RESUMEN
In July 2022, the Pennsylvania Department of Health received two reports of laboratory-confirmed Legionnaires disease in patients who had recently received lung transplants from the same donor at a single Pennsylvania hospital. The donor's cause of death was freshwater drowning in a river, raising suspicion of potential donor-derived transmission, because Legionella bacteria naturally live in fresh water. Further investigation of patients receiving other organs from the same donor did not identify additional legionellosis cases. Health care-associated infection caused by water exposure at the hospital was also evaluated as a potential source of infection and was found to be unlikely. Hospital water quality parameter measurements collected during May-June 2022 were within expected ranges and no water disruptions were noted, although no testing for Legionella was performed during this period. Notifiable disease data did not identify any other Legionnaires disease cases with exposure to this hospital within the 6 months before or after the two cases. Although laboratory testing did not confirm the source of recipient infections, available data suggest that the most likely source was the donor lungs. This cluster highlights the need for increased clinical awareness of possible infection with Legionella in recipients of lungs from donors who drowned in fresh water before organ recovery.
Asunto(s)
Legionella , Enfermedad de los Legionarios , Humanos , Receptores de Trasplantes , Pennsylvania/epidemiología , PulmónRESUMEN
In July 2022, the Pennsylvania Department of Health received two reports of laboratory-confirmed Legionnaires disease in patients who had recently received lung transplants from the same donor at a single Pennsylvania hospital. The donor's cause of death was freshwater drowning in a river, raising suspicion of potential donor-derived transmission, because Legionella bacteria naturally live in fresh water. Further investigation of patients receiving other organs from the same donor did not identify additional legionellosis cases. Health care-associated infection caused by water exposure at the hospital was also evaluated as a potential source of infection and was found to be unlikely. Hospital water quality parameter measurements collected during May-June 2022 were within expected ranges and no water disruptions were noted, although no testing for Legionella was performed during this period. Notifiable disease data did not identify any other Legionnaires disease cases with exposure to this hospital within the 6 months before or after the two cases. Although laboratory testing did not confirm the source of recipient infections, available data suggest that the most likely source was the donor lungs. This cluster highlights the need for increased clinical awareness of possible infection with Legionella in recipients of lungs from donors who drowned in fresh water before organ recovery.
Asunto(s)
Ahogamiento , Legionella , Enfermedad de los Legionarios , Humanos , Enfermedad de los Legionarios/diagnóstico , Pennsylvania/epidemiología , Receptores de Trasplantes , PulmónRESUMEN
BACKGROUND: Measuring the maximum occipitofrontal circumference only once at birth or within 24 h after birth may lead to misclassifications of microcephaly. This study compared the head circumference (HC) of newborns at birth or within 24 h after birth to their third day of life (DOL3) as well as evaluated maternal- and infant-specific factors associated with increased HC by DOL3. METHODS: This prospective study included 1131 live births between February and May 2019 with a gestational age > 27 weeks. All newborns had their HC measured at birth or within 24 h after birth as well as on DOL3 before discharge. HC measurements were performed by trained personnel using non-elastic tape measures. The World Health Organization (WHO) and Fenton Growth Charts were used as reference ranges for interpretation of full-term and preterm neonates, respectively. RESULTS: Paired sample t-test analyses found a statistically significant increase in HC measured on the DOL3 compared with HCs of the same newborns at birth or within 24 h of birth. The mean HC increase was 0.17 cm (95% confidence interval [0.13, 0.21], P < 0.001). The mean ± standard deviation HC within 24 h of birth and at DOL3 were 33.58 ± 1.53 cm and 33.75 ± 1.37 cm, respectively. Thirty-two newborns had HCs less than the third percentile (< P3) at birth, 25 of which had HC ≥ P3 at DOL3. After adjusting for mode of and presentation at delivery, newborns whose mothers experienced labor pains (ß = 0.31, P < 0.001) and were either symmetrically (ß = 0.59, P = 0.002) or asymmetrically small-for-gestational age (SGA; ß = 0.37, P = 0.03) had significantly increased HC at DOL3. On average, newborns whose mothers experienced labor pain had 0.31 cm increases in HC at DOL3. Symmetrical SGA newborns also had an average 0.59 cm increase in HC at DOL3. Parity and gestational age were not associated with changes in HC. CONCLUSIONS: Serial HC measurements on DOL3 or before newborns' discharge is crucial to classifying congenital microcephaly.
