Myocardial Infarction, Stroke, and Mortality in cART-Treated HIV Patients on Statins

Hypertension among people living with human immunodeficiency virus in sub-Saharan Africa: a systematic review and meta-analysis

We performed a systematic review and meta-analysis of hypertension in people living with human immunodeficiency virus (HIV) in sub-Saharan Africa (SSA). We searched the PubMed, Google Scholar, African Index Medicus, and Embase databases to identify studies published from January 1, 2010, to December 31, 2021. We used a random-effects model to estimate the pooled prevalence of hypertension and mean SBP/DBP level on a sex-specific basis. We included 48 studies reporting data on a pooled sample of 193,843 people living with HIV (PLW-HIV) in SSA. The pooled mean SBP/DBP level was 120 (95% CI 113-128)/77 (95%CI 72-82) mmHg, while the overall pooled prevalence of hypertension was 21.9% (95% CI 19.9-23.9%). Further meta-regression analyses suggested that the prevalence of hypertension was 1.33 times greater in males, 1.23 times greater in individuals receiving antiretroviral therapy (ART) and 1.45 times greater in those individuals with a CD4-count ≥ 200. This meta-analysis of the contemporary pattern of BP levels among PLW-HIV in SSA, suggests that around one in five of such individuals also have hypertension. Given the further context of greater access to ART and subsequently greater longevity, study findings support calls to integrate cardiovascular management into routine HIV care.

Role of Statin in Reducing Cardiovascular Diseases in Human Immunodeficiency Virus (HIV) Patients: A Systematic Review

Because of abnormal lipid profiles, the risk of patients living with human immunodeficiency virus (PLHIV) developing cardiovascular diseases (CVDs) is much greater than in the general population. Statins are known effective medications for reducing the risk of CVDs by influencing inflammatory mediators, endothelial function, angiogenesis, and thrombosis. However, their role in PLHIV has not been well confirmed. In this article, we aim to provide more clarity about the effects of statin in lowering CVDs in PLHIV. Cochrane Library, PubMed, PubMed Central (PMC), and Medical Literature Analysis and Retrieval System Online (MEDLINE) were screened and searched for articles that contained relevant data to our study. In this article, three clinical trials and five observational studies, including eight abstracts, were obtained and analyzed. We included articles that examined the efficacy of statins in reducing CVDs in those with PLHIV. Two reviewers independently abstracted and collected the data. We infer that the cardiovascular events in PLHIV were reduced by the potent effects of statins.

Influence of Statin Therapy on the Incidence of Cardiovascular Events, Cancer, and All-Cause Mortality in People Living With HIV: A Meta-Analysis

Background: Possible influences of statin therapy on the risk of cardiovascular events, cancer, and all-cause mortality in people living with HIV (PLWH) remain unclear. We performed a meta-analysis to systematically evaluate the efficacy of statin in PLWH.

Methods: Relevant cohort studies were retrieved via a search of the Medline, the Embase, and the Web of Science databases until June 14, 2021. The data were combined with a random-effects model by incorporating the between-study heterogeneity.

Results: A total of 12 multivariate cohort studies with 162,252 participants were eligible for the meta-analysis and 36,253 (22.3%) of them were statin users. Pooled results showed that statin use was independently related to a reduced mortality risk in PLWH [adjusted risk ratio (RR): 0.56, 95% CI: 0.44 to 0.72, p < 0.001, I² = 41%]. In addition, results of the meta-analysis showed that statin use was not significantly associated with a reduced risk of cardiovascular events in PLWH compared to the statin non-users (RR: 1.14, 95% CI: 0.80 to 1.63, p = 0.48, I² = 42%). However, statin use was significantly related to a reduced risk of cancer in PLWH (RR: 0.73, 95% CI: 0.58 to 0.93, p = 0.009, I² = 49%). Sensitivity analyses by excluding one study at a time showed consistent results. No significant publication biases were observed.

Conclusion: Statin use is associated with reduced all-cause mortality in PLWH. In addition, statin use is related to a reduced risk of cancer, although the risk of cardiovascular events seems not significantly affected.

Types of Stroke Among People Living With HIV in the United States

BACKGROUND

Most studies of stroke in people living with HIV (PLWH) do not use verified stroke diagnoses, are small, and/or do not differentiate stroke types and subtypes.

SETTING

CNICS, a U.S. multisite clinical cohort of PLWH in care.

