Impact of daily cotrimoxazole on clinical malaria and asymptomatic parasitemias in HIV-exposed, uninfected infants

Effects of Malaria and HIV Infection on Anemia and T-cells Levels in Children in Douala City, Cameroon

Introduction Human immunodeficiency virus (HIV) infection and malaria are priority health issues for sub-Saharan Africa. Both diseases worsen each other through their effect on the immune and hematological systems. This study aimed to determine the effects of HIV infection and asymptomatic malaria on anemia and T-cells counts in children in the city of Douala in the republic of Cameroon. Method From May to November 2016, 197 HIV infected and 98 HIV-free non-febrile children up to 19 years old (128 male and 167 female) participated in the study. All HIV-infected children were receiving antiretroviral treatment and co-trimoxazole. Malaria diagnosis was performed using Giemsa-stained thick blood film; immunological and hematological parameters were assessed through a flow cytometer and an automated analyzer respectively. Chi-squared or Fischer's exact tests was used to compare the proportions, Mann-Whitney and ANOVA tests were used for the means. Statistical significance was set at p˂0.05. Results The prevalence of malaria was 8.8%, and that of anemia was 40.7%. CD4⁺-T cells were higher in malaria-infected children, both in HIV positive and negative (p=0.049). No significant association was found between malaria parasitemia and CD8⁺-T cell levels, both in HIV-positive and negative children (p=0.41). Anemia was higher in HIV-positive children (p=0.019), especially in those with severe immunosuppression (p=0.001) and in younger children (p=0.0083). Children on HIV treatment presented lower malaria prevalence (8.6% versus 10.10%), though the difference was not significant (p=0.7068). Malaria infection was associated with lower hemoglobin levels (10.5±1.7 versus 11.2±1.4; p=0.016). Conclusion Malaria infection may enhance CD4⁺-T cells. Both malaria and HIV infection lead to a drop in hemoglobin levels. The HIV treatment protocol may reduce malaria prevalence.

Permethrin-treated baby wraps for the prevention of malaria: results of a randomized controlled pilot study in rural Uganda

Background

Progress against malaria has stalled and may even be slipping backwards in high-burden countries. This is due to a range of factors including insecticide resistance and mosquito feeding behaviours that limit contact with widely-employed interventions including long-lasting insecticidal nets and indoor-residual spraying. Thus, further innovations in malaria control are urgently needed.

Methods

The pilot was a randomized, placebo-controlled pilot study of permethrin-treated baby wraps—known locally as lesus—in children 6–18 months of age at a single site in rural western Uganda. Fifty mother–infant pairs were assigned to permethrin-treated or untreated lesus in a 1:1 allocation. Participants and clinical staff were blinded to group assignments through use of sham treatment and re-treatment of lesus. Participants attended scheduled clinic visits every 2 weeks for a total 12 weeks. The primary outcome of interest was the safety of the intervention, assessed as changes in the frequency of use, rates of discontinuation, and incidence of adverse events, such as skin rash. Secondary outcomes included acceptability and feasibility of the intervention as measured through participant satisfaction and completion of study activities, respectively.

Results

Overall, rates of retention and participation were relatively high with 86.0% (43 of 50) of participants completing all scheduled visits, including 18 (75.0%) and 25 (96.2%) in the intervention and control arms respectively. By the conclusion of the 12-week follow-up period, one adverse event (0.35 events per 100 person-weeks, one-sided 95% CI 0.0–1.65) was reported. Satisfaction with the lesu was high in both groups. In each study arm, there were five incident RDT positive results, but the only PCR-positive results were observed in the control group (n = 2).

Conclusions

Permethrin-treated baby wraps were well-tolerated and broadly acceptable. Adverse events were infrequent and mild. These findings support future trials seeking to determine the efficacy of treated wraps to prevent P. falciparum malaria infection in young children as a complementary tool to existing household-based interventions.

