Prognostic Implications of Early Albuminocytological Dissociation in Guillain-Barré Syndrome.

BACKGROUND: Half of Guillain-Barré syndrome (GBS) present elevated cerebrospinal fluid (CSF) protein levels within 1 week since symptom onset and 80% within 2 weeks. Our objective was to determine the clinical and prognostic implication of albuminocytological dissociation in early GBS. METHODS: An ambispective cohort study was conducted. Good outcome was considered if the patient was able to walk unaided (Guillain-Barré disability score [GDS] ≤ 2 points) at 3-month follow-up. Patients were classified into two groups: with and without albuminocytological dissociation; we compared clinical and paraclinic characteristics between the groups. We analyzed clinical and electrophysiological factors related to presenting early dissociation through a multivariate model. RESULTS: We included 240 patients who fulfilled Asbury criteria for GBS. On further selection, only 94 patients fulfilled inclusion. Mean age was 45.94 ± 17.1 years and 67% were male. Median time from symptom onset to admission was 5 days (IQR 3-6). Regarding albuminocytological dissociation and electrophysiological variants, we found a significant difference: acute inflammatory demyelinating polyneuropathy (AIDP) [60.6% vs 26.2%, p = 0.002], acute motor axonal neuropathy (AMAN) [21.2% vs 49.1%, p = 0.009] and acute motor sensory axonal neuropathy (AMSAN) [12.1% vs 1.6%, p = 0.05]. We did not observe significant differences in recovery of independent walking in short term between both groups. The presence of conduction block in any variant (OR 3.21, 95% CI 1.12-9.16, p = 0.02) and absence of sural registration (OR 5.69, 95% CI 1.48-21.83, p = 0.011) were independent factors related to early dissociation. CONCLUSIONS: Early dissociation (<7 days) is not associated with any particular clinical feature or unfavorable outcome. It is more common to see in AIDP rather than axonal variants.

Osmotic demyelination syndrome in patients with non-Hodgkin lymphoma: a case report and literature review.

INTRODUCTION: Osmotic demyelination syndrome (ODS) is a non-inflammatory process of the central nervous system caused by extracellular osmotic changes, which leads to oligodendrocyte apoptosis and disruption of myelin sheaths, usually affecting patients with underlying systemic conditions that impose susceptibility to osmotic stress. Description of ODS in patients with non-Hodgkin lymphoma (NHL) is limited to a few case reports. METHODS: Here, we report a 44-year-old man with NHL that had an incidental diagnosis of ODS. We conducted a literature review of the published cases of ODS in NHL patients from 1959 to 2020, aiming to describe the characteristics of these patients. RESULTS: A total of seven patients were summarized (four men and three women), including our case and six patients from published reports. Risk factors such as weight loss and alcoholism were reported in five (71.4%) patients. Hyponatremia was found in six (85.7%) of the cases, and none of them had overly rapid sodium correction. Four cases were asymptomatic, and diffuse large B-cell lymphoma was the most common subtype of NHL (85.7%). The outcome was favorable in most cases; only two deaths not directly related to ODS were reported. CONCLUSION: We wish to suggest that systemic and metabolic stress induced by NHL may be associated with the development of central osmotic demyelination, and therefore, NHL may be a novel risk factor for ODS. Clinicians should be aware of ODS in patients with hematological malignancies, even in the absence of traditional risk factors.

Posterior reversible encephalopathy syndrome during convalescence from COVID-19.

