Streptococcus pneumoniae serotype 19A in hospitalized children with invasive pneumococcal disease after the introduction of conjugated vaccines in Lima, Peru.

BACKGROUND: The Pneumococcal conjugate vaccine (PCV) has decreased cases of invasive pneumococcal disease (IPD) worldwide. However, the impact of PCVs introduction may be affected by the serotype distribution in a specific context. METHODS: Cross-sectional multicenter passive surveillance study of IPD cases in pediatric patients hospitalized in Lima, Peru between 2016 and 2019 (after PCV13 introduction) to determine the serotype distribution and antimicrobial resistance of Streptococcus pneumoniae. Serotyping was performed by a sequential multiplex PCR and confirmed by whole genome sequencing. RESULTS: Eighty-five S. pneumoniae isolates were recovered (4.07/100,000 among children <60 months of age). Serotype 19A was the most common (49.4%). Children infected with serotype 19A in comparison with children infected with other serotypes were younger, had a lower rate of meningitis and higher rates of pneumonia, complicated pneumonia and antimicrobial resistance; 28.6% of patients with serotype 19A have received at least one dose of PCV13 vs. 62.8% of patients with other serotypes. Using MIC-breakpoints, 81.2% (56/69) of non-meningitis strains and 31.2% (5/16) of meningitis strains were susceptible to penicillin; 18.8% (3/16) of meningitis strains had intermediate resistance to ceftriaxone. Resistance to azithromycin was 78.8% (67/85). Serotype 19A frequency increased over time in the same study population, from 4.2% (4/96) in 2006-2008, to 8.6% (5/58) in 2009-2011, to 49.4% (42/85) in the current study (2016-2019) (p < 0.001). CONCLUSIONS: After PCV13 introduction in Peru, serotype 19A remains the most prevalent; however, the vaccination coverage is still not optimal. Therefore, additonal surveillance studies are needed to determine the remaining IPD burden.

Risks of low vaccination coverage and strategies to prevent the resurgence of vaccine-preventable diseases in infants in the COVID-19 pandemic scenario: recommendations for Latin America and the Caribbean by the group of experts on infant immunization for Latin America.

INTRODUCTION: The WHO 2030 Immunization Agenda (IA-2030) harmonizes immunization activity plans at community, national, regional and global levels. Additionally, medical societies play an important role. The Latin American Group of Experts on Infant Immunization, established in 2018, advises on the harmonization, update, and optimization of infant vaccination programs in Latin America and the Caribbean (LAC). In September 2021, 41 such experts from 13 LAC countries met to develop recommendations for increasing regional vaccination coverage to avoid the reemergence of vaccine-preventable diseases and/or the occurrence of outbreaks. AREAS COVERED: The following items were evaluated: (i) immunization challenges before and during the COVID-19 pandemic; (ii) the status of current immunization programs, particularly infant pertussis and polio vaccination; (iii) possible solutions for overcoming vaccination challenges and achieving regional vaccination coverage targets. EXPERT OPINION/COMMENTARY: Medical societies provide valuable recommendations to guide and update vaccination schedules. In the LAC region, possible strategies to achieve target vaccination rates include the use of combination vaccines, strengthening surveillance systems, improving school attendance, advancing vaccine education and confidence, striving for vaccination equity, widening operational capacity, creating strategic alliances, and strengthening the role of medical groups. It is hoped that these recommendations will be implemented in the LAC region.

Pneumococcal serotypes and antibiotic resistance in healthy carriage children after introduction of PCV13 in Lima, Peru.

OBJECTIVE: To determinate the frequency of Streptococcus pneumoniae nasopharyngeal carriers, serotypes and antimicrobial resistance in healthy children in Lima, Peru, post-PCV13 introduction and to compare the results with a similar study conducted between 2006 and 2008 before PCV7 introduction (pre-PCV7). METHODS: A cross-sectional multicenter study was conducted between January 2018 and August 2019 in 1000 healthy children under two years of age. We use standard microbiological methods to determinate S. pneumoniae from nasopharyngeal swab, Kirby Bauer and minimum inhibitory concentration methods to determinate antimicrobial susceptibility and whole genomic sequencing to determinate pneumococcal serotypes. RESULTS: The pneumococcal carriage rate was 20.8 % vs. 31.1 % in pre-PCV7 (p < 0.001). The most frequent serotypes were 15C, 19A and 6C (12.4 %, 10.9 % and 10.9 % respectively). The carriage of PCV13 serotypes after PCV13 introduction decreased from 59.1 % (before PCV7 introduction) to 18.7 % (p < 0.001). Penicillin resistance was 75.5 %, TMP/SMX 75.5 % and azithromycin 50.0 %, using disk diffusion. Penicillin resistance rates using MIC breakpoint for meningitis (MIC ≥ 0.12) increased from 60.4 % to 74.5 % (p = 0.001). CONCLUSION: The introduction of PCV13 in the immunization program in Peru has decreased the pneumococcal nasopharyngeal carriage and the frequency of PCV13 serotypes; however, there has been an increase in non-PCV13 serotypes and antimicrobial resistance.

Recommendations for modernizing infant vaccination schedules with combination vaccines in Colombia and Peru.

The objective of this article was to consider the vaccination challenges in Colombia and Peru and the role of pediatric combination vaccines in overcoming these challenges. Barriers to including new vaccines with more antigens remain apparent in parts of these countries, where vaccine-preventable diseases in infants continue to be a major problem. The challenges include the heterogeneity of vaccine coverage within each country and in neighboring countries, which can contribute to poor rates of vaccination coverage; the adverse impact of the inward migration of unvaccinated individuals, which has favored the re-emergence of vaccine-preventable diseases; vaccine shortages; and the impact of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and the associated shifts in health care resources. To improve the coverage of pediatric vaccines in Colombia and Peru, it will be necessary to ensure the widespread integration into vaccine schedules of combination vaccines containing diphtheria, tetanus, acellular pertussis, inactivated poliovirus, Haemophilus influenzae type b and hepatitis B antigens with a three-dose primary series delivered at 2, 4 and 6 months of age followed by a booster at 18 months of age. Such vaccines play important roles in preventing diphtheria, tetanus and pertussis; eradicating polio; and providing boosting against H. influenzae type b.

