Effect of presumptive co-trimoxazole prophylaxis on pneumococcal colonization rates, seroepidemiology and antibiotic resistance in Zambian infants: a longitudinal cohort study

Exploring the pediatric nasopharyngeal bacterial microbiota with culture-based MALDI-TOF mass spectrometry and targeted metagenomic sequencing

The nasopharynx is an important reservoir of disease-associated and antimicrobial-resistant bacterial species. This proof-of-concept study assessed the utility of a combined culture, matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), and targeted metagenomic sequencing workflow for the study of the pediatric nasopharyngeal bacterial microbiota. Nasopharyngeal swabs and clinical metadata were collected from Cambodian children during a hospital outpatient visit and then biweekly for 12 weeks. Swabs were cultured on chocolate and blood-gentamicin agar, and all colony morphotypes were identified by MALDI-TOF MS. Metagenomic sequencing was done on a scrape of all colonies from a chocolate agar culture and processed using the mSWEEP pipeline. One hundred one children were enrolled, yielding 620 swabs. MALDI-TOF MS identified 106 bacterial species/40 genera: 20 species accounted for 88.5% (2,190/2,474) of isolates. Colonization by Moraxella catarrhalis (92.1% of children on ≥1 swab), Haemophilus influenzae (87.1%), and Streptococcus pneumoniae (83.2%) was particularly common. In S. pneumoniae-colonized children, a median of two serotypes [inter-quartile range (IQR) 1-2, range 1-4] was detected. For the 21 bacterial species included in the mSWEEP database and identifiable by MALDI-TOF, detection by culture + MALDI-TOF MS and culture + mSWEEP was highly concordant with a median species-level agreement of 96.9% (IQR 86.8%-98.8%). mSWEEP revealed highly dynamic lineage-level colonization patterns for S. pneumoniae which were quite different to those for S. aureus. A combined culture, MALDI-TOF MS, targeted metagenomic sequencing approach for the exploration of the young child nasopharyngeal microbiome was technically feasible, and each component yielded complementary data.

IMPORTANCE

The human upper respiratory tract is an important source of disease-causing and antibiotic-resistant bacteria. However, understanding the interactions and stability of these bacterial populations is technically challenging. We used a combination of approaches to determine colonization patterns over a 3-month period in 101 Cambodian children. The combined approach was feasible to implement, and each component gave complementary data to enable a better understanding of the complex patterns of bacterial colonization.

Co-trimoxazole prophylaxis for children who are HIV-exposed and uninfected: a systematic review

INTRODUCTION

Co-trimoxazole prophylaxis is recommended for children born to women with HIV to protect those who acquire HIV from opportunistic infections, severe bacterial infections and malaria. With scale-up of maternal antiretroviral therapy, most children remain HIV-exposed uninfected (HEU) and the benefits of universal co-trimoxazole are uncertain. We assessed the effect of co-trimoxazole on mortality and morbidity of children who are HEU.

METHODS

We performed a systematic review (PROSPERO number: CRD42021215059). We systematically searched MEDLINE, Embase, Cochrane CENTRAL, Global Health, CINAHL Plus, Africa-Wide Information, SciELO and WHO Global Index Medicus for peer-reviewed articles from inception to 4th January 2022 without limits. Ongoing randomized controlled trials (RCTs) were identified through registries. We included RCTs reporting mortality or morbidity in children who are HEU receiving co-trimoxazole versus no prophylaxis/placebo. The risk of bias was assessed using the Cochrane 2.0 tool. Data were summarized using narrative synthesis and findings were stratified by malaria endemicity.

RESULTS

We screened 1257 records and included seven reports from four RCTs. Two trials from Botswana and South Africa of 4067 children who are HEU found no difference in mortality or infectious morbidity in children randomized to co-trimoxazole prophylaxis started at 2-6 weeks of age compared to those randomized to placebo or no treatment, although event rates were low. Sub-studies found that antimicrobial resistance was higher in infants receiving co-trimoxazole. Two trials in Uganda investigating prolonged co-trimoxazole after breastfeeding cessation showed protection against malaria but no other morbidity or mortality differences. All trials had some concerns or a high risk of bias, which limited the certainty of evidence.

DISCUSSION

Studies show no clinical benefit of co-trimoxazole prophylaxis in children who are HEU, except to prevent malaria. Potential harms were identified for co-trimoxazole prophylaxis leading to antimicrobial resistance. The trials in non-malarial regions were conducted in populations with low mortality potentially reducing generalizability to other settings.

CONCLUSIONS

In low-mortality settings with few HIV transmissions and well-performing early infant diagnosis and treatment programmes, universal co-trimoxazole may not be required.

Antimicrobial resistance from a One Health perspective in Zambia: a systematic review

BACKGROUND

Antimicrobial resistance (AMR) is widely acknowledged as a global health problem, yet its extent is not well evaluated, especially in low-middle income countries. It is challenging to promote policies without focusing on healthcare systems at a local level, therefore a baseline assessment of the AMR occurrence is a priority. This study aimed to look at published papers relating to the availability of AMR data in Zambia as a means of establishing an overview of the situation, to help inform future decisions.

METHODS

PubMed, Cochrane Libraries, Medical Journal of Zambia and African Journals Online databases were searched from inception to April 2021 for articles published in English in accordance with the PRISMA guidelines. Retrieval and screening of article was done using a structured search protocol with strict inclusion/exclusion criteria.

RESULTS

A total of 716 articles were retrieved, of which 25 articles met inclusion criteria for final analysis. AMR data was not available for six of the ten provinces of Zambia. Twenty-one different isolates from the human health, animal health and environmental health sectors were tested against 36 antimicrobial agents, across 13 classes of antibiotics. All the studies showed a degree of resistance to more than one class of antimicrobials. Majority of the studies focused on antibiotics, with only three studies (12%) highlighting antiretroviral resistance. Antitubercular drugs were addressed in only five studies (20%). No studies focused on antifungals. The most common organisms tested, across all three sectors, were Staphylococcus aureus, with a diverse range of resistance patterns found; followed by Escherichia coli with a high resistance rate found to cephalosporins (24-100%) and fluoroquinolones (20-100%).

CONCLUSIONS

This review highlights three important findings. Firstly, AMR is understudied in Zambia. Secondly, the level of resistance to commonly prescribed antibiotics is significant across the human, animal, and environmental sectors. Thirdly, this review suggests that improved standardization of antimicrobial susceptibility testing in Zambia could help to better delineate AMR patterns, allow comparisons across different locations and tracking of AMR evolution over time.

Primary antibiotic resistance of Helicobacter pylori isolates is twofold more frequent in HIV-positive than HIV-negative individuals: A descriptive observational study

The antimicrobial susceptibility of Helicobacter pylori strains isolated from HIV-positive individuals is not well characterized. This study aimed to measure the prevalence and long-term trends associated with primary H. pylori antibiotic resistance, evaluate correlations with antibiotic consumption, and compare predictors for H. pylori antibiotic resistance between HIV-positive and HIV-negative individuals. In this longitudinal registry study, we evaluated consecutive adults with and without HIV infection, naïve to H. pylori treatment, who underwent upper gastrointestinal endoscopy and had a positive H. pylori culture, with susceptibility testing available, between 2004 and 2015. Outpatient antibiotic consumption data were based on nationwide aggregated numbers. H. pylori was isolated from gastric biopsies of 3008/8321 patients, 181/477 (37.9%) were HIV-positive and 2827/7844 (36.0%) HIV-negative. Overall cohort mean prevalence of H. pylori primary antibiotic resistance was 11.1% for clarithromycin, 17.8% levofloxacin, and 39.4% metronidazole. The prevalence of H. pylori primary resistance was significantly higher for these three drugs in HIV-positive individuals across the study period. Linear regression showed that the prevalence of clarithromycin and levofloxacin resistance correlated with the country aggregate daily dose consumption of macrolides and quinolones, respectively. Multivariable regression analysis showed that HIV infection is a strong independent risk factor for multiple H. pylori antibiotic resistance. In summary, HIV infection is a risk factor for carrying multi-resistant H. pylori strains and this is correlated with antibiotic consumption. Empirical therapies should be avoided in HIV-positive individuals. These data highlight the need to implement ongoing monitoring of H. pylori antimicrobial susceptibility among HIV-positive individuals. The study is registered at ISRCTN registry, number 13466428: https://www.isrctn.com/ISRCTN13466428.