METHODS

We implemented a centralized adjudication stroke protocol to identify stroke type, subtype, and precipitating conditions identified as direct causes including infection and illicit drug use in a large diverse HIV cohort.

RESULTS

Among 26,514 PLWH, there were 401 strokes, 75% of which were ischemic. Precipitating factors such as sepsis or same-day cocaine use were identified in 40% of ischemic strokes. Those with precipitating factors were younger, had more severe HIV disease, and fewer traditional stroke risk factors such as diabetes and hypertension. Ischemic stroke subtypes included cardioembolic (20%), large vessel atherosclerosis (13%), and small vessel (24%) ischemic strokes. Individuals with small vessel strokes were older, were more likely to have a higher current CD4 cell count than those with cardioembolic strokes and had the highest mean blood pressure of the ischemic stroke subtypes.

CONCLUSION

Ischemic stroke, particularly small vessel and cardioembolic subtypes, were the most common strokes among PLWH. Traditional and HIV-related risk factors differed by stroke type/subtype. Precipitating factors including infections and drug use were common. These results suggest that there may be different biological phenomena occurring among PLWH and that understanding HIV-related and traditional risk factors and in particular precipitating factors for each type/subtype may be key to understanding, and therefore preventing, strokes among PLWH.

Consistent use of lipid lowering therapy in HIV infection is associated with low mortality

BACKGROUND

In people living with HIV (PLWH), statins may be disproportionately effective but remain underutilized. A large prospective trial in patients with low to moderate cardiovascular (ASCVD) risk will reveal whether they should be considered in all PLWH. But its effect size may not apply to real-world PLWH with higher ASCVD and mortality risk. Also, the clinical role of non-statin lipid-lowering therapy (LLT) and LLT adherence in this population is unknown.

METHODS

Comparative multi-level marginal structural model for all-cause mortality examining four time-updated exposure levels to LLT, antihypertensives, and aspirin in a virtual cohort of older PLWH. Incident coronary, cerebrovascular, and overall ASCVD events, serious infections, and new cancer diagnoses served as explanatory outcomes.

RESULTS

In 23,276 HIV-infected US-veterans who were followed for a median of 5.2 years after virologic suppression overall mortality was 33/1000 patient years: > 3 times higher than in the US population. Use of antihypertensives or aspirin was associated with increased mortality. Past LLT use (> 1 year ago) had no effect on mortality. LLT exposure in the past year was associated with a reduced hazard ratio (HR) of death: 0.59, 95% confidence interval (CI) 0.51-0.69, p < 0.0001 for statin containing LLT and 0.71 (CI: 0.54-0.93), p = 0.03 for statin-free LLT. For consistent LLT use (> 11/12 past months) the HR of death was 0.48 (CI: 0.35-0.66) for statin-only LLT, 0.34 (CI: 0.23-0.52) for combination LLT, and 0.27 (CI: 0.15-0.48) for statin-free LLT (p < 0.0001 for all). The ASCVD risk in these patients was reduced in similar fashion. Use of statin containing LLT was also associated with reduced infection and cancer risk. Multiple contrasting subgroup analyses yielded comparable results. Confounding is unlikely to be a major contributor to our findings.

CONCLUSIONS

In PLWH, ongoing LLT use may lead to substantially lower mortality, but consistent long-term adherence may be required to reduce ASCVD risk. Consistent non-statin LLT may be highly effective and should be studied prospectively.

HIV-associated cardiovascular disease: importance of platelet activation and cardiac fibrosis in the setting of specific antiretroviral therapies