El objetivo de este artículo es considerar los desafíos que se enfrentan en Colombia y Perú con respecto a la vacunación y el papel de las vacunas combinadas pediátricas para superar estos desafíos. Los obstáculos para incluir vacunas nuevas con más antígenos siguen siendo evidentes en algunos lugares de estos países, donde las enfermedades prevenibles por vacunación en menores de 1 año continúan siendo un grave problema. Entre los desafíos se incluye la heterogeneidad de la cobertura de vacunación en cada país y en los países vecinos, lo que puede contribuir con que se registren tasas bajas de cobertura de vacunación; el impacto adverso de la migración interna de personas no vacunadas, lo que ha favorecido la reaparición de enfermedades prevenibles por vacunación; la escasez de vacunas, y el impacto de la pandemia del coronavirus de tipo 2 causante del síndrome respiratorio agudo grave (SARS-CoV-2) y los consiguientes cambios en los recursos de atención médica. Para mejorar la cobertura de las vacunas pediátricas en Colombia y Perú será necesario integrar de manera generalizada en los calendarios de vacunación vacunas combinadas con antígenos de difteria, tétanos, tos ferina acelular, poliovirus inactivados, Haemophilus influenzae tipo b y hepatitis B con una serie primaria de tres dosis administradas a los 2, 4 y 6 meses de edad, seguida de un refuerzo a los 18 meses de edad. Esas vacunas desempeñan un papel esencial en la prevención de la difteria, el tétanos y la tos ferina; la erradicación de la polio; y el refuerzo contra H. influenzae tipo b.

O objetivo deste artigo foi avaliar os desafios da vacinação na Colômbia e no Peru e o papel das vacinas pediátricas combinadas na superação de tais desafios. Os obstáculos para incluir novas vacinas com mais antígenos permanecem visíveis em partes desses países, onde doenças imunopreveníveis em lactentes continuam a ser um grande problema. Os desafios incluem a heterogeneidade da cobertura vacinal dentro de cada país e nos países vizinhos, o que pode contribuir para baixas taxas de cobertura vacinal; o impacto adverso da migração interna de pessoas não vacinadas, o que favoreceu o ressurgimento de doenças imunopreveníveis; a escassez de vacinas; e o impacto da pandemia de síndrome respiratória aguda grave do coronavírus 2 (SARS-CoV-2) e mudanças relacionadas nos recursos de atenção à saúde. Para melhorar a cobertura das vacinas pediátricas na Colômbia e no Peru, será necessário assegurar sua integração generalizada em esquemas de vacinas combinadas contendo antígenos de difteria, tétano, pertussis acelular, poliovírus inativado, Haemophilus influenzae tipo B e hepatite B, com uma série primária de três doses aplicadas aos 2, 4 e 6 meses de idade seguidas de um reforço aos 18 meses de idade. Tais vacinas desempenham papéis importantes na prevenção da difteria, tétano e coqueluche; na erradicação da poliomielite; e no reforço contra H. influenzae tipo b.

Recommendations for modernizing infant vaccination schedules with combination vaccines in Colombia and Peru

[ABSTRACT]. The objective of this article was to consider the vaccination challenges in Colombia and Peru and the role of pediatric combination vaccines in overcoming these challenges. Barriers to including new vaccines with more antigens remain apparent in parts of these countries, where vaccine-preventable diseases in infants continue to be a major problem. The challenges include the heterogeneity of vaccine coverage within each country and in neighboring countries, which can contribute to poor rates of vaccination coverage; the adverse impact of the inward migration of unvaccinated individuals, which has favored the re-emergence of vaccine-preventable diseases; vaccine shortages; and the impact of the severe acute respiratory syndrome coronavirus 2 (SARS- CoV-2) pandemic and the associated shifts in health care resources. To improve the coverage of pediatric vaccines in Colombia and Peru, it will be necessary to ensure the widespread integration into vaccine sched- ules of combination vaccines containing diphtheria, tetanus, acellular pertussis, inactivated poliovirus, Haemophilus influenzae type b and hepatitis B antigens with a three-dose primary series delivered at 2, 4 and 6 months of age followed by a booster at 18 months of age. Such vaccines play important roles in preventing diphtheria, tetanus and pertussis; eradicating polio; and providing boosting against H. influenzae type b.

[RESUMEN]. El objetivo de este artículo es considerar los desafíos que se enfrentan en Colombia y Perú con respecto a la vacunación y el papel de las vacunas combinadas pediátricas para superar estos desafíos. Los obstáculos para incluir vacunas nuevas con más antígenos siguen siendo evidentes en algunos lugares de estos países, donde las enfermedades prevenibles por vacunación en menores de 1 año continúan siendo un grave pro- blema. Entre los desafíos se incluye la heterogeneidad de la cobertura de vacunación en cada país y en los países vecinos, lo que puede contribuir con que se registren tasas bajas de cobertura de vacunación; el impacto adverso de la migración interna de personas no vacunadas, lo que ha favorecido la reaparición de enfermedades prevenibles por vacunación; la escasez de vacunas, y el impacto de la pandemia del corona- virus de tipo 2 causante del síndrome respiratorio agudo grave (SARS-CoV-2) y los consiguientes cambios en los recursos de atención médica. Para mejorar la cobertura de las vacunas pediátricas en Colombia y Perú será necesario integrar de manera generalizada en los calendarios de vacunación vacunas combinadas con antígenos de difteria, tétanos, tos ferina acelular, poliovirus inactivados, Haemophilus influenzae tipo b y hepatitis B con una serie primaria de tres dosis administradas a los 2, 4 y 6 meses de edad, seguida de un refuerzo a los 18 meses de edad. Esas vacunas desempeñan un papel esencial en la prevención de la difteria, el tétanos y la tos ferina; la erradicación de la polio; y el refuerzo contra H. influenzae tipo b.

[RESUMO]. O objetivo deste artigo foi avaliar os desafios da vacinação na Colômbia e no Peru e o papel das vacinas pediátricas combinadas na superação de tais desafios. Os obstáculos para incluir novas vacinas com mais antígenos permanecem visíveis em partes desses países, onde doenças imunopreveníveis em lactentes con- tinuam a ser um grande problema. Os desafios incluem a heterogeneidade da cobertura vacinal dentro de cada país e nos países vizinhos, o que pode contribuir para baixas taxas de cobertura vacinal; o impacto adverso da migração interna de pessoas não vacinadas, o que favoreceu o ressurgimento de doenças imu- nopreveníveis; a escassez de vacinas; e o impacto da pandemia de síndrome respiratória aguda grave do coronavírus 2 (SARS-CoV-2) e mudanças relacionadas nos recursos de atenção à saúde. Para melhorar a cobertura das vacinas pediátricas na Colômbia e no Peru, será necessário assegurar sua integração gen- eralizada em esquemas de vacinas combinadas contendo antígenos de difteria, tétano, pertussis acelular, poliovírus inativado, Haemophilus influenzae tipo B e hepatite B, com uma série primária de três doses aplica- das aos 2, 4 e 6 meses de idade seguidas de um reforço aos 18 meses de idade. Tais vacinas desempenham papéis importantes na prevenção da difteria, tétano e coqueluche; na erradicação da poliomielite; e no reforço contra H. influenzae tipo b.

