Diagnosis Of Infections In Infants Research Articles

Challenges in the Early Infant HIV Diagnosis and Treatment Cascade.

The first step in improving morbidity and mortality among children living with HIV is the timely and early identification of HIV infection, which must be followed by rapid engagement in care and provision of antiretroviral therapy. However, in 2018, only 59% of HIV-exposed infants received an infant nucleic acid diagnostic test by age 2 months and only 54% of children living with HIV received treatment. Because infant diagnosis requires molecular techniques to detect viral nucleic acid, programs for early diagnosis of infection in infants are more complex than those in adults and often require coordination and management of multiple health facilities as well as logistic, financial, and human resource challenges. This article will discuss challenges at each step in the early infant diagnosis cascade and innovations that may help overcome these challenges.

Optimal bacterial colony counts for the diagnosis of upper urinary tract infections in infants.

There are no consensus criteria for diagnosing upper urinary tract infections (UTI). Therefore, we conducted a study to assess whether bacterial colony counts of ≥ 103CFU/ml are optimal for diagnosing upper UTIs among infants. This retrospective observational study included 673 patients (<4months of age) with urine samples obtained by catheterization for bacterial cultures. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were obtained when cutoff values of 103, 104, and 105CFU/ml were used for diagnosing upper UTIs. Upper UTI patients were divided based on cutoff values: Group A (103CFU/ml), Group B (104CFU/ml), and Group C (≥ 105CFU/ml). Of the 197 positive (≥ 103CFU/ml) patients, 92 were diagnosed with an upper UTI. These patients were divided into Group A (n = 23), Group B (n = 16), and Group C (n = 53). No significant differences were detected in terms of clinical findings, including the incidence of vesicoureteral reflex. When cutoff values of 103, 104, and 105CFU/ml were used for diagnosing upper UTIs, the sensitivity/specificity percentages were 100/81.3, 75.0/95.9, and 57.6/97.5, and the PPVs/NPVs were 46.7/100, 75.0/95.9, and 79.1/93.4. Using ≥ 105CFU/ml as a diagnostic threshold leads to approximately 40% of positive cases being missed. In contrast when ≥ 103CFU/ml is used, all upper UTIs were identified. Therefore, bacterial colony counts of ≥ 103CFU/ml should be considered the cutoff value for the diagnosis of upper UTIs in infants (< 4months of age).

Point-of-care tests detecting HIV nucleic acids for diagnosis of HIV infection in infants and children aged 18 months or less

Point-of-care tests detecting HIV nucleic acids for diagnosis of HIV infection in infants and children aged 18 months or less

Prevalence of congenital cytomegalovirus infection in symptomatic newborns under 3\xa0weeks in Tehran, Iran

BackgroundCytomegalovirus (CMV) is a common cause of congenital infection worldwide and infants with symptomatic congenital CMV (cCMV) infection are at significantly increased risk of developing adverse long-term outcomes. This study aimed to determine the prevalence of cCMV infections in symptomatic infants under 3 weeks in Tehran, IRAN and to evaluate the usefulness of serologic markers in these neonates.MethodsUrine and serum samples of 100 symptomatic infants, under 3 weeks old, with clinical signs referred to Tehran medical centers from June 2013 to December 2014, were collected and tested for CMV-DNA and IgG/IgM antibody titers by PCR and ELISA, respectively.ResultsCMV-DNA was detected in urine of 58 cases, whereas only 20 cases had detectable CMV-IgM titers. All CMV-IgM positive cases excreted CMV-DNA through their urine. Of the 100 patients, only 59 had CMV-IgG antibody and CMV-DNA was found in the urine of only 40 of them.ConclusionsWe conclude that CMV is an important etiologic agent of congenital infections in symptomatic infants in Tehran, IRAN (prevalence: 58%) and CMV-DNA detection immediately after delivery is recommended for early treatment and reduction of post infection problems. Furthermore, our study showed that the serologic markers are unreliable for diagnosis of cCMV infection in infants. This is the first report of cCMV prevalence in symptomatic congenital infections in Iran showing similarity with the world averages.

Early infant diagnosis of HIV-1 infection in Luanda, Angola, using a new DNA PCR assay and dried blood spots.

