Volume 04 · Issue 03 · 2024

Prior to the coronavirus disease 2019 (COVID-19) outbreak, the only antiviral treatment widely used in clinical settings was for influenza. However, following the global pandemic, there has been renewed research interest in medications for respiratory viral infections. Clinical trials of antiviral medications often need to consider multiple dimensions because of the significant differences in disease severity among populations. For example, during respiratory viral epidemic seasons, the clinical spectrum of diseases is usually complex, including asymptomatic infections, symptomatic infections (mild to moderate without hospitalization), severe cases (requiring hospitalization), and fatalities.

Hepatitis B virus (HBV) infection is a major public health problem and cause of chronic liver disease that led to an estimated 820,000 deaths in 2019, mainly due to cirrhosis and liver cancer. In 2019, WHO estimated that 296 million people were chronically infected and living with hepatitis B, with a disproportionately high burden in low- and middle-income countries. The WHO African region, together with the South-East Asia Region and Western Pacific Region account for 88% of the global burden. Most of the global burden of chronic hepatitis B (CHB) can be attributed to mother-to-child transmission at the time of or shortly after birth, and such perinatal infections lead to a high rate of chronicity. Considerable progress has been made towards eliminating the perinatal transmission of HBV through universal infant HBV immunization, including the timely hepatitis B birth dose, which has been highly effective in reducing new infections among children. However, in 2022 hepatitis B birth-dose coverage was only 45% globally, with the lowest coverage (18%) in the WHO African Region. For people with CHB infection, nucleoside analogue treatment with currently recommended tenofovir and entecavir is highly effective and can delay the progression of cirrhosis, reduce the incidence of hepatocellular carcinoma (HCC) and improve long-term survival. However, a major testing and treatment gap remains. In 2019, only 10% of the estimated 296 million people with CHB had been diagnosed and 2% had been treated. Scaling up testing and treatment towards the elimination goals will require a radical simplification of treatment criteria and care pathways to overcome barriers in access to hepatitis B testing and treatment.

The aim of this consensus is to standardize the prevention, diagnosis, and treatment of chronic hepatitis B in children and to achieve the goal of "eliminating viral hepatitis as a major public health threat by 2030" issued by the World Health Organization. Formulated by organized experts of the Chinese Society of Infectious Diseases and Chinese Society of Hepatology, Chinese Medical Association; Group of Infectious Diseases, Chinese Pediatric Society, Chinese Medical Association; and the National Clinical Research Center for Infectious Diseases (Beijing), the consensus provides the latest evidence and recommendations for the prevention, diagnosis, and treatment of chronic hepatitis B in children.

Monkeypox (mpox) is a rare viral zoonotic disease, endemic to Central and West Africa, caused by the monkeypox virus, an orthopoxvirus similar to the variola virus (smallpox). Although sporadic travel-associated cases have historically occurred outside Africa, in May 2022, mpox began spreading globally in multiple nonendemic countries across several continents. In 2024, there has been an increase in globally reported confirmed cases of mpox and deaths from mpox, making it a public health emergency of international concern. The reasons for the unusual global spread are under investigation but likely relate to increased travel and waning population immunity to orthopoxviruses. Transmission now appears to be mainly through close, intimate contact, especially among men who have sex with men. Mpox is usually a self-limited disease. Although limited approved antiviral treatments are available, such as tecovirimat, which the European Medicines Agency approved in January 2022 for the treatment of mpox, their widespread availability and effectiveness in the current outbreak remain to be investigated. Public health control measures include surveillance, case identification/isolation, contact tracing, and targeted vaccination of contacts at high risk of exposure. However, challenges remain in curtailing the current unprecedented outbreak. Critical knowledge gaps include animal reservoir(s) responsible for initial spillover events, viral mutations that may enhance transmissibility, optimal diagnostics for noninvasive specimens, effective antiviral therapies, next-generation vaccines providing longer-term immunity, and building global capacity for outbreak response. This review summarizes the current literature on mpox virology, epidemiology, pathogenesis, clinical manifestations, diagnostics, treatment, prevention, and public health control measures. Ongoing investigation and research are needed to better understand mpox’s evolving epidemiology, pathogenicity, transmissibility, and ecology to guide strategies for containing the outbreak and preventing future global emergence.