Recommendations for modernizing infant vaccination schedules with combination vaccines in Colombia and Peru / Recomendaciones para modernizar los calendarios de vacunación infantil con vacunas combinadas en Colombia y Perú / Recomendações para modernizar os esquemas de vacinação infantil com vacinas combinadas na Colômbia e no Peru

ABSTRACT The objective of this article was to consider the vaccination challenges in Colombia and Peru and the role of pediatric combination vaccines in overcoming these challenges. Barriers to including new vaccines with more antigens remain apparent in parts of these countries, where vaccine-preventable diseases in infants continue to be a major problem. The challenges include the heterogeneity of vaccine coverage within each country and in neighboring countries, which can contribute to poor rates of vaccination coverage; the adverse impact of the inward migration of unvaccinated individuals, which has favored the re-emergence of vaccine-preventable diseases; vaccine shortages; and the impact of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic and the associated shifts in health care resources. To improve the coverage of pediatric vaccines in Colombia and Peru, it will be necessary to ensure the widespread integration into vaccine schedules of combination vaccines containing diphtheria, tetanus, acellular pertussis, inactivated poliovirus, Haemophilus influenzae type b and hepatitis B antigens with a three-dose primary series delivered at 2, 4 and 6 months of age followed by a booster at 18 months of age. Such vaccines play important roles in preventing diphtheria, tetanus and pertussis; eradicating polio; and providing boosting against H. influenzae type b.

RESUMEN El objetivo de este artículo es considerar los desafíos que se enfrentan en Colombia y Perú con respecto a la vacunación y el papel de las vacunas combinadas pediátricas para superar estos desafíos. Los obstáculos para incluir vacunas nuevas con más antígenos siguen siendo evidentes en algunos lugares de estos países, donde las enfermedades prevenibles por vacunación en menores de 1 año continúan siendo un grave problema. Entre los desafíos se incluye la heterogeneidad de la cobertura de vacunación en cada país y en los países vecinos, lo que puede contribuir con que se registren tasas bajas de cobertura de vacunación; el impacto adverso de la migración interna de personas no vacunadas, lo que ha favorecido la reaparición de enfermedades prevenibles por vacunación; la escasez de vacunas, y el impacto de la pandemia del coronavirus de tipo 2 causante del síndrome respiratorio agudo grave (SARS-CoV-2) y los consiguientes cambios en los recursos de atención médica. Para mejorar la cobertura de las vacunas pediátricas en Colombia y Perú será necesario integrar de manera generalizada en los calendarios de vacunación vacunas combinadas con antígenos de difteria, tétanos, tos ferina acelular, poliovirus inactivados, Haemophilus influenzae tipo b y hepatitis B con una serie primaria de tres dosis administradas a los 2, 4 y 6 meses de edad, seguida de un refuerzo a los 18 meses de edad. Esas vacunas desempeñan un papel esencial en la prevención de la difteria, el tétanos y la tos ferina; la erradicación de la polio; y el refuerzo contra H. influenzae tipo b.

RESUMO O objetivo deste artigo foi avaliar os desafios da vacinação na Colômbia e no Peru e o papel das vacinas pediátricas combinadas na superação de tais desafios. Os obstáculos para incluir novas vacinas com mais antígenos permanecem visíveis em partes desses países, onde doenças imunopreveníveis em lactentes continuam a ser um grande problema. Os desafios incluem a heterogeneidade da cobertura vacinal dentro de cada país e nos países vizinhos, o que pode contribuir para baixas taxas de cobertura vacinal; o impacto adverso da migração interna de pessoas não vacinadas, o que favoreceu o ressurgimento de doenças imunopreveníveis; a escassez de vacinas; e o impacto da pandemia de síndrome respiratória aguda grave do coronavírus 2 (SARS-CoV-2) e mudanças relacionadas nos recursos de atenção à saúde. Para melhorar a cobertura das vacinas pediátricas na Colômbia e no Peru, será necessário assegurar sua integração generalizada em esquemas de vacinas combinadas contendo antígenos de difteria, tétano, pertussis acelular, poliovírus inativado, Haemophilus influenzae tipo B e hepatite B, com uma série primária de três doses aplicadas aos 2, 4 e 6 meses de idade seguidas de um reforço aos 18 meses de idade. Tais vacinas desempenham papéis importantes na prevenção da difteria, tétano e coqueluche; na erradicação da poliomielite; e no reforço contra H. influenzae tipo b.

Increase of Macrolide-Resistance in Streptococcus pneumoniae Strains After the Introduction of the 13-Valent Pneumococcal Conjugate Vaccine in Lima, Peru.

Streptococcus pneumoniae upper respiratory infections and pneumonia are often treated with macrolides, but recently macrolide resistance is becoming an increasingly important problem. The 13-valent pneumococcal conjugate vaccine (PCV13) was introduced in the National Immunization Program of Peru in 2015. This study aimed to evaluate the temporal evolution of macrolide resistance in S. pneumoniae isolates collected in five cross-sectional studies conducted before and after this vaccine introduction, from 2006 to 2019 in Lima, Peru. A total of 521 and 242 S. pneumoniae isolates recovered from nasopharyngeal swabs from healthy carrier children < 2 years old (2 carriage studies) and samples from normally sterile body areas from pediatric patients with invasive pneumococcal disease (IPD) (3 IPD studies), respectively, were included in this study. Phenotypic macrolide resistance was detected using the Kirby-Bauer method and/or MIC test. We found a significant increase in macrolide resistance over time, from 33.5% to 50.0% in carriage studies, and from 24.8% to 37.5% and 70.8% in IPD studies. Macrolide resistance genes [erm(B) and mef(A/E)] were screened using PCR. In carriage studies, we detected a significant decrease in the frequency of mef(A/E) genes among macrolide-resistant S. pneumoniae strains (from 66.7% to 50.0%) after introduction of PCV13. The most common mechanism of macrolide-resistant among IPD strains was the presence of erm(B) (96.0%, 95.2% and 85.1% in the 3 IPD studies respectively). Macrolide resistance was more common in serotype 19A strains (80% and 90% among carriage and IPD strains, respectively) vs. non-serotype 19A (35.5% and 34.4% among carriage and IPD strains, respectively). In conclusion, S. pneumoniae macrolide resistance rates are very high among Peruvian children. Future studies are needed in order to evaluate macrolide resistance trends among pneumococcal strains, especially now after the COVID-19 pandemic, since azithromycin was vastly used as empiric treatment of COVID-19 in Peru.