Impact of mass and systematic antibiotic administration on antibiotic resistance in low- and middle-income countries? A systematic review

Antibiotic consumption is a key driver of antimicrobial resistance (AR), particularly in low- and middle-income countries (LMICs) where risk factors for AR emergence and spread are prevalent. However, the potential contribution of mass drug administration (MDA) and systematic drug administration (SDA) of antibiotics to AR spread is unknown. We conducted a systematic review to provide an overview of MDA/SDA in LMICs, including indications, antibiotics used and, if investigated, levels of AR over time. This systematic review is reported in accordance with the PRISMA statement. Of 2438 identified articles, 63 were reviewed: indications for MDA/SDA were various, and targeted populations were particularly vulnerable, including pregnant women, children, human immunodeficiency virus (HIV)-infected populations, and communities in outbreak settings. Available data suggest that MDA/SDA may lead to a significant increase in AR, especially following azithromycin administration. However, only 40% of studies evaluated AR. Integrative approaches that evaluate AR in addition to clinical outcomes are needed to understand the consequences of MDA/SDA implementation, combined with standardised AR surveillance for timely detection of AR emergence.

A Tale of 2 Pneumos: The Impact of Human Immunodeficiency Virus Exposure or Infection Status on Pediatric Nasopharyngeal Carriage of Streptococcus pneumoniae and Pneumocystis jiroveci: A Nested Case Control Analysis From the Pneumonia Etiology Research In Child Health Study

BACKGROUND

The majority of pediatric human immunodeficiency virus (HIV) cases in Africa reflect maternal-to-child transmission. HIV exposed but uninfected (HEU) children have increased rates of morbidity and mortality when compared to HIV unexposed and uninfected (HUU) children. The mechanisms behind these unexpected trends are only partially understood but could be explained by the differences in the immune response to infections triggered by an altered immune system state.

METHODS

Using quantitative reverse transcription polymerase chain reaction, we compared the nasopharyngeal carriage prevalence and density of Streptococcus pneumoniae (SP) and Pneumocystis jirovecii (PJ) between children living with HIV and HEU or HUU cases (pneumonia) and controls (without pneumonia).

RESULTS

The cohort included 1154 children (555 cases and 599 matched controls). The SP carriage prevalence rates were similar between cases and controls. Among SP carriers with pneumonia, carriage density was increased among children living with HIV, versus HEU or HUU children (15.8, 4.7, and 3.6 × 105 copies/mL, respectively). The rate of PJ carriage was significantly higher among children living with HIV than among HEU and HUU children (31%, 15%, and 10%, respectively; P < .05), as was carriage density (63.9, 20.9, and 4.8 × 103 copies/mL, respectively; P < .05).

CONCLUSIONS

Carriage prevalences and densities for SP and PJ show different kinetics in terms of their relationship with HIV exposure and clinical status, particularly for Pneumocystis jirovecii. This supports the theory that the increased morbidity and mortality observed among HEU children may reflect deficits not just in humoral immunity but in cell-mediated immunity as well.

Does cotrimoxazole prophylaxis in HIV patients increase the drug resistance of pneumococci? A comparative cross-sectional study in southern Ethiopia

BACKGROUND

Infections caused by antibiotic-resistant bacteria results in high rates of morbidity and mortality. Although the prolonged cotrimoxazole (CTX) prophylaxis is arguably associated with the risk of increasing drug resistance in the common pathogens, information regarding its impact on Streptococci pneumoniae / pneumococcus is very limited.

OBJECTIVE

This study was conducted to investigate the effect of cotrimoxazole prophylaxis on nasopharyngeal colonization rate and antimicrobial resistance using Streptococci pneumoniae (pneumococcus) as an indicator organism among HIV patients in Arba Minch, Ethiopia.

MATERIALS AND METHODS

A comparative cross-sectional study was designed and conducted among HIV patients attending the Anti-Retroviral Treatment (ART) clinic of Arba Minch General Hospital (AMGH) from April 01 to August 31, 2018. A total of 252 participants were systematically selected and clustered into two study groups based on their CTX prophylaxis status, one taking CTX prophylaxis, and the second one, the control group (without prophylaxis). A structured questionnaire was used to collect socio-demographic and clinical data from patients. A nasopharyngeal swab was collected and cultured for pneumococcal isolation and identification in accordance with standard microbiological techniques. An antibiotics sensitivity test was performed according to the CLSI guidelines. Data were analyzed using the Statistical package for social science (SPSS) version 20. The primary outcome was determined using logistic regression analysis.

RESULTS

Of the 252 enrolled HIV patients (mean age (37.38± 9.03 years), 144 (57.14%) were males. The overall, nasopharyngeal colonization rate of S. pneumoniae was 13.5% (95% CI: 8.4-15.6). Asymptomatic pneumococcal carriage rates among patients on CTX prophylaxis and the control group were 16.3%, and 10.3% respectively (p-value = 0.03). Regarding the risk factors analyzed, CTX prophylaxis (AOR: 2.2; 95% CI: 1.05-4.9) and gender (AOR: 2.5; 95% CI: 1.09-5.93) were significantly associated with pneumococcal colonization, showing a male preponderance. Cotrimoxazole-resistant pneumococci were 85.7% vs. 47.4% in the prophylaxis group and the control group respectively and it was statistically significant (AOR: 6.7; 95% CI: 1.3-36). Percentages of multi-drug resistant isolates in these two groups were 38.09 and 15.38 respectively (p-value = 0.04). Among the CTX resistant pneumococci isolates, 85% were also found to be co-resistant towards penicillin and was statistically significant.

CONCLUSION

The percentage prevalence of nasopharyngeal pneumococci colonization was higher in patients taking CTX prophylaxis. It was noted that CTX prophylaxis eventually results in the selection of cotrimoxazole resistance and multi-drug resistance in pneumococci. There is evidence of existing cross-resistance between cotrimoxazole and penicillin antibiotics. Therefore, CTX prophylaxis must be administered judiciously. Surveillance for antimicrobial susceptibility is warranted where the prophylaxis is common.

High rate of antimicrobial resistance and multiple mutations in the dihydrofolate reductase gene among Streptococcus pneumoniae isolated from HIV-infected adults in a community setting in Tanzania

OBJECTIVES

The aim of this study was to characterize molecular mechanisms of resistance to trimethoprim and other antibiotics in Streptococcus pneumoniae isolates from HIV-infected adults in Dar es Salaam, Tanzania.

METHODS

A total of 1877 nasopharyngeal swabs were collected and screened for pneumococcal colonization from 537 newly diagnosed individuals with HIV at four clinic visits during a 1-year follow-up from 2017-2018 as part of the randomized clinical trial CoTrimResist (ClinicalTrials.gov ID: NCT03087890).