BackgroundEarly diagnosis and treatment reduces HIV-1-related mortality, morbidity and size of viral reservoirs in infants infected perinatally. Commercial molecular tests enable the early diagnosis of infection in infants but the high cost and low sensitivity with dried blood spots (DBS) limit their use in sub-Saharan Africa.ObjectivesTo develop and validate a sensitive and cheap qualitative proviral DNA PCR-based assay for early infant diagnosis (EID) in HIV-1-exposed infants using DBS samples.Study designChelex-based method was used to extract DNA from DBS samples followed by a nested PCR assay using primers for the HIV-1 integrase gene. Limit of detection (LoD) was determined by Probit regression using limiting dilutions of newly produced recombinant plasmids with the integrase gene of all HIV-1 subtypes and ACH-2 cells. Clinical sensitivity and specificity were evaluated on 100 HIV-1 infected adults; 5 infected infants; 50 healthy volunteers; 139 HIV-1-exposed infants of the Angolan Pediatric HIV Cohort (APEHC) with serology at 18 months of life.ResultsAll subtypes and CRF02_AG were amplified with a LoD of 14 copies. HIV-1 infection in infants was detected at month 1 of life. Sensitivity rate in adults varied with viral load, while diagnostic specificity was 100%. The percentage of HIV-1 MTCT cases between January 2012 and October 2014 was 2.2%. The cost per test was 8-10 USD which is 2- to 4-fold lower in comparison to commercial assays.ConclusionsThe new PCR assay enables early and accurate EID. The simplicity and low-cost of the assay make it suitable for generalized implementation in Angola and other resource-constrained countries.

Evaluation of a single round polymerase chain reaction assay using dried blood spots for diagnosis of HIV-1 infection in infants in an African setting

BackgroundThe aim of this study was to develop an economical 'in-house' single round polymerase chain reaction (PCR) assay using filter paper-dried blood spots (FP-DBS) for early infant HIV-1 diagnosis and to evaluate its performance in an African setting.MethodsAn 'in-house' single round PCR assay that targets conserved regions in the HIV-1 polymerase (pol) gene was validated for use with FP-DBS; first we validated this assay using FP-DBS spiked with cell standards of known HIV-1 copy numbers. Next, we validated the assay by testing the archived FP-DBS (N = 115) from infants of known HIV-1 infection status. Subsequently this 'in-house' HIV-1 pol PCR FP-DBS assay was then established in Nairobi, Kenya for further evaluation on freshly collected FP-DBS (N = 186) from infants, and compared with findings from a reference laboratory using the Roche Amplicor® HIV-1 DNA Test, version 1.5 assay.ResultsThe HIV-1 pol PCR FP-DBS assay could detect one HIV-1 proviral copy in 38.7% of tests, 2 copies in 46.9% of tests, 5 copies in 72.5% of tests and 10 copies in 98.1% of tests performed with spiked samples. Using the archived FP-DBS samples from infants of known infection status, this assay was 92.8% sensitive and 98.3% specific for HIV-1 infant diagnosis. Using 186 FP-DBS collected from infants recently defined as HIV-1 positive using the commercially available Roche Amplicor v1.5 assay, 178 FP-DBS tested positive by this 'in-house' single-round HIV-1 pol PCR FP-DBS PCR assay. Upon subsequent retesting, the 8 infant FP-DBS samples that were discordant were confirmed as HIV-1 negative by both assays using a second blood sample.ConclusionsHIV-1 was detected with high sensitivity and specificity using both archived and more recently collected samples. This suggests that this 'in-house' HIV-1 pol FP-DBS PCR assay can provide an alternative cost-effective, reliable and rapid method for early detection of HIV-1 infection in infants.

CD4+/CD8+ T Cell Ratio for Diagnosis of HIV-1 Infection in Infants: Women and Infants Transmission Study

CD4+/CD8+ T Cell Ratio for Diagnosis of HIV-1 Infection in Infants: Women and Infants Transmission Study

Qualitative Human Immunodeficiency Virus RNA Analysis of Dried Blood Spots for Diagnosis of Infections in Infants

Qualitative Human Immunodeficiency Virus RNA Analysis of Dried Blood Spots for Diagnosis of Infections in Infants

Early diagnosis of HIV-1 infection in infants using RNA Quantitative PCR in Burkina Faso

Materials and methods From January to December 2008, 114 infants born to HIV-1 infected mothers were referred to the University Hospital Yalgado Ouedraogo (Ouagadougou, Burkina Faso), for early diagnosis of HIV infection. Two to 3 mL of blood sample were collected on EDTA/K3 microtubes from each infant. After centrifugation, the plasma samples were stored at -80°C, until their use. HIV-1 RNA was detected in each sample using Abbott RealTime HIV-1 Assay (Abbott Molecular) and m2000rt protocol: the RNA detection threshold was 40 copies/mL (1.6 Log). From each infant with RNA positive result, a second plasma sample was collected 4 weeks later to confirm the previous RNA result Sociodemographic data were collected from the infants and analysed.