Trial registration: ClinicalTrials.gov Identifier: NCT04102592, Registered 25 September 2019. Available at: https://clinicaltrials.gov/ct2/show/NCT04102592

Supplementary Information

The online version contains supplementary material available at 10.1186/s12936-022-04086-w.

Reduced Placental Transfer of Antibodies Against a Wide Range of Microbial and Vaccine Antigens in HIV-Infected Women in Mozambique

Transplacental transfer of antibodies is essential for conferring protection in newborns against infectious diseases. We assessed the impact of different factors, including gestational age and maternal infections such as HIV and malaria, on the efficiency of cord blood levels and placental transfer of IgG subclasses. We measured total IgG and IgG subclasses by quantitative suspension array technology against 14 pathogens and vaccine antigens, including targets of maternal immunization, in 341 delivering HIV-uninfected and HIV-infected mother-infant pairs from southern Mozambique. We analyzed the association of maternal HIV infection, Plasmodium falciparum exposure, maternal variables and pregnancy outcomes on cord antibody levels and transplacental transfer. Our results show that maternal antibody levels were the main determinant of cord antibody levels. Univariable and multivariable analysis showed that HIV reduced the placental transfer and cord levels of IgG and IgG1 principally, but also IgG2 to half of the antigens tested. P. falciparum exposure and prematurity were negatively associated with cord antibody levels and placental transfer, but this was antigen-subclass dependent. Our findings suggest that lower maternally transferred antibodies may underlie increased susceptibility to infections of HIV-exposed infants. This could affect efficacy of maternal vaccination, especially in sub-Saharan Africa, where there is a high prevalence of HIV, malaria and unfavorable environmental factors.

Cotrimoxazole Prophylaxis Increases Resistance Gene Prevalence and α-Diversity but Decreases β-Diversity in the Gut Microbiome of Human Immunodeficiency Virus-Exposed, Uninfected Infants

BACKGROUND

Prophylactic cotrimoxazole treatment is recommended in human immunodeficiency virus (HIV)-exposed, uninfected (HEU) infants, but the effects of this treatment on developing HEU infant gut microbiotas and resistomes are largely undefined.

METHODS

We analyzed whole-metagenome sequencing data from 163 longitudinally collected stool samples from 63 HEU infants randomized to receive (n = 34; CTX-T) or to not receive (n = 29; CTX-N) prophylactic cotrimoxazole treatment. We generated taxonomic, functional pathway, and resistance gene profiles for each sample and compared microbiome signatures between the CTX-T and CTX-N infants.

RESULTS

Metagenomic analysis did not reveal significant differences in taxonomic or functional pathway α-diversity between CTX-T and CTX-N infants. In contrast, resistance gene prevalence (P = .00719) and α-diversity (P = .0045) increased in CTX-T infants. These differences increased over time for both resistance gene prevalence measured by log-normalized abundance (4-month mean, 0.71 [95% confidence interval {CI}, .2-1.2] and 6-month mean, 0.85 [95% CI, .1-1.7]) and α-diversity (P = .0045). Unlike α-diversity, interindividual gut microbiome taxonomic (mean, -0.11 [95% CI, -.15 to -.077]), functional taxonomic (mean, -0.050 [95% CI, -.084 to -.017]), and resistance gene (mean, -0.13 [95% CI, -.17 to -.099]) β-diversity decreased in CTX-T infants compared with CTX-N infants. These results are consistent with persistent antibiotic selection pressure.

CONCLUSIONS

Cotrimoxazole prophylaxis in HEU infants decreased gut microbiome β-diversity and increased antibiotic resistance gene α-diversity and prevalence. Antibiotic resistance is a growing threat, especially in low- and middle-income countries where the higher perinatal HIV exposure rates result in cotrimoxazole prophylaxis. Understanding effects from current HEU infant antibiotic prophylaxis guidelines will inform guideline revisions and efforts to reduce increasing antibiotic resistance.

Malaria in a 2-Month-Old HIV-Exposed Nigerian Infant: Challenges of Care

Background:

Reports on malaria and HIV coinfections in exposed infants from tropical countries are scarce.