RESULTS

A total of 76 pneumococcal isolates were obtained. Of the 70 isolates that could be serotyped, 42 (60.0%) were vaccine serotypes included in pneumococcal conjugate vaccine 23 (PCV23). The majority of isolates (73.7%; 56/76) were non-susceptible to penicillin (MICs of 0.06-2μg/mL). Isolates were frequently resistant to co-trimoxazole (trimethoprim/sulfamethoxazole) (71.1%) but less so to azithromycin (22.4%), erythromycin (21.1%), chloramphenicol (18.4%), tetracycline (14.5%), clindamycin (10.5%) and levofloxacin (0%). Moreover, 26.3% were multidrug-resistant (resistant to ≥3 antibiotic classes). Vaccine-type pneumococci were resistant to more classes of antibiotics, were more frequently resistant to erythromycin, azithromycin, clindamycin and tetracycline, and had higher MICs to penicillin (median, 0.19μg/mL; range, 0.002-1.5μg/mL) compared with non-vaccine serotypes (median, 0.125μg/mL; range, 0.012-0.25μg/mL) (P=0.003). Co-trimoxazole-resistant isolates carried from 1 to 11 different mutations in the dihydrofolate reductase (DHFR) gene, most commonly Ile100Leu (100%), Glu20Asp (91.8%), Glu94Asp (61.2%), Leu135Phe (57.1%), His26Tyr (53.1%), Asp92Ala (53.1%) and His120Gln (53.1%).

CONCLUSION

Streptococcus pneumoniae isolated from HIV-diagnosed patients were frequently non-susceptible to penicillin and co-trimoxazole. Most isolates carried multiple mutations in DHFR.

Effect of co-trimoxazole prophylaxis on morbidity and mortality of HIV-exposed, HIV-uninfected infants in South Africa: a randomised controlled, non-inferiority trial

BACKGROUND

WHO guidelines recommend co-trimoxazole prophylaxis for HIV-exposed, HIV-uninfected infants. These guidelines date back to an era in which HIV testing of infants was impossible and mothers had poor access to antiretroviral treatment. To determine whether this guideline requires revision in the current era of effective prevention of mother-to-child transmission and early infant diagnosis programmes, we aimed to investigate whether receiving no co-trimoxazole prophylaxis is inferior to receiving co-trimoxazole prophylaxis in the resulting incidence of grade 3 or 4 common childhood illnesses or mortality in breastfed HIV-exposed, HIV-uninfected infants.

METHODS

We investigated our aim in a randomised controlled, non-inferiority trial. We enrolled the HIV-negative infants of mothers living with HIV who were actively involved in transmission prevention programmes in two clinics in Durban, South Africa. Infants were included in the study if they were breastfeeding at the screening and enrolment visits, and their mother was planning to breastfeed for at least 6 months; were a singleton birth and had a birthweight of 2 kg or more; had no clinically observed genetic disorders; and had no serious illnesses and had not received antibiotics or traditional medications (such as herbal remedies). Infants were randomly assigned (1:1) to receive co-trimoxazole or no co-trimoxazole. In the co-trimoxazole group, infants received the drug until all exposure to HIV had ceased (ie, 6 weeks after last exposure to breastmilk) and the infant was confirmed to be uninfected with HIV. The drug was administered by mothers in once-daily regimens of 20 mg trimethoprim and 100 mg sulfamethoxazole orally (age <6 months or bodyweight <5 kg), or 40 mg trimethoprim and 200 mg sulfamethoxazole orally (age >6 months or bodyweight >5 kg). Clinical and laboratory staff always remained masked to group assignment, but mothers and study counsellors were not. Infants and their mothers attended study visits at ages 6 weeks (for enrolment and randomisation), 10 weeks, 14 weeks, and then monthly from 4 to 12 months. Our primary outcome was the incidence of grade 3 or 4 common childhood illnesses (pneumonia or diarrhoea) or mortality in breastfed HIV-exposed, HIV-uninfected infants by age 12 months. A non-inferiority bound of 5% was used. The study is registered with the Pan African Clinical Trials Registry, number PACTR201311000621110, and the South African National Clinical Trials Registry, number DOH-27-0614-4728.

FINDINGS

We screened 1570 mother-child pairs for study enrolment, from whom (78%) eligible infants were enrolled into the study between Oct 16, 2013, and May 23, 2018. Of the infants enrolled, 611 (50%) were randomly assigned to the co-trimoxazole group and 609 (50%) were randomly assigned to the no co-trimoxazole group. One (<1%) infant in the no co-trimoxazole group was excluded from the analysis of the final outcomes for having received traditional medicine (which only became apparent after randomisation); therefore, 611 (50%) infants in the co-trimoxazole group and 608 (50%) infants in the no co-trimoxazole group were included in the final intention-to-treat analysis. 136 (22%) infants in the co-trimoxazole group and 139 (23%) infants in the no co-trimoxazole group did not complete the 12-month study visit, predominantly because of loss to follow-up (93 [15%] infants in the co-trimoxazole group; 90 [15%] infants in the no co-trimoxazole group). The cumulative probability of the composite primary outcome was 0·114 (95% CI 0·076 to 0·147; 49 events) in the co-trimoxazole group versus 0·0795 (0·044 to 0·115; 39 events) in the no co-trimoxazole group. The risk difference (no co-trimoxazole group minus co-trimoxazole group) was -0·0319 (-0·075 to 0·011), meaning that the risk was around 3 percentage points lower in the no co-trimoxazole group on the additive scale.

INTERPRETATION

We can conclude that no co-trimoxazole is not inferior to daily co-trimoxazole among breastfed HIV-exposed, HIV-uninfected infants whose mothers are accessing a prevention of mother-to-child transmission programme in an area unaffected by malaria. We therefore believe that WHO should revise the co-trimoxazole guidelines for HIV-exposed, HIV-uninfected infants in areas unaffected by malaria.

FUNDING

HIV Prevention Research Unit of the South African Medical Research Council and the Family Larsson-Rosenquist Foundation.

Streptococcus pneumoniae colonization in pneumococcal vaccine-naïve human immunodeficiency virus-exposed infected and -uninfected South African children

Pneumococcal nasopharyngeal colonization is a pre-requisite for pneumococcal disease; the risk for pneumococcal disease is high in children born to women living with human immunodeficiency virus (HIV). We investigated pneumococcal colonization, serotype distribution and antibiotic susceptibility of Streptococcus pneumoniae isolates carried by perinatal HIV-infected and HIV-exposed-uninfected (HEU) children.Serial nasopharyngeal swabs were collected from 331 HIV-infected and 491 HEU children, at up to 6 scheduled timepoints, between median ages of 25 to 181 weeks. Pneumococcus was identified by culture; serotyping and antibiotic susceptibility testing were done by conventional methods. No pneumococcal vaccine was given.HIV-infected children were less likely to be colonized with 7-valent pneumococcal conjugate vaccine 7 serotypes than HEU at a median of 25 weeks of age (23% vs 36%; P < .001); however, no differences in colonization between the 2 groups were observed at subsequent study-visits. Over the 36-months study-period pneumococcal colonization increased in both HIV-infected (from 45% to 77%) and HEU (from 57% to 61%) children. Over the study-period, pneumococcal isolates non-susceptible to cotrimoxazole decreased from 92% to 57% and had a similar trend to penicillin (from 65% to 42%) in HIV-infected children. Similarly, pneumococcal nonsusceptible to cotrimoxazole decreased from 93% to 57% and to penicillin from 69% to 37% in HEU children.Vaccine serotype colonization was common in this population and similar rates were observed in HIV-infected and HEU children. The prevalence of pneumococcal isolates non-susceptible to cotrimoxazole and penicillin decreased with age.

Evaluation of the impact of HIV-1 infection and density of common nasopharyngeal bacterial colonizers in South African children immunized with 7-valent pneumococcal conjugate vaccine

BACKGROUND

Due to limitations in standard culture methods, the impact of pneumococcal conjugate vaccine (PCV) immunization on nasopharyngeal bacterial carriage density is unclear, including among HIV-infected children.

METHODS

The prevalence and density of serotype/serogroup-specific pneumococcal and other nasopharyngeal colonizing bacteria were investigated in archived swabs of HIV-infected and HIV-uninfected, PCV-7 immunized (at 6, 10 and 14 weeks of age) South African children collected at 9 and 16 months of age. During the course of the study, PCV-immunization of children in Soweto was limited to study-participants, as the vaccine had not been introduced into the public immunization program.

