Mycobacterium africanum, an emerging disease in high-income countries?

BACKGROUND: Mycobacterium africanum is a cause of tuberculosis (TB) that has mainly been described in Africa, but immigration and travel patterns have contributed to the spread of the disease to other countries. METHODS: We retrospectively reviewed TB cases due to M. africanum during 2000-2010 in seven Spanish hospitals. Selected clinical charts were reviewed using a predefined protocol that included demographical, clinical and microbiological data and outcome. RESULTS: Although 57 cases were diagnosed, only 36 clinical charts were available for review: 82.8% were men and the mean age was 31.6 years (range 12-81). Forty-four cases were from Africa, 1 from the Philippines, 1 from India, and 4 from Spain, while the country of origin was unknown in 7 cases. The most frequent site of infection was the lung (58.3%). Four cases (6.9%) were resistant to at least one first-line anti-tuberculosis drug. CONCLUSIONS: Disease due to M. africanum in industrialised countries is mainly associated with immigration from endemic areas, although some cases also occur among native-born populations.

[Intrahospital mortality in patients with Clostridium difficile-associated diarrhea infection]. / Mortalidad intrahospitalaria en pacientes con diarrea asociada a infección por Clostridium difficile.

BACKGROUND: Clostridium difficile (C. difficile) is a gram-positive anaerobic bacillus capable of producing diarrhea or colitis in the hospitalized patient, particularly in those exposed to the use of antibiotics, and 6% to 38% mortality in patients with C. difficile-associated diarrhea (CDAD) has been described. AIMS: To determine the hospital death rate in patients presenting with CDAD. As a secondary aim, hospital stay and risk factors for unfavorable outcome were recorded. METHODS: A retrospective cohort study was carried out. The case records of hospitalized patients presenting with diarrhea and that tested positive for C. difficile through toxin A and B assays were reviewed. The number of non-surviving patients that presented with CDAD during hospitalization was recorded along with the principal factors associated with the worst outcome. RESULTS: Of the 66 patients enrolled in the study, 6 (9,1%) died during their hospitalization. The median age was lower in the group of surviving patients than in the group of non-surviving patients, with 51,5 years (range 36 to 66,75) and 81,5 years (range 69,5 to 83,25), respectively (p=0,002). Hospital stay was 32,50 days (range 8,25 to 64,25) in the group of non-surviving patients and was 6,5 days (range 4 to 15,75) (p=0,045) in the group with no deaths. CONCLUSIONS: The elevated mortality found in the hospitalized CDAD patients in the Intensive Care Unit makes the maintenance of strict surveillance in this population imperative so there can be opportune detection and treatment.

[Site of care provision, etiology and treatment of community-acquired pneumonia in Palma de Mallorca]. / Lugar de atención, etiología y tratamiento de las neumonías adquiridas en la comunidad de Palma de Mallorca.

BACKGROUND: It is not common that community-acquired pneumonias studies include patients non treated in hospital. The objectives were: to determine the cases managed in the ambulatory setting; to describe the clinical features; to identify the aetiological agents, and to describe the treatment, comparing inpatients with outpatients. PATIENTS AND METHODS: Observational prospective study. Population attended at three teaching primary care centers of Palma de Mallorca (60,450 habitants). Patients (> 14 years) were investigated when diagnosticated of community-acquired pneumoniae, from November 1992 to December 1994. Exclussions: HIV infection, patients living in a nursing home and tuberculosis. Data were collected in both Hospital and primary health care centers. Epidemiological, clinical, radiological and laboratory findings were recorded at the initial visit and 21 days after. RESULTS: 91 cases were investigated. 57% were managed at the primary care centers exclusively, 63.3% of the patients who went initially to the hospital were admitted in; but only 10.9% of those who went initially to the primary care centers (p < 0.005). 24 patients were hospitalized. 56 microbiological agents were identified in 48 patients (52.7%): Mycoplasma pneumoniae (10); Streptococcus pneumoniae (9); Influenza B (8); Chlamydia psittacci (7); Influenza A (7); Coxiella burnetii (5); Chlamydia pneumoniae (4); Legionella (3); Adenovirus (2); and Parainfluenza 3 (1). Mycoplasma was predominant in outpatients: 9 cases. S. pneumoniae in inpatients: 5 cases. Eritromycin was the most common treatment prescribed (76.9% of patients), alone or in combination with other antibiotics. Monotherapy was most common at primary care yield (96.7%) than at the hospital (45.2%) (p < 0.005). CONCLUSIONS: Most of the patients with community-acquired pneumonias are managed at primary health care centers. M. pneumoniae is the predominant microbiological agent in outpatients and S. pneumoniae in inpatients. Erithromycin is the most used antibiotic in both groups of patients.