Intranigral Administration of ß-Sitosterol-ß-D-Glucoside Elicits Neurotoxic A1 Astrocyte Reactivity and Chronic Neuroinflammation in the Rat Substantia Nigra.

Chronic consumption of ß-sitosterol-ß-D-glucoside (BSSG), a neurotoxin contained in cycad seeds, leads to Parkinson's disease in humans and rodents. Here, we explored whether a single intranigral administration of BSSG triggers neuroinflammation and neurotoxic A1 reactive astrocytes besides dopaminergic neurodegeneration. We injected 6 µg BSSG/1 µL DMSO or vehicle into the left substantia nigra and immunostained with antibodies against tyrosine hydroxylase (TH) together with markers of microglia (OX42), astrocytes (GFAP, S100ß, C3), and leukocytes (CD45). We also measured nitric oxide (NO), lipid peroxidation (LPX), and proinflammatory cytokines (TNF-α, IL-1ß, IL-6). The Evans blue assay was used to explore the blood-brain barrier (BBB) permeability. We found that BSSG activates NO production on days 15 and 30 and LPX on day 120. Throughout the study, high levels of TNF-α were present in BSSG-treated animals, whereas IL-1ß was induced until day 60 and IL-6 until day 30. Immunoreactivity of activated microglia (899.0 ± 80.20%) and reactive astrocytes (651.50 ± 11.28%) progressively increased until day 30 and then decreased to remain 251.2 ± 48.8% (microglia) and 91.02 ± 39.8 (astrocytes) higher over controls on day 120. C3(+) cells were also GFAP and S100ß immunoreactive, showing they were neurotoxic A1 reactive astrocytes. BBB remained permeable until day 15 when immune cell infiltration was maximum. TH immunoreactivity progressively declined, reaching 83.6 ± 1.8% reduction on day 120. Our data show that BSSG acute administration causes chronic neuroinflammation mediated by activated microglia, neurotoxic A1 reactive astrocytes, and infiltrated immune cells. The severe neuroinflammation might trigger Parkinson's disease in BSSG intoxication.

Synthetic Monopartite Peptide That Enables the Nuclear Import of Genes Delivered by the Neurotensin-Polyplex Vector.

Neurotensin (NTS)-polyplex is a multicomponent nonviral vector that enables gene delivery via internalization of the neurotensin type 1 receptor (NTSR1) to dopaminergic neurons and cancer cells. An approach to improving its therapeutic safety is replacing the viral karyophilic component (peptide KPSV40; MAPTKRKGSCPGAAPNKPK), which performs the nuclear import activity, by a shorter synthetic peptide (KPRa; KMAPKKRK). We explored this issue and the mechanism of plasmid DNA translocation through the expression of the green fluorescent protein or red fluorescent protein fused with KPRa and internalization assays and whole-cell patch-clamp configuration experiments in a single cell together with importin α/ß pathway blockers. We showed that KPRa electrostatically bound to plasmid DNA increased the transgene expression compared with KPSV40 and enabled nuclear translocation of KPRa-fused red fluorescent proteins and plasmid DNA. Such translocation was blocked with ivermectin or mifepristone, suggesting importin α/ß pathway mediation. KPRa also enabled NTS-polyplex-mediated expression of reporter or physiological genes such as human mesencephalic-derived neurotrophic factor (hMANF) in dopaminergic neurons in vivo. KPRa is a synthetic monopartite peptide that showed nuclear import activity in NTS-polyplex vector-mediated gene delivery. KPRa could also improve the transfection of other nonviral vectors used in gene therapy.

Unilateral intranigral administration of ß-sitosterol ß-D-glucoside triggers pathological α-synuclein spreading and bilateral nigrostriatal dopaminergic neurodegeneration in the rat.

The spreading and accumulation of α-synuclein and dopaminergic neurodegeneration, two hallmarks of Parkinson's disease (PD), have been faithfully reproduced in rodent brains by chronic, oral administration of ß-sitosterol ß-D-glucoside (BSSG). We investigated whether a single injection of BSSG (6 µg BSSG/µL DMSO) in the left substantia nigra of Wistar rats causes the same effects. Mock DMSO injections and untreated rats formed control groups. We performed immunostainings against the pathological α-synuclein, the dopaminergic marker tyrosine hydroxylase (TH), the neuroskeleton marker ß-III tubulin, the neurotensin receptor type 1 (NTSR1) as non-dopaminergic phenotype marker and Fluro-Jade C (F-J C) label for neurodegeneration. Using ß-galactosidase (ß-Gal) assay and active caspase-3 immunostaining, we assessed cell death mechanisms. Golgi-Cox staining was used to measure the density and types of dendritic spines of striatal medium spiny neurons. Motor and non-motor alterations were also evaluated. The study period comprised 15 to 120 days after the lesion. In the injured substantia nigra, BSSG caused a progressive α-synuclein aggregation and dopaminergic neurodegeneration caused by senescence and apoptosis. The α-synuclein immunoreactivity was also present within microglia cells. Decreased density of dopaminergic fibers and dendritic spines also occurred in the striatum. Remarkably, all the histopathological changes also appeared on the contralateral nigrostriatal system, and α-synuclein aggregates were present in other brain regions. Motor and non-motor behavioral alterations were progressive. Our data show that the stereotaxic BSSG administration reproduces PD α-synucleinopathy phenotype in the rat. This approach will aid in identifying the spread mechanism of α-synuclein pathology and validate anti-synucleinopathy therapies.

Acute Neuroinflammatory Response in the Substantia Nigra Pars Compacta of Rats after a Local Injection of Lipopolysaccharide.

