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Gorgas Case 2018-11 |
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This is our last Case of the Week for 2018. We hope you have enjoyed the 2018 series of live cases each week from Peru. The Gorgas Diploma Course, in February and March, and the Gorgas Advanced course, in August, are held annually and we will be in touch at the beginning of next year’s case series.
Publishing these case reports would not be possible without the assistance of an extremely dedicated group of people. We would like to thank in particular UPCH Case Editor: Carlos Seas, UPCH Associate Coordinators: Karen Luhmann and Carlos McFarlane, UAB Case Editor: David O. Freedman, Course Director Emeritus, for case selection and coordination of case summaries and images, Dr. German Henostroza, UAB Course Director and Alfredo Guzman of the Gorgas Center for Geographic Medicine at the UAB Division of Infectious Diseases for all publishing on the Gorgas Course website. The following patient was seen in the inpatient department of the 36-bed Tropical Disease Unit at Cayetano Heredia National Hospital in Lima-Peru. Carlos Seas & German Henostroza Course Directors  History: 53 yo male with a 1 year history of profuse watery diarrhea (10 times per day) with nausea, vomiting and diffuse abdominal pain. He visited several private sector emergency rooms for intravenous rehydration and received short treatment courses of ciprofloxacin and TMP/SMX with only partial improvement. He lost 18 kg since the beginning of his illness. No cough, no fever, no night sweats. The patient was referred to our Institute for further evaluation.
Epidemiology: Born and lives in the Lima area where he works as street vendor. Currently married but over 15 total sexual partners including female sex workers. Alcohol abuse since age 14 yr. No known TB exposure. No relevant past medical history. Physical Examination: BP 100/70, HR 73, RR 19, T 36.6°C, body weight 41 kg, BMI 16 kg/m2. Pale, no jaundice or rash. No lymphadenopathy. Chest and cardiovascular normal. Moderate abdominal pain to deep palpation in the right upper quadrant. Negative Murphy's sign. No visceromegaly, no peritoneal signs. Normal neurologic examination. Laboratory Results and Imaging: Hb 12.4, WBC 6 300 (0 bands, 52 neutrophils, 2 eosinophils, 37 lymphs), platelets 446 000, creatinine 0.5 mg/dl, total protein 5.1 g/dl. albumin 2.3 g/dl. ALT/AST 111/113 UI/L (<40), alkaline phosphatase: 183U/L (<104). Serological tests for Hepatitis B, C, Syphilis and HIV were non-reactive.
Chest x-ray was normal Abdominal ultrasound showed moderate hepatomegaly and chronic calculous cholecystitis. Colonoscopy showed normal colonic mucosa. Upper endoscopy showed superficial erosive gastritis in the fundus and gastric body. A stool wet mount preparation is shown in Image A. UPCH Case Editors: Carlos Seas, Course Director / Carlos McFarlane, Associate Coordinator UAB Case Editor: David O. Freedman, Course Director Emeritus / German Henostroza, Course Director |
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Diagnosis: Chronic diarrhea due to Cystoisospora belli. HTLV-1 infection.
 Discussion: Image B is a modified acid-fast stained stool showing a 10 μm x 20 μm oval oocyst of C. belli (long black arrow) containing two sporoblasts (two black arrows). C. belli can be diagnosed by observing these oocysts in, either, a stool wet-mount preparation or much better through a modified acid-fast or auraminerhodamine stain. Modified acid-fast staining is not regularly done when a request for stool O & P is made in most places. Therefore, it needs to be specifically thought of and ordered. Multiple samples using a stool concentration technique may be required for diagnosis. PCR is also available but usually not in developing countries. Stool culture was negative and no Strongyloides was found in several stool samples. In addition, HTLV-1 ELISA and Western blot tests were positive. On further questioning the patient disclosed that he had being diagnosed with cystoisosporiasis several months before and had been treated with short courses of antimicrobials with only partial response. C. belli was identified as causing human disease during World War I. The genus previously named Isospora was recently reclassified, separating the species infecting birds from those infecting mammals, now termed Cystoisospora [Curr Opin Infect Dis. 2013;26:479]. This coccidian parasite has global distribution, with predominance in tropical and sub-tropical areas of the world. Transmission occurs by ingestion of contaminated food or by drinking contaminated water. Infections mainly occur in children in endemic areas, whereas