Effectiveness of mRNA-1273, BNT162b2, and BBIBP-CorV vaccines against infection and mortality in children in Argentina, during predominance of delta and omicron covid-19 variants: test negative, case-control study

OBJECTIVE

To estimate the effectiveness of a two dose vaccine schedule (mRNA-1273, BNT162b2, and BBIBP-CorV) against SARS-CoV-2 infection and covid-19 related death and short term waning of immunity in children (3-11 years old) and adolescents (12-17 years old) during periods of delta and omicron variant predominance in Argentina.

DESIGN

Test negative, case-control study.

SETTING

Database of the National Surveillance System and the Nominalized Federal Vaccination Registry of Argentina.

PARTICIPANTS

844 460 children and adolescents without previous SARS-CoV-2 infection eligible to receive primary vaccination schedule who were tested for SARS-CoV-2 by polymerase chain reaction or rapid antigen test from September 2021 to April 2022. After matching with their corresponding controls, 139 321 (60.3%) of 231 181 cases remained for analysis.

EXPOSURES

Two dose mRNA-1273, BNT162b2, and BBIBP-CorV vaccination schedule.

MAIN OUTCOME MEASURES

SARS-CoV-2 infection and covid-19 related death. Conditional logistic regression was used to estimate the odds of SARS-CoV-2 infection among two dose vaccinated and unvaccinated participants. Vaccine effectiveness was estimated as (1-odds ratio)×100%.

RESULTS

Estimated vaccine effectiveness against SARS-CoV-2 infection was 61.2% (95% confidence interval 56.4% to 65.5%) in children and 66.8% (63.9% to 69.5%) in adolescents during the delta dominant period and 15.9% (13.2% to 18.6%) and 26.0% (23.2% to 28.8%), respectively, when omicron was dominant. Vaccine effectiveness declined over time, especially during the omicron period, from 37.6% (34.2% to 40.8%) at 15-30 days after vaccination to 2.0% (1.8% to 5.6%) after ≥60 days in children and from 55.8% (52.4% to 59.0%) to 12.4% (8.6% to 16.1%) in adolescents.Vaccine effectiveness against death related to SARS-CoV-2 infection during omicron predominance was 66.9% (6.4% to 89.8%) in children and 97.6% (81.0% to 99.7%) in adolescents.

CONCLUSIONS

Vaccine effectiveness in preventing mortality remained high in children and adolescents regardless of the circulating variant. Vaccine effectiveness in preventing SARS-CoV-2 infection in the short term after vaccination was lower during omicron predominance and decreasing sharply over time.

TRIAL REGISTRATION

National Registry of Health Research IS003720.

Carbapenem-resistant Enterobacteriaceae bloodstream infections: A case-control study from a pediatric referral hospital in Argentina

Background

Antibiotic-resistant gram-negative bloodstream infections (BSI) remain a leading cause morbidity and mortality in pediatric patients with a high impact on the public health system. Data in resource-limited countries, including those in Latin America and the Caribbean region, are scarce. The aim of the study was to identify risk factors for acquiring carbapenem-resistant Enterobacteriaceae (CRE) bacteremia in children and to assess the use of resources.

Methods

A retrospective case-control study was conducted to analyze demographic, epidemiological, clinical, microbiological, and outcome data as well as the use of resources between 2014 and 2019. Univariate and logistic regression analysis was performed in order to identify risk factors associated with CRE-BSI. The R software version 4.1.2 was used.

Results

A total of 46 cases with CRE-BSI and 92 controls with gram-negative non-CRE-BSI were included. No statistical difference was observed regarding: median age (36 months; IQR, 11.2-117 vs. 48 months, IQR 13-119), male sex (50 vs. 60%), and underlying disease (98 vs. 91%) in cases vs. controls, respectively. The most frequent mechanism of CRE bacteremia were: KPC in 74%, OXA in 15%, and NDM in 6.5%. A total of 54.3% of cases vs. 32.6 % (p = 0.016) of controls were admitted to the pediatric intensive care unit (PICU), and 48 vs. 21% (p = 0.001) required mechanical ventilation. Bacteremia secondary to intra-abdominal infection was observed in 56.5% of cases vs. 35% of controls (p = 0.032). Previous colonization with CRE was detected in 76% of cases vs. 8% of controls. Combination antimicrobial treatment was most frequent in cases vs. control (100 vs. 56.5%). No difference was observed in median length of hospital stay (22 days; IQR, 19-31 in cases vs. 17.5 days; IQR, 10-31 in controls; p = 0.8). Overall case fatality ratio was 13 vs. 5.5%, respectively. The most statistically significant risk factors included previous PICU stay (OR, 4; 95%CI, 2-8), invasive procedures/surgery (OR, 3; 95%CI, 1-7), central venous catheter placement (OR, 6.5; 95%CI, 2-19), urinary catheter placement (OR, 9; 95%CI 4-20), mechanical ventilation (OR, 4; 95%CI, 2-10), liver transplantation (OR, 8; 95%CI, 2-26), meropenem treatment (OR, 8.4; 3.5-22.6) in univariate analysis. The logistic regression model used for multivariate analysis yielded significant differences for previous meropenem treatment (OR, 13; 95%CI, 3-77; p = 0.001), liver transplantation (OR, 13; 95%CI, 2.5-100; p = 0.006), and urinary catheter placement (OR, 9; 95%CI, 1.4-94; p = 0.03).