Models of Parkinson's disease with neurotoxins have shown that microglial activation does not evoke a typical inflammatory response in the substantia nigra, questioning whether neuroinflammation leads to neurodegeneration. To address this issue, the archetypal inflammatory stimulus, lipopolysaccharide (LPS), was injected into the rat substantia nigra. LPS induced fever, sickness behavior, and microglial activation (OX42 immunoreactivity), followed by astrocyte activation and leukocyte infiltration (GFAP and CD45 immunoreactivities). During the acute phase of neuroinflammation, pro- and anti-inflammatory cytokines (TNF-α, IL-1ß, IL-6, IL-4, and IL-10) responded differentially at mRNA and protein level. Increased NO production and lipid peroxidation occurred at 168 h after LPS injection. At this time, evidence of neurodegeneration could be seen, entailing decreased tyrosine hydroxylase (TH) immunoreactivity, irregular body contour, and prolongation discontinuity of TH+ cells, as well as apparent phagocytosis of TH+ cells by OX42+ cells. Altogether, these results show that LPS evokes a typical inflammatory response in the substantia nigra that is followed by dopaminergic neurodegeneration.

Resistencia antibiótica y distribución de serotipos en cepas neumocócicas invasivas en adultos hospitalizados en Lima, Perú / Antibiotic resistance and distribution of serotypes of invasive pneumococcal strains isolated from hospitalized adults in Lima, Peru

RESUMEN Objetivos. Describir las características clínicas, resistencia antibiótica y distribución de serotipos de cepas causantes de enfermedad neumocócica invasiva (ENI) en adultos. Materiales y métodos. Estudio tipo serie de casos. Se recolectaron cepas de neumococo de pacientes adultos hospitalizados con ENI en cinco hospitales nacionales y dos laboratorios de Lima durante los años 2009-2011. Resultados. Se estudiaron datos de 43 pacientes con ENI, el 58,2% fueron mayores de 60 años. Los diagnósticos fueron neumonía 39,5%, meningitis 30,2%, bacteriemia 13,9%, peritonitis 11,6%, artritis séptica 4,8%. El porcentaje de fallecidos fue 28,9%, de los cuales el 72,7% fueron mayores de 60 años. Las cepas de neumococo presentaron la siguiente resistencia: penicilina 0% en cepas no meningitis y 30,8% en cepas meningitis; ceftriaxona 4,5% y 16,7% de resistencia intermedia en cepas no meningitis y cepas meningitis respectivamente; 69% a trimetoprim/sulfametoxazol y 35,7% a eritromicina. Los serotipos más comunes fueron 19F, 23F, 6B, 14 y 6C. El porcentaje de cepas vacunales fue 44,2% para la vacuna conjugada siete-valente (PCV7) y para la PCV10, 51,2% para PCV13 y 60,4% para la vacuna polisacárida veintitrés-valente (PPV23). Conclusiones. El neumococo es un patógeno relevante en adultos, en especial en los adultos mayores, debido a su elevada mortalidad.

ABSTRACT Objectives. To describe the clinical characteristics, antibiotic resistance, and distribution of serotypes of bacterial strains that cause invasive pneumococcal disease (IPD) in adults. Materials and methods. Case series. Pneumococcal strains were isolated from 2009 to 2011 from hospitalized adult patients with IPD in five hospitals and two laboratories located in Lima. Results. The analysis of data from 43 patients with IPD indicated that 58.2% were older than 60 years. The most common complications were pneumonia (39.5%), meningitis (30.2%), bacteremia (13.9%), peritonitis (11.6%), and septic arthritis (4.8%). The mortality rate was 28.9%, and 72.7% of cases involved patients older than 60 years. The pneumococcal strains were resistant to the following antibiotics: penicillin, 0% and 30.8% in non-meningitis and meningitis strains, respectively; ceftriaxone, 4.5% and 16.7% in non-meningitis and meningitis strains, respectively; trimethoprim/sulfamethoxazole, 69.0%; and erythromycin, 35.7%. The most common serotypes were 19F, 23F, 6B, 14, and 6C. The percentage of vaccine strains was 44.2% for the 7-valent conjugate pneumococcal vaccine (PCV7) and PCV10, 51.2% for PCV13, and 60.4% for the 23-valent polysaccharide vaccine (PPV23). Conclusions. Pneumococcus is an important pathogen in adults, particularly in older adults, owing to its high mortality rate.

Key features of invasive pneumococcal isolates recovered in Lima, Peru determined through whole genome sequencing.

Before PCV7 introduction, invasive pneumococcal disease (IPD) was responsible for approximately 12,000-18,000 deaths annually among children <5years in Latin America. In Peru, PCV7 was introduced in 2009. We used whole genome sequencing to deduce key features of invasive strains collected in Lima, Peru from 2006 to 2011. We sequenced 212 IPD isolates from 16 hospitals in Lima pre (2006-2009; n=133) and post (2010-2011; n=79) PCV7 introduction; 130 (61.3%) isolates were from children≤5years old. CDC's Streptococcus lab bioinformatics pipeline revealed serotypes, sequence types (STs), pilus genes, PBP types and other resistance determinants. During the pre-PCV7 period, serotype 14 was the most common serotype (24.8%), followed by 6B (20.3%), 19F (10.5%), and 23F (6.8%). Post-PCV7, the proportion of PCV7 serotype 6B decreased significantly (to 6.3%), while 19F (16.3%), 14 (15.0%), 23F (7.5%), and 19A (7.5%) were the most common serotypes; only serotypes 3 and 10A increased significantly. Overall, 82% (n=173) of all isolates carried at least one resistance determinant, including 72 (34%) isolates that carried resistance determinants against 3 or more antimicrobial classes; of these 72 isolates, 56 (78%) belonged to a PCV7 serotype. Eighty-two STs were identified, with 53 of them organized in 14 clonal complexes. ST frequencies were distributed differently pre and post-PCV7 introduction, with only 18 of the 57 STs identified in years 2006-2009 isolates also observed in years 2010-2011 isolates. The apparent expansion of a 19F/ST1421 lineage with predicted ß-lactam resistance (PBP type 13:16:20) and carrying resistance determinants against four additional antimicrobial classes was observed.

[Antibiotic resistance and distribution of serotypes of invasive pneumococcal strains isolated from hospitalized adults in Lima, Peru]. / Resistencia antibiótica y distribución de serotipos en cepas neumocócicas invasivas en adultos hospitalizados en Lima, Perú.

