Etiology of Severe Acute Watery Diarrhea in Children in the Global Rotavirus Surveillance Network Using Quantitative Polymerase Chain Reaction

Background

The etiology of acute watery diarrhea remains poorly characterized, particularly after rotavirus vaccine introduction.

Methods

We performed quantitative polymerase chain reaction for multiple enteropathogens on 878 acute watery diarrheal stools sampled from 14643 episodes captured by surveillance of children <5 years of age during 2013-2014 from 16 countries. We used previously developed models of the association between pathogen quantity and diarrhea to calculate pathogen-specific weighted attributable fractions (AFs).

Results

Rotavirus remained the leading etiology (overall weighted AF, 40.3% [95% confidence interval {CI}, 37.6%-44.3%]), though the AF was substantially lower in the Americas (AF, 12.2 [95% CI, 8.9-15.6]), based on samples from a country with universal rotavirus vaccination. Norovirus GII (AF, 6.2 [95% CI, 2.8-9.2]), Cryptosporidium (AF, 5.8 [95% CI, 4.0-7.6]), Shigella (AF, 4.7 [95% CI, 2.8-6.9]), heat-stable enterotoxin-producing Escherichia coli (ST-ETEC) (AF, 4.2 [95% CI, 2.0-6.1]), and adenovirus 40/41 (AF, 4.2 [95% CI, 2.9-5.5]) were also important. In the Africa Region, the rotavirus AF declined from 54.8% (95% CI, 48.3%-61.5%) in rotavirus vaccine age-ineligible children to 20.0% (95% CI, 12.4%-30.4%) in age-eligible children.

Conclusions

Rotavirus remained the leading etiology of acute watery diarrhea despite a clear impact of rotavirus vaccine introduction. Norovirus GII, Cryptosporidium, Shigella, ST-ETEC, and adenovirus 40/41 were also important. Prospective surveillance can help identify priorities for further reducing the burden of diarrhea.

Estimated reductions in hospitalizations and deaths from childhood diarrhea following implementation of rotavirus vaccination in Africa

INTRODUCTION

Rotavirus is the leading cause of hospitalizations and deaths from diarrhea. 33 African countries had introduced rotavirus vaccines by 2016. We estimate reductions in rotavirus hospitalizations and deaths for countries using rotavirus vaccination in national immunization programs and the potential of vaccine introduction across the continent. Areas covered: Regional rotavirus burden data were reviewed to calculate hospitalization rates, and applied to under-5 population to estimate baseline hospitalizations. Rotavirus mortality was based on 2013 WHO estimates. Regional pre-licensure vaccine efficacy and post-introduction vaccine effectiveness studies were used to estimate summary effectiveness, and vaccine coverage was applied to calculate prevented hospitalizations and deaths. Uncertainties around input parameters were propagated using boot-strapping simulations. In 29 African countries that introduced rotavirus vaccination prior to end 2014, 134,714 (IQR 112,321-154,654) hospitalizations and 20,986 (IQR 18,924-22,822) deaths were prevented in 2016. If all African countries had introduced rotavirus vaccines at benchmark immunization coverage, 273,619 (47%) (IQR 227,260-318,102) hospitalizations and 47,741 (39%) (IQR 42,822-52,462) deaths would have been prevented. Expert commentary: Rotavirus vaccination has substantially reduced hospitalizations and deaths in Africa; further reductions are anticipated as additional countries implement vaccination. These estimates bolster wider introduction and continued support of rotavirus vaccination programs.

Early impact of rotavirus vaccine in under 5year old children hospitalized due to diarrhea, Swaziland

BACKGROUND

Swaziland introduced rotavirus vaccine in the National Immunization Program, in May 2015, with the objective of reducing the burden of rotavirus diarrheal disease. We monitored the early impact of the vaccine in reducing rotavirus diarrhea.

METHODS

We conducted sentinel rotavirus surveillance from January 2013 to December 2016 in children under five years of age admitted due to diarrhea attending Mbabane Government Referral Hospital in the Hhohho Region and Raleigh Fitkin Memorial Hospital in the Manzini Region. All cases had stool samples collected and tested for rotavirus antigen by enzyme immunoassay.

RESULTS

Between 2013 and 2016, 596 samples were collected and tested. Rotavirus positivity reduced from average of 50.8% (172/338) (in 2013-2014 (pre vaccine period)) to 29% (24/82) in 2016, post-vaccine introduction. The median age of children with rotavirus infection increased from average of 10months in 2013-2014 to 13.7months in 2016. The peak season for all-cause diarrhea and rotavirus-specific hospitalizations among children under five years of age was June-August in all years with a blunting of the peak season in 2016. Rotavirus positivity among children 0-11months reduced from an average of 49% in 2013-2014 (116/236) to 33% (15/45) in 2016, a 33% reduction following rotavirus vaccine introduction.