Results:

The case of a 2-month-old HIV-exposed Nigerian infant who presented with intermittent fever at a Nigerian tertiary hospital is reported. The rarity of the case and the challenges associated with making the diagnosis informed our decision to report the case.

Conclusion:

Diagnosing malaria in HIV-exposed infants in early infancy requires a high index of suspicion, good knowledge of the clinical presentation, and appropriate microbiological investigations for sepsis and malaria. Further studies need to be conducted on the association between malaria and HIV exposure.

Peripheral blood mononuclear cell transcriptomes reveal an over-representation of down-regulated genes associated with immunity in HIV-exposed uninfected infants

HIV-exposed uninfected (HEU) infants are disproportionately at a higher risk of morbidity and mortality, as compared to HIV-unexposed uninfected (HUU) infants. Here, we used transcriptional profiling of peripheral blood mononuclear cells to determine immunological signatures of in utero HIV exposure. We identified 262 differentially expressed genes (DEGs) in HEU compared to HUU infants. Weighted gene co-expression network analysis (WGCNA) identified six modules that had significant associations with clinical traits. Functional enrichment analysis on both DEGs and the six significantly associated modules revealed an enrichment of G-protein coupled receptors and the immune system, specifically affecting neutrophil function and antibacterial responses. Additionally, malaria pathogenicity genes (thrombospondin 1-(THBS 1), interleukin 6 (IL6), and arginine decarboxylase 2 (ADC2)) were down-regulated. Of interest, the down-regulated immunity genes were positively correlated to the expression of epigenetic factors of the histone family and high-mobility group protein B2 (HMGB2), suggesting their role in the dysregulation of the HEU transcriptional landscape. Overall, we show that genes primarily associated with neutrophil mediated immunity were repressed in the HEU infants. Our results suggest that this could be a contributing factor to the increased susceptibility to bacterial infections associated with higher morbidity and mortality commonly reported in HEU infants.

The prevalence and antifolate drug resistance profiles of Plasmodium falciparum in study participants randomized to discontinue or continue cotrimoxazole prophylaxis

Objective

Cotrimoxazole prevents opportunistic infections including falciparum malaria in HIV-infected individuals but there are concerns of cross-resistance to other antifolate drugs such as sulphadoxine-pyrimethamine (SP). In this study, we investigated the prevalence of antifolate-resistance mutations in Plasmodium falciparum that are associated with SP resistance in HIV-infected individuals on antiretroviral treatment randomized to discontinue (STOP-CTX), or continue (CTX) cotrimoxazole in Western Kenya.

Design

Samples were obtained from an unblinded, non-inferiority randomized controlled trial where participants were recruited on a rolling basis for the first six months of the study, then followed-up for 12 months with samples collected at enrollment, quarterly, and during sick visits.

Method

Plasmodium DNA was extracted from blood specimens. Initial screening to determine the presence of Plasmodium spp. was performed by quantitative reverse transcriptase real-time PCR, followed by genotyping for the presence of SP-resistance associated mutations by Sanger sequencing.

Results

The prevalence of mutant haplotypes associated with SP-resistant parasites in pfdhfr (51I/59R/108N) and pfdhps (437G/540E) genes were significantly higher (P = 0.0006 and P = 0.027, respectively) in STOP-CTX compared to CTX arm. The prevalence of quintuple haplotype (51I/59R/108N/437G/540E) was 51.8% in STOP-CTX vs. 6.3% (P = 0.0007) in CTX arm. There was a steady increase in mutant haplotypes in both genes in STOP-CTX arm overtime through the study period, reaching statistical significance (P < 0.0001).

Conclusion

The frequencies of mutations in pfdhfr and pfdhps genes were higher in STOP-CTX arm compared to CTX arm, suggesting cotrimoxazole effectively controls and selects against SP-resistant parasites.

