Coexisting cytomegalovirus colitis in an immunocompetent patient with Clostridioides difficile colitis:A case report

BACKGROUND Clostridioides difficile(C.difficile)colitis is one of the most common infections in hospitalized patients,characterized by fever and diarrhea.It usually improves after appropriate antibiotic treatment;if not,comorbidities should be considered.Cytomegalovirus(CMV)colitis is a possible co-existing diagnosis in patients with C.difficile infection with poor treatment response.However,compared with immunocompromised patients,CMV colitis in immunocompetent patients is not well studied.CASE SUMMARY We present an unusual case of co-existing CMV colitis in an immunocompetent patient with C.difficile infection.An 80-year-old female patient was referred to the infectious disease department due to diarrhea,abdominal discomfort,and fever for 1 wk during her hospitalization for surgery.C.difficile toxin B polymerase chain reaction on stool samples was positive.After C.difficile infection was diagnosed,oral vancomycin treatment was administered.Her symptoms including diarrhea,fever and abdominal discomfort improved for ten days.Unfortunately,the symptoms worsened again with bloody diarrhea and fever.Therefore,a sigmoidoscopy was performed for evaluation,showing a longitudinal ulcer on the sigmoid colon.Endoscopic biopsy confirmed CMV colitis,and the clinical symptoms improved after using ganciclovir.CONCLUSION Co-existing CMV colitis should be considered in patients with aggravated C.difficile infection on appropriate treatment,even in immunocompetent hosts.

Delayed hypersensitivity reaction resulting in maculopapular-type eruption due to entecavir in the treatment of chronic hepatitis B

Several clinical trials have demonstrated the potent antiviral efficacy of entecavir (ETV), and this relatively new nucleoside analogue drug has rapidly become a frequently prescribed therapy for chronic hepatitis B (CHB) worldwide. While the studies have also shown a good overall safety profile for ETV, adverse drug reactions (ADRs) in patients with advanced cirrhosis have been reported and represent a broad spectrum of drug-induced injuries, including lactic acidosis, myalgia, neuropathy, azotemia, hypophosphatemia, muscular weakness, and pancreatitis, as well as immune-mediated responses (i.e., allergic reactions). Cutaneous ADRs associated with ETV are very rare, with only two case reports in the publicly available literature; both of these cases were classified as unspecified hypersensitivity allergic (type I) ADR, but neither were reported as pathologically proven or as evaluated by cytokine release analysis. Here, we report the case of a 45-year-old woman who presented with a generalized maculopapular rash after one week of ETV treatment for lamivudine-resistant CHB. The patient reported having experienced a similar skin eruption during a previous three-month regimen of ETV, for which she had self-discontinued the medication. Histopathological analysis of a skin biopsy showed acanthotic epidermis with focal parakeratosis and a perivascular lymphocytic infiltrate admixed with interstitial eosinophils in the papillary and reticular dermis, consistent with a diagnosis of drug sensitivity. A lymphocyte stimulation test showed significantly enhanced IL-4, indicating a classification of type IVb delayed hypersensitivity. The patient was switched to an adefovir-lamivudine combination regimen and the skin eruption resolved two weeks after the ETV withdrawal. This case represents the first pathologically and immunologically evidenced ETV-induced delayed type hypersensitivity skin reaction reported to date. Physicians should be aware of the potential, although rare, for cutaneous ADRs associated with ETV treatment.

Increased type III interferons and NK cell functions in SARS-CoV-2-infected children

Dear Editor,Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection is more likely to progress to severe disease in the elderly,and the rates of hospitalization for coronavirus disease 2019(COVID-19)increase with age.1,2 Herein,we comprehensively compared adaptive and innate immune responses between children and adults infected with SARS-CoV-2.

T cell epitopes in SARS-CoV-2 proteins are substantially conserved in the Omicron variant

In November 2021,the Omicron variant(B.1.1.529)emerged and was designated a variant of concern(VOC)by the World Health Organization.Recently,Omicron was reported to extensively escape neutralizing antibodies elicited by COVID-19 vaccination or natural infection[1,2,3].However,whether Omicron evades the T cell immunity elicited by COVID-19 vaccination or natural infection remains to be elucidated.To address this issue,we analyzed the amino acid sequences of T cell epitopes identified from the original SARS-CoV-2 strain(Wuhan-Hu-1)in the Omicron variant(hCoV-19/South Africa/CERI-KRISP-K032284/2021).

Seroprevalence of Severe Fever with Thrombocytopenia Syndrome Phlebovirus in Domesticated Deer in South Korea

Severe fever with thrombocytopenia syndrome phlebovirus(SFTSV)has a wide host range.Not only has it been found in humans,but also in many wild and domesticated animals.The infection of breeding deer on farms is a particularly worrisome public health concern due to the large amount of human contact and the diverse use of deer products,including raw blood.To investigate the prevalence of breeding domesticated deer,we examined the SFTSV infection rate on deer farms in South Korea from 2015 to 2017.Of the 215 collected blood samples,0.9%(2/215)were found to be positive for viral RNA by PCR,and sequence analysis showed the highest homology with the KADGH human isolate.Both SFTSVspecific recombinant N and Gn protein-based ELIS As revealed that 14.0%(30/215)and 7.9%(17/215)of collected blood specimens were positive for SFTSV antibody.These results demonstrate that the breeding farm deer are exposed to SFTSV and could be a potential infection source for humans through direct contact or consumption of byproducts.

SARS-CoV-2 mutations, vaccines, and immunity: implication of variants of concern

In a recent study published in Nature,Wang et al.1 investigated the neutralizing activities of antibodies elicited by COVID-19 mRNA vaccines and natural infection with SARS-CoV-2 against SARS-CoV-2 variants.The devastating impact of the ongoing COVID-19 pandemic on public health,the economy,and society has made vaccine development a top priority for global health.Thus,vaccine development is progressing at an unprecedented pace as an urgent response to COVID-19.