelerated vaccination schedules (if available); vaccinating at the first appointment, regardless of whether a person's vaccination history or serological status were known (if clinically safe); operating for a longer duration; offering training to staff about working with people who are homeless; widely promoting clinics; considering education, reminders, incentives, and co-interventions; ensuring no out-of-pocket costs; and working collaboratively with stakeholders, including people who are homeless themselves. These findings will inform evidence-based vaccination strategies, including for COVID-19, in people who are homeless, and improve associated health outcomes in this at-risk, hard-to-reach group.

Pneumococcal infections and homelessness

Objective

To assess the prevalence of pneumococcal nasopharyngeal carriage, the role of potential risk factors, and the pneumococcal vaccination coverage among sheltered homeless people in Marseille, France.

Methods

During the winters 2015-2018, we enrolled 571 sheltered homeless males and 54 non-homeless controls. Streptococcus pneumoniae was directly searched from nasal/pharyngeal samples using real-time polymerase chain reaction.

Results

The homeless people were mostly migrants from African countries, with a mean age of 43 years. Pneumococcal vaccination coverage was low (3.1%). The overall pneumococcal carriage rate was 13.0% and was significantly higher in homeless people (15.3% in 2018) than in controls (3.7%), with p = 0.033. Among homeless people, being aged ≥ 65 years (1.97, 95% CI; 1.01-3.87), living in a specific shelter (OR = 1.80, 95% CI: 1.06-3.05), and having respiratory signs and symptoms at the time of enrolment (OR = 2.55, 95% CI: 1.54-4.21) were independently associated with pneumococcal carriage.

Conclusion

Pneumococcal nasopharyngeal carriage, which is a precursor for pneumococcal disease in at-risk individuals, is frequent among French homeless people. Studies conducted in other countries have also reported outbreaks of pneumococcal infections in homeless people. Pneumococcal vaccination should be systematically considered for sheltered homeless people in France, as is being done in Canada since 2008.

Understanding Dermatologic Concerns Among Persons Experiencing Homelessness: A Scoping Review and Discussion for Improved Delivery of Care

There is a paucity of information surrounding dermatologic care for persons experiencing homelessness (PEH). This scoping review aims to map existing literature and provide a summary of the most common cutaneous manifestations among PEH, risk factors for dermatologic disease, describe any reported interventions, as well as identify research gaps for future studies. Search strategies developed for MEDLINE and hand searching yielded 486 articles. Out of the 486 articles screened, 93 articles met the inclusion criteria. The majority were cohort studies, cross-sectional studies, and case-control studies concentrated in North America and Europe. Excluding the pediatric population, the prevalence of dermatologic conditions ranged from 16.6% to 53.5%. Common skin conditions described in PEH were: acne, psoriasis, seborrheic dermatitis, atopic dermatitis, and lichen simplex chronicus. There were no studies comparing the extent or severity of these cutaneous diseases in PEH and the general population. PEH have a higher prevalence of skin infections and non-melanoma skin cancers. This scoping review has direct implications on public health interventions for PEH and highlights the need for evidence-based interventions to provide optimum and safe dermatologic healthcare for PEH. We propose several recommendations for improved care delivery, including addressing upstream factors and comorbidities impacting skin health, providing trauma informed care, reducing barriers to care, preventing and managing skin conditions, as well as including PEH in the planning and implementation of any proposed intervention.

Differentiating Upper Extremity Necrotizing Soft Tissue Infection From Serious Cellulitis and Abscess

Introduction

Necrotizing soft tissue infection (NSTI) of the upper extremity (UE) is a rapidly progressing infection that requires early diagnosis and emergent treatment to decrease risks of loss of limb or life. Clinical presentation, particularly of early NSTI, can appear similar to serious cellulitis or abscess. The purpose of this study was to identify factors that are associated with NSTI rather than serious cellulitis and abscess to differentiate patients with similar clinical presentations.

Methods

This study uses a retrospective cohort design that compares patients ultimately diagnosed with UE NSTI versus those diagnosed with UE serious cellulitis or abscess. Cohorts were matched using the Laboratory Risk Indicators for Necrotizing Fasciitis (LRINEC) score in the setting of UE soft tissue infection. Laboratory values, vital signs, subjective symptoms, and social factors including substance abuse and domiciled status were recorded. Continuous variables were compared using the Mann-Whitney U test, whereas categorical variables were compared using the chi-squared test or the Fisher exact test (for expected values less than 5). A binary logistic regression for continuous and categorical variables was also performed. Significance was set at p<0.05. Univariate and multivariate analyses were performed.

Results

Multivariate statistical analysis and clinical interpretation of data identified four factors more associated with a diagnosis of NSTI than serious cellulitis or abscess: elevated lactate on hospital presentation, a patient-reported history of fever, male gender, and homelessness. 