HIV infection is a risk factor for cardiovascular disease (CVD). This risk is accentuated by certain combination antiretroviral therapies (cARTs), independent of their effects on lipid metabolism and insulin sensitivity. We sought to define potential mechanisms for this association through systematic review of clinical and preclinical studies of CVD in the setting of HIV/cART from the English language literature from 1989 to March 2018. We used PubMed, Web of Knowledge and Google Scholar, and conference abstracts for the years 2015-March 2018. We uncovered three themes: (1) a critical role for the HIV protease inhibitor (PI) ritonavir and certain other PI-based regimens. (2) The importance of platelet activation. Virtually all PIs, and one nucleoside reverse transcriptase inhibitor, abacavir, activate platelets, but a role for this phenomenon in clinical CVD risk may require additional postactivation processes, including: release of platelet transforming growth factor-β1; induction of oxidative stress with production of reactive oxygen species from vascular cells; suppression of extracellular matrix autophagy; and/or sustained proinflammatory signalling, leading to cardiac fibrosis and dysfunction. Cardiac fibrosis may underlie an apparent shift in the character of HIV-linked CVD over the past decade from primarily left ventricular systolic to diastolic dysfunction, possibly driven by cART. (3) Recognition of the need for novel interventions. Switching from cART regimens based on PIs to contemporary antiretroviral agents such as the integrase strand transfer inhibitors, which have not been linked to clinical CVD, may not mitigate CVD risk assumed under prior cART. In conclusion, attention to the effects of specific antiretroviral drugs on platelet activation and related profibrotic signalling pathways should help: guide selection of appropriate anti-HIV therapy; assist in evaluation of CVD risk related to novel antiretrovirals; and direct appropriate interventions.

Statin use and all-cause mortality in people living with HIV: a systematic review and meta-analysis

Background

It is unknown whether statin use among people living with HIV results in a reduction in all-cause mortality. We aimed to evaluate the effect of statin use on all-cause mortality among people living with HIV.

Methods

We conducted comprehensive literature searches of Medline, Embase, CINAHL, the Cochrane Library, and cross-references up to April 2018. We included randomised, quasi-randomised trials and prospective cohort studies that examined the association between statin use and cardio-protective and mortality outcomes among people living with HIV. Two reviewers independently abstracted the data. Hazard ratios (HRs) were pooled using empirical Bayesian random-effect meta-analysis. A number of sensitivity analyses were conducted.

Results

We included seven studies with a total of 35,708 participants. The percentage of participants on statins across the studies ranged from 8 to 35%. Where reported, the percentage of participants with hypertension ranged from 14 to 35% and 7 to 10% had been diagnosed with diabetes mellitus. Statin use was associated with a 33% reduction in all-cause mortality (pooled HR = 0.67, 95% Credible Interval 0.39 to 0.96). The probability that statin use conferred a moderate mortality benefit (i.e. decreased risk of mortality of at least 25%, HR ≤ 0.75) was 71.5%. Down-weighting and excluding the lower quality studies resulted in a more conservative estimate of the pooled HR.

Conclusion

Statin use appears to confer moderate mortality benefits in people living with HIV.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3162-1) contains supplementary material, which is available to authorized users.

Benefits and Risks of Statin Therapy in the HIV-Infected Population

PURPOSE OF REVIEW

HIV-infected patients face an increased risk for cardiovascular disease (CVD), estimated at 1.5- to 2-fold as compared to HIV-uninfected persons. This review provides a recent (within preceding 5 years) summary of the role of statin therapy and associated role in CVD risk reduction among HIV-infected patients on anti-retroviral therapy.

RECENT FINDINGS

Statins remain the preferred agents for reducing risk for CVD among HIV-infected populations based on guidance extrapolated from general population (HIV-uninfected) cholesterol treatment guidelines across different settings globally. However, HIV-infected patients are consistently under prescribed statin therapy when compared to their HIV-uninfected counterparts. The most commonly studied statins in clinical care and small randomized and cohort studies have been rosuvastatin and atorvastatin. Both agents are preferred for their potent lipid-lowering effects and their favorable or neutral pleotropic effects on chronic inflammation, renal function, and hepatic steatosis among others. However, growing experience with the newer glucuronidated pitavastatin suggests that this agent has virtually no adverse drug interactions with ART or effects on glucose metabolism-all marked additional benefits when compared with rosuvastatin and atorvastatin while maintaining comparable anti-lipid effects. Pitavastatin is therefore the statin of choice for the ongoing largest trial (6500 participants) to test the benefits of statin therapy among HIV-infected adults. Statins are underutilized in the prevention of CVD in HIV-infected populations based on criteria in established cholesterol guidelines. There is a potential role for statin therapy for HIV-infected patients who do not meet guideline criteria which will be further delineated through ongoing clinical trials.

Association of Human Immunodeficiency Virus Infection and Risk of Peripheral Artery Disease

BACKGROUND

The effect of human immunodeficiency virus (HIV) on the development of peripheral artery disease (PAD) remains unclear. We investigated whether HIV infection is associated with an increased risk of PAD after adjustment for traditional atherosclerotic risk factors in a large cohort of HIV-infected (HIV+) and demographically similar HIV-uninfected veterans.