Asunto(s)
Microcefalia , Embarazo , Lactante , Femenino , Humanos , Recién Nacido , Microcefalia/diagnóstico , Estudios Prospectivos , Cefalometría , Edad Gestacional , Recién Nacido Pequeño para la Edad GestacionalRESUMEN
A 42-year-old man, with up-to-date COVID-19 vaccination, experienced symptomatic SARS-CoV-2 infection in December 2021. Mutation tests suggested a non-Omicron variant. After his recovery, and 24 days after the first positive SARS-CoV-2 test, he had onset of symptomatic infection with the BA.1.1 (Omicron) variant, which was confirmed by whole-genome sequencing.
Asunto(s)
COVID-19 , SARS-CoV-2 , Adulto , COVID-19/diagnóstico , Vacunas contra la COVID-19 , Genoma Viral , Humanos , Pennsylvania , SARS-CoV-2/genéticaRESUMEN
In April 2020, during the peak of the coronavirus disease 2019 (COVID-19) pandemic in Europe, a cluster of children with hyperinflammatory shock with features similar to Kawasaki disease and toxic shock syndrome was reported in England* (1). The patients' signs and symptoms were temporally associated with COVID-19 but presumed to have developed 2-4 weeks after acute COVID-19; all children had serologic evidence of infection with SARS-CoV-2, the virus that causes COVID-19 (1). The clinical signs and symptoms present in this first cluster included fever, rash, conjunctivitis, peripheral edema, gastrointestinal symptoms, shock, and elevated markers of inflammation and cardiac damage (1). On May 14, 2020, CDC published an online Health Advisory that summarized the manifestations of reported multisystem inflammatory syndrome in children (MIS-C), outlined a case definition, and asked clinicians to report suspected U.S. cases to local and state health departments. As of July 29, a total of 570 U.S. MIS-C patients who met the case definition had been reported to CDC. A total of 203 (35.6%) of the patients had a clinical course consistent with previously published MIS-C reports, characterized predominantly by shock, cardiac dysfunction, abdominal pain, and markedly elevated inflammatory markers, and almost all had positive SARS-CoV-2 test results. The remaining 367 (64.4%) of MIS-C patients had manifestations that appeared to overlap with acute COVID-19 (2-4), had a less severe clinical course, or had features of Kawasaki disease.§ Median duration of hospitalization was 6 days; 364 patients (63.9%) required care in an intensive care unit (ICU), and 10 patients (1.8%) died. As the COVID-19 pandemic continues to expand in many jurisdictions, clinicians should be aware of the signs and symptoms of MIS-C and report suspected cases to their state or local health departments; analysis of reported cases can enhance understanding of MIS-C and improve characterization of the illness for early detection and treatment.
Asunto(s)
Infecciones por Coronavirus/complicaciones , Neumonía Viral/complicaciones , Síndrome de Respuesta Inflamatoria Sistémica/epidemiología , Síndrome de Respuesta Inflamatoria Sistémica/virología , Adolescente , COVID-19 , Niño , Preescolar , Infecciones por Coronavirus/epidemiología , Femenino , Humanos , Masculino , Pandemias , Neumonía Viral/epidemiología , Estados Unidos/epidemiologíaRESUMEN
BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of healthcare-associated infections. An important control strategy is hand hygiene; however, non-compliance has been a major problem in healthcare settings. Furthermore, modeling studies have suggested that the law of diminishing return applies to hand hygiene. Other additional control strategies such as environmental cleaning may be warranted, given that MRSA-positive individuals constantly shed contaminated desquamated skin particles to the environment. METHODS: We constructed and analyzed a deterministic environmental compartmental model of MRSA fate, transport, and exposure between two hypothetical hospital rooms: one with a colonized patient, shedding MRSA; another with an uncolonized patient, susceptible to exposure. Healthcare workers (HCWs), acting solely as vectors, spread MRSA from one patient room to the other. RESULTS: Although porous surfaces became highly contaminated, their low transfer efficiency limited the exposure dose to HCWs and the uncolonized patient. Conversely, the high transfer efficiency of nonporous surfaces allows greater MRSA transfer when touched. In the colonized patient's room, HCW exposure occurred more predominantly through the indirect (patient to surfaces to HCW) mode compared to the direct (patient to HCW) mode. In contrast, in the uncolonized patient's room, patient exposure was more predominant in the direct (HCW to patient) mode compared to the indirect (HCW to surfaces to patient) mode. Surface wiping decreased MRSA exposure to the uncolonized patient more than daily surface decontamination. This was because wiping allowed higher cleaning frequency and cleaned more total surface area per day. CONCLUSIONS: Environmental cleaning should be considered as an integral component of MRSA infection control in hospitals. Given the previously under-appreciated role of surface contamination in MRSA transmission, this intervention mode can contribute to an effective multiple barrier approach in concert with hand hygiene.