RESULTS

At 9 months of age, the prevalence of overall pneumococcal colonization was lower in HIV-infected (58.6%) than HIV-uninfected children (69.9%, p = 0.02), mainly due to lower prevalence of non-vaccine-serotype colonization (27.8% vs. 40%, respectively; p = 0.047). The mean-log₁₀ density of pneumococcal colonization was, however, higher in HIV-infected (4.81 CFU/ml) than HIV-uninfected pneumococcal colonized children (4.44 CFU/ml; p = 0.014); mainly due to higher mean-log₁₀ density of PCV7-serotype colonization (4.21 vs. 3.72 CFU/ml; p = 0.014). No difference in the prevalence or density of overall pneumococci was found at 16 months of age. The prevalence of non-vaccine serotype colonization remained 1.7 fold higher in HIV-uninfected (60.4%) than HIV-infected children (50.9%, p = 0.049). Other differences included a lower prevalence of H. influenzae colonization in HIV-infected (42.3% and 56%) than HIV-uninfected children (64.2% and 73.4%) at both 9 and 16 months of age respectively; however, the density of colonization was similar.

CONCLUSION

Increased carriage density of residual PCV7-serotypes might cause HIV-infected children to have a higher risk of pneumococcal disease. The higher carriage density observed in HIV-infected children could be attributed to a combination of factors, including HIV treatment and impaired host immunity. Additional studies are needed.

Impact of Trimethoprim-sulfamethoxazole Urinary Tract Infection Prophylaxis on Non-UTI Infections

In this secondary analysis of the Randomized Intervention for Children with Vesicoureteral Reflux cohort, we found that daily prophylaxis with trimethoprim-sulfamethoxazole was not associated with an increased or decreased risk of skin and soft tissue infections, pharyngitis or sinopulmonary infections in otherwise healthy children 2-71 months of age.

Diversity of upper respiratory tract infections and prevalence of Streptococcus pneumoniae colonization among patients with fever and flu-like symptoms

BACKGROUND

Many upper respiratory pathogens cause similar symptoms. In China, routine molecular tests for upper respiratory pathogens are not widely performed and antibiotics abuse in treating upper respiratory tract infections (URTIs) is a major public health concern.

METHODS

We performed qualitative real-time PCR tests to detect common upper respiratory tract pathogens including 9 viruses and 3 bacteria in 1221 nasopharyngeal swabs from patients with fever and influenza-like symptoms in a Chinese city. A quantitative real-time PCR was also performed to measure the bacterial density of the colonizing Streptococcus pneumoniae in these samples.

RESULTS

We found very diverse pathogens including 81.7% viruses, 11.6% bacteria and 6.7% mixed viruses and bacteria. S. pneumoniae colonization was found in 8.0% of the cases but most of them had low bacterial density (Mean = 3.9 log cfu/ml). We also discovered an increase of S. pneumoniae colonization frequency (but not the density) in patients with detectable upper respiratory tract pathogens, in a pathogen variety-dependent manner.

CONCLUSIONS

Our study provided strong evidence against empiric antibiotic use for treating URTIs, and highlighted a strong need for improving the diagnostic capacity for URTIs by using more molecular testing in China.

HIV-related pneumococcal disease prevention in adults

INTRODUCTION

HIV-infected persons are particularly susceptible to the development of severe pneumococcal disease, even in the setting of combination antiretroviral therapy (cART), due to slow, incomplete recovery of anti-pneumococcal host defenses. This risk is increased by avoidable aspects of lifestyle, particularly smoking, which intensify immunosuppression. Clearly, more effective preventive measures are needed to counter this threat. Areas covered: This is a detailed review of the published literature focusing on currently available strategies for prevention of pneumococcal infection in HIV-infected patients, including cotrimoxazole prophylaxis, cART, pneumococcal vaccination, and smoking cessation strategies. This is preceded by a consideration of the epidemiology, clinical presentation, risk factors, and outcome of pneumococcal disease. Expert commentary: Cotrimoxazole prophylaxis has been shown to reduce morbidity and mortality in HIV-infected patients, although there is inconsistent data on the preventive efficacy against pneumococcal infections. Some recent studies have documented unchanged incidences of IPD in adult patients in the cART era. With regard to pneumococcal vaccination, routine acceptance of the efficacy of the PCV13/PPV23 sequential administration prime-boost strategy awaits the outcome of clinical trials in those with HIV infection. Smoking cessation, and discontinuation of excessive alcohol consumption and intravenous drug abuse, are priority strategies to prevent severe pneumococcal infection.

Challenges facing effective implementation of co-trimoxazole prophylaxis in children born to HIV-infected mothers in the public health facilities

BACKGROUND

If children born to HIV-infected mothers are not identified early, approximately 30% of them will die within the first year of life due to opportunistic infections. In order to prevent morbidity and mortality due to opportunistic infections in children, the World Health Organization recommends the use of prophylaxis using co-trimoxazole. However, the challenges affecting effective implementation of this policy in Tanzania have not been documented.

AIM

In this study, we assessed the challenges facing the provision of co-trimoxazole prophylaxis among children born to HIV-infected mothers in the public hospitals of Dar es Salaam, Tanzania.

METHODOLOGY

Four hundred and ninety-eight infants' PMTCT (Prevention of Mother-to-Child Transmission of HIV) register books for the past 2 years were reviewed to obtain information regarding the provision of co-trimoxazole prophylaxis. One hundred and twenty-six health care workers were interviewed to identify success stories and challenges in the provision of co-trimoxazole prophylaxis in children. In addition, 321 parents and guardians of children born to HIV-infected mothers were interviewed in the health facilities.

RESULTS

Approximately 80% of children were initiated with co-trimoxazole prophylaxis within 2 months after birth. Two hundred and ninety-one (58.4%) children started using co-trimoxazole within 4 weeks after birth. Majority (n=458, 91.8%) of the children were prescribed 120 mg of co-trimoxazole per day, whereas 39 (7.8%) received 240 mg per day. Only a small proportion (n=1, 0.2%) of children received 480 mg/day. Dose determination was based on the child's age rather than body weight. Parents and guardians reported that 42 (13.1%) children had missed one or more doses of co-trimoxazole during the course of prophylaxis. The majority of health care workers (89.7%) reported that co-trimoxazole is very effective for the prevention of opportunistic infections among children, but frequent shortage of co-trimoxazole in the health facilities was the main challenge.

CONCLUSION

Most children who were initiated with co-trimoxazole prophylaxis did not experience significant opportunistic infections, and the drug was well tolerated. The major barrier for co-trimoxazole prophylaxis was due to frequent out-of-stocks of pediatric co-trimoxazole formulations in the health facilities. Dose determination was based on the age rather than the weight of children, thus creating potential for under- or over-dosing of children.

Longitudinal study on Streptococcus pneumoniae, Haemophilus influenzae and Staphylococcus aureus nasopharyngeal colonization in HIV-infected and -uninfected infants vaccinated with pneumococcal conjugate vaccine

BACKGROUND

Streptococcus pneumoniae, Haemophilus influenzae and Staphylococcus aureus are all potentially pathogenic, which frequently colonize the nasopharynx (NP) prior to causing disease. We studied bacterial NP-colonization in 321 HIV-infected and 243 HIV-uninfected children vaccinated with 7-valent pneumococcal conjugate vaccine (PCV7) at 6, 10 and 14 weeks of age.

METHODS

HIV-uninfected infants included those born to HIV-uninfected (HUU) and HIV-infected women (HEU); HIV-infected children with CD4+ lymphocyte ≥25% were randomized to initiate antiretroviral therapy immediately (ART-Immed) or when clinically indicated (ART-Def). Nasopharyngeal swabs for bacterial culture were taken prior to each PCV7 dose (Visits 1-3) and at 20, 39, 47 and 67 weeks of age (Visits 4-7). Swabs were cultured by standard methods and pneumococcal serotyping done by the Quellung method.