Trial registration

ClinicalTrials.gov NCT01425073

Cotrimoxazole, an antifolate, is a fixed-dose trimethoprim-sulfamethoxazole used to prevent opportunistic infections including malaria in HIV-infected individuals. There are concerns that widespread use of cotrimoxazole for prophylaxis may result in selection of P. falciparum parasites with cross-resistance to other antifolate drugs such as sulphadoxine-pyrimethamine (SP), which is used as intermittent preventive treatment of malaria in pregnancy (IPTp) and in infants (IPTi) in Africa. This sub-study used samples from a clinical trial in which HIV-infected individuals on antiretroviral treatment were randomized to discontinue (STOP-CTX) or continue (CTX) cotrimoxazole prophylaxis for 12 months. The sub-study was designed to assess whether taking cotrimoxazole increased the risk of selecting for parasites with SP-resistant mutations in HIV-infected individuals. Samples were genotyped by sequencing to assess the prevalence of mutations associated with SP-resistance. We found there was no risk of selecting for parasites with SP-resistance mutations while on cotrimoxazole. In fact, the opposite was true; cotrimoxazole controlled parasites carrying SP-resistance mutations as evident by the gradual increase in the prevalence of parasites with mutant alleles in the STOP-CTX arm and not in the CTX-arm. We concluded that cotrimoxazole remains effective in controlling malaria infection despite of the high prevalence of SP-resistant parasites, and its use does not select for SP mutations.

Prescription of Antibacterial Drugs for HIV-Exposed, Uninfected Infants, Malawi, 2004-2010

Antimicrobial drug resistance is a serious health hazard driven by overuse. Administration of antimicrobial drugs to HIV-exposed, uninfected infants, a population that is growing and at high risk for infection, is poorly studied. We therefore analyzed factors associated with antibacterial drug administration to HIV-exposed, uninfected infants during their first year of life. Our study population was 2,152 HIV-exposed, uninfected infants enrolled in the Breastfeeding, Antiretrovirals and Nutrition study in Lilongwe, Malawi, during 2004-2010. All infants were breastfed through 28 weeks of age. Antibacterial drugs were prescribed frequently (to 80% of infants), and most (67%) of the 5,329 prescriptions were for respiratory indications. Most commonly prescribed were penicillins (43%) and sulfonamides (23%). Factors associated with lower hazard for antibacterial drug prescription included receipt of cotrimoxazole preventive therapy, receipt of antiretroviral drugs, and increased age. Thus, cotrimoxazole preventive therapy may lead to fewer prescriptions for antibacterial drugs for these infants.

Cotrimoxazole prophylaxis was associated with enteric commensal bacterial resistance among HIV-exposed infants in a randomized controlled trial, Botswana

Introduction

Despite declining risk of vertical HIV transmission, prophylactic cotrimoxazole (CTX) remains widely used to reduce morbidity and mortality in the event of HIV infection among exposed infants, with an inherent risk of conferring commensal antimicrobial resistance. Using data from a randomized, placebo‐controlled trial of infant CTX prophylaxis, we sought to quantify emergence of antibiotic resistance.

Methods

HIV‐exposed uninfected infants enrolled in the Botswana Mpepu study were randomized to prophylactic CTX or placebo between 14 and 34 days of life and continued through 15 months. Stool samples were collected from a subset of participating infants at randomization, three, and six months, and stored at −70°C prior to culture. Specimens that grew Escherichia coli (E. coli) or Klebsiella species (Klebsiella spp.) underwent antibiotic susceptibility testing by Kirby Bauer method using CTX (CTX 1.25/23.75 μg) and Amoxicillin (10 μg) in Mueller Hinton agar. Fisher's exact testing was used to compare prevalence of resistance by randomization arm (CTX/placebo).