Asunto(s)
Infección Hospitalaria/transmisión , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Infecciones Estafilocócicas/transmisión , Infección Hospitalaria/microbiología , Infección Hospitalaria/prevención & control , Descontaminación , Hospitales , Humanos , Higiene , Control de Infecciones , Transmisión de Enfermedad Infecciosa de Profesional a Paciente/prevención & control , Transmisión de Enfermedad Infecciosa de Profesional a Paciente/estadística & datos numéricos , Resistencia a la Meticilina , Staphylococcus aureus Resistente a Meticilina/genética , Staphylococcus aureus Resistente a Meticilina/fisiología , Modelos Biológicos , Infecciones Estafilocócicas/microbiología , Infecciones Estafilocócicas/prevención & controlRESUMEN
We evaluated 19 children using 220-300 mg/m of indinavir (IDV) boosted with 100 mg ritonavir (RTV) (n = 12) or full-dose RTV (n = 7). Geometric mean (GM) (90% confidence interval, CI) of IDV Ctrough in children who took IDV with 100 mg RTV (n = 12) was 0.17 (0.06-0.50) mg/L. For children who took IDV with full-dosage RTV, GM (90% CI) was 0.40 (0.10-1.61) mg/L. C2hours were less than 10 mg/L in all subjects. Eighteen children had good virologic response. This report demonstrates that smaller IDV dosages given with RTV provide efficacious plasma concentrations and can be safely used.
Asunto(s)
Infecciones por VIH/tratamiento farmacológico , Indinavir/administración & dosificación , Ritonavir/administración & dosificación , Terapia Antirretroviral Altamente Activa/métodos , Niño , Sinergismo Farmacológico , Femenino , Infecciones por VIH/sangre , Humanos , Indinavir/sangre , Masculino , Ritonavir/sangre , TailandiaRESUMEN
For over a decade, indinavir has been approved for the treatment of HIV/AIDS; however, following the introduction of new protease inhibitors (PIs) with improved safety and pharmacologic profiles, its use in developed countries has become almost obsolete. In contrast, in resource-limited settings where the majority of people living with HIV/AIDS reside, indinavir is part of the most affordable PI-based highly active antiretroviral treatment regimen. A major drawback of indinavir use is renal toxicity, but low-dose indinavir plus ritonavir (400/100 mg) twice daily is both efficacious and tolerable. Similar low dosing levels in children have also proven successful, but data in pregnant women remains limited. Due to its low cost and proven efficacy indinavir remains a key component of HIV/AIDS treatment in resource-limited settings.
Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/tratamiento farmacológico , Infecciones por VIH/tratamiento farmacológico , Indinavir/uso terapéutico , Ritonavir/uso terapéutico , Síndrome de Inmunodeficiencia Adquirida/economía , Terapia Antirretroviral Altamente Activa/economía , Terapia Antirretroviral Altamente Activa/métodos , Área Bajo la Curva , Países en Desarrollo/economía , Infecciones por VIH/economía , Inhibidores de la Proteasa del VIH/farmacocinética , Inhibidores de la Proteasa del VIH/uso terapéutico , Humanos , Indinavir/química , Indinavir/farmacocinética , Estructura Molecular , Ritonavir/farmacocinéticaRESUMEN
The objective of this study was to evaluate a practical method to assess adherence to antiretroviral therapy by observing virological and immunological responses. We conducted a 12-month longitudinal cohort study of 162 HIV-infected Thai children. Adherence was assessed using 5 methods (self reporting calendar, records of missed doses, pill counts, physician assessment, and an interview questionnaire). CD4 count, percentage and viral load were performed at baseline and at 12 months. Mean adherence rates at 2, 6, and 12 months were 98, 100, and 99% by the calendar method; 98, 100, and 100% by recording missed doses; 96, 96, and 92% by pill count; and 90, 94, and 97% by physician assessment. Poor agreement (kappa < or = 0.1) was found among the methods. There was a statistically significant difference (p = 0.05) in virological response between participants with > or = 95% adherence (0.8 log10) and those with < 95% adherence (0.2 log10) when pill counts were used to assess adherence. In conclusion, despite poor agreement among these tools, a pill count appeared to be the only practical, validated method to differentiate the virological outcome between those who were fully and partially adhere to the treatment regimen.