RESULTS

Colonization patterns for pneumococcus, H. influenzae and S. aureus did not differ between HUU and HEU children; and were also generally similar between ART-Def and ART-Immed children. Prevalence of PCV7-serotype colonization was similar between HIV-infected and HIV-uninfected children, however, overall pneumococcal and specifically non-vaccine serotype colonization tended to be lower in HIV-infected children. HIV-infected children also had a 44% lower prevalence of S. aureus colonization at Visit-1 (p=0.010); and H. influenzae colonization was also lower among HIV-infected than HIV-uninfected children at Visit-2, Visit-3, Visit-6 and Visit-7.

CONCLUSION

Vaccine-serotype colonization is similar in PCV-immunized HIV-infected and HIV-uninfected children. We, however, identified a lower prevalence of overall-pneumococcal and H. influenzae colonization in HIV-infected children post-PCV vaccination, the clinical-relevance of which warrants further study.

The expanding role of co-trimoxazole in developing countries

Co-trimoxazole is an inexpensive, broad-spectrum antimicrobial drug that is widely used in developing countries. Before antiretroviral therapy (ART) scale-up, co-trimoxazole prophylaxis reduced morbidity and mortality in adults and children with HIV by preventing bacterial infections, diarrhoea, malaria, and Pneumocystis jirovecii pneumonia, despite high levels of microbial resistance. Co-trimoxazole prophylaxis reduces early mortality by 58% (95% CI 39-71) in adults starting ART. Co-trimoxazole provides ongoing protection against malaria and non-malaria infections after immune reconstitution in ART-treated individuals in sub-Saharan Africa, leading to a change in WHO guidelines, which now recommend long-term co-trimoxazole prophylaxis for adults and children in settings with a high prevalence of malaria or severe bacterial infections. Co-trimoxazole prophylaxis is recommended for HIV-exposed infants from age 4-6 weeks; however, the risks and benefits of co-trimoxazole during infancy are unclear. Co-trimoxazole prophylaxis reduces anaemia and improves growth in children with HIV, possibly by reducing inflammation, either through direct immunomodulatory activity or through effects on the intestinal microbiota leading to reduced microbial translocation. Ongoing trials are now assessing the ability of adjunctive co-trimoxazole to reduce mortality in children after severe anaemia or severe acute malnutrition. In this Review, we discuss the mechanisms of action, benefits and risks, and clinical trials of co-trimoxazole in developing countries.

Carriage of Streptococcus pneumoniae and other respiratory bacterial pathogens in low and lower-middle income countries: a systematic review and meta-analysis

BACKGROUND

Infection with Streptococcus pneumoniae is a major cause of childhood morbidity and mortality worldwide, especially in low income countries where pneumococcal conjugate vaccines (PCVs) are still underused. In countries where PCVs have been introduced, much of their efficacy has resulted from their impact on nasopharyngeal carriage in vaccinated children. Understanding the epidemiology of carriage for S. pneumoniae and other common respiratory bacteria in developing countries is crucial for implementing appropriate vaccination strategies and evaluating their impact.

METHODS AND FINDINGS

We have systematically reviewed published studies reporting nasopharyngeal or oropharyngeal carriage of S. pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, and Neisseria meningitidis in children and adults in low and lower-middle income countries. Studies reporting pneumococcal carriage for healthy children <5 years of age were selected for a meta-analysis. The prevalences of carriage for S. pneumoniae, H. influenzae, and M. catarrhalis were generally higher in low income than in lower-middle income countries and were higher in young children than in adults. The prevalence of S. aureus was high in neonates. Meta-analysis of data from young children before the introduction of PCVs showed a pooled prevalence estimate of 64.8% (95% confidence interval, 49.8%-76.1%) in low income countries and 47.8% (95% confidence interval, 44.7%-50.8%) in lower-middle income countries. The most frequent serotypes were 6A, 6B, 19A, 19F, and 23F.

CONCLUSIONS

In low and lower-middle income countries, pneumococcal carriage is frequent, especially in children, and the spectrum of serotypes is wide. However, because data are limited, additional studies are needed to adequately assess the impact of PCV introduction on carriage of respiratory bacteria in these countries.

Nasopharyngeal bacterial colonisation in HIV-positive children in Cambodia

OBJECTIVE

To determine patterns of nasopharyngeal colonisation in HIV-positive children.

METHODS

Nasopharyngeal, nasal and ear swabs were prospectively taken from all children living in two paediatric nursing homes for HIV-positive orphans in Cambodia from 2004 to 2011.

RESULTS

A total of 882 swabs were taken, of which 586 tested positive for bacteria. Staphylococcus aureus was the most frequently isolated species (178 isolates; 30.4%) followed by Streptococcus pneumoniae (103 isolates; 17.6%) and Klebsiella pneumoniae (99 isolates; 16.9%). The rate of S. pneumoniae decreased in 2009 when a vaccination programme was introduced.

CONCLUSIONS

The respiratory tract of HIV-positive children receiving highly active antiretroviral therapy is commonly colonised by S. aureus and S. pneumoniae, while other species normally found in the respiratory tract, such as Moraxella catarrhalis, are far less frequent.

Factors associated with coverage of cotrimoxazole prophylaxis in HIV-exposed children in South Africa

BACKGROUND

The World Health Organisation and the Joint United Nations Programme in 2006 reaffirmed the earlier recommendation of 2000 that all HIV-exposed infants in resource-poor countries should commence cotrimoxazole (CTX) prophylaxis at 6-weeks of life. CTX prophylaxis should be continued until the child is confirmed HIV-uninfected and there is no further exposure to breastmilk transmission. We determined CTX coverage and explored factors associated with CTX administration in HIV-exposed infants at a primary health clinic in South Africa.

METHODS

In a cross-sectional study of HIV-exposed infants 6-18 months of age attending a child immunisation clinic, data from the current visit and previous visits related to CTX prophylaxis, feeding practice and infant HIV testing were extracted from the child's immunisation record. Further information related to the administration of CTX prophylaxis was obtained from an interview with the child's mother.

RESULTS

One-third (33.0%) HIV-exposed infants had not initiated CTX at all and breastfed infants were more likely to have commenced CTX prophylaxis as compared to their non-breastfed counterparts (78.7% vs 63.4%) (p = 0.008). Availability of infant's HIV status was strongly associated with continuation or discontinuation of CTX after 6 months of age or after breastfeeding cessation. Maternal self-reports indicated that only 52.5% (95%CI 47.5-57.5) understood the reason for CTX prophylaxis, 126 (47%) did not dose during weekends; 55 (21%) dosed their infants 3 times a day and 70 (26%) dosed their infants twice daily.

CONCLUSION

A third of HIV-exposed children attending a primary health care facility in this South African setting did not receive CTX prophylaxis. Not commencing CTX prophylaxis was strongly associated with infants not breastfeeding and unnecessary continued exposure to CTX in this paediatric population was due to limited availability of early infant diagnosis. Attendance at immunization clinics can be seen as missed opportunities for early infant diagnosis of HIV and related care.

Acquisition of Streptococcus pneumoniae in pneumococcal conjugate vaccine-naïve South African children and their mothers

BACKGROUND

Pneumococcal nasopharyngeal colonization is a prerequisite to developing pneumococcal disease. We investigated the dynamics of pneumococcal colonization in perinatal HIV-unexposed and HIV-exposed children and their mothers and risk factors associated with new serotypes acquisition.