OBJECTIVES.: To describe the clinical characteristics, antibiotic resistance, and distribution of serotypes of bacterial strains that cause invasive pneumococcal disease (IPD) in adults. MATERIALS AND METHODS.: Case series. Pneumococcal strains were isolated from 2009 to 2011 from hospitalized adult patients with IPD in five hospitals and two laboratories located in Lima. RESULTS.: The analysis of data from 43 patients with IPD indicated that 58.2% were older than 60 years. The most common complications were pneumonia (39.5%), meningitis (30.2%), bacteremia (13.9%), peritonitis (11.6%), and septic arthritis (4.8%). The mortality rate was 28.9%, and 72.7% of cases involved patients older than 60 years. The pneumococcal strains were resistant to the following antibiotics: penicillin, 0% and 30.8% in non-meningitis and meningitis strains, respectively; ceftriaxone, 4.5% and 16.7% in non-meningitis and meningitis strains, respectively; trimethoprim/sulfamethoxazole, 69.0%; and erythromycin, 35.7%. The most common serotypes were 19F, 23F, 6B, 14, and 6C. The percentage of vaccine strains was 44.2% for the 7-valent conjugate pneumococcal vaccine (PCV7) and PCV10, 51.2% for PCV13, and 60.4% for the 23-valent polysaccharide vaccine (PPV23). CONCLUSIONS.: Pneumococcus is an important pathogen in adults, particularly in older adults, owing to its high mortality rate.

OBJETIVOS.: Describir las características clínicas, resistencia antibiótica y distribución de serotipos de cepas causantes de enfermedad neumocócica invasiva (ENI) en adultos. MATERIALES Y MÉTODOS.: Estudio tipo serie de casos. Se recolectaron cepas de neumococo de pacientes adultos hospitalizados con ENI en cinco hospitales nacionales y dos laboratorios de Lima durante los años 2009-2011. RESULTADOS.: Se estudiaron datos de 43 pacientes con ENI, el 58,2% fueron mayores de 60 años. Los diagnósticos fueron neumonía 39,5%, meningitis 30,2%, bacteriemia 13,9%, peritonitis 11,6%, artritis séptica 4,8%. El porcentaje de fallecidos fue 28,9%, de los cuales el 72,7% fueron mayores de 60 años. Las cepas de neumococo presentaron la siguiente resistencia: penicilina 0% en cepas no meningitis y 30,8% en cepas meningitis; ceftriaxona 4,5% y 16,7% de resistencia intermedia en cepas no meningitis y cepas meningitis respectivamente; 69% a trimetoprim/sulfametoxazol y 35,7% a eritromicina. Los serotipos más comunes fueron 19F, 23F, 6B, 14 y 6C. El porcentaje de cepas vacunales fue 44,2% para la vacuna conjugada siete-valente (PCV7) y para la PCV10, 51,2% para PCV13 y 60,4% para la vacuna polisacárida veintitrés-valente (PPV23). CONCLUSIONES.: El neumococo es un patógeno relevante en adultos, en especial en los adultos mayores, debido a su elevada mortalidad.

[Epidemiologic, clinical and bacteriologic characteristics of pneumococcal meningitis in pediatric patients from Lima, Peru]. / Características epidemiológicas, clínicas y bacteriológicas de meningitis neumocócica en pacientes pediátricos de Lima, Perú.

OBJECTIVES.: To describe the clinical characteristics, lethality, antibiotic susceptibility, and serotype distribution of pneumococcal meningitis in pediatric patients in Lima, Peru. MATERIALS AND METHODS.: A case series of pneumococcal meningitis in children less than 16 years of age from two prospective, multicenter, passive surveillance studies of invasive pneumococcal diseases held in Lima-Peru from 2006 to 2008 and 2009 to 2011. RESULTS.: We report 44 pneumococcal meningitis episodes; 68.2% of them were in children less than 2 years old. The overall case fatality rate was 32.6%; 92.9% of fatal cases were in children less than 2 years of age (p<0.05). Malnutrition was associated with fatal cases (p<0.05). 64.3% of fatal cases died within the first two days. 41.9% of pneumococcal isolates were resistant to penicillin, 23.3% were intermediate resistant to ceftriaxone (none were highly resistant) and 9.3% were resistant to chloramphenicol. The most common serotypes were 6B, 14, 19F and 23F, which accounted for 68.3% of all strains; 84.1% of strains were PCV13 serotypes. CONCLUSIONS.: Pneumococcal meningitis continues to be a lethal disease, especially in children less than 2 years of age. Since almost two third of lethal cases lead to death within the first 48 hours, prompt diagnosis and management is critical, as well as assurance of immunization with pneumococcal vaccine.

Oxacillin disk diffusion testing for the prediction of penicillin resistance in Streptococcus pneumoniae.

Objective To 1) describe the correlation between the zones of inhibition in 1-µg oxacillin disk diffusion (ODD) tests and penicillin and ceftriaxone minimum inhibitory concentrations (MICs) of meningeal and non-meningeal strains of Streptococcus pneumoniae and 2) evaluate the usefulness of the ODD test as a predictor of susceptibility to penicillin in S. pneumoniae and as a quick and cost-effective method easily implemented in a routine clinical laboratory setting. Methods S. pneumoniae isolates from healthy nasopharyngeal carriers less than 2 years old, obtained in a multicentric cross-sectional study conducted in various Peruvian hospitals and health centers from 2007 to 2009, were analyzed. Using Clinical and Laboratory Standards Institute (CLSI) breakpoints, the correlation between the zones of inhibition of the ODD test and the MICs of penicillin and ceftriaxone was determined. Results Of the 571 S. pneumoniae isolates, 314 (55%) showed resistance to penicillin (MIC ≥ 0.12 µg/mL) and 124 (21.7%) showed resistance to ceftriaxone (MIC ≥ 1 µg/mL). Comparison of the ODD test zones of inhibition and the penicillin MICs, using the CLSI meningeal breakpoints, showed good correlation (Cohen's kappa coefficient = 0.8239). Conclusions There was good correlation between ODD zones of inhibition and penicillin meningeal breakpoints but weak correlation between the ODD results and non-meningeal breakpoints for both penicillin and ceftriaxone. Therefore, the ODD test appears to be a useful tool for predicting penicillin resistance in cases of meningeal strains of S. pneumoniae, particularly in low- and middle- income countries, where MIC determination is not routinely available.