METHODS

We studied participants in the Veterans Aging Cohort Study from April 1, 2003 through December 31, 2014. We excluded participants with known prior PAD or prevalent cardiovascular disease (myocardial infarction, stroke, coronary heart disease, and congestive heart failure) and analyzed the effect of HIV status on the risk of incident PAD events after adjusting for demographics, PAD risk factors, substance use, CD4 cell count, HIV-1 ribonucleic acid, and antiretroviral therapy. The primary outcome is incident peripheral artery disease events. Secondary outcomes include mortality and amputation in subjects with incident PAD events by HIV infection status, viral load, and CD4 count.

RESULTS

Among 91 953 participants, over a median follow up of 9.0 years, there were 7708 incident PAD events. Rates of incident PAD events per 1000 person-years were higher among HIV+ (11.9; 95% confidence interval [CI], 11.5-12.4) than uninfected veterans (9.9; 95% CI, 9.6-10.1). After adjustment for demographics, PAD risk factors, and other covariates, HIV+ veterans had an increased risk of incident PAD events compared with uninfected veterans (hazard ratio [HR], 1.19; 95% CI, 1.13-1.25). This risk was highest among those with time-updated HIV viral load >500 copies/mL (HR, 1.51; 95% CI, 1.38-1.65) and CD4 cell counts <200 cells/mm³ (HR, 1.91; 95% CI, 1.71-2.13). In contrast, HIV+ veterans with time updated CD4 cell count ≥500 cells/mm³ had no increased risk of PAD (HR, 1.03; 95% CI, 0.96-1.11). Mortality rates after incident PAD events are high regardless of HIV status. HIV infection did not affect rates of amputation after incident PAD events.

CONCLUSIONS

Infection with HIV is associated with a 19% increased risk of PAD beyond that explained by traditional atherosclerotic risk factors. However, for those with sustained CD4 cell counts <200 cells/mm³, the risk of incident PAD events is nearly 2-fold higher whereas for those with sustained CD4 cell counts ≥500 cells/mm³ there is no excess risk of incident PAD events compared with uninfected people.

Evaluation of Statin Eligibility, Prescribing Practices, and Therapeutic Responses Using ATP III, ACC/AHA, and NLA Dyslipidemia Treatment Guidelines in a Large Urban Cohort of HIV-Infected Outpatients

Statin coverage has been examined among HIV-infected patients using Adult Treatment Panel III (ATP III) and American College of Cardiology/American Heart Association (ACC/AHA) guidelines, although not with newer National Lipid Association (NLA) guidelines. We investigated statin eligibility, prescribing practices, and therapeutic responses using these three guidelines. Sociodemographic, clinical, and laboratory data were collected between 2011 and 2016 for HIV-infected outpatients enrolled in the DC Cohort, a multi-center, prospective, observational study in Washington, DC. This analysis included patients aged ≥21 years receiving primary care at their HIV clinic site with ≥1 cholesterol result available. Of 3312 patients (median age 52; 79% black), 52% were eligible for statins based on ≥1 guideline, including 45% (NLA), 40% (ACC/AHA), and 30% (ATP III). Using each guideline, 49% (NLA), 56% (ACC/AHA), and 73% (ATP III) of eligible patients were prescribed statins. Predictors of new prescriptions included older age (aHR = 1.16 [1.08-1.26]/5 years), body mass index ≥30 (aHR = 1.50 [1.07-2.11]), and diabetes (aHR = 1.35 [1.03-1.79]). Hepatitis C coinfection was inversely associated with statin prescriptions (aHR = 0.67 [0.45-1.00]). Among 216 patients with available cholesterol results pre-/post-prescription, 53% achieved their NLA cholesterol goal after 6 months. Hepatitis C coinfection was positively associated (aHR = 1.87 [1.06-3.32]), and depression (aHR = 0.56 [0.35-0.92]) and protease inhibitor use (aHR = 0.61 [0.40-0.93]) were inversely associated, with NLA goal achievement. Half of patients were eligible for statins based on current US guidelines, with the highest proportion eligible based on NLA guidelines, yet, fewer received prescriptions and achieved treatment goals. Greater compliance with recommended statin prescribing practices may reduce cardiovascular disease risk among HIV-infected individuals.

