Juan Carlos Lona-Reyes

Introduction: Electrolyte imbalances in pediatric patients can range from mild to severe. These disorders can be caused by underlying diseases or the inappropriate use of intravenous solutions, particularly in hospitalized patients who are fasting. Methods: A prospective cohort study was conducted from January 2023 to September 2024 at the Nuevo Hospital Civil de Guadalajara Dr. Juan I Menchaca (HCGJIM), Jalisco, México. Patients aged 1 month to 17.9 years who were admitted to the emergency department and fasted were included, with follow-up from admission until 48 hours. A non-probability sampling method was used for consecutive cases. Frequencies and percentages were estimated for qualitative variables, and means and standard deviations were obtained for quantitative variables. Results: 423 patients were included; 56.7% were male. The median age was 4 years (IQR 8). Upon admission, the most common electrolyte imbalances were hyponatremia (19.4%) and hypocalcemia (18.4%). The main cause of admission was infectious disease (34%, n= 144). The most frequently used intravenous maintenance solution was Hartmann's solution (54.6%). After 12 hours of fasting, significant changes in potassium and chloride were observed. At 24 and 48 hours, changes were seen in calcium, potassium, and chloride. Conclusion: In hospitalized patients who are fasting, monitoring serum electrolytes is recommended due to the frequency of electrolyte imbalances. Furthermore, basal electrolyte requirements, according to age, should be added to maintenance solutions.

Background: Measles remains a global public health threat despite the availability of an effective vaccine and substantial progress toward elimination in many countries. Outbreaks in highly vaccinated settings suggest that waning vaccine-induced immunity, particularly among adults, may create silent susceptibility gaps capable of sustaining viral transmission. Aim: To evaluate age- and cohort-specific patterns of measles-specific antibody levels in Mexican adults and to examine evidence suggesting lower vaccine-induced antibody levels in younger vaccinated cohorts. Methods: A cross-sectional seroepidemiological study was conducted among 302 voluntary blood donors aged 18–70 years. Demographic, clinical, and vaccination data were collected through structured interviews. Serum anti-measles-virus (MV) IgG levels were quantified using a commercial ELISA. Antibody concentrations were analyzed according to age, sex, vaccination history, self-reported measles infection, and historical vaccination strategies. Multivariate linear models were applied to identify factors associated with IgG levels. Results: Anti-MV IgG seropositivity (>200 mIU/mL) was 67.2%, with a geometric mean concentration (GMC) of 270.43 mIU/mL. A positive correlation was observed between age and antibody levels (r_s = 0.161, p = 0.005). Individuals born before the introduction of the measles vaccine (pre-1970) had significantly higher GMCs (1096.63 mIU/mL) than younger cohorts. A history of natural infection tended to be associated with higher antibody levels (GMC: 428.38 vs. 257.24 mIU/mL; p = 0.051). In multivariate analysis, historical vaccination strategy emerged as the primary factor associated with antibody levels, whereas age alone was not significant. Conclusions: Cohort-specific differences in measles IgG levels suggest generational patterns of immunity and are consistent with diminished vaccine-induced antibody levels in younger adults in the absence of natural boosting. These findings highlight the importance of ongoing serological surveillance in post-elimination settings and underscore the need for targeted public health interventions.

Dengue is considered the most prevalent mosquito-borne arboviral disease worldwide, representing a public health challenge as its incidence has tripled in the last 30 years. The World Health Organization reports 390 million infections annually in more than 129 countries, with approximately 96 million symptomatic cases and around 40,000 deaths. Mexico is a hyperendemic country, with high prevalence and significant outbreaks. In 2024, a surge was observed, with approximately 125,000 infections and nearly 480 deaths. The states with the most cases and deaths were Colima and Jalisco, respectively, placing significant strain on healthcare services and driving up costs. The disease’s epidemiology from 2014 to 2025 is characterized by marked seasonality and periodicity, and by the simultaneous circulation of all four serotypes. In recent years, a notable increase in DENV-3 has been observed. In 2025, there were 21,981 confirmed cases; Sonora recorded the highest incidence, while Jalisco and Sinaloa reported the highest number of deaths. This study provides a unique decadal analysis of the epidemiological characteristics of dengue in Mexico, highlighting potential challenges and emphasizing the importance of epidemiological surveillance and future approaches, such as vaccine provision in the country, to mitigate the high mortality rate and associated costs.

Background: Neonatal sepsis is a serious condition that increases neonatal mortality. The objective of this study was to describe the microorganisms causing ...

Background: Inborn errors of immunity originate from monogenic mutations that should be considered in the suggestive diagnosis of patients with recurrent or severe infections, allergies, autoimmunity, autoinflammatory diseases, bone marrow failure and malignancy. Case report: Pediatric patient, male, 4 years old, treated in the medical service for fever of 39°C, difficult to control. The simple chest x-ray reported left pulmonary consolidation. The infectious condition evolved into necrotizing pneumonia of the left upper lobe, so it was decided to perform a lobectomy. The diagnosis of some inborn error of immunity was suspected. The determination of serum immunoglobulins reported IgA below the reference values. At 4 years he continued to have decreased serum IgA (5.5 mg/dL). Conclusion: The diagnosis of selective IgA deficiency is established after 4 years of life; However, due to the patient’s severe infection, addressing some inborn error of immunity had to be implemented. Keywords: Recurrent infections; Inborn error of immunity; Necrotizing pneumonia; Lobectomy; IgA; Selective IgA deficiency.