M. Elvira Balcells

Prevalence of tuberculosis and its impact on mortality among HIV infected patients in Chile

BACKGROUND Tuberculosis (TB) in Chile is reaching the elimination phase; however, in HIV positive individuals the incidence of TB in still very high. AIM To describe the association between TB and HIV in different geographical regions in Chile, and to determine the association between TB and HIV/AIDS mortality. PATIENTS AND METHODS A retrospective study that included individuals from the main HIV clinics from four regions with different TB prevalence in the general population (per 100,000): Arica (>30), Concepcion/Arauco (25-29), Valparaiso/San Antonio (20-24) and Metropolitana Sur-Oriente (SSMSO) (<20), attended between January 1998 and September 2004. RESULTS Nine hundred and twelve HIV positive individuals were included. Global prevalence of TB was 6.2% [95% confidence intervals (Cl) 5.2-7.2%]. TB was more common in older subjects (p =0.039) and those with lower CD4 counts (p <0.001) and higher HIV viral load (p =0.033). In 66% of cases, the disease had a pulmonary localization. TB was the recorded cause of death in 7.4% of subjects. Only 29% of patients had a tuberculin skin test performed at the moment of HIV diagnosis. The prevalence of TB in HIV positive patients, followed the trend of TB prevalence in the general population: Concepcion/Arauco (11.9%), Valparaiso/San Antonio (7.1%) and SSMSO (3.9%). However HIV positive subjects from Arica showed an unexpectedly low TB prevalence (5.5%). CONCLUSIONS TB in HIV/AIDS patients included in this study is over 300 times more prevalent than in the general population. TB prevalence in HIV positive subjects follows regional TB prevalence, excepting Arica. Effectiveness and feasibility of latent TB diagnostic strategies and treatment in HIV positive individuals should be reviewed.

Pesquisa de infección tuberculosa latente en personal de la salud en cuatro instituciones de salud en Santiago de Chile

BACKGROUND It is currently unknown which is the prevalence of latent tuberculosis infection in healthcare workers in Chile, but this group has been described as at higher risk of developing active tuberculosis than general population. OBJECTIVES To determine the prevalence of latent tuberculosis infection in a sample of healthcare workers from at risk areas. METHODOLOGY A cross-sectional, descriptive study, conducted in health care workers from clinical laboratories or respiratory care areas in four hospitals in Santiago. Latent tuberculosis infection detection was determined by Quantiferon® TB Gold In Tube testing (QFT). RESULTS QFT resulted positive in 20 of 76 (26.3%) of the individuals tested. Test positivity reached 62.5% among the personnel that reported history of past TB contact in the community, 50% among the personnel who belonged to the national tuberculosis control program and 38% among those doing induced sputum, acid fast smear or mycobacterial cultures. The proportion of individuals with positive QFT was significantly lower in those personnel who had no such risk factors (15.7%, p = 0.03). The proportion of latent tuberculosis infection also increased in direct relation to the age of the subject. CONCLUSION Latent tuberculosis infection as detected by QFT testing was highly prevalent in healthcare workers included in the present study. Further exploring the limitations and possible scenarios for this new diagnostic tool is needed, with emphasis on health personnel at higher-risk and younger individuals.Background: It is currently unknown which is the prevalence of latent tuberculosis infection in healthcare workers in Chile, but this group has been described as at higher risk of developing active tuberculosis than general population. Objectives: To determine the prevalence of latent tuberculosis infection in a sample of healthcare workers from at risk areas. Methodology: A cross-sectional, descriptive study, conducted in health care workers from clinical laboratories or respiratory care areas in four hospitals in Santiago. Latent tuberculosis infection detection was determined by Quantiferon® TB Gold In Tube testing (QFT). Results: QFT resulted positive in 20 of 76 (26.3%) of the individuals tested. Test positivity reached 62.5% among the personnel that reported history of past TB contact in the community, 50% among the personnel who belonged to the national tuberculosis control program and 38% among those doing induced sputum, acid fast smear or mycobacterial cultures. The proportion of individuals with positive QFT was significantly lower in those personnel who had no such risk factors (15.7%, p = 0.03). The proportion of latent tuberculosis infection also increased in direct relation to the age of the subject. Conclusion: Latent tuberculosis infection as detected by QFT testing was highly prevalent in healthcare workers included in the present study. Further exploring the limitations and possible scenarios for this new diagnostic tool is needed, with emphasis on health personnel at higher-risk and younger individuals.