Asunto(s)
Antirretrovirales/administración & dosificación , Infecciones por VIH/tratamiento farmacológico , Cooperación del Paciente/estadística & datos numéricos , Adolescente , Recuento de Linfocito CD4 , Niño , Preescolar , Estudios de Cohortes , Esquema de Medicación , Femenino , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Humanos , Estudios Longitudinales , Masculino , Estudios Prospectivos , Autoadministración/estadística & datos numéricos , Tailandia , Carga ViralRESUMEN
OBJECTIVE: To evaluate the steady state pharmacokinetics of nevirapine (NVP) in HIV-infected children receiving a fixed-dose combination of stavudine, lamivudine and NVP. METHODS: This cross-sectional study enrolled 34 children (18 girls) who had received GPO-VIR S30 (30 mg stavudine, 150 mg lamivudine and 200 mg NVP) for at least 8 weeks. Tablets were divided into quarter fractions (1/4, 1/2, 3/4 or 1 tablet) to attain the NVP dosages of 120-200 mg/m every 12 h. Plasma NVP levels were measured at predose, and at 2 and 6 h after drug administration. RESULTS: The median age was 8.4 years (range, 3-15). Median CD4 lymphocyte count and percentage at study entry was 576 x 10 cells/l and 20.25%, respectively. The median pharmacokinetics parameters were area under the curve at 12 h, 78.4 h x mug/ml; minimum plasma drug concentration, 5.98 microg/ml; plasma half-life, 25.5 h; apparent oral clearance, 0.079 l/kg per h; and volume of distribution, 2.95 l/kg. Only one child had a minimum plasma drug concentration < 3.4 microg/ml (2.57 microg/ml). Of the 13 children who received GPO-VIR as their first-line regimen, 12 had plasma HIV-1 RNA < 400 copies/ml at 6-18 months, with a median CD4 lymphocyte increase of 216 and 433 x 10 cells/l at 6 and 12 months of treatment, respectively. CONCLUSIONS: The administration of GPO-VIR S30 fixed-dose combination tablets in fractions or as a whole tablet to children resulted in appropriate NVP exposure and satisfactory virological and immunological benefit. This finding confirms the effectiveness of using a fixed-dose combination as a "transitional option" while waiting for a paediatric fixed-dose combination drug formulation.
Asunto(s)
Fármacos Anti-VIH/farmacocinética , Infecciones por VIH/tratamiento farmacológico , Lamivudine/administración & dosificación , Nevirapina/farmacocinética , Estavudina/administración & dosificación , Adolescente , Fármacos Anti-VIH/administración & dosificación , Terapia Antirretroviral Altamente Activa , Niño , Preescolar , Estudios Transversales , Combinación de Medicamentos , Evaluación de Medicamentos , Femenino , Humanos , Lactante , Masculino , Nevirapina/administración & dosificación , ComprimidosRESUMEN
BACKGROUND: The appropriate timing of antiretroviral (ARV) therapy initiation in children with human immunodeficiency virus (HIV) infection has been uncertain. There was evidence of poorer outcome in adults who initiated treatment at lower baseline CD4 cell count. However, early initiation may not be possible in resource-limited setting and would increased risk of long term side effects and non-adherence. OBJECTIVE: To elucidate the outcome of HIV-infected children who ARV treatment was initiated at different disease stages. MATERIAL AND METHOD: Data from medical records of HIV-infected children who had been followed at Infectious Disease Division, Department of Pediatric Siriraj Hospital were retrospectively reviewed. Clinical response and outcome data were analyzed. RESULTS: From September 1996 to March 2004, there were 200 patients with a median age at treatment initiation of 38 (2-175) months. The median duration of follow up period was 26 (1-91) months. The median baseline CD4 cell count was 545 (2-5016) cells/mm3. The median baseline CD4 percentage was 14.25 (0.11-60). Monotherapy or dual nucleoside reverse transcriptase inhibitor (NRTI) regimens were initiated in 134 (67%), and HAARTwas initiated in 66 (33%) patients. The survival rate in patients who initiated with HAART tended to be better than those initiated with dual NRTI regimens but salvaged appropriately (p=0.2377). The survival rate in those initiated treatment at baseline CD4 > or = 15% was better than those initiated at baseline CD4 < 15% (p=0.0471). CONCLUSION: Initiation of ARV treatment at CD4 more than 15% resulted in a better survival rate than at CD4 below 15%. Initiation with HAART regimen tended to improve survival and resulted in higher CD4 gain especially in cases with baseline CD4< 15%.