Results and Discussion

A total of 381 stool samples from 220 infants were cultured: 118 at randomization, 151 at three months, and 112 at six‐months. E. coli was isolated from 206 specimens and Klebsiella spp. from 138 specimens. Resistance to CTX was common in both E. coli and Klebsiella spp. at the randomization visit (52.2% and 37.7% respectively) and did not differ by study arm. E. Coli isolates from CTX recipients at three and six months had 94.9% and 84.2% CTX resistance, as compared with 51.4% and 57.5% CTX resistance in isolates from placebo recipients (p=0.01). Klebsiella spp. isolates from CTX recipients had 79.0% and 68.8% CTX resistance at three and six months, as compared with 19.1% and 14.3% in isolates from placebo recipients (p<0.01).

Conclusions

HIV‐exposed infants randomized to CTX prophylaxis had increased CTX‐resistant commensal gastrointestinal bacteria compared with placebo recipients. Additional research is needed to determine the longer‐term clinical, microbiologic, and public health consequences of antimicrobial resistance selected by infant CTX prophylaxis.

Effects of concurrent exposure to antiretrovirals and cotrimoxazole prophylaxis among HIV-exposed, uninfected infants

BACKGROUND

Given the potential of cotrimoxazole preventive therapy (CPT) to prevent bacterial and malarial infections in HIV-exposed, uninfected (HEU) infants, it is important to evaluate the effects of its concurrent use with antiretroviral agents that have overlapping toxicity profiles.

METHODS

We used data from the Breastfeeding, Antiretrovirals, and Nutrition study (2004-2010) to evaluate the association of CPT and antiretrovirals with hematologic measures (hemoglobin, neutrophil, and alanine aminotransferase levels) from 6 to 48 weeks of age in 2006 HEU infants in Lilongwe, Malawi. Hazards of severe outcomes (anemia, neutropenia, and elevated alanine aminotransferase), as defined by the National Institutes of Health, were compared using Cox regression models, according to time-varying CPT (implemented June 2006), antiretroviral treatment arm (maternal triple antiretroviral, infant nevirapine, or none during 6 months of breastfeeding), and their interaction. The effects of these treatments on hemoglobin, neutrophil, and alanine aminotransferase levels were assessed using linear mixed models.

RESULTS

In Cox models, CPT was associated with an increase in severe neutropenia [hazard ratio 1.97 (1.01, 3.86)] and a decrease in severe anemia (hazard ratio 0.65 (0.48, 0.88)]. Interactions between CPT and antiretroviral treatment were not significant. By 36 weeks, there was a significant association of CPT with increased hemoglobin levels regardless of antiretroviral drug exposure.

CONCLUSIONS

In addition to expected associations with increased hazard of severe neutropenia and decreased neutrophil count, CPT was associated with reduced hazard of severe anemia and higher infant blood hemoglobin. This provides further support for CPT use in HEU infants in malaria-endemic resource-limited settings where anemia is prevalent.

Burden of asymptomatic malaria, anemia and relationship with cotrimoxazole use and CD4 cell count among HIV1-infected adults living in Gabon, Central Africa

Objective : This study determined the prevalence of asymptomatic Plasmodium (P.) falciparum infection and anemia in adults living with HIV/AIDS (PLHIV) and compared malaria prevalence between 858 HIV-infected (PLHIV) and 272 uninfected individuals in Gabon where such information are lacking. Factors influencing malaria and anemia were also investigated.

PATIENTS AND METHODS

Participants were screened for malaria. Available hemoglobin level, socio-demographic and use of prevention or treatment data were compared between both groups.

RESULTS

The prevalence of asymptomatic parasitemia was 13.5%, lower in PLHIV (7.1%) than uninfected individuals (33.8%) (p<0.01). Among the PLHIV, females (p<0.01), those aged below 25 years old (p=0.03), those with primary education (p=0.03) and those with a CD4 cell count below 200/mm3 (p=0.03) had a higher median parasitemia. Cotrimoxazole use was associated with a lower prevalence of malaria (p<0.01). Age below 25 years was independently associated with malaria in PLHIV (p<0.01). Anemia prevalence was 42.1% among the PLHIV, higher in the youngest and those with low CD4 cell count (p<0.01). P.falciparum-infected PLHIV aged below 25 years old, not under ART, with low CD4 cell count and under cotrimoxazole had the lowest median hemoglobin level.