Background and aim: With an ever-increasing population of patients recovering form severe coronavirus disease 2019 (COVID-19), recognizing long-standing and delayed neurologic manifestations is crucial. Here, we present a patient developing posterior reversible encephalopathy syndrome (PRES) in the convalescence form severe coronavirus disease 2019 (COVID-19).Case presentation: A 61-year-old woman with severe (COVID-19) confirmed by nasopharyngeal real-time reverse transcription-polymerase chain reaction (RT-PCR) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) required invasive mechanical ventilation 24-hours after admission. During her intensive care unit stay, she developed transient acute kidney injury and septic shock. She was extubated after 22 days. On day 25, she developed generalized tonic-clonic seizures. Magnetic resonance imaging (MRI) of the brain showed bilateral subcortical lesions on the parietal and occipital lobes and multiple micro-and macro-bleeds, consistent with PRES. At this point, RT-PCR for SARS-CoV-2 in a respiratory specimen and cerebrospinal fluid was negative. She was discharged home 35 days after admission on oral levetiracetam. Control MRI five months after discharge showed bilateral focal gliosis. On follow-up, she remains seizure-free on levetiracetam.Conclusions: PRES has been observed before as a neurological manifestation of acute COVID-19; to our knowledge, this is the first PRES case occurring in a hospitalized patient already recovered from COVID-19. A persistent proinflammatory/prothrombotic state triggered by SARS-CoV-2 infection may lead to long-standing endothelial dysfunction, resulting in delayed PRES in patients recovering from COVID-19. With a rapid and exponential increase in survivors of acute COVID-19, clinicians should be aware of delayed (post-acute) neurological damage, including PRES.

Neurocognitive and psychiatric post-coronavirus disease 2019 conditions: pathogenic insights of brain dysfunction following severe acute respiratory syndrome coronavirus 2 infection.

PURPOSE OF REVIEW: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of coronavirus disease 2019 (COVID-19), can trigger a myriad of neuropsychiatric manifestations. As a 2-year-old disease (at the writing of this manuscript), its long-term cognitive and neuropsychiatric implications, known as post-COVID-19 conditions, are incompletely recognized and mechanistically obscure. RECENT FINDINGS: Fatigue, anxiety, depression, posttraumatic stress disorder, and cognitive dysfunction are reported more frequently in COVID-19 survivors than in matching, non-COVID-19 population. Risk factors are unclear, including comorbidities, age at COVID-19 onset, or disease severity; women, however, have been reported to be at increased risk than men. Although the frequency of these symptoms decreases over time, at least one in five will have persistent cognitive and neuropsychiatric manifestations one year after recovering from COVID-19. SUMMARY: Neurocognitive and psychiatric post-COVID-19 long-term conditions are frequent and complex multifactorial sequelae. Several acute and chronic factors such as hypoxemia, cerebral thrombotic and inflammatory endothelial damage, and disruption of the blood-brain barrier (leading to parenchymal translocation of pro-inflammatory molecules, cytokines, and cytotoxic T lymphocytes) are involved, leading to microglial activation and astrogliosis. As an evolving topic, evidence derived from prospective studies will expand our understanding of post-COVID-19 these long-term outcomes.

Anaphylaxis to SARS-CoV-2 Vaccines in the Setting of a Nationwide Passive Epidemiological Surveillance Program.

BACKGROUND: Information on anaphylaxis among recipients of vaccines against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains scarce. OBJECTIVE: To identify the observed incidence of anaphylaxis in recipients of different anti-SARS-CoV-2 vaccines. METHODS: A nationwide observational study among recipients of 61,414,803 doses of seven different anti-SARS-CoV-2 vaccines, describing the incidence and characteristics of adult patients (age ≥ 18 years) who developed anaphylaxis as an adverse event following immunization (AEFI) against SARS-CoV-2 vaccines between December 24, 2020, and October 15, 2021, in Mexico. RESULTS: Sixty-six patients developed anaphylaxis as an AEFI, for an overall observed incidence of 1.07 cases per 1,000,000 (95% CI 0.84-1.37) administered doses. Eighty-six percent of the patients were female, consistent with previous reports of AEFI to COVID-19 vaccines. mRNA-based vaccine recipients had the highest frequency of anaphylaxis, followed by adenovirus-vectored vaccines and inactivated virus recipients, with an observed incidence of 2.5, 0.7, and 0.2 cases per 1,000,000 doses administered, respectively. Only 46% of the patients received correct treatment with epinephrine as the first-line treatment through the appropriate route and dose. We detected one case of anaphylactic reaction-related death occurring 5 min following immunization with ChAdOx1 nCov-19 for a mortality rate of 1.5% among those who developed this AEFI. CONCLUSIONS: In our population, anaphylactic reactions were infrequent. Our study provides further evidence supporting the security of these newly developed vaccines.

