Tuberculosis (TB) remains a significant global health challenge. Miliary TB is a rare manifestation of TB that involves systemic lymphohematogenous dissemination of infection and presents diagnostic challenges due to its often asymptomatic or non-specific nature. This case report documents a rare occurrence of gastrointestinal (GI) bleeding secondary to miliary TB without pulmonary symptoms in an 81-year-old Filipino-American male living in the United States. Extensive imaging studies revealed a mass in the right colon with multiple bleeding vessels draped around it; it was not amendable to treatment with embolization and required right hemicolectomy with end ileostomy. The pathology report of the excised mass demonstrated miliary TB with necrotizing granulomas and granulomatous lymphadenopathy involving 23 lymph nodes. The patient was started on anti-tuberculosis medical management; however, the patient remained clinically unstable and expired on postoperative day 39. This case highlights the importance of the heightened clinical awareness required during times of globalization and in regions with dense immigrant populations. We aim to delineate the clinical understanding of gastrointestinal TB (GITB) and review possible indications for surgical management. We aim to help reduce diagnostic delay, therefore improving patient outcomes and limiting the spread of disease.

Attempts were made to improve the efficacy of PCR amplified immunoassay (I-PCR) for diagnosing abdominal TB cases by utilizing the gold nanoparticle (AuNP)-based I-PCR, where AuNPs were functionalized with detection antibodies/oligonucleotides that exhibited 84.3% sensitivity and 95.1% specificity. This assay would improve the ongoing algorithms used in abdominal TB diagnosis.

Tuberculosis (TB) is a chronic granulomatous inflammatory disease that affects any part of our body. TB is a significant problem in developing countries. Intestinal TB accounts for 2% of TB cases worldwide. Terminal ileum and cecum are the two commonly affected regions because of abundant lymphoid tissue, physiologic stasis, limited digestive activity and increased fluid and electrolyte absorption rate. Intestinal obstruction is the leading complication of intestinal TB, and it occurs because of intestinal luminal narrowing, multiple strictures or adhesions. The clinical presentation of patients with intestinal TB and post-TB intestinal obstruction is non-specific. It can be acute, chronic, or acute on chronic. Uncomplicated cases of intestinal TB can be managed medically. Surgery is reserved for complicated cases of intestinal TB, which includes peritonitis, intestinal obstruction and perforations. Here, we present a 37-year-old man who presented with long-standing, intermittent crampy abdominal pain and vomiting. He was diagnosed with chronic partial small bowel obstruction secondary to possibly small bowel carcinoma. We did segmental ileal resection and end-to-end ileo-ileal anastomosis. Postoperatively, the histopathology result turned out to be intestinal TB. This case report aims to make physicians aware of the rare condition of small bowel obstruction secondary to intestinal TB. Clinicians need to have a high index of suspicion in any patient with long-standing symptoms of partial obstruction and consider surgery and anti-TB once diagnosed.

Portal vein thrombosis associated with peritoneal tuberculosis is an uncommon manifestation of extrapulmonary tuberculosis. We report one such case of a 33-year-old male with a one-year history of dyspepsia, having been on proton pump inhibitors all this time with temporary relief. In view of ongoing symptoms, an endoscopy was done, which at first showed duodenal ulcer. On repeat endoscopy after an interval, there was evidence of mucosa-associated lymphoid tissue (MALT) lymphoma, which prompted a host of investigations in the patient. A positron emission tomography (PET) scan revealed extensive omento-peritoneal involvement along with a hypodense lesion in the liver with interval development of portal vein thrombosis on a CT scan of the abdomen. The biopsy of the hepatic lesion showed granulomatous inflammation. Faced with a diagnostic dilemma, finally, a laparoscopic biopsy was done, which confirmed the diagnosis of peritoneal TB with portal vein thrombosis. This case highlights the importance of keeping a high index of suspicion to include tuberculosis as a differential when presented with a case such as this and to conduct appropriate investigations to establish the correct diagnosis.