CONCLUSION

The prevalence of asymptomatic malaria is low among the PLHIV while the burden of anemia is considerable. Age below 25 years and CD4 cell count are associated factors. The cotrimoxazole use reduces the frequency of malaria.

Co-trimoxazole Prophylaxis, Asymptomatic Malaria Parasitemia, and Infectious Morbidity in Human Immunodeficiency Virus-Exposed, Uninfected Infants in Malawi: The BAN Study

Background

Human immunodeficiency virus (HIV)-exposed infants are disproportionately at risk of morbidity and mortality compared with their HIV-unexposed counterparts. The role of co-trimoxazole preventive therapy (CPT) in reducing leading causes of infectious morbidity is unclear.

Methods

We used data from the Breastfeeding, Antiretrovirals and Nutrition (BAN) clinical trial (conducted 2004-2010, Malawi) to assess the association of (1) CPT and (2) asymptomatic malaria parasitemia with respiratory and diarrheal morbidity in infants. In June 2006, all HIV-exposed infants in BAN began receiving CPT (240 mg) from 6 to 36 weeks of age, or until weaning occurred and HIV infection was ruled out. All HIV-exposed, uninfected infants (HEIs) at 8 weeks of age (n = 1984) were included when CPT was the exposure. A subset of HEIs (n = 471) were tested for malarial parasitemia using dried blood spots from 12, 24, and 36 weeks of age. Cox proportional hazards models for recurrent gap-time data were used to examine the association of time-varying exposures on morbidity.

Results

CPT was associated with a 36% reduction in respiratory morbidity (hazard ratio [HR], 0.64 [95% confidence interval {CI}, .60-.69]) and a 41% reduction in diarrheal morbidity (HR, 0.59 [95% CI, .54-.65]). Having asymptomatic malaria parasitemia was associated with a 40% increase in respiratory morbidity (HR, 1.40 [95% CI, 1.13-1.74]) and a 50% increase in diarrheal morbidity (HR, 1.50 [95% CI, 1.09-2.06]), after adjusting for CPT.

Conclusions

CPT may have an important role to play in reducing the leading global causes of morbidity and mortality in the growing population of HEIs in malaria-endemic resource-limited settings.

Effect of co-trimoxazole on mortality in HIV-exposed but uninfected children in Botswana (the Mpepu Study): a double-blind, randomised, placebo-controlled trial

BACKGROUND

Co-trimoxazole prophylaxis reduces mortality among HIV-infected children, but efficacy in HIV-exposed but uninfected (HEU) children in a non-malarial, low-breastfeeding setting with a low risk of mother-to-child transmission of HIV is unclear.

METHODS

HEU children in Botswana were randomly assigned to receive co-trimoxazole (100 mg/20 mg once daily until age 6 months and 200 mg/40 mg once daily thereafter) or placebo from age 14-34 days to age 15 months. Mothers chose whether to breastfeed or formula feed their children. Breastfed children were randomly assigned to breastfeeding for 6 months (Botswana guidelines) or 12 months (WHO guidelines). The primary outcome, analysed by a modified intention-to-treat approach, was cumulative child mortality from treatment assignment to age 18 months. We also assessed HIV-free survival by duration of breastfeeding. This trial is registered with ClinicalTrials.gov, number NCT01229761.