Seizures following COVID-19 vaccination in Mexico: A nationwide observational study.

The COVID-19 pandemic led to the development and emergency approval of an array of effective vaccines against SARS-CoV-2. Given the relatively small number of patients included in vaccine trials, postapproval epidemiological surveillance is crucial to detect infrequent vaccine-related adverse events. We conducted a nationwide retrospective descriptive study evaluating the incidence of seizures among recipients of SARS-CoV-2 vaccines in Mexico from December 24, 2020 (date of administration of first doses nationwide) to October 29, 2021. Among 81 916 351 doses of any vaccine that were administered, we documented seizures in 53 patients, of which 31 (60%) were new onset seizures. The incidence rate of seizures per million doses was highest for mRNA-1273 (Moderna) with 2.73 per million, followed by BNT162b2 (Pfizer-BioNTech) with 1.02 per million, and Ad5-nCoV (CanSino) with 1.01 per million. Thus, we found that seizures following SARS-CoV-2 vaccination are exceedingly rare events.

Antiphospholipid syndrome-mediated acute cerebrovascular diseases and long-term outcomes.

OBJECTIVES: The antiphospholipid syndrome (APS) is an autoimmune disease associated with thrombotic and non-thrombotic neurologic manifestations. APS is classified as primary (PAPS) or secondary (SAPS) when it co-exists with another autoimmune disease. We aim to describe the spectrum of acute cerebrovascular disease among patients with APS, their differences between stroke subtypes, and long-term functional outcomes. METHODS: Retrospective cohort study including adult (≥18 years) patients with APS followed in the stroke clinic of a tertiary-care reference center for autoimmune diseases in Mexico from 2009 to 2019. RESULTS: We studied 120 cases; 99 (82.5%) women; median age 43 years (interquartile range 35-52); 63.3% with SAPS. Demographics, comorbidities, and antiphospholipid antibodies (aPL) positivity were similar between APS type and stroke subtypes. Amongst index events, we observed 84 (70%) acute ischemic strokes (AIS), 19 (15.8%) cerebral venous thromboses (CVT), 11 (9.2%) intracerebral hemorrhages (ICH), and six (5%) subarachnoid hemorrhages (SAH). Sixty-seven (55.8%) were known patients with APS; the median time from APS diagnosis to index stroke was 46 months (interquartile range 12-96); 64.7% of intracranial hemorrhages (ICH or SAH) occurred ≥4 years after APS was diagnosed (23.5% anticoagulation-related); 63.2% of CVT cases developed before APS was diagnosed or simultaneously. Recurrences occurred in 26 (22.8%) patients, AIS, in 18 (69.2%); intracranial hemorrhage, in eight (30.8%). Long-term functional outcomes were good (modified Rankin Scale ≤2) in 63.2% of cases, during follow-up, the all-cause mortality rate was 19.2%. CONCLUSION: We found no differences between stroke subtypes and APS types. aPL profiles were not associated with any of the acute cerebrovascular diseases described in this cohort. CVT may be an initial thrombotic manifestation of APS with low mortality and good long-term functional outcome.

Incidence of Guillain-Barré syndrome following SARS-CoV-2 immunization: Analysis of a nationwide registry of recipients of 81 million doses of seven vaccines.