Entamoeba histolytica: liver invasion and abscess production by intraperitoneal inoculation of trophozoites in hamsters, Mesocricetus auratus.

Intraperitoneal inoculation of axenically cultured Entamoeba histolytica trophozoites constitutes an easy to perform, highly reproducible procedure for inducing amebic liver abscesses in hamsters. Efficiency in abscess production (95% of infected animals after 1 week) was similar to data reported using direct intrahepatic or intraportal inoculation. The morphological sequence of infection shows that amebas in the peritoneal cavity initially produce a large exudate constituted mainly of acute inflammatory cells. These cells form a rim of polymorphonuclear leukocytes surrounding the amebas, which adhere to the trophozoite and can sometimes be observed polarized to one end of the parasite, suggesting capping of surface receptors. Early stages are also characterized by the production of distant inflammatory reactions in the hepatic portal spaces. At 6 h postintraperitoneal inoculation, larger foci of inflammatory reactions surrounding amebas are developed in the peritoneum, extending to and damaging the liver surface membranes as well as the serosa of other internal organs. Thereafter, tissue damage progresses deeper into the liver parenchyma, and a few days later, coalescing granulomas and large necrotic areas are observed in the liver tissue. Based on the present morphological time-sequence study, we suggest that inflammatory cells associated with E. histolytica trophozoites play an important role in commencing the damage of liver sheaths and producing the subsequent parenchymal lesions. The simplicity and reliability of this model are important factors to consider when large numbers of experimentally induced amebic liver abscesses are needed.

Entamoeba histolytica: erythrophagocytosis, collagenolysis, and liver abscess production as virulence markers.

High rates of erythrophagocytosis and collagenolysis in vitro have been regarded as indicative of virulence in vivo of Entamoeba histolytica trophozoites. In the present study, the erythrophagocytic index and the collagenolytic activity of 3 axenic lines of E. histolytica, strain HM1:IMSS, were measured. The 3 lines shared the same pathogenic zymodeme but showed clear-cut differences in the extent of liver damage induced in hamsters. A direct correlation between collagenolysis in vitro and the size of liver abscesses produced by each line of E. histolytica trophozoites was found. In contrast, the line with the highest erythrophagocytic index produced small amoebic abscesses in hamsters, whereas the line with a relatively low erythrophagocytic index produced the largest liver lesions. It is concluded that the extent of collagenolytic activity is a better marker of virulence of E. histolytica cultured under axenic conditions than is erythrophagocytosis.

[Experimental hepatic amebiasis: acute inflammation in the rat]. / Amibiasis hepática experimental: inflamación aguda en la rata.

Rat livers inoculated intraportally with trophozoites of E. histolytica were studied by light and electron microscopy. At one hour post-inoculation, trophozoites were localized at the hepatic sinusoids without inflammatory reaction and only slight vascular congestion. From two hours post-inoculation, trophozoites were associated with small inflammatory foci distributed at random. At three to four hours, trophozoites showed signs of cellular damage. After eight hours, no parasites were seen and only some lymphoplasmocytic infiltration were detected. It is suggested that in the experimental hepatic amebic infection in the rat the acuta inflammatory reaction associated to trophozoites plays a role in the parasite rejection.