Infection and vaccination can provide protective immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the emergence of SARS-CoV-2 variants has persisted, leading to breakthrough infections. Owing to the original antigenic sin (OAS), variant breakthrough infection or vaccination potentially induces a stronger antibody response against the ancestral strain than to subsequent variants, as in the case of influenza. Thus, overcoming OAS is important for the development of future vaccine designs. This review summarizes the recent findings on OAS in the antibody response to SARS-CoV-2 and its variants, with an emphasis on future vaccine designs.

Tuberculosis (TB), caused byMycobacterium tuberculosis, remains a leading cause of death among infectious diseases worldwide. Latent tuberculosis infections (LTBI) contribute to the global burden of TB disease. TB preventive treatment (TPT) is a key intervention to achieve the End TB Strategy targets. The World Health Organization recommends LTBI treatment regimens, including 6 or 9 months of once-daily isoniazid (INH, H), 4 months of once-daily rifampin (RIF, R), 3 months of once-weekly rifapentine (RPT, P) plus INH (3HP), 3 months of once-daily RIF plus INH, or 1 month of daily RPT plus INH (1HP). Clinicians and individuals with LTBI may be reluctant to implement TPT due in part to concerns regarding adherence to the long treatment duration and drug toxicity of the currently recommended LTBI treatment regimens. Shorter, better-tolerated, and cost-effective TPT regimens are highly desirable. Rifapentine is a long-acting rifamycin, and rifamycin-based regimens are now the preferred LTBI treatment because they have similar or better efficacy and higher completion rates due to their shorter duration. Based on our experiences with TPT practice among Chinese people with silicosis, we found that the 3HP regimen was not well tolerated due to an unexpectedly high frequency of adverse events (AEs) (70.4%) and grade 3 or 4 AEs (7.9%), especially the high incidence of flu-like systemic drug reactions (SDRs) (10.8%).^[1]This result is consistent with that of a contemporaneous clinical trial conducted among elderly Chinese individuals.^[2]The high incidence of AEs contributed to a low completion rate of the 3HP regimen. Pharmacokinetic analysis in our trial revealed that the geometric mean Area Under the Curve from time zero to infinity (AUC_0-inf) for rifapentine and its metabolite were over 2-fold and 1.6-fold greater, respectively than those observed in the TBTC and PREVENT TB studies.^[1]Additionally, the geometric mean concentrations 24 hours after administration were also two-fold greater than those in the PREVENT TB study. Meanwhile, flu-like SDRs commonly occur in individuals receiving intermittent rifampin, usually following high doses.^[3]Thus, we devised a novel one-month, thrice-weekly regimen consisting of INH plus RPT, referred to as the 1H₃P₃regimen. The aim was to mitigate peak concentrations by reducing the single dose of medication and increasing the frequency of administration, thereby avoiding SDRs associated with intermittent dosing.

Mycoplasma hominis is an opportunistic microorganism that colonizes the genitourinary tract and causes genitourinary infections. However, pulmonary infections caused by M. hominis have rarely been reported in immunocompetent individuals. Herein, we report a rare case of an immunocompetent adult male with M. hominis pneumonia who presented with multiple pulmonary nodules that progressed to a cavitary mass with a halo sign. The presence of M. hominis infection was confirmed using multiplex polymerase chain reaction (mPCR) of the bronchoalveolar lavage fluid. The patient demonstrated no response to the initial levofloxacin therapy; however, the symptoms subsequently improved after the administration of moxifloxacin. M. hominis may be an underestimated causative agent of community-acquired pneumonia of unknown etiology in immunocompetent adults, and the involvement of the organism should be especially suspected in sexually active patients. Molecular diagnostic methods, such as mPCR, can be used to identify the etiology of atypical pneumonia. Appropriate antibiotics are crucial for effective treatment.

The genus Citrobacter commonly found in water and soil as well as the intestinal and urinary tracts of animals and humans. Although Citrobacter infections are infrequently diagnosed in environmental contexts, the rising incidence of nosocomial manifestations underscores the importance of considering this organism in the differential diagnosis of hospital-acquired infections. We present a case of patient with septic arthritis of the shoulder who had been originally admitted for the management of acute-on-chronic congestive heart failure exacerbation and severe sepsis. On hospital day 1, joint aspiration cultures and Gram stain confirmed the presence of Citrobacter koseri, a pathogen not commonly associated with septic arthritis, and ceftriaxone was administered to target it. On hospital day 7, antibiotic was transitioned to levofloxacin, every other day for 4 weeks. The patient was discharged to an acute rehabilitation facility after a 14-day hospital stay. This case stresses the importance of maintaining a broad differential diagnosis for any patients who present with fever and joint inflammation or swelling, especially in a postoperative setting.