Rwanda was the first low-income African country to introduce RotaTeq vaccine into its Expanded Programme on Immunization in May 2012. To gain insights into the overall genetic make-up and evolution ...of Rwandan G1P8 strains pre- and post-vaccine introduction, rotavirus positive fecal samples collected between 2011 and 2016 from children under the age of 5 years as part of ongoing surveillance were genotyped with conventional RT-PCR based methods and whole genome sequenced using the Illumina MiSeq platform. From a pool of samples sequenced (n = 158), 36 were identified as G1P8 strains (10 pre-vaccine and 26 post-vaccine), of which 35 exhibited a typical Wa-like genome constellation. However, one post vaccine strain, RVA/Human-wt/RWA/UFS-NGS:MRC-DPRU442/2012/G1P8, exhibited a RotaTeq vaccine strain constellation of G1-P8-I2-R2-C2-M2-A3-N2-T6-E2-H3, with most of the gene segments having a close relationship with a vaccine derived reassortant strain, previously reported in USA in 2010 and Australia in 2012. The study strains segregated into two lineages, each containing a paraphyletic pre- and post-vaccine introduction sub-lineages. In addition, the study strains demonstrated close relationship amongst each other when compared with globally selected group A rotavirus (RVA) G1P8 reference strains. For VP7 neutralization epitopes, amino acid substitutions observed at positions T91A/V, S195D and M217T in relation to the RotaTeq vaccine were radical in nature and resulted in a change in polarity from a polar to non-polar molecule, while for the VP4, amino acid differences at position D195G was radical in nature and resulted in a change in polarity from a polar to non-polar molecule. The polarity change at position T91A/V of the neutralizing antigens might play a role in generating vaccine-escape mutants, while substitutions at positions S195D and M217T may be due to natural fluctuation of the RVA. Surveillance of RVA at whole genome level will enhance further assessment of vaccine impact on circulating strains, the frequency of reassortment events under natural conditions and epidemiological fitness generated by such events.
Although the introduction of rotavirus vaccines has substantially contributed to the reduction in rotavirus morbidity and mortality, concerns persist about the re-emergence of variant strains that ...might alter vaccine effectiveness in the long term. The G9 strains re-emerged in Africa during the mid-1990s and have more recently become predominant in some countries, such as Ghana and Zambia. In Rwanda, during the 2011 to 2015 routine surveillance period, G9P8 persisted during both the pre- and post-vaccine periods. The pre-vaccination cohort was based on the surveillance period of 2011 to 2012, and the post-vaccination cohort was based on the period of 2013 to 2015, excluding 2014. The RotaTeq
vaccine that was first introduced in Rwanda in 2012 is genotypically heterologous to Viral Protein 7 (VP7) G9. This study elucidated the whole genome of Rwandan G9P8 rotavirus strains pre- and post-RotaTeq
vaccine introduction. Fecal samples from Rwandan children under the age of five years (pre-vaccine n = 23; post-vaccine n = 7), conventionally genotyped and identified as G9P8, were included. Whole-genome sequencing was then performed using the Illumina
MiSeq platform. Phylogenetic analysis and pair-wise sequence analysis were performed using MEGA6 software. Distinct clustering of three post-vaccination study strains was observed in all 11 gene segments, compared to the other Rwandan G9P8 study strains. Specific amino acid differences were identified across the gene segments of these three 2015 post-vaccine strains. Important amino acid differences were identified at position N242S in the VP7 genome segment of the three post-vaccine G9 strains compared to the other G9 strains. This substitution occurs at a neutralization epitope site and may slightly affect protein interaction at that position. These findings indicate that the Rwandan G9P8 strains revealed a distinct sub-clustering pattern among post-vaccination study strains circulating in Rwanda, with changes at neutralization epitopes, which may play a role in neutralization escape from vaccine candidates. This emphasizes the need for continuous whole-genome surveillance to better understand the evolution and epidemiology of the G9P8 strains post-vaccination.
With increased availability of paediatric combination antiretroviral therapy (cART) in resource limited settings, cART outcomes and factors associated with outcomes should be assessed.