OBJECTIVE: Diagnosis of abdominal TB is an exigent task due to variable anatomical sites and non-specific clinical manifestations that closely resemble other diseases. Most of the available diagnostic modalities yield low sensitivities and need expertise to handle the specialized equipment. Hence, there is an urgent need to develop a rapid and reliable diagnostic test, so as to reduce the unnecessary morbidity. Therefore, we designed a multi-targeted loop-mediated isothermal amplification (MT-LAMP) for diagnosing abdominal TB.
METHODS: We evaluated an MT-LAMP (using mpt64 and IS6110) to diagnose abdominal TB within ascitic fluids and intestinal/peritoneal biopsies and compared these results with multiplex-PCR (M-PCR) using the same targets. MT-LAMP products were analyzed by gel electrophoresis and visual detection methods, that is, hydroxy naphthol blue and SYBR Green I reaction.
RESULTS: Sensitivities of 80.9% and 84.6% were obtained in suspected (n = 42) and total abdominal TB (n = 52) cases, respectively by gel-based MT-LAMP, with 97.3% (n = 37) specificity in non-TB controls. Notably, sensitivities attained by gel-based/SYBR Green I MT-LAMP in both clinically suspected and total abdominal TB cases were significantly higher (P < 0.05) than M-PCR. Furthermore, sensitivity obtained with SYBR Green I was equivalent to that of gel-based MT-LAMP, while somewhat lesser specificity (94.6%) was attained with SYBR Green I, compared with gel-based MT-LAMP.
CONCLUSIONS: Both gel-based and SYBR Green MT-LAMP exhibited equivalent sensitivities to diagnose abdominal TB. Because SYBR Green LAMP is easier to perform than a gel-based assay, we are currently focused on improving the specificity of this assay so as to develop a diagnostic kit.

Precise and timely detection of tuberculosis (TB) is crucial to reduce transmission. This study aims to assess the accuracy of Xpert MTB/RIF Ultra on stool samples and systematically review the performance of Xpert MTB/RIF Ultra with different sample types by meta-analysis. Stool samples of smear-negative pulmonary TB (PTB), cervical lymph node TB, and abdominal TB patients were tested on the Xpert MTB/RIF Ultra system. Meta-analysis was performed on a set of 44 studies. Data were grouped by sample type, and the pooled sensitivity and specificity of Xpert MTB/RIF Ultra were calculated. The sensitivity of Xpert MTB/RIF Ultra with stool samples was 100% for smear-negative PTB, 27.27% for cervical lymph node TB, and 50% for abdominal TB patients, with 100% specificity for all included TB groups. The summary estimate for all PTB samples showed 84.2% sensitivity and 94.5% specificity, and EPTB samples showed 88.6% sensitivity and 96.4% specificity. Among all sample types included in our meta-analysis, urine showed the best performance for EPTB diagnosis. This pilot study supports the use of stool as an alternative non-invasive sample on Xpert MTB/RIF Ultra for rapid testing, suitable for both PTB and EPTB diagnosis.

Ascites is defined as a massive collection of fluid in the peritoneal cavity, and it is most commonly caused by portal hypertension due to liver cirrhosis, acute liver failure, and heart failure. We report a case of ascites in a 39-year-old male who presented to the ED complaining of abdominal distention, sporadic pain on the epigastric area, unintentional weight loss over the past two months, night sweats, and blood-mixed stool. We conducted several imaging investigations and laboratory studies and none of them revealed any significant findings except for the abdominal CT with contrast, which showed large ascites along with submucosal fat deposition in the long segment of the transverse colon, suggestive of chronic inflammation [probably inflammatory bowel disease (IBD)], omental caking, and thickening. Peritoneal malignancy was highly suspected. A diagnostic/therapeutic paracentesis was performed, through which 8 L of fluid was drained. Cytology was also performed and this showed mostly reactive mesothelial cells, negative acid-fast bacilli (AFB) culture, and negative polymerase chain reaction (PCR). We also discuss the other investigations performed, none of which helped in establishing a diagnosis.