BACKGROUND AND PURPOSE: Information on Guillain-Barré syndrome (GBS) as an adverse event following immunization (AEFI) against SARS-CoV-2 remains scarce. We aimed to report GBS incidence as an AEFI among adult (≥18 years) recipients of 81,842,426 doses of seven anti-SARS-CoV-2 vaccines between December 24, 2020, and October 29, 2021, in Mexico. METHODS: Cases were retrospectively collected through passive epidemiological surveillance. The overall observed incidence was calculated according to the total number of administered doses. Vaccines were analyzed individually and by vector as mRNA-based (mRNA-1273 and BNT162b2), adenovirus-vectored (ChAdOx1 nCov-19, rAd26-rAd5, Ad5-nCoV, and Ad26.COV2-S), and inactivated whole-virion-vectored (CoronaVac) vaccines. RESULTS: We identified 97 patients (52 males [53.6%]; median [interquartile range] age 44 [33-60] years), for an overall observed incidence of 1.19/1,000,000 doses (95% confidence interval [CI] 0.97-1.45), with incidence higher among Ad26.COV2-S (3.86/1,000,000 doses, 95% CI 1.50-9.93) and BNT162b2 recipients (1.92/1,00,000 doses, 95% CI 1.36-2.71). The interval (interquartile range) from vaccination to GBS symptom onset was 10 (3-17) days. Preceding diarrhea was reported in 21 patients (21.6%) and mild COVID-19 in four more (4.1%). Only 18 patients were tested for Campylobacter jejuni (positive in 16 [88.9%]). Electrophysiological examinations were performed in 76 patients (78.4%; axonal in 46 [60.5%] and demyelinating in 25 [32.8%]); variants were similar across the platforms. On admission, 91.8% had a GBS disability score ≥3. Seventy-five patients (77.3%) received intravenous immunoglobulin, received seven plasma exchange (7.2%), and 15 (15.5%) were treated conservatively. Ten patients (10.3%) died, and 79.1% of survivors were unable to walk independently. CONCLUSIONS: Guillain-Barré syndrome was an extremely infrequent AEFI against SARS-CoV-2. The protection provided by these vaccines outweighs the risk of developing GBS.

Paradoxical manifestations during tuberculous meningitis treatment among HIV-negative patients: a retrospective descriptive study and literature review.

BACKGROUND: Tuberculous meningitis (TBM) is the most frequent, severe, and disabling form of central nervous system (CNS) tuberculosis (TB). TBM paradoxical manifestations are characterized by clinical or paraclinical worsening after 1 month of effective anti-TB treatment in patients who initially responded to treatment despite the use of adjunctive corticosteroids. METHODS: Retrospective descriptive study of consecutive HIV-negative adult patients (≥ 18 years) with definitive TBM who developed a paradoxical manifestation following anti-TB in a tertiary-care hospital in Mexico from 2009 to 2019; we also conducted a literature review of published cases/series of paradoxical manifestations in HIV-negative patients from 1980 to 2020. RESULTS: We detected 84 cases of definitive TBM; 55 (68.7%) HIV-negative patients and 29 (36.3%) HIV-infected patients. Among HIV-negative patients, four (7.3%), three female and one male (19-49 years old), developed a paradoxical manifestation within 4-14 weeks following treatment initiation despite receiving adequate corticosteroid doses; Mycobacterium bovis was isolated from the cerebrospinal fluid of three cases and Mycobacterium tuberculosis in one more. Two patients developed vasculopathy-related cerebral infarctions, one severe basilar meningitis, and hydrocephalus, one more a tuberculoma. Two were treated with intravenous cyclophosphamide, and two with steroids. One of the patients treated with steroids died; patients who received cyclophosphamide had a good clinical response. CONCLUSIONS: This case series illustrates the diverse clinical/radiologic paradoxical manifestations of TBM in HIV-negative patients. Cyclophosphamide may be safe and effective in treating TBM-associated paradoxical manifestations. Specific diagnostic and care protocols for these patients are needed.

Critical role of acute hypoxemia on the cognitive impairment after severe COVID-19 pneumonia: a multivariate causality model analysis.

BACKGROUND: A high proportion of coronavirus disease 2019 (COVID-19) survivors may develop long-term cognitive impairment. We aimed to develop a multivariate causal model exposing the links between COVID-19-associated biomarkers, illness-related variables, and their effects on cognitive performance. METHODS: In this prospective study, we assess the potential drivers for the development of cognitive impairment in patients with severe COVID-19 pneumonia aged ≥ 18 years at 6-month follow-up after hospital discharge, using the Montreal Cognitive Assessment (MoCA). Patients with pre-existing cognitive impairment were excluded. Laboratory results at hospital admission were clustered by principal component analysis (PCA) and included in a path analysis model evaluating the causal relationship between age, comorbidities, hypoxemia, invasive mechanical ventilation (IMV) requirement, in-hospital delirium, and cognitive performance. RESULTS: We studied 92 patients: 54 (58.7%) men and 38 (41.3%) women, with median age of 50 years (interquartile range 42-55), among whom 50 (54.4%) tested positive for cognitive impairment at 6-month follow-up. Path analysis revealed a direct link between the thrombo-inflammatory component of PCA (C-reactive protein, fibrinogen, and neutrophils) and hypoxemia severity at hospital admission. Our model showed that low PaO2/FiO2 ratio values, unlike the thrombo-inflammatory component, had a direct effect on cognitive performance, independent from age, in-hospital delirium, and invasive mechanical ventilation. CONCLUSION: In this study, biomarkers of thrombo-inflammation in COVID-19 and low PaO2/FiO2 had a negative effect on cognitive performance 6 months after hospital discharge. These results highlight the critical role of hypoxemia as a driver for impaired cognition in the mid-term.