outbreaks and point-source epidemics related to contamination of fresh produce occur in developed countries [Curr Opin Infect Dis. 2013;26:479]. C. belli should be included in the differential diagnosis of patients with persistent diarrhea, during waterborne or foodborne outbreaks, in travelers to endemic areas, and in immunocompromised patients. C. belli infects both immunocompetent and immunosuppressed patients. The disease is usually mild in the former and it is characterized by fever, nausea and vomiting and watery diarrhea. Prolonged diarrhea with malabsorption and weight loss may also occur. Peripheral eosinophilia is a distinctive feature of this pathogen; no other coccidian parasites cause eosinophilia. Immunosuppressed patients present with more severe and prolonged diarrhea, and also may present with extra-intestinal manifestations. The parasite has been identified in samples from mesenteric lymph nodes, liver and from the spleen. Patients with advanced HIV-infection present with prolonged diarrhea are sometimes refractory to standard treatment [Rev Chilena Infectol. 2017;34:347]. Severely immunosuppressed HIV-infected patients and transplant patients may preset with gallbladder and biliary tract infection [Case Rep Infect Dis. 2018;2018:3170238]. C. belli and Cryptosporidium spp. should be included in the differential diagnosis in these settings. Patients with diarrhea who are found to have cystoisosporiasis should be immediately investigated for HIV and other immunocompromising conditions. Immunosuppressive conditions associated with cystoisosporiasis include Hodgkin’s lymphoma, thymoma and acute leukemias. In a recent study in Brazil among cancer patients, C. belli was found in 4.4% of 73 patients [Braz J Biol. 2018;78:574]. There are few reports of C. belli in HTLV-1 infected patients. In one report, C. belli was found in the stools of an HIV negative patient with chronic diarrhea preceding the diagnosis of HTLV-1, as in our patient [Case Rep Infect Dis 2012; 640104]. HTLV-1 infection was documented and the patient developed adult T-cell leukemia lymphoma and died. In another report, a patient with adult T-cell lymphoma associated with HTLV-1 presented recurrent C. belli infection and co-infection with C. difficile [ID Cases 2017;10:122]. Another report document the case of an Iranian women with severe diarrhea and weight loss [Iran J Parasitol 2016;11:121] In Peru, HTLV-1 is highly endemic (2-3% prevalence) in Andean areas of the country in Quechua populations who have had no contact with Japanese immigrants to the country. Other South American countries with significant rates of HTLV-1 include Brazil, Colombia, and Ecuador. We have seen over 800 infected families to date at the Tropical Medicine Institute in Lima. Disseminated strongyloidiasis is the most common and severe intestinal parasitic complication [see Gorgas Cases 2007-4; 2010-10; 2012-3], but a number of other conditions are associated with HTLV-1 infection; [see Lancet Infect Dis. 2007 Apr;7(4):266-81 for a detailed discussion]. Crusted (Norwegian) scabies [see also Gorgas Case 2008 #8] : tropical spastic paraparesis (TSP), also called HAM (HTLV-1 associated myelopathy) [see Gorgas Case 2002 #8], infective dermatitis [see Gorgas Case 2004 #7], adult T-cell leukemia/lymphoma (ATLL) [see Gorgas Case 2009 #11], autoimmune disease including uveitis, Sjögrens, arthropathy, polymyositis, and thyroiditis. Associations with bronchiectasis (Clin Infect Dis. 2012 Jan;54(1):43-50) and paracoccidiodomycosis Clin Infect Dis. 2010 Jul 15;51(2):250-1 are recently described. This patient did not have any neurological findings. More than 90% of individuals with HTLV-1 infection remain asymptomatic for life. Worldwide, approximately 0.3-4.0% develop TSP and 1-5% develop ATLL. Although the pathogenetic mechanisms of these two major complications likely differ, the low rates of each means that it is rare to see both sequelae in the same patient. There is limited experience with the treatment of C. belli in patients with immunosuppressive conditions other than HIV. TMP/SMX is the drug of choice; the double strength preparation twice-daily for 7-10 days is the drug and regimen of choice. The oral route is preferred, but the intravenous route in patients with poor oral tolerance is advised [N Engl J Med 1986;315:87]. Oral suppressive therapy is recommended in HIV infected patients due to the high relapse rate, but no good information is available in other immunosuppressive conditions. Alternative agents with less efficacy than TMP/SMX include ciprofloxacin, nitazoxanide and pyrimethamine. Our patient was treated with a 10-day course of TMP/SMX with resolution of symptoms. |