BACKGROUND: Abdominal tuberculosis (TB) is a common epitome of extrapulmonary TB (EPTB), wherein peritoneal and intestinal TB are the most prevalent forms. Diagnosis of abdominal TB is a daunting challenge owing to variable anatomical locations, paucibacillary nature of specimens and atypical clinical presentations that mimic other abdominal diseases, such as Crohn\'s disease and malignancies. In this review, we made a comprehensive study on the diagnosis of abdominal TB.
METHODS: Various modalities employed for abdominal TB diagnosis include clinical features, imaging, bacteriological tests (smear/culture), histopathological/cytological observations, interferon-gamma release assays and nucleic acid amplification tests (NAATs). Among NAATs, loop-mediated isothermal amplification assay, PCR, multiplex-PCR, nested PCR, real-time PCR and GeneXpert® MTB/RIF were discussed. Identification of circulating Mycobacterium tuberculosis cell-free DNA by real-time PCR within ascitic fluids is another useful approach.
CONCLUSIONS: Several novel molecular/immunological methods, such as GeneXpert Ultra, aptamer-linked immobilized sorbent assay, immuno-PCR (I-PCR) and nanoparticle-based I-PCR have recently been developed for detecting pulmonary TB and several EPTB types, which may also be explored for abdominal TB diagnosis. Precise and prompt diagnosis of abdominal TB may initiate an early therapy so as to reduce the complications, i.e. abdominal pain, ascites, abdominal distension, intestinal obstruction/perforation, etc., and avoid surgical involvement.Plain Language SummaryAbdominal tuberculosis (TB) is a manifestation of extrapulmonary TB (EPTB), where peritoneal and intestinal TB are two major forms. Diagnosis of abdominal TB is difficult owing to low bacterial load present in clinical samples and non-specific clinical presentations as it mimics other diseases such as inflammatory bowel diseases, abdominal malignancies, etc. Bacteriological tests (smear/culture) almost fail owing to poor sensitivities and it is not always possible to get representative tissue samples for histopathological and cytological observations. In recent years, molecular tests i.e. nucleic acid amplification tests (NAATs), such as PCR/multiplex-PCR (M-PCR), nested PCR and GeneXpert are widely employed. Markedly, PCR/M-PCR and nested PCR exhibited reasonable good sensitivities/specificities, while GeneXpert revealed low sensitivity in most of the studies but high specificity, thus it could assist in differential diagnosis of intestinal TB and Crohn\'s disease. Further, novel molecular/immunological tests employed for pulmonary TB and other EPTB types were described and those tests can also be utilized to diagnose abdominal TB. Reliable and rapid diagnosis of abdominal TB would initiate an early start of anti-tubercular therapy and reduce the severe complications.

Diagnosing intestinal tuberculosis (TB) with uncommon clinical manifestations is often challenging. Here, we report a case of an alcoholic patient who presented with vague symptoms and was later diagnosed with intestinal TB. This patient experienced multiorgan failure causing hemodynamic instability requiring ionotropic support; acute hypoxic respiratory failure managed with non-invasive positive pressure ventilation, hepatic failure, transudative peritoneal effusion, and transudative pleural effusion. These conditions clouded our judgment to pursue colonoscopy for a definite diagnosis and delayed the anti-tuberculosis treatment. When intestinal tuberculosis TB is suspected, the differential diagnosis must be established with other gastrointestinal involving diseases, including mycobacterium avium complex (MAC) and Crohn\'s disease (CD). MAC can show overlapping features with intestinal TB or coexist with it; Acid-fast stain and tissue culture are the key tests to differentiate these two. In the presence of diagnostic uncertainty between intestinal TB and CD, a therapeutic trial with anti-tuberculous therapy may be warranted.

High proportion of TB in people living with HIV (PLHIV) is undiagnosed. Due to this active TB case finding is recommended for HIV clinics in high TB burden countries. Presently sputum examination and chest radiography are frontline tests recommended for HIV infected TB presumptives. Abdominal TB which occurs frequently in PLHIV may be missed even by existing programmatic intensified case finding protocols. This study evaluated the routine use of ultrasonography (USG) for active case finding of abdominal TB in HIV clinics.
Retrospective analysis of eight years\' data from an HIV Clinic in a TB hospital in India. Patients underwent chest x-ray, sputum examination, USG abdomen and routine blood tests at entry to HIV care. Case forms were scrutinized for diagnosis of TB, USG findings and CD4 cell counts. Abdominal TB was classified as probable or possible TB. Probable TB was based on presence of two major USG (abdomen) findings suggestive of active TB, or one major USG finding with at least two minor USG findings or at least two symptoms, or any USG finding with microbiologically confirmed active TB at another site. Possible TB was based on the presence of one major USG finding, or the presence of two minor USG findings with at least two symptoms. Bacteriological confirmation was not obtained.
Eight hundred and eighty-nine people PLHIV underwent a baseline USG abdomen. One hundred and thirteen of 340 cases already diagnosed with TB and 87 of the 91 newly diagnosed with TB at time of HIV clinic registration had abdominal TB. Non-abdominal symptoms like weight loss, fever and cough were seen in 53% and 22% cases had no symptoms at all. Enlarged abdominal lymph nodes with central caseation, ascitis, splenic microabsesses, bowel thickening and hepatosplenomegaly were the USG findings in these cases.
Abdominal TB is a frequent TB site in PLHIV presenting with non-abdominal symptoms. It can be easily detected on basis of features seen on a simple abdominal ultrasound. Abdominal USG should be essential part of intensified TB case finding algorithms for HIV infected people living in high TB burden settings.