Presencia del genotipo Beijing entre cepas del complejo Mycobacterium tuberculosis en dos centros de salud de la Región Metropolitana-Chile

BACKGROUND Genotyping of Mycobacterium tuberculosis complex (cMtb) allows us to know geographically predominant lineages. Some lineages spread more rapidly and are associated with multidrug resistance, particularly Beijing, which has been reported in Latin America (Peru). There is little information about this topic in Chile and there are no reports of the presence of the Beijing genotype. AIM To determine the most prevalent lineages in the Metropolitan Region of Chile with emphasis on the search for Beijing in two health centers. METHODS Two complementary molecular methods were used: spoligotyping, based on the variations of the direct repeat regions in the genome of cMtb and MIRU-VNTR, based in the variable number of tandem repeats of mycobacterial interspersed repetitive units, and subsequent analysis in international databases. A designed lineage was assigned to 37 of the 43 strains studied (86%); 6 isolates could not be assigned to any genotype. LAM and T genotype were the most frequent (39.5 and 32.5%, respectively) followed by Haarlem (7.0%), Beijing (4.7%) and X (2.3%). CONCLUSION We describe for the first time the presence of the Beijing genotype in Chile. cMtb molecular surveillance should be implemented in our country in order to know the dynamics of its transmission.

Comparación de adenosina deaminasa y detección de anticuerpos anti-antígeno A60 para el diagnóstico de meningitis tuberculosa

BACKGROUND Diagnosis of tuberculous meningitis (TBM) is hampered by the lack of rapid and accurate diagnostic tools. We evaluated the immunological response to Mycobacterium tuberculosis anti-A60 antibodies in cerebrospinal fluid (CSF) in comparison to adenosine deaminase (ADA) determination, for the diagnosis of TBM. METHODS A total of 63 CSF samples were analyzed by indirect ELISA for the detection of anti- A60 IgG, IgM and IgA. These include samples from 17 patients with confirmed TBM and 46 control patients with other infections. RESULTS The mean individual anti-A60 IgM, IgG and IgA CSF antibody titers were significantly higher in TBM in comparison with control groups (p < 0.01). The best discriminatory CSF antibody for confirming TBM diagnosis was IgM, with an area under the receiver operating characteristic curve of 0.928 (95%CI 0.834-0.978), compared to 0.863 (95% CI: 0.752-0.936) for ADA testing (p = NS). The sensitivity of anti- A60 IgM CSF antibody titers (cutoff > 0.06 U/ml) was 94.1% compared to 88.2% for ADA (cutoff > 6.2 U/ml), p = NS. Both anti A60 IgM and ADA showed the same moderate specificity (80.4%). Two cases of TBM were correctly identified by anti-A60 IgM but missed by ADA. CONCLUSION The ELISA test for anti-antigen A60 antibodies (IgM) is a rapid and sensitive tool for the rapid diagnosis of TBM that can be a complement to ALDA determination. The specificity of both tests is still a limitation in TBM diagnosis.

Perfil clínico y epidemiológico de los casos de tuberculosis atendidos en una red de salud universitaria en Santiago de Chile entre los años 2000-2010

BACKGROUND The incidence and epidemiological profile of tuberculosis (TB) has changed significantly in the recent years in Chile. AIM To evaluate the clinical and epidemiological characteristics of TB cases diagnosed in the last decade at a university hospital in Santiago. MATERIAL AND METHODS The Mycobacterium tuberculosis culture registry of the microbiology laboratory was reviewed. Medical records of patients with a positive culture registered between 2000 and 2010 were retrieved and analyzed. RESULTS Two hundred forty positive Mycobacterium tuberculosis cultures were identified and the medical records of 158 of these patients were accessed for analysis. The median age was 53 years (range: 3 to 89), 55.1% were female and nearly 42% had extra-pulmonary TB. Among known risk factors, 32.9% of patients were older than 65 years, 4.4% were health care workers and 3.9% immigrants. Twenty eight percent (41/145) had some type of immunosuppression at diagnosis: 11.7% HIV infection and 16.6% were using immunosuppressive drugs. In this group, a previous tuberculin skin test was done in only 5 cases (12.2%). Adverse events related to TB treatment were reported in 21.3% of cases (17/80). No cases of fulminant hepatitis or death from this cause were identified. Four of 92 patients that had a complete follow up during treatment, died. Two of these patients were receiving steroids. CONCLUSIONS Almost one third of TB cases occurred among immunosuppressed patients and 42% were extra-pulmonary forms. The prevention of TB reactivation in this group should be strengthened.

Micobacterias atípicas en cinco pacientes adultos sin evidencias de inmunosupresión: Construyendo una experiencia