FINDINGS

From June 7, 2011, to April 2, 2015, 2848 HEU children were randomly assigned to receive co-trimoxazole (n=1423) or placebo (n=1425). The data and safety monitoring board stopped the study early because of a low likelihood of benefit with co-trimoxazole. Only 153 (5%) children were lost to follow-up (76 in the co-trimoxazole group and 77 in the placebo group), and 2053 (72%) received treatment continuously to age 15 months, death, or study closure. Mortality after the start of study treatment was similar in the two study groups: 30 children died in the co-trimoxazole group, compared with 34 in the placebo group (estimated mortality at 18 months 2·4% vs 2·6%; difference -0·2%, 95% CI -1·5 to 1·0, p=0·70). We saw no difference in hospital admissions between groups (12·5% in the co-trimoxazole group vs 17·4% in the placebo group, p=0·19) or grade 3-4 clinical adverse events (16·5% vs 18·4%, p=0·18). Grade 3-4 anaemia did not differ between groups (8·1% vs 8·3%, p=0·93), but grade 3-4 neutropenia was more frequent in the co-trimoxazole group than in the placebo group (8·1% vs 5·8%, p=0·03). More co-trimoxazole resistance in commensal Escherichia coli isolated from stool samples was seen in children aged 3 or 6 months in the co-trimoxazole group than in the placebo group (p=0·001 and p=0·01, respectively). 572 (20%) children were breastfed. HIV infection and mortality did not differ significantly by duration of breastfeeding (3·9% for 6 months vs 1·9% for 12 months, p=0·21).

INTERPRETATION

Prophylactic co-trimoxazole seems to offer no survival benefit among HEU children in non-malarial, low-breastfeeding areas with a low risk of mother-to-child transmission of HIV.

FUNDING

US National Institutes of Health.

Malaria burden in a birth cohort of HIV-exposed uninfected Ugandan infants living in a high malaria transmission setting

Background

HIV-exposed, uninfected (HEU) infants suffer high morbidity and mortality in the first year of life compared to HIV-unexposed, uninfected (HUU) infants, but accurate data on the contribution of malaria are limited.

Methods

The incidence of febrile illnesses and malaria were evaluated in a birth cohort of HEU infants. Infants were prescribed daily trimethoprim–sulfamethoxazole (TS) prophylaxis from 6 weeks of age until exclusion of HIV-infection after cessation of breastfeeding. Infants were followed for all illnesses using passive surveillance and routine blood smears were done monthly. Malaria was diagnosed as a positive blood smear plus fever. Placental malaria was determined by histopathology, placental blood smear and PCR. Risk factors for time to first episode of malaria were assessed using a Cox proportional hazards model. Malaria incidence among HEU infants aged 6–12 months was compared to that in other cohorts of HEU and HUU infants from the same region.

Results

Among 361 HEU infants enrolled, 248 completed 12 months of follow-up resulting in 1562 episodes of febrile illness and 253 episodes of malaria after 305 person-years of follow-up. The incidence of febrile illness was 5.12 episodes per person-year (PPY), ranging from 4.13 episodes PPY in the first 4 months of life to 5.71 episodes PPY between 5 and 12 months of age. The overall malaria incidence was 0.83 episodes per person-year (PPY), increasing from 0.03 episodes PPY in the first 2 months of life to 2.00 episodes PPY between 11 and 12 months of age. There were no episodes of complicated malaria. The prevalence of asymptomatic parasitaemia was 1.2 % (19 of 1568 routine smears positive). Infants born to mothers with parasites detected from placental blood smears were at higher risk of malaria (hazard ratio = 4.51, P < 0.001). HEU infants in this study had a 2.4- to 3.5-fold lower incidence of malaria compared to HUU infants in other cohort studies from the same area.

Conclusion

The burden of malaria in this birth cohort of HEU infants living in a high-transmission setting and taking daily TS prophylaxis was relatively low. Alternative etiologies of fever should be considered in HEU-infants taking daily TS prophylaxis who present with fever.

Trial Registration NCT00993031, registered 8 October, 2009

Delayed acquisition of Plasmodium falciparum antigen-specific CD4(+) T cell responses in HIV-exposed uninfected Malawian children receiving daily cotrimoxazole prophylaxis

Background

Cotrimoxazole (CTX) prophylaxis, recommended in HIV-exposed uninfected (HEU) children primarily against HIV-related opportunistic infections, has been shown to have some efficacy against Plasmodium falciparum malaria. The effects of CTX prophylaxis on the acquisition of P. falciparum antigen specific CD4⁺ T cells-mediated immunity in HEU children is still not fully understood.