Características epidemiológicas, clínicas y bacteriológicas de meningitis neumocócica en pacientes pediátricos de Lima, Perú / Epidemiologic, clinical and bacteriologic characteristics of pneumococcal meningitis in pediatric patients from Lima, Peru

RESUMEN Objetivos. Describir las características clínicas, letalidad, susceptibilidad antibiótica y distribución de serotipos de meningitis neumocócica en pacientes pediátricos de Lima, Perú. Materiales y Métodos. Serie de casos de meningitis neumocócica en niños menores de 16 años. Los datos fueron obtenidos de dos estudios multicéntricos prospectivos, de vigilancia pasiva de enfermedad neumocócica invasiva realizados en Lima-Perú desde los años 2006 al 2008, y del 2009 al 2011. Resultados. Reportamos 44 episodios de meningitis neumocócica; 68,2% fueron en niños menores de 2 años. La tasa de letalidad fue 32,6; y 92,9% de los casos letales ocurrieron en niños menores de dos años (p<0,05). La desnutrición estuvo asociada a los casos letales (p<0,05). El 64,3% de los casos fatales murieron dentro de los 2 primeros días. El 41,9% de los cultivos con neumococo fueron resistentes a la penicilina, 23,3% mostró resistencia intermedia a ceftriaxona (ninguno mostró resistencia completa) y 9,3% mostró resistencia a cloranfenicol. Los serotipos más frecuentes fueron 6B, 14, 19F y 23F, los cuales constituyeron el 68,3% de todas las cepas; 84,1% de las cepas encontradas están incluidas en los serotipos de la vacuna 13 valente. Conclusiones. La meningitis neumocócica continúa siendo una enfermedad letal, especialmente en niños menores de 2 años. Dado que aproximadamente dos tercios de los casos letales fallecen en las primeras 48 h, es crítico un diagnóstico y tratamiento oportuno, así como asegurar el cumplimiento de la inmunización con la vacuna neumocócica.

ABSTRACT Objectives. To describe the clinical characteristics, lethality, antibiotic susceptibility, and serotype distribution of pneumococcal meningitis in pediatric patients in Lima, Peru. Materials and Methods. A case series of pneumococcal meningitis in children less than 16 years of age from two prospective, multicenter, passive surveillance studies of invasive pneumococcal diseases held in Lima-Peru from 2006 to 2008 and 2009 to 2011. Results. We report 44 pneumococcal meningitis episodes; 68.2% of them were in children less than 2 years old. The overall case fatality rate was 32.6%; 92.9% of fatal cases were in children less than 2 years of age (p<0.05). Malnutrition was associated with fatal cases (p<0.05). 64.3% of fatal cases died within the first two days. 41.9% of pneumococcal isolates were resistant to penicillin, 23.3% were intermediate resistant to ceftriaxone (none were highly resistant) and 9.3% were resistant to chloramphenicol. The most common serotypes were 6B, 14, 19F and 23F, which accounted for 68.3% of all strains; 84.1% of strains were PCV13 serotypes. Conclusions. Pneumococcal meningitis continues to be a lethal disease, especially in children less than 2 years of age. Since almost two third of lethal cases lead to death within the first 48 hours, prompt diagnosis and management is critical, as well as assurance of immunization with pneumococcal vaccine.

Oxacillin disk diffusion testing for the prediction of penicillin resistance in Streptococcus pneumoniae / Prueba de difusión con discos de oxacilina para predecir la resistencia a la penicilina de Streptococcus pneumoniae

ABSTRACT Objective To 1) describe the correlation between the zones of inhibition in 1-µg oxacillin disk diffusion (ODD) tests and penicillin and ceftriaxone minimum inhibitory concentrations (MICs) of meningeal and non-meningeal strains of Streptococcus pneumoniae and 2) evaluate the usefulness of the ODD test as a predictor of susceptibility to penicillin in S. pneumoniae and as a quick and cost-effective method easily implemented in a routine clinical laboratory setting. Methods S. pneumoniae isolates from healthy nasopharyngeal carriers less than 2 years old, obtained in a multicentric cross-sectional study conducted in various Peruvian hospitals and health centers from 2007 to 2009, were analyzed. Using Clinical and Laboratory Standards Institute (CLSI) breakpoints, the correlation between the zones of inhibition of the ODD test and the MICs of penicillin and ceftriaxone was determined. Results Of the 571 S. pneumoniae isolates, 314 (55%) showed resistance to penicillin (MIC ≥ 0.12 µg/mL) and 124 (21.7%) showed resistance to ceftriaxone (MIC ≥ 1 µg/mL). Comparison of the ODD test zones of inhibition and the penicillin MICs, using the CLSI meningeal breakpoints, showed good correlation (Cohen’s kappa coefficient = 0.8239). Conclusions There was good correlation between ODD zones of inhibition and penicillin meningeal breakpoints but weak correlation between the ODD results and non-meningeal breakpoints for both penicillin and ceftriaxone. Therefore, the ODD test appears to be a useful tool for predicting penicillin resistance in cases of meningeal strains of S. pneumoniae, particularly in low- and middle- income countries, where MIC determination is not routinely available.

RESUMEN Objetivo 1) Describir la correlación entre las zonas de inhibición observadas en la prueba de difusión con discos de oxacilina de 1 µg y la concentración inhibitoria mínima (CIM) de penicilina y ceftriaxona frente a cepas meníngeas y no meníngeas de Streptococcus pneumoniae y 2) evaluar si la prueba de difusión con discos de oxacilina permite predecir la sensibilidad de S. pneumoniae a la penicilina y sirve como método rápido y eficaz en función de los costos, y resulta fácil de aplicar en los laboratorios clínicos ordinarios. Métodos Se analizaron colonias de S. pneumoniae aisladas de la nasofaringe de portadores sanos menores de 2 años obtenidas en un estudio transversal multicéntrico realizado en diversos hospitales y centros de salud del Perú entre los años 2007 y 2009. Se determinó la correlación entre las zonas de inhibición observadas en la prueba de difusión con discos y la CIM de la penicilina y la ceftriaxona utilizando los valores críticos definidos por el Instituto de Estándares Clínicos y de Laboratorio. Resultados De las 571 colonias aisladas de S. pneumoniae, 314 (55 %) presentaron resistencia a la penicilina (CIM ≥ 0,12 µg/ml) y 124 (21,7%), resistencia a la ceftriaxona (CIM ≥ 1 µg/ml). Se observó una buena correlación (coeficiente κ de Cohen = 0,8239) entre las zonas de inhibición de la prueba de difusión con discos y la CIM de la penicilina utilizando los valores críticos del Instituto respecto de las cepas meníngeas. Conclusiones Se encontró una buena correlación entre las zonas de inhibición de la prueba de difusión con discos y los valores críticos de CIM de la penicilina respecto de las cepas meníngeas, pero una correlación débil entre los resultados de la prueba de difusión y los valores críticos tanto de la penicilina como de la ceftriaxona respecto de las cepas no meníngeas. Por consiguiente, la prueba de difusión con discos es un método de utilidad para predecir la resistencia a la penicilina de las cepas meníngeas de S. pneumoniae, en particular en los países de ingresos bajos y medianos, donde no suele ser posible determinar la CIM.