METHODS

Two hundred forty-three mother-child pairs (120 HIV-infected, 123 HIV-uninfected mothers) were studied at 4.4, 7.2, 9.4, 12.3 and 16.0 months of the child's age. Demographic data, nasopharyngeal swabs, as well as oropharyngeal swabs, from mothers were collected for pneumococcal conventional culture and serotyping by the Quellung method.

RESULTS

The rate of new serotype acquisition during the 16 months did not differ between HIV-exposed (49.1%) and HIV-unexposed (52.0%) children, or between HIV-infected (18.9%) and HIV-uninfected (19.5%) mothers. Serotypes included in the 7-valent pneumococcal conjugate vaccine (PCV7) were acquired more often by HIV-infected (10.0%) compared with HIV-uninfected mothers (6.4%; P = 0.03). On multivariate analysis, day-care attendance (adjusted odds ratio [AOR], = 1.80, P = 0.02) and maternal pneumococcal colonization (AOR = 1.54, P = 0.01) were positively associated with pneumococcal acquisition in the child, whereas breast-feeding had a protective effect on PCV7-serotype acquisition in HIV-uninfected children. New acquisition of PCV7 and PCV13 serotypes in the mother was positively associated with colonization in the child (AOR = 2.01, P = 0.006 and AOR = 2.04, P = 0.002, respectively).

CONCLUSIONS

There is an association of acquisition of PCV7 and PCV13 serotypes between young children and their mothers. The higher prevalence of PCV7 serotype in HIV-infected mothers suggests that they may be a reservoir for transmission of these serotypes, which could delay indirect effects of PCV in settings with a high HIV burden.

Health outcomes of HIV-exposed uninfected African infants

OBJECTIVES

To evaluate severe (grade 3/4) morbidity and mortality in HIV-exposed, uninfected infants.

DESIGN

: Secondary data analysis of The Breastfeeding, Antiretrovirals, and Nutrition (BAN) clinical trial.

METHODS

BAN randomized 2369 mother-infant pairs to maternal, infant, or no extended antiretroviral prophylaxis during breastfeeding. Morbidity outcomes examined were pneumonia/serious febrile illness, diarrhea/growth faltering, and malaria. Infant death was defined as neonatal (≤30 days of life), and postneonatal (31 days to 48 weeks of life). Cox proportional hazards models were used to evaluate the effect of covariates on infant morbidity and mortality.

RESULTS

The rate of pneumonia/serious febrile illness was highest in the first 12 weeks (0.83/100 person-weeks) before rapidly decreasing; rates of all morbidity outcomes increased after 24 weeks. Rates of pneumonia/serious febrile illness and diarrhea/growth faltering were higher during the rainy season. Prophylactic infant cotrimoxazole significantly decreased the rates of all morbidity outcomes. White blood cell (WBC) count less than 9000/μl at birth was associated with increased diarrhea/growth faltering [adjusted hazard ratio (aHR) 1.73, P = 0.04] and malaria (aHR 2.18, P = 0.02). Low birth weight (2000-2499 g) was associated with neonatal death (aHR 12.3, P < 0.001). Factors associated with postneonatal death included rainy season (aHR 4.24, P = 0.002), infant cotrimoxazole (aHR 0.48, P = 0.03), and low infant WBC count at birth (aHR 2.53, P = 0.02).

CONCLUSION

Infant morbidity rates increased after 24 weeks, when BAN infants weaned. Introduction of prophylactic cotrimoxazole was associated with reduced rates of morbidity and mortality in HIV-exposed uninfected infants. Unexpectedly, a low WBC count at birth was significantly associated with later infant morbidity and mortality in this cohort.

Dynamics of nasopharyngeal bacterial colonisation in HIV-exposed young infants in Tanzania

OBJECTIVES

To estimate the prevalence of nasopharyngeal bacterial colonisation (NPBC) patterns in young Tanzanian HIV-exposed infants and to analyse the influence of maternal NPBC and of the infant's HIV status on the NPBC pattern.

METHODS

Longitudinal cohort study of neonates born to HIV-infected mothers visiting Kilimanjaro Christian Medical Centre, Tanzania, between 2005 and 2009. Demographic and clinical data and nasopharyngeal bacterial cultures were obtained at the age of 6 weeks, 3 and 6 months, and at one time point, a paired mother-infant nasopharyngeal swab was taken.

RESULTS

Four hundred and twenty-two swabs were taken from 338 eligible infants. At 6 weeks of age, colonisation rates were 66% for Staphylococcus aureus, 56% for Streptococcus pneumoniae, 50% for Moraxella catarrhalis and 14% for Haemophilus influenzae. Colonisation with S. aureus diminished over time and was more common in HIV-infected infants. S. pneumoniae and H. influenzae colonisation rose over time and was more prevalent in HIV-uninfected children. Co-colonisation of S. pneumoniae with H. influenzae or M. catarrhalis was mostly noticed in HIV-infected infants. S. pneumoniae and M.catarrhalis colonisation of the mother was a risk factor for colonisation in HIV-uninfected infants, while maternal S. aureus colonisation was a risk factor for colonisation in HIV-infected infants. Among the 104 S. pneumoniae isolates, 19F was most prevalent, and 57 (55%) displayed capsular serotypes represented in the 13-valent pneumococcal conjugate vaccine.

CONCLUSIONS

NPBC was common in Tanzanian HIV-exposed infants. The significant prevalence of pneumococcal vaccine serotypes colonising this paediatric population justifies the use of the 13-valent pneumococcal vaccine to reduce the burden of pneumococcal invasive disease.

Effects of cotrimoxazole prophylactic treatment on adverse health outcomes among HIV-exposed, uninfected infants

BACKGROUND

The World Health Organization guidelines recommend cotrimoxazole prophylactic treatment (CPT) for all HIV-exposed infants from age 6 weeks to the cessation of breastfeeding and the exclusion of HIV infection. There are limited data on the effects of CPT among this population of infants. We examined the effects of CPT on adverse health outcomes among HIV-exposed infants during the first 36 weeks of life using data from the Breastfeeding, Antiretrovirals and Nutrition study, a large clinical trial of antiretroviral drugs given to the mother or infant for the prevention of HIV transmission during breastfeeding.

METHODS

For the analysis, we assigned a status of CPT-exposed to infants who were participating in the study after the CPT program started. We estimated unadjusted and adjusted hazard ratios for the effect of CPT status on time to incident malaria, severe illness or death, anemia, and weight-for-age Z score < -2.0. Participation in the study was limited to focus exclusively on HIV-exposed, uninfected infants.

RESULTS

The hazard ratio for the effect of CPT on incident malaria was 0.35 (95% confidence interval: 0.21, 0.57) during the first 10 weeks of CPT exposure and 0.93 (95% confidence interval: 0.67, 1.29) for the remaining 20 weeks. CPT was not associated with the other outcomes examined.

CONCLUSIONS

CPT offered temporary protection against malaria among HIV-exposed, uninfected infants. However, CPT offered no protection against anemia, low weight for age or the collapsed outcome of severe illness or death.

A longitudinal study of Streptococcus pneumoniae carriage in a cohort of infants and their mothers on the Thailand-Myanmar border

Background

Pneumococcal disease is a major cause of childhood death. Almost a third of the world's children live in Southeast Asia, but there are few data from the region on pneumococcal colonization or disease. Our aim was to document the dynamics of pneumococcal carriage in a rural SE Asian birth cohort.

Methods

We studied 234 Karen mother-infant pairs in Northwestern Thailand. Infants were followed from birth and nasopharyngeal swabs were taken from mother and infant at monthly intervals until 24 months old.