HIV-infected ...children <15 years of age, initiating cART in Kigali, Rwanda, were followed for 18 months. Prospective clinical and laboratory assessments included weight-for-age (WAZ) and height-for-age (HAZ) z-scores, complete blood cell count, liver transaminases, creatinine and lipid profiles, CD4 T-cell count/percent, and plasma HIV-1 RNA concentration. Clinical success was defined as WAZ and WAZ >-2, immunological success as CD4 cells ≥500/mm3 and ≥25% for respectively children over 5 years and under 5 years, and virological success as a plasma HIV-1 RNA concentration <40 copies/mL.
Between March 2008 and December 2009, 123 HIV-infected children were included. The median (interquartile (IQR) age at cART initiation was 7.4 (3.2, 11.5) years; 40% were <5 years and 54% were female. Mean (95% confidence interval (95%CI)) HAZ and WAZ at baseline were -2.01 (-2.23, -1.80) and -1.73 (-1.95, -1.50) respectively and rose to -1.75 (-1.98, -1.51) and -1.17 (-1.38, -0.96) after 12 months of cART. The median (IQR) CD4 T-cell values for children <5 and ≥5 years of age were 20% (13, 28) and 337 (236, 484) cells/mm3 respectively, and increased to 36% (28, 41) and 620 (375, 880) cells/mm3. After 12 months of cART, 24% of children had a detectable viral load, including 16% with virological failure (HIV-RNA>1000 c/mL). Older age at cART initiation, poor adherence, and exposure to antiretrovirals around birth were associated with virological failure. A third (33%) of children had side effects (by self-report or clinical assessment), but only 9% experienced a severe side effect requiring a cART regimen change.
cART in Rwandan HIV-infected children was successful but success might be improved further by initiating cART as early as possible, optimizing adherence and optimizing management of side effects.
Africa has a high level of genetic diversity of rotavirus strains, which is suggested to be a possible reason contributing to the suboptimal effectiveness of rotavirus vaccines in this region. One ...strain that contributes to this rotavirus diversity in Africa is the G8P4. This study aimed to elucidate the entire genome and evolution of Rwandan G8P4 strains. Illumina sequencing was performed for twenty-one Rwandan G8P4 rotavirus strains. Twenty of the Rwandan G8P4 strains had a pure DS-1-like genotype constellation, and one strain had a reassortant genotype constellation. Notable radical amino acid differences were observed at the neutralization sites when compared with cognate regions in vaccine strains potentially playing a role in neutralization escape. Phylogenetic analysis revealed that the closest relationship was with East African human group A rotavirus (RVA) strains for five of the genome segments. Two genome sequences of the NSP4 genome segment were closely related to bovine members of the DS-1-like family. Fourteen VP1 and eleven VP3 sequences had the closest relationships with the RotaTeq™ vaccine WC3 bovine genes. These findings suggest that the evolution of VP1 and VP3 might have resulted from reassortment events with RotaTeq™ vaccine WC3 bovine genes. The close phylogenetic relationship with East African G8P4 strains from Kenya and Uganda suggests co-circulation in these countries. These findings highlight the need for continued whole-genomic surveillance to elucidate the evolution of G8P4 strains, especially after the introduction of rotavirus vaccination.
All infants born to HIV-positive mothers have maternal HIV antibodies, sometimes persistent for 18 months. When Polymerase Chain Reaction (PCR) is not available, August 2006 World Health Organization ...(WHO) recommendations suggest that clinical criteria may be used for starting antiretroviral treatment (ART) in HIV seropositive children <18 months. Predictors are at least two out of sepsis, severe pneumonia and thrush, or any stage 4 defining clinical finding according to the WHO staging system.
From January 2005 to October 2006, we conducted a prospective study on 236 hospitalized children <18 months old with a positive HIV serological test at the national reference hospital in Kigali. The following data were collected: PCR, clinical signs and CD4 cell count. Current proposed clinical criteria were present in 148 of 236 children (62.7%) and in 95 of 124 infected children, resulting in 76.6% sensitivity and 52.7% specificity. For 87 children (59.0%), clinical diagnosis was made based on severe unexplained malnutrition (stage 4 clinical WHO classification), of whom only 44 (50.5%) were PCR positive. Low CD4 count had a sensitivity of 55.6% and a specificity of 78.5%.