Qualitative Human Immunodeficiency Virus RNA Analysis of Dried Blood Spots for Diagnosis of Infections in Infants

The Gen-Probe Aptima human immunodeficiency virus type 1 (HIV-1) RNA assay was adapted for the diagnosis of HIV infection in infants by using dried blood spots. The assay was 99% sensitive (128/129) and 100% specific (162/162). This may prove useful in resource-limited settings, since it precludes the need for a phlebotomist and maintenance of a cold chain.

The New Challenges in management of HIV-infected patients

Dramatic advances in prevention and treatment of pediatric HIV infection occur in high-resource countries, but only 1% of the 2.3 million HIV-infected children live in these regions. Thus, two pediatric HIV epidemics have evolved, one in high-resource countries and one in low-resource countries. About the first epidemic, effective antiretroviral therapies for HIV in children have prolonged life and quality of life. As in adults, there has been evolution in causes of death over time, with decrease in AIDS-opportunistic infections and increase in ‘end-stage AIDS’ multiorgan failure, sepsis, and renal disease. In addition, spectrum of disease has changed: drug resistance (primary and acquired), lack of salvage drugs for children, complications of therapy, adherence, mental health, and adolescence-transition to adult care are the main problems that have emerged in the last years. In low-resource countries, few women know they are infected and there is poor access to antiretrovirals to prevent mother-to-child transmission, so children often present to health system with advanced disease and about 1000 infants are newly infected each day. Moreover, both diagnosis of infection in infants and drug access remain problematic: despite rapid progression and high mortality due to HIV in children, few receive treatment and, when available, it is started late. In this current evolving clinical context, we reviewed the epidemiology, clinical features, and treatment-related infectious complications of these two HIV-related epidemics.

Hepatitis B vaccine efficacy in HCV vertical infected infants

Patients and methods 105 infants born to HCV infected mothers were vaccinated against hepatitis B virus (recombinant vaccine, 10 μg, 0-1-6 month schedule). The diagnosis of HCV infection in infants was based on positive viral RNA in serum by PCR (Amplicor v 2,0 Roche) on at least two separate speciments in the first year of life. HCV infection was confirmed in 18 children. 87 children who were HCV uninfected formed the control group. Anti-HBs titers were measured 3-6 months after the third dose of immunization in HCV infected children and in control group. Seroconversion was considered if anti-HBs level was ≥ 10 mIU/mL. Non-responders were tested for HBV infection by PCR.

A Reverse Transcriptase Assay for Early Diagnosis of Infant HIV Infection in Resource-limited Settings

Early diagnosis of pediatric HIV infection is confounded by persistence of maternal antibodies until 18 months, necessitating the use of expensive assays such as HIV-1 DNA PCR, an untenable option in resource-limited settings. This is the first report of a low-cost, commercial, reverse transcriptase (RT) assay for the diagnosis of HIV-1 infection in infants. RT assays were performed on 42 samples from 30 HIV-exposed Kenyan infants under 15 months of age. When correlated with serologic testing conducted after 18 months, the sensitivity, specificity, positive and negative predictive values of the RT assay were 92%, 93%, 87% and 96%. A low-cost assay for infant HIV diagnosis is urgently needed, and these results merit further evaluation.

PEDIATRIC HIV INFECTION: DIAGNOSTIC LABORATORY METHODS

The diagnosis of HIV-1 infection in infants and children continues to present challenges. Currently available virologic assays are sensitive and specific and allow early detection of perinatally acquired HIV infection. Identification soon after birth allows for the rapid initiation of antiretroviral therapy and preservation of the infant's immune system. Serologic diagnostic methods, including HIV-ELISA, Western blot, and immunofluorescence Assay can be used to make the diagnosis of HIV infection in infants older than 18 months of age, children, and adolescents. Recently developed rapid tests allow for testing outside clinical sites, provide results in a short period of time, and allow for prompt initiation of effective prophylaxis in cases of exposure particularly maternal to child transmission. We discuss here the diagnostic management of HIV-exposed infants and HIV-infected children.