Asunto(s)
Antirretrovirales/uso terapéutico , Infecciones por VIH/tratamiento farmacológico , Adolescente , Terapia Antirretroviral Altamente Activa , Niño , Preescolar , Femenino , Infecciones por VIH/mortalidad , Humanos , Lactante , Masculino , Estudios Retrospectivos , Análisis de SupervivenciaRESUMEN
BACKGROUND: Increasing number of children with perinatally acquired HIV-infection are now surviving into school age and adolescence. Disclosure of diagnosis to these children has become an important clinical issue. Clinical reports and studies from other countries suggest that a significant number of these children have not been told of their HIV status. The objective of this study was to assess diagnosis disclosure status of perinatally acquired HIV-infected Thai children. MATERIAL AND METHOD: Primary caregivers of 96 HIV-infected children aged 5 years and older were interviewed to assess the child disclosure status and the caregivers reasons to disclose or not to disclose the diagnosis to the child. The disclosed children were also interviewed to assess perception of their illness. RESULTS: Nineteen of 96 children (19.8%) had been told of their HIV diagnosis by their caregivers. The mean age of the disclosed children was 9.6 years. Eighty-four percent of the disclosed children reported perception of their illness as having HIV infection or AIDS. Common reasons for non-disclosing were concerns that the child was too young, that the child might be psychologically harmed, and that the child could not keep the secret. Of 77 non-disclosing caregivers, 54 reported that they plan to disclose HIV status to the children in the future. CONCLUSION: This study demonstrates that diagnosis disclosure was made in only 1/5 of HIV-infected children, and that most of the caregivers were reluctant in disclosing serostatus to the child. Development of an appropriate guideline for assisting the caregivers and the children to deal with the difficult disclosure process is needed.
Asunto(s)
Infecciones por VIH/diagnóstico , Revelación de la Verdad , Adolescente , Niño , Preescolar , Femenino , Infecciones por VIH/psicología , Humanos , Masculino , TailandiaRESUMEN
We report a prospective study of mouse brain derived inactivated Japanese encephalitis (JE) vaccine, given in 3-dose EPI program to human immune deficiency virus (HIV)-exposed Thai infants. 18 HIV-infected receiving antiretroviral therapy with median baseline CD4 of 33.1%, and 92 HIV-uninfected children were studied. All but one HIV-infected child seroconverted after the second dose. The geometric mean titers (GMTs) 3 months after the second and third doses in HIV-infected vs HIV-uninfected children were 247 vs 938 (p=0.022), and 2273 vs 24069 (p=0.009), respectively. Urticaria or angioedema found in 4% and 6% in HIV-infected and -uninfected children, respectively (p=1.0). The vaccine was safe and immunogenic but antibody response in HIV-infected children was not as high as in uninfected children.