Conclusions

In patients with upper extremity infections, the clinical presentation of NSTI and serious cellulitis or abscess may appear similar. In this retrospective cohort of patients matched with LRINEC scores, elevated lactate, subjective fever, male gender, and homelessness were significantly associated with NSTI rather than serious cellulitis or abscess. 

Burden of invasive group B Streptococcus disease in non-pregnant adults: A systematic review and meta-analysis

Background

Streptococcus agalactiae or group B Streptococcus (GBS) has emerged as an important cause of invasive disease in adults, particularly among the elderly and those with underlying comorbidities. Traditionally, it was recognised as an opportunistic pathogen colonising and causing disease in pregnant women, neonates, and young infants. Reasons for the upsurge of invasive GBS (iGBS) among the elderly remain unclear, although it has been related to risk factors such as underlying chronic diseases, immunosenescence, impaired inflammatory response, and spread of virulent clones. Antibiotics are successfully as treatment or prophylaxis against iGBS. Several candidate vaccines against iGBS are under development.

Objectives

To conduct a systematic review of the current literature on invasive GBS in order to determine disease incidence and case fatality ratio (CFR) among non-pregnant adults. Additionally, information on risk factors, clinical presentation, serotype distribution, and antimicrobial resistance was also retrieved.

Methods

Between January and June 2020, electronic searches were conducted in relevant databases: MEDLINE, EMBASE, Global Health, and SCOPUS. Studies were included in the systematic review if they met the inclusion/exclusion criteria. The authors assessed the selected studies for relevance, risk of bias, outcome measures, and heterogeneity. Meta-analyses on incidence and CFR were conducted after evaluating the quality of methods for assessment of exposure and outcomes.

Results

Pooled estimates of iGBS incidence in non-pregnant adults 15 years and older were 2.86 cases per 100.000 population (95% CI, 1.68–4.34). Incidence rates in older adults were substantially higher, 9.13 (95%CI, 3.53–17.22) and 19.40 (95%CI, 16.26–22.81) per 100.000 population ≥50 and ≥ 65 years old, respectively. Incidence rates ranged from 0.40 (95% CI, 0.30–0.60) in Africa to 5.90 cases per 100.000 population (95% CI, 4.30–7.70) in North America. The overall CFR was and 9.98% (95% CI, 8.47–11.58). CFR was highest in Africa at 22.09% (95% CI, 12.31–33.57). Serotype V was the most prevalent serotype globally and in North America accounting for 43.48% (n = 12926) and 46,72% (n = 12184) of cases, respectively. Serotype Ia was the second and serotype III was more prevalent in Europe (25.0%) and Asia (29.5%). Comorbidities were frequent among non-pregnant adult iGBS cases. Antimicrobial resistance against different antibiotics (i.e., penicillin, erythromycin) is increasing over time.

Conclusions

This systematic review revealed that iGBS in non-pregnant adults has risen in the last few years and has become a serious public health threat especially in older adults with underlying conditions. Given the current serotype distribution, vaccines including serotypes predominant among non-pregnant adults (i.e., serotypes V, Ia, II, and III) in their formulation are needed to provide breadth of protection. Continued surveillance monitoring potential changes in serotype distribution and antimicrobial resistance patterns are warranted to inform public health interventions.

Differentiating Lower Extremity Necrotizing Soft Tissue Infection from Severe Cellulitis by Laboratory Parameters and Relevant History Points

Background

Necrotizing soft tissue infection (NSTI) of the lower extremity (LE) is a rapidly progressing infection that requires early diagnosis and prompt treatment to decrease risks of loss of limb or life. Clinical presentation, particularly of early NSTI, can appear similar to severe cellulitis. The purpose of this study is to identify factors that are associated with NSTI rather than severe cellulitis to differentiate patients with similar clinical presentation.

Methods

This retrospective cohort design study compares patients finally diagnosed with LE NSTI versus those diagnosed with severe cellulitis. Cohorts were matched using the modified Laboratory Risk Indicator for Necrotizing Fasciitis (m-LRINEC) score in the setting of LE soft tissue infection. Laboratory values, vital signs, subjective symptoms, and social factors including substance abuse were recorded. Univariate and multivariate analyses were performed.

Results

Multivariate statistical analysis and clinical interpretation of data identified four factors more associated with a diagnosis of NSTI than severe cellulitis: elevated lactate, a patient-reported history of fever, male gender, and intravenous substance user.

Conclusion

In patients with lower extremity infections, the clinical presentation of NSTI and severe cellulitis may appear similar. In this retrospective cohort of patients matched with m-LRINEC scores, elevated lactate, subjective fever, male gender, and intravenous substance abuser were significantly associated with NSTI rather than severe cellulitis. Further studies of these factors in the clinical setting can help tailor the differential diagnosis in the care of patients with severe lower extremity infections. Matched with m-LRINEC scores, elevated lactate, subjective fever, male gender, and intravenous substance abuser were significantly associated with NSTI rather than severe cellulitis. Further studies of these factors in the clinical setting can help tailor the differential diagnosis in the care of patients with severe lower extremity infections.

