Association between Helicobacter spp.infections and hepatobiliary malignancies:A review

Hepatobiliary cancers are highly lethal cancers that comprise a spectrum of invasive carcinomas originating in the liver hepatocellular carcinoma,the bile ducts intrahepatic cholangiocarcinoma and extrahepaticcholangiocarcinoma,the gallbladder and the ampulla of Vater(collectively known as biliary tract cancers).These tumors account for approximately 13% of all annual cancer-related deaths worldwide and for 10%-20% of deaths from hepatobiliary malignancies.Cholangiocarcinoma(CCA) is a devastating disease that displays a poor survival rate for which few therapeutic options are available.Population genetics,geographical and environmental factors,cholelithiasis,obesity,parity,and endemic infection with liver flukes have been identified as risk factors that influence the development of biliary tract tumors.Other important factors affecting the carcinogenesis of these tumors include chronic inflammation,obstruction of the bile ducts,and impaired bile flow.It has been suggested that CCA is caused by infection with Helicobacter species,such as Helicobacter bilis and Helicobacter hepaticus,in a manner that is similar to the reported role of Helicobacter pylori in distal gastric cancer.Due to the difficulty in culturing these Helicobacter species,molecular methods,such as polymerase chain reaction and sequencing,or immunologic assays have become the methods of choice for diagnosis.However,clinical studies of benign or malignant biliary tract diseases revealed remarkable variability in the methods and the findings,and the use of uniform and validated techniques is needed.

Occult hepatitis B virus infection among Mexican human immunodeficiency virus-1-infected patients

AIM: To determine the frequency of occult hepatitis B infection(OHBI) in a group of human immunodeficiency virus(HIV)-1+/ hepatitis B surface antigen negative(HBsAg)- patients from Mexico. METHODS: We investigated the presence of OHBI in 49 HIV-1+/HBsAg- patients. Hepatitis B virus(HBV) DNA was analyzed using nested PCR to amplify the Core(C) region and by real-time PCR to amplify a region of the S and X genes. The possible associations between the variables and OHBI were investigated using Pearson's χ2 and/or Fisher's exact test.RESULTS: We found that the frequency of OHBI was 49% among the group of 49 HIV-1+/HBsAg- patients studied. The presence of OHBI was significantly associated with the HIV-1 RNA viral load [odds ratio(OR) = 8.75; P = 0.001; 95%CI: 2.26-33.79] and with HIVantiretroviral treatment with drugs that interfere with HBV replication(lamivudine, tenofovir or emtricitabine)(OR = 0.25; P = 0.05; 95%CI: 0.08-1.05). CONCLUSION: The OHBI frequency is high among 49 Mexican HIV-1+/HBsAg- patients and it was more frequent in patients with detectable HIV RNA, and less frequent in patients who are undergoing HIV-ARV treatment with drugs active against HBV.

Management of Helicobacter pylori infection in Latin America: A Delphi technique-based consensus

AIM: To optimize diagnosis and treatment guidelines for this geographic region, a panel of gastroenterologists, epidemiologists, and basic scientists carried out a structured evaluation of available literature.METHODS: Relevant questions were distributed among the experts, who generated draft statements for consideration by the entire panel. A modified three-round Delphi technique method was used to reach consensus. Critical input was also obtained from representatives of the concerned medical community. The quality of the evidence and level of recommendation supporting each statement was graded according to United States Preventive Services Task Force criteria.RESULTS: A group of ten experts was established. The survey included 15 open-ended questions that were distributed among the experts, who assessed the articles associated with each question. The levels of agreement achieved by the panel were 50% in the first round, 73.3% in the second round and 100% in the third round. Main consensus recommendations included:(1) when available, urea breath and stool antigen test(HpSA) should be used for non-invasive diagnosis;(2) detect and eradicate Helicobacter pylori(H. pylori) in all gastroscopy patients to decrease risk of peptic ulcer disease, prevent o retard progression in patients with preneoplastic lesions, and to prevent recurrence in patients treated for gastric cancer;(3) further investigate implementation issues and health outcomes of H. pylorieradication for primary prevention of gastric cancer in high-risk populations;(4) prescribe standard 14-d triple therapy or sequential therapy for first-line treatment;(5) routinely assess eradication success post-treatment in clinical settings; and(6) select second- and third-line therapies according to antibiotic susceptibility testing.CONCLUSION: These achievable steps toward better region-specific management can be expected to improve clinical health outcomes.

Tick-Borne Rickettsial Pathogens in Rodents from Mexico

Tick-Borne Rickettsial Diseases (TBRD) are emerging zoonotic diseases, and a problem of human health and veterinary medication. The distribution of these diseases is related to the distribution of vector. The presence of pathogens in the host is a risk indicator of population exposure to these areas. A total of 478 tissues samples from rodents, A. phagocytophilum 18 (3.7%), E. canis 47 (9.8%), Rickettsia rickettsii 18 (3.7%) and E. chaffeensis 19 (3.9%) were detected using species-specific PCR assay. It is the first report in Mexico the presence of rodents infected with A. phagocytophilum and E. chaffeensis. The rodent Peromyscus spp. were the most commonly prevalent host of infection for all the bacteria’s. We have to consider as host of TBRD transmitter and provide a useful contribution to understanding their epidemiology. The health sector should be considered all the fevers of unknown causes in humans and animals in Mexico as infections by these vector-borne rickettsial pathogens.