Asunto(s)
Anticuerpos Antivirales/sangre , Encefalitis Japonesa/prevención & control , Infecciones por VIH/virología , Vacunas contra la Encefalitis Japonesa/inmunología , Anticuerpos Antivirales/inmunología , Formación de Anticuerpos , Preescolar , Encefalitis Japonesa/inmunología , Femenino , Infecciones por VIH/inmunología , Humanos , Inmunización Secundaria , Lactante , Vacunas contra la Encefalitis Japonesa/administración & dosificación , Masculino , Estudios Prospectivos , TailandiaRESUMEN
BACKGROUND: Pediatric fixed-dose combinations (FDCs) are needed to facilitate antiretroviral therapy in children. We evaluated the relative bioavailability, safety, and therapeutic adequacy of a novel chewable pediatric FDC tablet of stavudine (7 mg), lamivudine (30 mg), and nevirapine (50 mg), referred to as GPO-VIR S7, and compared it with the individual original brand-name liquid formulations in human immunodeficiency virus-infected Thai children. METHODS: The International Maternal Pediatric Adolescent AIDS Clinical Trials group (IMPAACT) P1056 study was a phase I/II, 2-arm, randomized, open-label, multidose pharmacokinetic cross-over study. Children ≥6 to ≤30 kg receiving nevirapine-based HAART for at least 4 weeks were randomized to receive GPO-VIR S7 chewable tablets or the equivalent liquid formulations. Children were stratified by weight and dosing was weight-based. Intensive 12-hour blood sampling was performed on day 28, and subjects then crossed-over to the alternate formulation at equal doses with identical 12-hour sampling on day 56. Pharmacokinetic indices were determined by noncompartmental analysis. RESULTS: Thirty-four children completed the study. While taking Government Pharmaceutical Organization (GPO)-VIR S7 the geometric mean (90% CI) area under the curve was 1.54 µg·hr/mL (1.42-1.67) for stavudine, 6.39 (5.82-7.00) for lamivudine, and 74.06 (65.62-83.60) for nevirapine. Nevirapine drug exposure for GPO-VIR S7 was therapeutically adequate. Geometric mean area under the curve ratios (90% CI) of GPO-VIR S7/liquid formulation for stavudine, lamivudine, and nevirapine were 0.97 (0.92-1.02), 1.41 (1.30-1.53), and 1.08 (1.04-1.13), respectively. No serious drug-related toxicity was reported. CONCLUSIONS: The chewable FDC was safe and provided therapeutically adequate plasma drug exposures in human immunodeficiency virus-infected children. Substituting the FDC for liquid formulations can simplify antiretroviral therapy.
Asunto(s)
Fármacos Anti-VIH/farmacocinética , Infecciones por VIH/tratamiento farmacológico , Lamivudine/farmacocinética , Nevirapina/farmacocinética , Estavudina/farmacocinética , Administración Oral , Fármacos Anti-VIH/administración & dosificación , Fármacos Anti-VIH/efectos adversos , Niño , Preescolar , Estudios Cruzados , Femenino , Humanos , Lactante , Lamivudine/administración & dosificación , Lamivudine/efectos adversos , Masculino , Nevirapina/administración & dosificación , Nevirapina/efectos adversos , Plasma/química , Estavudina/administración & dosificación , Estavudina/efectos adversos , Comprimidos/administración & dosificación , Comprimidos/efectos adversos , TailandiaRESUMEN
We tested 109 unique, vancomycin-susceptible, methicillin-resistant Staphylococcus aureus (MRSA) strains for vancomycin heteroresistance by a selection method, i.e., step-wise exposure of large inoculums to increasing concentrations of vancomycin. Although no strains demonstrated stable heteroresistance, 81 strains (74%) demonstrated unstable heteroresistance. Unstable heteroresistance is common among clinical isolates of MRSA and may represent a cause of therapeutic failure.
Asunto(s)
Farmacorresistencia Bacteriana , Resistencia a la Meticilina , Staphylococcus aureus/efectos de los fármacos , Vancomicina/farmacología , Adulto , Niño , Humanos , Pruebas de Sensibilidad Microbiana , Infecciones Estafilocócicas/tratamiento farmacológico , Staphylococcus aureus/aislamiento & purificación , Staphylococcus aureus/ultraestructuraRESUMEN
Increasing numbers of patients are treated with mega-highly active antiretroviral therapy (HAART), or multiple-combination antiretroviral therapy, in an attempt to overcome the viral resistance that has contributed to treatment failure. Studies of human immunodeficiency virus (HIV) viral dynamics are used to quantify the potency of a given regimen. While mega-HAART is expected to provide potent therapy, its potency among heavily experienced HIV-infected children who have failed previous treatment is untested. HIV dynamics studies performed in children have provided minimal information on viral dynamics during mega-HAART. The present study estimates first- and second-phase viral dynamics in six children on mega-HAART, following failure of combination therapy. The first phase of viral decay was rapid, relative to rates reported in previous pediatric studies (median delta = 0.778d(-1), range = 0.583 to 1.088, half-life 1 [t1(1/2)] = 0.894d), while the second phase revealed results similar to those of previous studies (median mu = 0.026d(-1), range = -0.005 to 0.206, t2(1/2) = 9.316d). This indicates that mega-HAART can provide potent therapy among heavily experienced pediatric patients.