Guillain-Barré Syndrome in Mexico: An Updated Review Amid the Coronavirus Disease 2019 ERA.

Guillain-Barré syndrome (GBS) is the most frequent cause of acute flaccid paralysis and if not diagnosed and treated timely, a significant cause of long-term disability. Incidence in Latin America ranges from 0.71 to 7.63 cases/100,000 person-years. Historically, GBS has been linked to infections (mainly gastrointestinal by Campylobacter jejuni) and vaccines (including those against severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]); however, a trigger cannot be detected in most cases. Regarding SARS-CoV-2, epidemiological studies have found no association with its development. Acute motor axonal neuropathy is the most common electrophysiological variant in Mexico and Asian countries. Intravenous immunoglobulin or plasma exchanges are still the treatment cornerstones. Mortality in Mexico can be as high as 12%. Avances in understanding the drivers of nerve injury in GBS that may provide the basis for developing targeted therapies have been made during the past decade; despite them, accurate criteria for selecting patients requiring acute treatment, prognostic biomarkers, and novel therapies are still needed. The newly-developed vaccines against SARS-CoV-2 have raised concerns regarding the potential risk for developing GBS. In the midst of coronavirus disease 2019 and vaccination campaigns against SARS-CoV-2, this review discusses the epidemiology, clinical presentation, management, and outcomes of GBS in Mexico.

Guillain-Barré syndrome is infrequent among recipients of the BNT162b2 mRNA COVID-19 vaccine.

Vaccines are the most effective strategy to mitigate the global impact of COVID-19. However, vaccine hesitancy is common, particularly among minorities. Guillain-Barré syndrome (GBS) is the most common autoimmune illness of the peripheral nervous system, occurring at an incidence of 1.1/100,000 worldwide. A causal link between mRNA vaccines and GBS has not been previously evaluated. We analyzed a cohort of 3,890,250 Hispanic/Latinx recipients of the BNT162b2 mRNA vaccine (613,780 of whom had already received both doses) for incident GBS occurring within 30 days from vaccine administration. Seven cases of GBS were detected among first-dose recipients, for an observed incidence of 0.18/100,000 administered doses during the prespecified timeframe of 30 days. No cases were reported after second-dose administration. Our data suggest that, among recipients of the BNT162b2 mRNA vaccine, GBS may occur at the expected community-based rate; however, this should be taken with caution as the current incidence of GBS among the unvaccinated population against COVID-19 is still undetermined. We hope that this preliminary data will increase the public perception of safety toward mRNA-based vaccines and reduce vaccine hesitancy.

Neurologic adverse events among 704,003 first-dose recipients of the BNT162b2 mRNA COVID-19 vaccine in Mexico: A nationwide descriptive study.

mRNA vaccines against SARS-CoV-2 are remarkably effective. Limited information exists about the incidence of adverse events following immunization (AEFI) with their use. We conducted a prospective observational study including data from 704,003 first-doses recipients; 6536 AEFI were reported, of whom 65.1% had at least one neurologic AEFI (non-serious 99.6%). Thirty-three serious events were reported; 17 (51.5%) were neurologic (observed frequency, 2.4/100,000 doses). At the time of writing this report, 16/17 cases had been discharged without deaths. Our data suggest that the BNT162b2 mRNA COVID-19 vaccine is safe; its individual and societal benefits outweigh the low percentage of serious neurologic AEFI. This information should help to dissipate hesitancy towards this new vaccine platform.