As PCR is not yet widely available, clinical diagnosis is often necessary, but these criteria have poor specificity and therefore have limited use for HIV diagnosis. Unexplained malnutrition is not clearly enough defined in WHO recommendations. Extra pulmonary tuberculosis (TB), almost impossible to prove in young children, may often be the cause of malnutrition, especially in HIV-affected families more often exposed to TB. Food supplementation and TB treatment should be initiated before starting ART in children who are staged based only on severe malnutrition.
Congenital heart diseases (CHD) are commonly associated with genetic defects. Our study aimed at determining the occurrence and pattern of CHD association with genetic defects among pediatric ...patients in Rwanda.
A total of 125 patients with clinical features suggestive of genetic defects were recruited. Echocardiography and standard karyotype studies were performed in all patients.
CHDs were detected in the majority of patients with genetic defects. The commonest isolated CHD was ventricular septal defect found in many cases of Down syndrome. In total, chromosomal abnormalities represented the majority of cases in our cohort and were associated with various types of CHDs.
Our findings showed that CHDs are common in Rwandan pediatric patients with genetic defects. These results suggest that a routine echocardiography assessment combined with systematic genetic investigations including standard karyotype should be mandatory in patients presenting characteristic clinical features in whom CHD is suspected to be associated with genetic defect.
In some settings, rotavirus vaccines have been associated with a small risk of intussusception. This study describes the demographics, clinical characteristics and outcomes of children with ...intussusception in Rwanda before vaccine introduction in May 2012.
We retrospectively reviewed data on pediatric patients treated for intussusception at University Teaching Hospital of Kigali from January 2009 to June 2012. Hospital registries were reviewed to identify intussusception cases. Archived patient files were abstracted to collect data on demographics, clinical presentation, surgery and outcome.
During the study period, 70 children ≤19 years of age were treated for intussusception and patient files were retrieved for 60 (86%) cases. Over half of patients (58%) were <1 year of age and 90% were transferred from a district hospital. Only 30% of patients presented within 3 days of symptom onset and 35% experienced a delay of ≥6 hours between surgical review and surgery. Surgical complications were experienced by 35% of children. Over 1 quarter (28%) of children died. Compared with children who survived, children who died were significantly more likely to have experienced complications (21% vs. 71%; P < 0.001) and to be female (28% vs. 65%; P = 0.009).
Mortality due to intussusception was high among Rwanda children. Delays in presentation and treatment were common. Assessing trends in the number of cases to monitor for vaccine-associated intussusception will be difficult. Additional work is needed to further understand risk factors for mortality, to calculate incidence rates and to monitor the safety of the rotavirus vaccination program.
To determine the long-term outcomes of treatment and prevalence of genotypic drug resistance in children and adolescents on combination antiretroviral therapy.
A cross-sectional study (September 2009 ...to October 2010) in which clinical, immunologic and virologic outcomes were assessed at a single-study visit and through patient records in a cohort of HIV-infected children and adolescents. Risk factors for clinical and immunologic responses and virologic outcome were evaluated using logistic regression, and the accuracy of clinical and immunologic criteria in identifying virologic failure was assessed.
Four hundred twenty-four patients were enrolled with a median age of 10.8 years (range: 1.7-18.8) and a median duration on combination antiretroviral therapy of 3.4 years (range: 1.0-8.1). Thirty-three percent were stunted and 17% underweight. Eighty-four percent (95% confidence interval: 79-87) of children >5 years had CD4 ≥350 cells/mm and in 74% (95% confidence interval: 62-84) of younger children CD4% was ≥25. CD4 values and age at combination antiretroviral therapy initiation were independently associated with CD4 outcomes; 124 (29%) had HIV-1 RNA ≥1000 copies/mL, with no significant predictors. Sensitivity for weight-for-age and height-for-age and CD4 cells (<350/mm) remained under 50% (15-42%); CD4 cells showed the best specificity, ranging from 91% to 97%. Of 52 samples tested, ≥1 mutations were observed in 91% (nucleoside reverse transcriptase inhibitors) and 95% (non-nucleoside reverse transcriptase inhibitors); 1 to 2 thymidine analogue-associated mutations were detected in 16 (31%) and ≥3 thymidine analogue-associated mutations in 7 (13%).