Signal-Boosted Qualitative Ultrasensitive p24 Antigen Assay for Diagnosis of Subtype C HIV-1 Infection in Infants Under the Age of 2 Years

The gold standard for diagnosis of HIV-1 infection in infants under the age of 2 years is DNA or reverse transcriptase polymerase chain reaction. However, these tests are expensive and therefore not available in resource-limited countries. With the increasing availability of antiretroviral drugs for prevention of mother-to-child transmission of HIV and treatment of AIDS in resource-poor countries, there is an urgent need to develop cheaper, alternative, and cost-effective laboratory methods for early diagnosis of infant HIV-1 infection that will be useful in identifying infected infants who may benefit from early cotrimoxazole prophylaxis or commencement of antiretroviral therapy. We evaluated an alternative method, the enzyme-linked immunosorbent assay-based qualitative ultrasensitive p24 antigen assay for diagnosis of subtype C HIV-1 infection in infants under the age of 2 years using DNA polymerase chain reaction as the reference method. The assay showed a sensitivity of 96.7% (95% CI: 93.0-100) for detection of HIV-1 infection among infants 0-18 months of age with a specificity of 96.1% (95% CI: 91.7-100). These evaluated parameters were not statistically different between infants aged 0-6 and 7-18 months. The ultrasensitive p24 antigen assay is a useful diagnostic test for detection of HIV-1 infection among infants aged 0-18 months.

T lymphocytes among HIV-infected and -uninfected infants: CD4/CD8 ratio as a potential tool in diagnosis of infection in infants under the age of 2 years

BackgroundSerologic tests for HIV infection in infants less than 18 months do not differentiate exposure and infection since maternally acquired IgG antibodies may be detected in infants. Thus, the gold standard for diagnosis of HIV-1 infection in infants under the age of 2 years is DNA or reverse transcriptase polymerase chain reaction. There is an urgent need to evaluate alternative and cost effective laboratory methods for early diagnosis of infant HIV-1 infection as well as identifying infected infants who may benefit from cotrimoxazole prophylaxis and/or initiation of highly active antiretroviral therapy.MethodsWhole blood was collected in EDTA from 137 infants aged 0 to 18 months. DNA polymerase chain reaction was used as the reference standard for diagnosis of HIV-1 infection. T-cell subset profiles were determined by flow cytometry.ResultsSeventy-six infants were DNA PCR positive while 61 were negative. The median CD4 counts of PCR negative infants were significantly higher than those of the PCR positive infants, p < 0.001. The median CD4/CD8 ratio and the %CD4 of the PCR positive infants were both significantly lower than those of the negative infants, p < 0.001. The CD4/CD8 ratio had a >98% sensitivity for diagnosis of HIV-1 infection and a specificity of >98%.ConclusionThe CD4/CD8 ratio appears useful in identifying HIV-infected infants. The development of lower cost and more robust flow cytometric methods that provide both CD4/CD8 ratio and %CD4 may be cost-effective for HIV-1 diagnosis and identification of infants for cotrimoxazole prophylaxis and/or highly active antiretroviral therapy.

Affordable diagnosis of human immunodeficiency virus infection in infants by p24 antigen detection.

The expense of PCR testing limits diagnosis of HIV infection in infancy in low resource settings. The ultrasensitive p24 antigen assay has been proposed as an accurate substitute; however, its ability to detect different HIV viral subtypes remains to be determined. A sensitivity of 98.1% and specificity of 98.7% was obtained testing 203 samples from 24 HIV-infected and 66 uninfected infants born to HIV subtype C-infected women.

IgA antibodies to human immunodeficiency virus in serum, saliva and urine for early diagnosis of immunodeficiency virus infection in Ugandan infants.

The value of HIV-1 IgA antibodies for early diagnosis of HIV infection in infants in serum, saliva and urine was investigated at Mulago Hospital, Kampala. Sensitivity and specificity in serum of HIV-infected infants at different ages were: 0 to 1 months, 88 and 95%; 1 to 3 months, 88 and 97%; 4 to 6 months, 80 and 96%. They decreased between 67 and 77% and 80 to 91%, respectively, in older age groups. Sensitivity for saliva was lower (53 to 79%) and urine only 37 to 62%, although specificity was reasonably high (>85%). The high proportion of infants with raised HIV IgA in the first months of life (88%) may represent prenatal infection. Sensitivity of serum and especially salivary and urinary HIV IgA is too low to be of practical value for early diagnosis of HIV infection in infants.

Suprapubic aspiration of urine in the diagnosis of urinary tract infection in infants

Suprapubic aspiration of urine in the diagnosis of urinary tract infection in infants

Evaluation of a human immunodeficiency virus specific IgA capture enzyme immunoassay for the diagnosis of human immunodeficiency virus infection in infants.

Evaluation of a human immunodeficiency virus specific IgA capture enzyme immunoassay for the diagnosis of human immunodeficiency virus infection in infants.