Durability of Second Antiretroviral Regimens in the Italian Cohort Naive Antiretrovirals Foundation Study and Factors Associated with Discontinuation

The study was designed to investigate the median duration of second antiretroviral regimens and factors associated with early discontinuation in HIV patients who switched with an undetectable viral load. We conducted a retrospective analysis of the Italian Cohort Naive Antiretrovirals Foundation Study (ICONA), which collects data throughout the country. Patients who started first antiretroviral therapy (ART) after January 1, 2008 in any center involved in this cohort and then switched to a second regimen were included in the study. Second ART failure was described as two HIV-RNA >200 copies/mL or the discontinuation of any drug. Statistical analysis was performed utilizing Kaplan-Meier curves and Cox regression model. The study population included 835 patients and the median duration of first ART regimens was 16 months with HIV-RNA undetectable for 13 months. The main causes of switch to second ART regimens were toxicity (42.5%) and simplification (37.5%). The switch mostly involved the third drug (63.5%) and almost one third of the population received a single-tablet regimen (STR) as second treatment (30.6%). The median duration of second ART regimens was 9.2 months and the probabilities of treatment discontinuation at 12, 24, and 36 months were 21%, 35%, and 48.2%, respectively. STR formulations had a protective effect against second ART discontinuation. Almost half of our population needed a third regimen within 3 years, but STR could improve second ART durability.

Understanding mechanisms to promote successful aging in persons living with HIV

The mortality rate associated with HIV infection plummeted after the introduction of effective antiretroviral therapy pioneered two decades ago. As a result, HIV-infected people now have life expectancies comparable to that of HIV-uninfected individuals. Despite this, increased rates of osteoporosis, chronic liver disease, and in particular cardiovascular disease have been reported among people living with HIV infection. With the aging HIV-infected population, the burden of these comorbid illnesses may continue to accrue over time. In this paper, we present an overview of the aging HIV-infected population, its epidemiology and the many challenges faced. How to define and measure successful aging will also be reviewed. Finally, opportunities that may help mitigate the challenges identified and ensure successful aging among people living with HIV infection will be examined.

Trends and Correlates of Cigarette Smoking and Its Impacts on Health-Related Quality of Life Among People Living with HIV: Findings from the Ontario HIV Treatment Network Cohort Study, 2008-2014

We sought to examine the trends of cigarette smoking, identify correlates of smoking, and examine the impacts of smoking on health-related quality of life (HRQOL) among people living with HIV in Ontario, Canada. Study sample included 4473 individuals receiving care and enrolled in the Ontario HIV Treatment Network Cohort Study. Self-report data on cigarette smoking, HRQOL, and demographic and sociobehavioral variables were collected between 2008 and 2014 through annual face-to-face interviews. Clinical data were abstracted from participants' medical records and enhanced through linkage with a provincial public health laboratory database. Analyses included descriptive statistics, generalized logit regression, and linear mixed-effects modeling. At first interview, 1760 participants (39.3%) were current cigarette smokers. Smoking prevalence declined annually by 1.6% between 2008 and 2014, but remained much higher than the prevalence in the general population. Current cigarette smokers were more likely to be younger, male, white or indigenous, Canadian-born, single, unemployed with lower education, heavy drinkers, nonmedicinal drug users, and to have current depression than former cigarette smokers or those who never smoked. Current cigarette smokers also had significantly (p < 0.001) worse SF-12 physical component summary (β = -2.07) and SF-12 mental component summary (β = -1.08) scores than those who never smoked after adjusting for demographic, socioeconomic, and HIV-related clinical variables. To reduce the burden of cigarette smoking, cessation interventions that take into account the complex social, economic, and medical needs of people living with HIV are needed urgently.

Thrombotic Microangiopathy in the Setting of HIV Infection: A Case Report and Review of the Differential Diagnosis and Therapy