Conclusion

CRE-BSI affects hospitalized children with underlying disease, mainly after liver transplantation, with previous urinary catheter use and receiving broad-spectrum antibiotics, leading to high PICU requirement and mortality. These risk factors will have to be taken into account in our region in order to establish adequate health policies and programs to improve antimicrobial stewardship.

Multisystem Inflammatory Syndrome Temporally Related to COVID-19 in Children From Latin America and the Caribbean Region: A Systematic Review With a Meta-Analysis of Data From Regional Surveillance Systems

Background

With the emergence of the COVID-19 pandemic, increasing numbers of cases of the multisystem inflammatory syndrome in children (MIS-C) have been reported worldwide; however, it is unclear whether this syndrome has a differential pattern in children from Latin America and the Caribbean (LAC). We conducted a systematic review and meta-analysis to analyze the epidemiological, clinical, and outcome characteristics of patients with MIS-C in LAC countries.

Methods

A systematic literature search was conducted in the main electronic databases and scientific meetings from March 1, 2020, to June 30, 2021. Available reports on epidemiological surveillance of countries in the region during the same period were analyzed.

Results

Of the 464 relevant studies identified, 23 were included with 592 patients with MIS-C from LAC. Mean age was 6.6 years (IQR, 6-7.4 years); 60% were male. The most common clinical manifestations were fever, rash, and conjunctival injection; 59% showed Kawasaki disease. Pool proportion of shock was 52%. A total of 47% of patients were admitted to the pediatric intensive care unit (PICU), 23% required mechanical ventilation, and 74% required vasoactive drugs. Intravenous gamma globulin alone was administered in 87% of patients, and in combination with steroids in 60% of cases. Length of hospital stay was 10 days (IQR, 9-10) and PICU stay 5.75 (IQR, 5-6). Overall case fatality ratio was 4% and for those hospitalized in the PICU it was 7%.

Conclusion

Limited information was available on the clinical outcomes. Improvements in the surveillance system are required to obtain a better epidemiologic overview in the region.

[Histoplasmosis in Argentina: case series in children]

BACKGROUND

Histoplasmosis is a fungal disease, endemic in South America, and seldom reported in paediatrics.

AIMS

To report the epidemiology, clinical features and outcome of children diagnosed with histoplasmosis in an Argentinian Children's Hospital.

METHODS

A retrospective and descriptive study was performed from January 2008 to December 2016 in Hospital de Pediatría 'Prof. Dr. Juan Pedro Garrahan'. Patients under 18 years with clinical features, serological tests, cultures and/or histological findings compatible with histoplasmosis were included. Thirteen patients were selected (seven male and six female; mean age was 9 years with interquartile range 3.4-13); three children (23%) were from Buenos Aires province, three (23%) from Santa Fe province, and seven (54%) from other provinces.

RESULTS

In ten cases (77%) the clinical form was disseminated, and it was pulmonary in three (23%). Eight cases (62%) suffered other comorbidities. Serological tests were positive in seven patients (54%), with positive cultures obtained in nine patients (69%). Histological findings compatible with histoplasmosis were found in 10 cases (77%). All patients received treatment with amphotericin B (liposomal formulation in seven cases, deoxycholate in six), with 10 patients continuing with oral itraconazole. Three patients (23%) died from causes unrelated to histoplasmosis.

CONCLUSIONS

The majority of children in the series had comorbidities and disseminated histoplasmosis. Mortality was not directly associated with histoplasmosis.

[Use of posaconazole in children: Experience in a tertiary pediatric hospital]

There is limited information on the use of posaconazole in children. This retrospective and descriptive study was conducted to evaluate the clinical, microbiological characteristics and evolution of patients treated with posaconazole between August 2010 and March 2017. We included 16 children. Median age: 161 months (interquartile range -IQR- 69-173 m). All had underlying disease and a proven invasive fungal infection. The most frequent isolated were Mucor spp. and Aspergillus spp. The mean posaconazole dose was 600 mg/day (400-800 mg/day) and the median duration of treatment was 223 days (IQR 48-632). Ten patients had adverse effects, but only one required suspension of the antifungal treatment due to hydroelectrolytic disorders.

Osteomyelitis in burn children: Ten years of experience

INTRODUCTION

Osteomyelitis is uncommon among burn patients.

OBJECTIVE

To describe the clinical, microbiological, and evolutionary characteristics of burn children with osteomyelitis hospitalized in a tertiary care facility.

METHODS

Retrospective and descriptive study conducted between January 2007 and January 2017.

RESULTS

Out of 600 burn children, 12 developed osteomyelitis (incidence: 2%). Eleven patients had a burn caused by direct fire. Patients' median age was 42.5 months (interquartile range [IQR]: 27-118 months), and their median burned surface area was 33.5% (IQR: 18.5-58%). Osteomyelitis was diagnosed at a median period of 30 days following the burn injury. The most common locations were the upper limbs and the cranial vault. Fever was the most frequent clinical manifestation. The most common microorganisms isolated in bone tissue were fungi in 9 patients. All showed compatible anatomopathological findings. The treatment lasted a median of 44.5 days (IQR: 34.5-65.5 days). Six patients had motor sequelae and 1 died.

CONCLUSION

Fungal osteomyelitis was the most commonly observed etiology. Half of patients had functional sequelae and only 1 patient died.