Nearly 1 in 3 children showed virologic failure, and >10% of the subgroup of children with treatment failure in whom genotyping was performed demonstrated multiple HIV drug resistance mutations. Neither clinical condition nor CD4 cells were good indicators for treatment failure.
To date, an estimated 10% of children eligible for antiretroviral treatment (ART) receive it, and the frequency of retention in programs is unknown. We evaluated the 2-year risks of death and loss to ...follow-up (LTFU) of children after ART initiation in a multicenter study in sub-Saharan Africa.
Pooled analysis of routine individual data from 16 participating clinics produced overall Kaplan-Meier estimates of the probabilities of death or LTFU after ART initiation. Risk factors analysis used Weibull regression, accounting for between-cohort heterogeneity.
The median age of 2405 children at ART initiation was 4.9 years (12%, younger than 12 months), 52% were male, 70% had severe immunodeficiency, and 59% started ART with a nonnucleoside reverse transcriptase inhibitor. The 2-year risk of death after ART initiation was 6.9% (95% confidence interval CI: 5.9 to 8.1), independently associated with baseline severe anemia (adjusted hazard ratio aHR: 4.10 CI: 2.36 to 7.13), immunodeficiency (adjusted aHR: 2.95 CI: 1.49 to 5.82), and severe clinical status (adjusted aHR: 3.64 CI: 1.95 to 6.81); the 2-year risk of LTFU was 10.3% (CI: 8.9 to 11.9), higher in children with severe clinical status.
Once on treatment, the 2-year risk of death is low but the LTFU risk is substantial. ART is still mainly initiated at advanced disease stage in African children, reinforcing the need for early HIV diagnosis, early initiation of ART, and procedures to increase program retention.
The aim of this study was to determine the prevalence of hepatitis B virus (HBV) infection in a cohort of HIV-infected Rwandan children and adolescents on combination antiretroviral therapy (cART), ...and the success rate of HBV vaccination in those children found to be HBV negative.
HIV-infected children and adolescents (age 8-17 years) receiving cART with CD4 T-cells count ≥200 cells/mm and/or ≥15% and without prior HBV vaccination (by history, vaccination cards and clinic records) underwent serologic testing for past (negative HBV surface antigen HBsAg with positive antibody to HBV core antigen cAb and to HBsAg anti-HBs) or active HBV infection (positive HBsAg). Children with any positive HBV serologic tests were excluded from further vaccination; all others completed 3 HBV immunizations with 10 µg of ENGERIX-B. Anti-HBs titer was measured 4-6 weeks after the last immunization.
Of 88 children, 6 (7%) children had active HBV infection and 8 (9%) had past HBV infection. The median (interquartile range) age, CD4 T-cell count and cART duration were 12.3 (10.1-13.9) years, 626 (503 to 942) cells/mm and 1.9 (1.5-2.7) years, respectively. Seventeen children had detectable plasma HIV-1 RNA. Seventy-3 children completed 3 immunizations with median (interquartile range) postimmunization anti-HBs concentration of 151 mIU/mL (1.03-650). Overall, 52 children (71%, 95% confidence interval: 61-82) developed a protective anti-HBs response. HIV-1 RNA and CD4 T-cell count were independent predictors of a protective anti-HBs response. Protective anti-HBs response was achieved in 82% of children with undetectable HIV-1 RNA and 77% with CD4 T cells ≥350/mm.
The substantial HBV prevalence in this cohort suggests that HIV-infected Rwandan children should be screened for HBV before cART initiation. HIV viral suppression and CD4 T cells ≥350/mm favored the likelihood of a protective response after HBV vaccination.
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