Before the modern era of HIV/AIDS therapeutics, which enabled a cascade of early recognition of infection, prompt initiation of effective antiretroviral therapies, and close follow-up, severe forms of microvascular clotting disorders known as thrombotic microangiopathies (TMAs) were frequent in the setting of advanced HIV disease. Their incidence was as high as 7% in the period 1984-1999, but fell dramatically, to <0.5%, by 2002. This profound change was predicated on one critical development: availability of new classes of anti-HIV drugs, enabling reduction and maintenance of HIV viral loads to undetectable levels. Another development in the period 1999-2002 related to TMA therapy: with recognition of autoantibodies against the von Willebrand factor cleaving protease ADAMTS13 as the etiology of most cases of one major form of TMA, thrombotic thrombocytopenic purpura, it permitted appropriate use of life-saving interventions based on plasma exchange and immune suppression. A more recent factor in TMA therapeutics was the 2011 approval by the US FDA and European EMA of eculizumab, a humanized monoclonal antibody against complement component C5, for the treatment of atypical hemolytic uremic syndrome, another major form of TMA. Despite these milestones, life- and organ-threatening TMAs still occur in untreated HIV disease and, to a much lesser extent, in those patients with suppressed viral loads. Confusion in terms of the differential diagnosis of these TMAs also impedes use of directed treatments. This report utilizes a case study of a young woman with advanced AIDS who presented with a severe TMA, characterized by coma and renal failure, to highlight the diagnostic and therapeutic challenges raised by complex hematologic conditions occurring in the setting of HIV.

Pathophysiology and management of cardiovascular disease in patients with HIV

Results from several studies have suggested that people with HIV have an increased risk of cardiovascular disease, especially coronary heart disease, compared with people not infected with HIV. People living with HIV have an increased prevalence of traditional cardiovascular disease risk factors, and HIV-specific mechanisms such as immune activation. Although older, more metabolically harmful antiretroviral regimens probably contributed to the risk of cardiovascular disease, new data suggest that early and continuous use of modern regimens, which might have fewer metabolic effects, minimises the risk of myocardial infarction by maintaining viral suppression and decreasing immune activation. Even with antiretroviral therapy, however, immune activation persists in people with HIV and could contribute to accelerated atherosclerosis, especially of coronary lesions that are susceptible to rupture. Therefore, treatments that safely reduce inflammation in people with HIV could provide additional cardiovascular protection alongside treatment of both traditional and non-traditional risk factors.

High Prevalence of Metabolic Syndrome and Cardiovascular Disease Risk Among People with HIV on Stable ART in Southwestern Uganda

The objectives of this study were to determine the epidemiology and correlates of cardiovascular disease (CVD) risk among Ugandans on first-line antiretroviral therapy (ART). We conducted a cross-sectional study at an HIV clinic in southwestern Uganda. We enrolled adult patients on non-nucleoside-based ART regimens for a minimum of 2 years. We collected anthropometric and clinical measurements, smoking history, and blood for fasting lipid profile and blood sugar (FBS). Outcomes of interest were (1) presence of metabolic syndrome (at least two of the following: FBS >100 mg/dL, blood pressure of ≥130/85 mmHg, triglycerides ≥150 mg/dL, HDL <40 mg/DL, or waist circumference ≥94 cm in males or ≥80 cm in females); and (2) a Framingham score correlating to >5% 10-year CVD risk. Of the 250 participants enrolled, metabolic syndrome was detected in 145/250 (58%) of participants (62% in females and 50% in males). Forty-three participants (17%) had a Framingham risk correlating to a 5% or greater risk for CVD within 10 years (26% in males and 13% in females). In multivariate analyses, being female (AOR 3.13; 95% CI: 1.0-9.70; p = 0.04) and over 40 years of age (AOR 1.78; 95% CI: 1.00-3.17; p = 0.05) was independently associated with having metabolic syndrome. We found no independent risk factors for a Framingham risk score 10-year risk exceeding 5%, or associations between ART regimen and CVD risk profiles. We conclude that metabolic abnormalities are common among patients on first-line ART in rural Uganda, and appear to be more common in women than men.

Infection and Stroke: an Update on Recent Progress

The role of infection in cerebrovascular disease is complex and remains incompletely understood. Over the last 5 years, investigators have made notable inroads in untangling this thorny topic. In this review, we examine these recent developments, concentrating on four aspects of the relationship between infection and stroke. We first discuss specific infectious agents as direct causes of stroke, focusing on recent work implicating herpesviruses and HIV in cerebral vasculopathy. We then discuss systemic infection of any type as a stroke trigger, focusing on the relationship of infection to timing of acute stroke, both in children and adults, as well as the role of vaccination in stroke prevention. We examine the evidence for chronic infection or "infectious burden" as a stroke risk factor. Finally, we discuss recent work on infection as a risk factor for increased morbidity after stroke, possible mechanisms mediating this effect, and the evidence for prophylactic antibiotics.