Prediction of acute neurovascular syndromes with prehospital clinical features witnessed by bystanders.

BACKGROUND: The prompt recognition of an acute neurovascular syndrome by the patient or a bystander witnessing the event can directly influence outcome. We aimed to study the predictive value of the medical history and clinical features recognized by the patients' bystanders to preclassify acute stroke syndromes in prehospital settings. METHODS: We analyzed 369 patients: 209 (56.6%) with acute ischemic stroke (AIS), 107 (29.0%) with intracerebral hemorrhage (ICH), and 53 (14.4%) with subarachnoid hemorrhage (SAH). All patients had neuroimaging as diagnostic gold standard. We constructed clinical prediction rules (CPRs) with features recognized by the bystanders witnessing the stroke onset to classify the acute neurovascular syndromes before final arrival to the emergency room (ER). RESULTS: In all, 83.2% cases were referred from other centers, and only 16.8% (17.2% in AIS, 15% in ICH, and 18.9% in SAH) had direct ER arrival. The time to first assessment in ≤ 3 h occurred in 72.4% (73.7%, 73.8%, and 64.2%, respectively), and final ER arrival in ≤ 3 h occurred in 26.8% (32.1%, 15.9%, and 28.3%, respectively). Clinical features referred by witnesses had low positive predictive values (PPVs) for stroke type prediction. Language or speech disorder + focal motor deficit showed 63.3% PPV, and 77.0% negative predictive value (NPV) for predicting AIS. Focal motor deficit + history of hypertension had 35.9% PPV and 78.8% NPV for ICH. Headache alone had 27.9% PPV and 95.3% NPV for SAH. In multivariate analyses, seizures, focal motor deficit, and hypertension increased the probability of a time to first assessment in ≤ 3 h, while obesity was inversely associated. Final ER arrival was determined by age and a direct ER arrival without previous referrals. CONCLUSION: CPRs constructed with the witnesses' narrative had only adequate NPVs in the prehospital classification of acute neurovascular syndromes, before neuroimaging confirmation.

Detection of Pulmonary Shunts by Transcranial Doppler in Hospitalized Non-mechanically Ventilated Coronavirus Disease-19 Patients.

In severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-associated disease coronavirus disease 2019 (COVID-19), hypoxemia mechanisms differ from those observed in acute respiratory distress syndrome. Hypoxemia and respiratory failure in COVID- 19 are attributed to pulmonary angiopathy, increasing physiological pulmonary shunting1-3.

Reliability of Bystander Recognition of Clinical Features in Pre-Hospital Classification of Acute Cerebrovascular Syndromes: Preliminary Findings.

BACKGROUND: The recognition of stroke symptoms by patients or bystanders directly affects the outcomes of patients with acute cerebrovascular disease. OBJECTIVE: The objective of the study was to assess the predictive value of the medical his- tory and clinical features recognized by the patients' bystanders to classify neurovascular syndromes in pre-hospital settings. METHODS: We included 150 stroke patients of two Mexican referral centers: 50 with acute ischemic stroke (AIS), 50 with intracerebral hemorrhage (ICH), and 50 with subarachnoid hemorrhage (SAH). The performance of clinical prediction rules (CPR) to identify the stroke types was evaluated with features recognized by the patients' bystanders before hospital arrival. The impact of CPRs on early arrival and in-hospital mortality was also analyzed. RESULTS: Overall, 72% of the patients had previous medical evaluations in other centers before final referral to our hospitals, and therefore, only 45% had a final onset- to-door time <6 h, even when the first medical assessment had occurred in ≤1 h in 75% of cases. Clinical features noticed by the patients' bystanders had low positive predictive values (PPV) for any stroke type. The CPR "language or speech disor- der + focal motor deficit" had 93% sensitivity and a negative predictive value (NPV) of 84% to distinguish AIS. In SAH, head- ache alone showed a sensitivity of 84% and NPV of 97%. No CPR had an adequate performance on ICH. CPRs were not as- sociated with final onset-to-door time. Altered consciousness, age ≥65 years, indirect arrival with stops before final referral, and atrial fibrillation increased in-hospital mortality. CONCLUSION: Clinical features referred by the witness of a neurovascular emergency have limited PPV, but adequate NPV in ruling-out AIS and SAH among stroke types. The use of CPRs had no impact on onset-to-door time or in-hospital mortality when the final arrival to a third-level center occurs with previous medical refer- rals.