Results

8,386 swabs were cultured and 4,396 pneumococci characterized. Infants became colonized early (median 45.5 days; 95% confidence interval [CI] 44.5-46.0) and by 24 months had a median of seven (range 0–15) carriage episodes. Maternal smoking and young children in the house were associated with earlier colonization (hazard ratio [HR] 1.5 (95% CI 1.1–2.1) and 1.4 (95% CI 1.0–1.9)). For the four commonest serotypes and non-typeable pneumococci, previous exposure to homologous or heterologous serotypes resulted in an extended interval to reacquisition of the same serotype. Previous colonization by serotypes 14 and 19F was also associated with reduced carriage duration if subsequently reacquired (HR [first reacquisition] 4.1 (95% CI 1.4–12.6) and 2.6 (1.5–4.7)). Mothers acquired pneumococci less frequently, and carried them for shorter periods, than infants (acquisition rate 0.5 vs. 1.1 /100 person-days, p<0.001; median duration 31.0 vs. 60.5 days, p = 0.001). 55.8% of pneumococci from infants were vaccine serotypes (13-valent pneumococcal conjugate vaccine, PCV13), compared with 27.5% from mothers (p<0.001). Non-typeable pneumococcal carriage was common, being carried at least once by 55.1% of infants and 32.0% of mothers.

Conclusions

Pneumococcal carriage frequency and duration are influenced by previous exposure to both homologous and heterologous serotypes. These data will inform vaccination strategies in this population.

Regional dissemination of a trimethoprim-resistance gene cassette via a successful transposable element

Background

Antimicrobial resistance is a growing international problem. We observed a 50% increase in the prevalence of trimethoprim resistance among fecal Escherichia coli from healthy Nigerian students between 1998 and 2005, a trend to increase that continued in 2009.

Methods and Findings

A PCR-based screen revealed that 131 (43.1%) of isolates obtained in Nigeria in 2005 and 2009 carried integron-borne dfrA cassettes. In the case of 67 (51.1%) of these isolates, the cassette was a class 1-integron-borne dfrA7 gene, which has been reported at high prevalence from E. coli isolates from other parts of Africa. Complete sequencing of a 27 Kb dfrA7-bearing plasmid from one isolate located the dfrA7 gene within a Tn21-type transposon. The transposon also contained an IS26-derived bla/sul/str element, encoding resistance to β-lactams, sulphonamides and streptomycin, and mercury resistance genes. Although the plasmid backbone was only found in 12 (5.8%) of trimethoprim-resistant isolates, dfrA7 and other transposon-borne genes were detected in 14 (16.3%) and 32 (26.3%) of trimethoprim resistant isolates collected in Nigeria in 2005 and 2009, respectively. Additionally, 37 (19.3%) of trimethoprim-resistant E. coli isolates collected between 2006 and 2008 from Ghana were positive for the dfrA7 and a transposon marker, but only 4 (2.1%) harbored the plasmid backbone.

Conclusions

Our data point to transposition as a principal mechanism for disseminating dfrA7 among E. coli from Nigeria and Ghana. On-going intensive use of the affordable broad-spectrum antibacterials is likely to promote selective success of a highly prevalent transposable element in West Africa.

Persistent high burden of invasive pneumococcal disease in South African HIV-infected adults in the era of an antiretroviral treatment program

Background

Highly active antiretroviral treatment (HAART) programs have been associated with declines in the burden of invasive pneumococcal disease (IPD) in industrialized countries. The aim of this study was to evaluate trends in IPD hospitalizations in HIV-infected adults in Soweto, South Africa, associated with up-scaling of the HAART program from 2003 to 2008.

Methods

Laboratory-confirmed IPD cases were identified from 2003 through 2008 through an existing surveillance program. The period 2003-04 was designated as the early-HAART era, 2005–06 as the intermediate-HAART era and 2007–08 as the established-HAART era. The incidence of IPD was compared between the early-HAART and established-HAART eras in HIV-infected and–uninfected individuals.

Results

A total of 2,567 IPD cases among individuals older than 18 years were reported from 2003 through 2008. Overall incidence of IPD (per 100,000) did not change during the study period in HIV-infected adults (207.4 cases in the early-HAART and 214.0 cases in the established-HAART era; p = 0.55). IPD incidence, actually increased 1.16-fold (95% CI: 1.01; 1.62) in HIV-infected females between the early-and established-HAART eras (212.1 cases and 246.2 cases, respectively; p = 0.03). The incidence of IPD remained unchanged in HIV-uninfected adults across the three time periods.

Conclusion

Despite a stable prevalence of HIV and the increased roll-out of HAART for treatment of AIDS patients in our setting, the burden of IPD has not decreased among HIV-infected adults. The study indicates a need for ongoing monitoring of disease and HAART program effectiveness to reduce opportunistic infections in African adults with HIV/AIDS, as well as the need to consider alternate strategies including pneumococcal conjugate vaccine immunization for the prevention of IPD in HIV-infected adults.

Does trimethoprim-sulfamethoxazole prophylaxis for HIV induce bacterial resistance to other antibiotic classes? Results of a systematic review

BACKGROUND

Trimethoprim-sulfamethoxazole (TMP-SMX) prophylaxis has long been recommended for immunosuppressed HIV-infected adults and children born to HIV-infected women. Despite this, many resource-limited countries have not implemented this recommendation, partly because of fear of widespread antimicrobial resistance not only to TMP-SMX, but also to other antibiotics. We aimed to determine whether TMP-SMX prophylaxis in HIV-infected and/or exposed individuals increases bacterial resistance to antibiotics other than TMP-SMX.

METHODS

A literature search was conducted in Medline, Global Health, Embase, Web of Science, ELDIS, and ID21.

RESULTS

A total of 501 studies were identified, and 17 met the inclusion criteria. Only 8 studies were of high quality, of which only 2 had been specifically designed to answer this question. Studies were classified as (1) studies in which all participants were infected and/or colonized and in which rates of bacterial resistance were compared between those taking or not taking TMP-SMX and (2) studies comparing those who had a resistant infection with those who were not infected. Type 1 studies showed weak evidence that TMP-SMX protects against resistance. Type 2 studies provided more convincing evidence that TMP-SMX protects against infection.

CONCLUSION

There was some evidence that TMP-SMX prophylaxis protects against resistance to other antibiotics. However, more carefully designed studies are needed to answer the question conclusively.

Pneumococcal nasopharyngeal carriage among infants born to human immunodeficiency virus-infected mothers immunized with pneumococcal polysaccharide vaccine during gestation

BACKGROUND

We have previously shown that 23-valent pneumococcal polysaccharide vaccine (PPV) is immunogenic in human immunodeficiency virus (HIV)-infected mothers and provides vaccine-induced antibodies to the infant. We compared the nasopharyngeal pneumococcal colonization (NPC) rates in <6-month-old infants born to HIV-infected mothers, according to immunization with PPV during pregnancy.

METHODS

NPC was evaluated in 45 term infants born to vaccinated women (PPV+) and in 60 infants in a control group (PPV-), at 2 months (±30 days), 4 months (±30 days), and 6 months (±30 days) of age.

RESULTS

A total of 82 infants completed the study (at least 2 of 3 evaluations), 35 (77%) in the PPV+ and 47 (78.3%) in the PPV- groups, respectively. Infant gender, HIV infection status, number of adults, children, and smokers in the household, day-care attendance, occurrence of respiratory signs, and cotrimoxazole use were similar in both groups. NPC rates increased equally with age in both groups (2 months = 26.7% vs. 25.6%; 4 months = 34.5% vs. 38.6%; 6 months = 38.7% vs. 56.3%, in PPV+ and PPV-, respectively). After controlling for potential confounders, we found no association between maternal vaccination and infant pneumococcal carriage (adjusted odds ratio = 0.70; 95% confidence interval: 0.23, 2.21)

CONCLUSIONS

Vaccination of HIV-infected mothers with PPV did not protect infants younger than 6 months of age from nasopharyngeal pneumococcal carriage.