Is there a need for pneumococcal vaccination programs for the homeless to prevent invasive pneumococcal disease?

INTRODUCTION

Homeless are a vulnerable segment of society at risk for infections. Invasive pneumococcal disease (IPD) infections are increasingly identified in homeless as a major contributor of morbidity and mortality. Very few countries have recommended pneumococcal vaccination programs for the homeless.

AREAS COVERED

A literature review of IPD in the homeless from 1980 to 2020 in PubMed and Scopus using terms, 'homeless,' and 'homelessness,' and after 'chronic' or 'transitory' homeless was conducted. Gray literature from the CDC, WHO and major governmental agencies/organizations were included. Terms for IPD eligible for inclusion in the database search included 'pneumococcal disease,' 'invasive pneumococcal disease,' 'Streptococcus pneumoniae.' This included outbreaks of pneumococcal disease in the homeless, clinical characteristics associated with pneumococcal disease in the homeless, pneumococcal vaccines and vaccination recommendations for the homeless.

EXPERT OPINION

Homeless populations are at increased risk for IPD in comparison to the general population. This is due to clinical conditions experienced by the homeless including alcoholism and cigarette smoking. In addition, a collection of specific pneumococcal serotypes are associated with IPD in this group. Pneumococcal vaccine programs aimed at this population would likely decrease the incidence of IPD for this group and contribute to better overall health for the homeless.

Invasive Group A Streptococcal Infections: Benefit of Clindamycin, Intravenous Immunoglobulins and Secondary Prophylaxis

Introduction: Mortality associated with invasive group A streptococcal infections (iGAS) remains high among adults, with lower mortality in children. The added value of both clindamycin and immunoglobulins in such treatment is still controversial, as is the need for antibiotic secondary prophylaxis. It is unlikely that conclusive randomized clinical studies will ever definitively end these controversies. Materials and Methods: A clinical and experimental literature review was conducted in Pubmed, Cochrane, and lay literature to determine the benefit of adding clindamycin and immunoglobulins to β-lactams in the management of iGAS, as well as the need for secondary prophylaxis measures in close contacts. Results: This review includes two meta-analyses, two randomized controlled trials, four prospective studies, five retrospective studies, and microbiological studies. To reduce mortality and morbidity, it appears useful to add clindamycin to β-lactams in severe clinical presentations, including necrotizing fasciitis or streptococcal toxic shock syndrome, and immunoglobulins for the latter two presentations. The high risk of secondary infection in household contacts justifies the need of taking preventive measures. Conclusions: Both clinical studies and available experimental evidence suggest that adding clindamycin and immunoglobulins as adjunctive therapies in the management of invasive group A streptococcal infections may reduce mortality. Household contacts should be warned about the increased risk of secondary infection, and chemoprophylaxis may be considered in certain situations.

Vaccine-preventable diseases other than tuberculosis, and homelessness: A scoping review of the published literature, 1980 to 2020

BACKGROUND

Homelessness may result in the breakdown of regular health services, including routine vaccination programmes. A scoping review was conducted to describe vaccine-preventable diseases (VPD) other than tuberculosis in people experiencing homelessness (PEH).

METHODS

We followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). We searched peer-reviewed literature published in English, French, Spanish or Portuguese reporting the outbreak of VPD or VPD prevalence in both infant and adult homeless populations published between 1980 and 2020, using PubMed/Medline, SciELO, Google Scholar, and Web of Science databases. Relevant information from the studies was charted in Microsoft Excel and results were summarised using a descriptive analytical method.

RESULTS

Eighty-one articles were included. A high prevalence of past hepatitis B virus (HBV) and hepatitis A virus (HAV) infections were observed through serosurveys, mostly in high income countries or high-middle income countries (USA, Canada, France, Iran or Brazil). Ten outbreaks of HAV infection were also reported, with lethality rates ranging from 0 to 4.8%. The studies identified numerous risk factors positively associated with HBV infection, including older age, homosexual or bisexual practice, injected drug use (IDU), and, with HAV infection including IDU, having sexual partner(s) with a history of unspecified hepatitis, insertive anal penetration, or originating from a country with a high prevalence of anti-HAV antibody. Eleven outbreaks of pneumococcal infection affecting PEH were reported in Canada and USA, with lethality rates from 0 to 15.6%. Six diphtheria outbreaks were reported. Vaccination status was rarely documented in these studies.

CONCLUSIONS

The literature suggests that homeless populations generally experience a high VPD burden suggesting the need for a national vaccination programme and planning for delivering vaccines in this population.