El objetivo de este trabajo es reportar la experiencia acumulada sobre infecciones por micobacterias atipicas en pacientes sin inmunosupresion. Entre el ano 2008 y 2013 se observaron cinco pacientes con infeccion por micobacterias atipicas: dos con infeccion cutanea y tres con infeccion pulmonar. Ninguno de estos pacientes tenia evidencias de inmunosupresion. Un paciente con bursitis de codo por M. chelonae tuvo un estudio citoquimico con aumento de celularidad de predominio mononuclear y desarrollo de bacterias al quinto dia; respondio favorablemente a claritromicina. Un caso con infeccion cutanea por M. fortuitum evoluciono en forma prolongada con supuracion ganglionar antes del diagnostico y el cultivo solicitado a los 13 dias fue positivo. Los tres pacientes con aislados pulmonares presentaron tos y expectoracion y tenian en comun ser mujeres en edad post-menopausica y presentar pequenos infiltrados nodulares asociados a bronquiectasias en el estudio de imagenes pulmonares, un patron descrito en la literatura cientifica. En estos tres casos, la latencia entre la toma de muestra y el informe definitivo tuvo un rango de 40 a 89 dias. El aislamiento de micobacterias atipicas en muestras de expectoracion en pacientes sin inmunosupresion se da en un contexto tipico pero plantea dificultades diagnosticas y terapeuticas. El lento crecimiento de estos microorganismos en el laboratorio contribuye a este problema.BACKGROUND Respiratory infection caused by Pneumocystis jiroveci is a common opportunistic infection in patients with human immunodeficiency virus (HIV) with CD4 counts < 200 cells/mm³. However, it has also been reported in patients with other causes of immunosuppression. OBJECTIVES To compare the characteristics, severity and mortality of respiratory infection by P. jiroveci in patients with and without HIV infection. METHODS Retrospective cohort follow-up of adult patients admitted to our hospital with infection by P. jiroveci since 2006 to 2013. RESULTS We included 82 patients with respiratory infection by P. jiroveci of which 55% (45) were not infected with HIV. In this group, 68.8% (31) had diagnosis of cancer and 20% (9) received solid-organ transplant. 57.9% (26) were hospitalized in an intensive care unit. 42.2% (19) suffered multiple organ failure (MOF), 46.7% (21) required mechanical ventilation (MV) and 40.9% (18) inotropic drugs. Mortality was 33.3% (15). Statistically significant differences were observed between groups in age (p <0.001), requirement of MV (p <0.001) inotropic drugs (p 0.001) and MOF (p <0.001). Mortality was higher in the HIV-positive group, reaching statistical significance (p 0.007). CONCLUSION Pneumocystis pneumonia mortality was higher in patients without HIV, who suffered more complications and progression to respiratory failure with MOF.Background: Respiratory infection caused by Pneumocystis jiroveci is a common opportunistic infection in patients with human immunodeficiency virus (HIV) with CD4 counts Introduccion: La infeccion respiratoria por Pneumocystis jiroveci constituye una patologia oportunista frecuente en pacientes infectados con virus de inmunodeficiencia humana (VIH), con recuentos de LTCD4

Angiomatosis bacilar por Bartonella quintana como primera manifestación de infección por VIH: Report of one case

Bacillary angiomatosis is an unusual infectious disease, with angioproliferative lesions, typical of immunocompromised patients. It is caused by Bartonella quintana and Bartonella henselae, two infectious agents of the genus Bartonella, which trigger variable clinical manifestations, including cutaneous vascular and purpuric lesions, and regional lymphadenopathy, and even a systemic disease with visceral involvement. We report a 38-year-old HIV positive male presenting with a history of six months of cutaneous growing purple angiomatous lesions, located also in nasal fossae, rhinopharynx and larynx. The skin biopsy was compatible with bacillary angiomatosis. Polymerase chain reaction of a tissue sample showed homology with B. quintana strain Toulouse. The patient was treated with azithromycin and ciprofl oxacin with a favorable evolution. (Rev Med Chile 2012; 140: 910-914).

Evaluación de la técnica Xpert® MTB/RIF para la detección de Mycobacterium tuberculosis complex en muestras extra-pulmonares

Extra-pulmonary tuberculosis (TB) represents the 26.2% of total TB cases in Chile. Culture is the gold standard method, but the process is extremely slow. Xpert®MTB/RIF technique detects Mycobacterium tuberculosis complex (MTBc) through real time PCR in less than 3 h. However, it has been validated only for respiratory specimens. We aimed to determine the performance of Xpert®MTB/RIF test in detecting MTBc in extra-respiratory specimens compared with a combined gold standard consisting in a positive (liquid and solid) mycobacterial culture and/or a positive validated molecular method (q-RPC, Cobas®TaqMan®-MTB). Fifty extra-respiratory specimens were analyzed, from which 25 were positive and 25 negative for MTBc based on the combined gold standard. The 25 positive specimens had a positive result by Xpert®MTB/RIF; from the 25 negative specimens, 24 had a negative result and one had a positive result. We obtained an overall concordance of 98% between Xpert®MTB/RIF and the combined gold standard. Xpert®MTB/RIF test was able to detect 12 smear-negative specimens and 3 culture-negative specimens, all of them corresponding to extra-pulmonary TB cases. Xpert®MTB/RIF showed similar sensitivity to q-RPC in detecting MTBc in extra-respiratory specimens. This procedure allowed a substantial reduction in the time of diagnosis.

Cluster of Imported Vivax Malaria in Travelers Returning From Peru

We report a cluster of imported vivax malaria in three of five Chilean travelers returning from Peru in March 2015. The cluster highlights the high risk of malaria in the Loreto region in northern Peru, which includes popular destinations for international nature and adventure tourism. According to local surveillance data, Plasmodium vivax is predominating, but Plasmodium falciparum is also present, and the incidence of both species has increased during recent years. Travelers visiting this region should be counseled about the prevention of malaria and the options for chemoprophylaxis.