A man with diffuse vesicular rash and epigastric pain

Viral-Attributed Acute Pancreatitis: A Systematic Review

Infectious etiologies are rare cause of acute pancreatitis (AP). We sought to investigate the frequency of viral-attributed AP (VIAP) and describe its natural course and clinical features. Comprehensive review of PubMed and EMBASE in English until December 31, 2019, was performed. AP diagnosis and severity were defined per the Revised Atlanta Classification. Viral infections were diagnosed by serology and/or histology. A diagnosis of viral infection, with a concurrent AP diagnosis, a temporal resolution of both entities, and the attempt to exclude the most common etiologies of AP defined VIAP. Two independent reviewers reviewed eligible publications. Bias risk was assessed with the Murad tool. A total of 209 cases identified in 128 publications met inclusion criteria. Mean age was 38.9 ± 1.28 years. Male-to-female ratio was 2.2:1, and 28% of patients were immunocompromised. Viral hepatitis (A, B, C, D and E) was the most common virus and accounted for 34.4% of cases, followed by coxsackie and echoviruses (14.8%), hemorrhagic fever viruses (12.4%), CMV (12.0%), VZV (10.5%), mumps and measles (3.8%), primary HIV infection (3.8%), HSV (1.9%), EBV (1.9%), and the remainder of cases (2.9%) attributed to adenovirus, influenza H1N1, and multiple viruses. Severity of AP was: 43.1% mild, 11.7% moderately severe, 32.4% severe. Death occurred in 42 (20.1%) patients. A significant portion of VIAP patients were immunocompromised (28.0%) and accounted for 71.4% of mortality cases. Mortality was higher than that reported for AP from other etiologies in the literature.

Infectious causes of acute pancreatitis: A systematic review

BACKGROUND

Infectious etiologies of acute pancreatitis (AP) are rare and include viruses, bacteria, mycobacteria, parasites, and fungi. We aimed to conduct a comprehensive review on infectious etiologies of AP analyzing the frequency, clinical features, and outcomes of individuals presenting with this condition.

METHODS

Eligible articles reporting on AP attributed to infectious etiologies were included. A comprehensive literature search of PubMed from time of inception and until September 6,2019 was performed using all relevant MeSH (medical subject heading) keywords. Articles were assessed for eligibility and independently reviewed by two reviewers for clinical features of AP, local complications, and mortality. Methodological quality of included studies was evaluated using the Murad tool.

RESULTS

A total of 212 articles were included, of which 168 (79.2%) were at high risk of bias. 320 cases of AP were identified. Viruses were the leading etiology of infection attributed AP (65.3%) followed by helminths (19.1%), and bacteria (12.5%). Protozoa, mycobacteria, and fungi accounted for the remaining 3.1% of cases. Mean age was 40.5 ± 18.4 years and M:F ratio was 1.94:1. Mortality occurred in 50 patients. Mortality rate was higher in the virus attributed AP patients than AP from other infectious etiologies (21.8% vs. 7.0%, p < 0.0005).

INTERPRETATION

Literature quality on infection attributed AP is limited. Virus attributed AP appears to carry a higher mortality than other etiologies of infection attributed AP.

HSV1/2 Genital Infection in Mice Cause Reversible Delayed Gastrointestinal Transit: A Model for Enteric Myopathy

In an interesting investigation by Khoury-Hanold et al. (1), genital infection of mice with herpes simplex virus 1 (HSV1) were reported to cause multiple pelvic organ involvement and obstruction. A small subset of mice succumbed after the first week of HSV1 infection. The authors inferred that the mice died due to toxic megacolon. In a severe form of mechanical and/or functional obstruction involving gross dilation of the colon and profound toxemia, the presentation is called "toxic megacolon." The representative observations by Khoury-Hanold likely do not resemble toxic megacolon. The colon was only slightly dilated and benign appearing. Importantly, HSV1 infection affected the postjunctional mechanisms of smooth muscle relaxation like the sildenafil-response proteins, which may have been responsible for defective nitrergic neurotransmission and the delayed transit. Orally administered polyethylene glycol reversed the gastrointestinal "obstruction," suggesting a mild functional type of slowed luminal transit, resembling constipation, rather than toxic megacolon, which cannot be reversed by an osmotic laxative without perforating the gut. The authors suggest that the mice did not develop HSV1 encephalitis, the commonly known cause of mortality. The premature death of some of the mice could be related to the bladder outlet obstruction, whose backflow effects may alter renal function, electrolyte abnormalities and death. Muscle strip recordings of mechanical relaxation after electrical field stimulation of gastrointestinal, urinary bladder or cavernosal tissues shall help obtain objective quantitative evidence of whether HSV infection indeed cause pelvic multi-organ dysfunction and impairment of autonomic neurotransmission and postjunctional electromechanical relaxation mechanisms of these organs.