Epidemiological and clinical characteristics of patients with human monkeypox infection in Mexico: a nationwide observational study.

Background: Human monkeypox, a zoonosis historically endemic to West and South Africa, has led to a worldwide outbreak driven by human-to-human transmission resulting in an international public health emergency. Endemic and outbreak monkeypox cases may differ in their affected populations, clinical features, and outcomes. Thus, profiling cases of the current monkeypox outbreak worldwide is crucial. Methods: We performed a nationwide observational surveillance-based study from May 24 to September 5, 2022. Patients that met the operational clinical definition of monkeypox or symptomatic close contacts of confirmed cases were tested by real-time polymerase chain reaction. Clinical data were collected with a standardized case-report form. We report epidemiologic, sociodemographic, and clinical characteristics of confirmed cases. Findings: Five-hundred and sixty-five human monkeypox confirmed cases were analysed; 97.2% were men, of whom 59.5% identified as men who have sex with men, and 54.5% had human immunodeficiency virus infection. The median age was 34 years. All patients but one had rash (99.8%), 78.9% had fever, and 47.8% reported myalgia. The anogenital area was the most commonly affected one by rash (49.6%), and proctitis occurred in 6.2% of patients. Six patients required hospitalization, of which one died due to causes unrelated to monkeypox. Interpretation: The 2022 monkeypox outbreak in Mexico is mainly driven by middle-aged men who have sex with men, of which a large proportion are persons who live with human immunodeficiency virus infection. Clinical features such as the high proportion of anogenital lesions suggest sexual contact is a pivotal transmission mechanism in this outbreak. Funding: This research was supported by grant A1-S-18342 from Consejo Nacional de Ciencia y Tecnología (CONACyT), Mexico (to S.I.V.-F.).

Effectiveness of a nationwide COVID-19 vaccination program in Mexico against symptomatic COVID-19, hospitalizations, and death: a retrospective analysis of national surveillance data.

OBJECTIVES: Vaccination has been effective in ameliorating the impact of COVID-19. Here, we report vaccine effectiveness (VE) of the nationally available COVID-19 vaccines in Mexico. METHODS: Retrospective analysis of a COVID-19 surveillance system to assess the VE of the BNT162b2, messenger RNA (mRNA)-12732, Gam-COVID-Vac, Ad5-nCoV, Ad26.COV2.S, ChAdOx1, and CoronaVac vaccines against SARS-CoV-2 infection, COVID-19 hospitalization, and death in Mexico. The VE was estimated using time-varying Cox proportional hazard models in vaccinated and unvaccinated adults, adjusted for age, sex, and comorbidities. VE was also estimated for adults with diabetes, aged ≥60 years, and comparing the predominance of SARS-CoV-2 variants B.1.1.519 and B.1.617.2. RESULTS: We assessed 793,487 vaccinated and 4,792,338 unvaccinated adults between December 24, 2020 and September 27, 2021. The VE against SARS-CoV-2 infection was the highest for fully vaccinated individuals with mRNA-12732 (91.5%, 95% confidence interval [CI] 90.3-92.4) and Ad26.COV2.S (82.2%, 95% CI 81.4-82.9); for COVID-19 hospitalization, BNT162b2 (84.3%, 95% CI 83.6-84.9) and Gam-COVID-Vac (81.4% 95% CI 79.5-83.1), and for mortality, BNT162b2 (89.8%, 95% CI 89.2-90.2) and mRNA-12732 (93.5%, 95% CI 86.0-97.0). The VE decreased for all vaccines in adults aged ≥60 years, people with diabetes, and periods of Delta variant predominance. CONCLUSION: All the vaccines implemented in Mexico were effective against SARS-CoV-2 infection, COVID-19 hospitalization, and death. Mass vaccination with multiple vaccines is useful to maximize vaccination coverage.