High rates of colonization with drug resistant hemophilus influenzae type B and Streptococccus Pneumoniae in unvaccinated HIV infected children from West Bengal

OBJECTIVE

To determine nasopharyngeal colonization rates of two vaccine preventable bacterial pathogens Hemophilus influenzae type b (Hib), and Streptococcus pneumoniae (Pneumococcus), antibiotic susceptibility of isolates, factors associated with their colonization, and immunization history in a cohort of HIV infected children.

METHODS

The authors conducted a cross-sectional nasopharyngeal swab survey of 151 children affected with HIV presenting for routine outpatient care in West Bengal, India.

RESULTS

151 HIV affected children were enrolled. The median age was 6, 148/151 children were HIV positive, 65% had moderate to severe malnutrition, 53% were moderately to severely immunosuppressed, 17% were on antiretroviral therapy (ART), 90% were on cotrimoxazole prophylaxis (TMP/SMX). None had received the pneumococcal or Hib conjugate vaccines. Hib prevalence was 13% and pneumococcal prevalence was 28%. Children with normal or moderate immune suppression had high rates of colonization compared to those with severe immunosuppression (71% Hib, 61% pneumococcus). Hib and pneumococcal isolates had high rates of resistance to tested antibiotics including TMP/SMX and third generation cephalosporins. Neither ART nor TMP/SMX prevented colonization. Children colonized with multidrug resistant isolates had high rates of exposure to TMP/SMX.

CONCLUSIONS

HIV infection, late access to ART, high rates of colonization to resistant organisms and lack of access to vaccines makes this population vulnerable to invasive disease from Hib and pneumococcus.

A randomized controlled trial of intermittent compared with daily cotrimoxazole preventive therapy in HIV-infected children

OBJECTIVE

Cotrimoxazole preventive therapy (CPT) reduces morbidity and mortality in HIV-infected children. The WHO recommends prolonged daily CPT for HIV-infected infants and children. In adults, intermittent CPT has been associated with less adverse events than daily, with increased tolerability and equal efficacy. We investigated the efficacy and tolerability of intermittent CPT compared with daily CPT in HIV-infected children over a 5-year period.

DESIGN

A prospective randomized controlled study.

METHODS

HIV-infected children aged at least 8 weeks were randomized to thrice weekly or daily CPT. Outcome measures were mortality, bacterial infections, hospitalizations and adverse events.

RESULTS

Three hundred and twenty-four children (median age 23 months) were followed for 672 child-years; 165 (51%) were randomized to intermittent CPT. Most children (287, 89%) were Centers for Disease Control and Prevention clinical category B or C; 207 (64%) received HAART during the study. Mortality (53 deaths, 16%) was similar in the intermittent CPT compared with the daily CPT group {24 (14%) vs. 29 (18%), hazard ratio 0.75 [95% confidence interval (CI) 0.44-1.29]}. The predominant causes of death in both groups were sepsis (17, 32%), pneumonia (13, 25%) or diarrhoea (8, 15%). Intermittent CPT was associated with more bacteraemias [incidence rate ratio 2.36 (95% CI 1.21-4.86)]. Children receiving intermittent CPT also spent more days in hospital [incidence rate ratio 1.15 (95% CI 1.04-1.28)]. The rate of serious adverse events was similar between groups [incidence rate ratio 1.07 (95% CI 0.58-2.02)].

CONCLUSION

Intermittent CPT was associated with more invasive bacterial disease than daily CPT, but survival was similar. Both regimens were well tolerated. On balance, daily CPT remains preferable to intermittent therapy for HIV-infected children.

Impact of cotrimoxazole on carriage and antibiotic resistance of Streptococcus pneumoniae and Haemophilus influenzae in HIV-infected children in Zambia

This is a substudy of a larger randomized controlled trial on HIV-infected Zambian children, which revealed that cotrimoxazole prophylaxis reduced morbidity and mortality despite a background of high cotrimoxazole resistance. The impact of cotrimoxazole on the carriage and antibiotic resistance of Streptococcus pneumoniae and Haemophilus influenzae as major causes of childhood mortality in HIV-infected children was investigated since these are unclear. Representative nasopharyngeal swabs were taken prior to randomization for 181 of 534 children (92 on cotrimoxazole and 89 on placebo). Bacterial identification and antibiotic susceptibility were performed by routine methods. Due to reduced mortality, prophylactic cotrimoxazole increased the median time from randomization to the last specimen from 48 to 56 months (P = 0.001). The carriage of H. influenzae was unaltered by cotrimoxazole. Carriage of S. pneumoniae increased slightly in both arms but was not statistically significant in the placebo arm. In S. pneumoniae switching between carriage and no carriage in consecutive pairs of samples was unaffected by cotrimoxazole (P = 0.18) with a suggestion that the probability of remaining carriage free was lower (P = 0.10). In H. influenzae cotrimoxazole decreased switching from carriage to no carriage (P = 0.02). Cotrimoxazole resistance levels were higher in postbaseline samples in the cotrimoxazole arm than in the placebo arm (S. pneumoniae, P < 0.0001; H. influenzae, P = 0.005). Cotrimoxazole decreased switching from cotrimoxazole resistance to cotrimoxazole sensitivity in S. pneumoniae (P = 0.002) and reduced the chance of H. influenzae remaining cotrimoxazole sensitive (P = 0.05). No associations were observed between the percentage of CD4 (CD4%), the change in CD4% from baseline, child age at date of specimen, child gender, or sampling month with carriage of either pathogen.

Prevention of diarrhoea in children with HIV infection or exposure to maternal HIV infection

BACKGROUND

Diarrhoea is a major cause of morbidity and mortality among infants and children worldwide, especially in low- and middle-income countries. Human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) is a condition that similarly disproportionately affects low- and middle-income countries; of the nearly 2.1 million children under age 15 years living with HIV/AIDS, the large majority reside in sub-Saharan Africa. Infants and children with HIV infection have more frequent and more severe diarrhoea than children without HIV. Interventions including vitamin A, zinc and cotrimoxazole may contribute substantially to preventing diarrhoea in children with HIV infection or exposure to HIV.

OBJECTIVES

We perform a systematic review of randomised controlled trials and nonrandomised studies that examine the effectiveness of vitamin A, zinc and cotrimoxazole on mortality and morbidity from diarrhoea in HIV-infected and -exposed infants and children.

SEARCH STRATEGY

Electronic databases including Pubmed, Central and EMBASE were searched without limits to language from 1980 to April 2010. Conference database searches were performed, experts were contacted and bibliographies were handsearched.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and nonrandomised studies (NRSs) that examined the effectiveness of the three interventions were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed citations for eligibility and double-extracted included studies. Assessment of bias of individual studies was performed independently by both reviewers. Only two summary estimates were performed due to heterogeneity in study design and interventions.

MAIN RESULTS

Four RCTs were identified for vitamin A. One RCT was identified for zinc. One RCT and two NRSs were identified for cotrimoxazole. Vitamin A reduced mortality overall in children with HIV infection (four studies). A pooled estimate of three studies for reduction in mortality from vitamin A compared to placebo had a relative risk (DerSimonian and Laird method, random effects) of 0.50 (95% confidence interval (CI): 0.31 to 0.79) in 267 patients. Diarrheoa-specific mortality did not reach statistical significance and diarrhoeal morbidity outcomes were variable in three trials. Zinc supplementation reduced the number of physician visits for watery diarrhoea in one trial. Cotrimoxazole reduced mortality and hospitalisations compared to placebo in one RCT, although diarrhoea-specific morbidities were not significant.

AUTHORS' CONCLUSIONS

Vitamin A shows benefits in reduction of mortality in HIV-infected children. The effect of vitamin A on children with HIV exposure is not clear and needs further review. Zinc and combination vitamin A, zinc and micronutrient supplementation did not show an effect compared to vitamin A alone in children with HIV infection. Cotrimoxazole reduced mortality and some morbidity in children with HIV infection. Further research may clarify the effects of these interventions on morbidity from diarrhoea and in the population of children with HIV exposure.