Methods

Peripheral blood was collected from HEU and HIV-unexposed uninfected (HUU) children at 6, 12 and 18 months of age. Proportion of CD4⁺ T cells subsets were determined by immunophenotyping. P. falciparum antigen-specific CD4⁺ T cells responses were measured by intracellular cytokine staining assay.

Results

There were no differences in the proportions of naïve, effector and memory CD4⁺ T cell subsets between HEU and HUU children at all ages. There was a trend showing acquisition of P. falciparum-specific IFN-γ and TNF-producing CD4⁺ T cells with age in both HUU and HEU children. There was, however, lower frequency of P. falciparum-specific IFN-γ-producing CD4⁺ T cells in HEU compared to HUU at 6 and 12 months, which normalized 6 months after stopping CTX prophylaxis.

Conclusion

The results demonstrate that there is delayed acquisition of P. falciparum-specific IFN-γ-producing CD4⁺ T cells in HEU children on daily cotrimoxazole prophylaxis, which is evident at 6 and 12 months of age in comparison to HUU age-matched controls. However, whether this delayed acquisition of P. falciparum-specific IFN-γ-producing CD4⁺ T cells leads to higher risk to malaria disease remains unknown and warrants further investigation.

Maternal Human Immunodeficiency Virus-Associated Hypergammaglobulinemia Reduces Transplacental Transfer of Immunoglobulin G to Plasmodium falciparum Antigens in Cameroonian Neonates

Background. Human immunodeficiency virus (HIV) infection reduces placental transfer of antibodies from mother to the fetus for many antigens; however, conflicting data exist for transfer of immunoglobulin G (IgG) to malarial antigens. The mechanism(s) underlying reduced placental transfer is unknown.

Methods. Levels of maternal and cord total IgG, IgG subclasses, and cord-to-mother ratios (CMRs) were measured in 107 mother-cord pairs to 3 malarial antigens: circumsporozoite protein (CSP), apical membrane antigen 1 (AMA-1), merozoite surface protein 1 (MSP-1), and tetanus toxoid C-fragment (TTc).

Results. Immunoglobulin G levels to CSP and TTc were lower in HIV+ mothers, and cord IgG to CSP, MSP-1, and TTc were significantly lower in neonates born to HIV+ mothers (all P values <.05). The prevalence of mothers with hypergammaglobulinemia was significantly higher among HIV+ women (68%) compared with HIV− mothers (8%) (P < .0001). Maternal hypergammaglobulinemia was associated with reduction in transplacental transfer of antibodies to CSP (P = .03), MSP-1 (P = .004), and TTc (P = .012), and CMRs <1 were found for MSP-1 (odds ratio [OR] = 6.5), TTc (OR = 4.95), and IgG1 to CSP (OR = 3.75, P = .025) in statistical models adjusted for maternal IgG.

Conclusions. Data confirmed that HIV infections are associated with lower cord antibody levels to malarial antigens and that hypergammaglobulinemia may contribute to reduced antibody transfer.

HIV-exposed, uninfected infants: new global challenges in the era of paediatric HIV elimination

The number of infants infected with HIV is declining with the rise in interventions for the elimination of paediatric HIV infection, but the number of uninfected infants exposed to HIV through their HIV-infected mothers is increasing. Interest in the health outcomes of HIV-exposed, uninfected infants has grown in the past decade, with several studies suggesting that these infants have increased mortality rates, increased infectious morbidity, and impaired growth compared with HIV-unexposed infants. However, heterogeneous results might reflect the inherent challenges in studies of HIV-exposed, uninfected infants, which need large populations with appropriate, contemporaneous comparison groups and repeated HIV testing throughout the period of breastfeeding. We review the effects of HIV exposure on mortality, morbidity, and growth, discuss the immunological abnormalities identified so far, and provide an overview of interventions that could be effective in this susceptible population. As the number of infants infected with HIV declines, the health needs of HIV-exposed, uninfected infants should be prioritised further, to ensure that post-2015 Sustainable Development Goals are achieved.