Oxacillin disk diffusion testing for the prediction of penicillin resistance in Streptococcus pneumoniae / Prueba de difusión con discos de oxacilina para predecir la resistencia a la penicilina de Streptococcus pneumoniae

Objective. To 1) describe the correlation between the zones of inhibition in 1-μg oxacillin disk diffusion (ODD) tests and penicillin and ceftriaxone minimum inhibitory concentrations (MICs) of meningeal and non-meningeal strains of Streptococcus pneumoniae and 2) evaluate the usefulness of the ODD test as a predictor of susceptibility to penicillin in S. pneumoniae and as a quick and cost-effective method easily implemented in a routine clinical laboratory setting. Methods. S. pneumoniae isolates from healthy nasopharyngeal carriers less than 2 years old, obtained in a multicentric cross-sectional study conducted in various Peruvian hospitals and health centers from 2007 to 2009, were analyzed. Using Clinical and Laboratory Standards Institute (CLSI) breakpoints, the correlation between the zones of inhibition of the ODD test and the MICs of penicillin and ceftriaxone was determined. Results. Of the 571 S. pneumoniae isolates, 314 (55%) showed resistance to penicillin (MIC ≥ 0.12 μg/mL) and 124 (21.7%) showed resistance to ceftriaxone (MIC ≥ 1 μg/mL). Comparison of the ODD test zones of inhibition and the penicillin MICs, using the CLSI meningeal breakpoints, showed good correlation (Cohen’s kappa coefficient = 0.8239). Conclusions. There was good correlation between ODD zones of inhibition and penicillin meningeal breakpoints but weak correlation between the ODD results and non-meningeal breakpoints for both penicillin and ceftriaxone. Therefore, the ODD test appears to be a useful tool for predicting penicillin resistance in cases of meningeal strains of S. pneumoniae, particularly in low- and middle- income countries, where MIC determination is not routinely available

Objetivo. 1) Describir la correlación entre las zonas de inhibición observadas en la prueba de difusión con discos de oxacilina de 1 μg y la concentración inhibitoria mínima (CIM) de penicilina y ceftriaxona frente a cepas meníngeas y no meníngeas de Streptococcus pneumoniae y 2) evaluar si la prueba de difusión con discos de oxacilina permite predecir la sensibilidad de S. pneumoniae a la penicilina y sirve como método rápido y eficaz en función de los costos, y resulta fácil de aplicar en los laboratorios clínicos ordinarios. Métodos. Se analizaron colonias de S. pneumoniae aisladas de la nasofaringe de portadores sanos menores de 2 años obtenidas en un estudio transversal multicéntrico realizado en diversos hospitales y centros de salud del Perú entre los años 2007 y 2009. Se determinó la correlación entre las zonas de inhibición observadas en la prueba de difusión con discos y la CIM de la penicilina y la ceftriaxona utilizando los valores críticos definidos por el Instituto de Estándares Clínicos y de Laboratorio.. Resultados. De las 571 colonias aisladas de S. pneumoniae, 314 (55 %) presentaron resistencia a la penicilina (CIM ≥ 0,12 μg/ml) y 124 (21,7%), resistencia a la ceftriaxona (CIM ≥ 1 μg/ml). Se observó una buena correlación (coeficiente κ de Cohen = 0,8239) entre las zonas de inhibición de la prueba de difusión con discos y la CIM de la penicilina utilizando los valores críticos del Instituto respecto de las cepas meníngeas. Conclusiones. Se encontró una buena correlación entre las zonas de inhibición de la prueba de difusión con discos y los valores críticos de CIM de la penicilina respecto de las cepas meníngeas, pero una correlación débil entre los resultados de la prueba de difusión y los valores críticos tanto de la penicilina como de la ceftriaxona respecto de las cepas no meníngeas. Por consiguiente, la prueba de difusión con discos es un método de utilidad para predecir la resistencia a la penicilina de las cepas meníngeas de S. pneumoniae, en particular en los países de ingresos bajos y medianos, donde no suele ser posible determinar la CIM.

A Controlled Study of Tuberculosis Diagnosis in HIV-Infected and Uninfected Children in Peru.

BACKGROUND: Diagnosing tuberculosis in children is challenging because specimens are difficult to obtain and contain low tuberculosis concentrations, especially with HIV-coinfection. Few studies included well-controls so test specificities are poorly defined. We studied tuberculosis diagnosis in 525 children with and without HIV-infection. METHODS AND FINDINGS: 'Cases' were children with suspected pulmonary tuberculosis (n = 209 HIV-negative; n = 81 HIV-positive) and asymptomatic 'well-control' children (n = 200 HIV-negative; n = 35 HIV-positive). Specimens (n = 2422) were gastric aspirates, nasopharyngeal aspirates and stools analyzed by a total of 9688 tests. All specimens were tested with an in-house hemi-nested IS6110 PCR that took <24 hours. False-positive PCR in well-controls were more frequent in HIV-infection (P≤0.01): 17% (6/35) HIV-positive well-controls versus 5.5% (11/200) HIV-negative well-controls; caused by 6.7% (7/104) versus 1.8% (11/599) of their specimens, respectively. 6.7% (116/1719) specimens from 25% (72/290) cases were PCR-positive, similar (P>0.2) for HIV-positive versus HIV-negative cases. All specimens were also tested with auramine acid-fast microscopy, microscopic-observation drug-susceptibility (MODS) liquid culture, and Lowenstein-Jensen solid culture that took ≤6 weeks and had 100% specificity (all 2112 tests on 704 specimens from 235 well-controls were negative). Microscopy-positivity was rare (0.21%, 5/2422 specimens) and all microscopy-positive specimens were culture-positive. Culture-positivity was less frequent (P≤0.01) in HIV-infection: 1.2% (1/81) HIV-positive cases versus 11% (22/209) HIV-negative cases; caused by 0.42% (2/481) versus 4.7% (58/1235) of their specimens, respectively. CONCLUSIONS: In HIV-positive children with suspected tuberculosis, diagnostic yield was so low that 1458 microscopy and culture tests were done per case confirmed and even in children with culture-proven tuberculosis most tests and specimens were false-negative; whereas PCR was so prone to false-positives that PCR-positivity was as likely in specimens from well-controls as suspected-tuberculosis cases. This demonstrates the importance of control participants in diagnostic test evaluation and that even extensive laboratory testing only rarely contributed to the care of children with suspected TB. TRIAL REGISTRATION: This study did not meet Peruvian and some other international criteria for a clinical trial but was registered with the ClinicalTrials.gov registry: ClinicalTrials.gov NCT00054769.