CONCLUSION

There has been a rapid reduction of all-cause diarrhea and rotavirus hospitalizations in Swaziland, particularly in young children and during the rotavirus season, after the introduction rotavirus vaccine. Continued surveillance is needed to monitor the long-term impact of rotavirus vaccine introduction.

Monovalent Rotavirus Vaccine Effectiveness and Impact on Rotavirus Hospitalizations in Zanzibar, Tanzania: Data From the First 3 Years After Introduction

Background

Low-income settings challenge the level of protection provided by live attenuated oral rotavirus vaccines. Rotarix (RV1) was introduced in the United Republic of Tanzania in early 2013, with 2 doses given at the World Health Organization-recommended schedule of ages 6 and 10 weeks, along with oral poliovirus vaccine.

Methods

We performed active surveillance for rotavirus hospitalizations at the largest hospital in Zanzibar, Tanzania, from 2010 through 2015. Using a case-test-negative control design, we estimated the vaccine effectiveness (VE) of 2 RV1 doses in preventing rotavirus hospitalizations.

Results

Based on 204 rotavirus case patients and 601 test-negative controls aged 5-23 months, the VE of 2 RV1 doses against hospitalization for rotavirus diarrhea was 57% (95% confidence interval, 14%-78%). VE tended to increase against hospitalizations with higher severity, reaching 69% (95% confidence interval, 15%-88%) against the severity score for the top quarter of case patients. Compared with the prevaccine period, there were estimated reductions of 40%, 46%, and 69% in the number of rotavirus hospitalizations among infants in 2013, 2014, and 2015, respectively, and reductions of 36%, 26%, and 64%, respectively, among children aged <5 years.

Conclusions

With data encompassing 3 years before and 3 years after vaccine introduction, our results indicate that successful delivery of RV1 on the current World Health Organization schedule can provide substantial health benefits in a resource-limited setting.

Review of Naturally Occurring Intussusception in Young Children in the WHO African Region prior to the Era of Rotavirus Vaccine Utilization in the Expanded Programme of Immunization

Rotavirus vaccines, Rotarix and RotaTeq, are increasingly being introduced in national immunization programmes in Africa to prevent severe dehydrating acute gastroenteritis. A low-level risk of intussusception has been associated with rotavirus vaccines. We reviewed published data on intussusception in children <2 years of age in Africa. PubMed electronic database search was used to retrieve papers published on intussusception. The search was further refined to identify surveillance reports and case series conducted from 1980 to 2014, with at least 25 cases. The initial search identified 34 studies, and the refined search yielded 16. Intussusception occurred naturally in infants 2-4 months and peaked around 5-8 months of age. Delayed presentation was common and required surgical intervention in 87% (1008 of 1158) of cases with a high CFR, 10-33.7%. In African children, intussusception has been reported infrequently at a young age when the first dose of rotavirus vaccine is administered.

Feasibility of using regional sentinel surveillance to monitor the rotavirus vaccine impact, effectiveness and intussusception incidence in the African Region

The 9th African rotavirus symposium was held in Maputo, Mozambique from the 8th to 10th of December 2015, including a total of 101 delegates from 17 countries, 15 of which were African countries. This forum brought together participants with various expertise including scientists, clinicians, immunization program managers, public health officials and policymakers. By the time of the symposium, 29/47 (61%) of countries in the World Health Organization (WHO) African Region had introduced rotavirus vaccine into their routine immunization program. Countries that had started monitoring impact and effectiveness of the rotavirus vaccines as well as potential adverse events following immunization (AEFI) including intussusception) also participated. Seven Rotarix® vaccine-using countries and another four countries that are using the Rotateq® vaccine are conducting systematic surveillance on intussusception and report data to the WHO and partners. The symposium concluded that the regional rotavirus surveillance network has played a crucial role in pre-vaccine data through documenting burden and epidemiology of rotavirus diarrhea in Africa, seasonal trends and identifying common rotavirus genotypes. The sentinel surveillance platform is now being used to assess the impact of the vaccines and monitoring adverse events with a focus on intussusception.

Effectiveness of Pentavalent Rotavirus Vaccine Under Conditions of Routine Use in Rwanda

BACKGROUND

Rotavirus vaccine efficacy is lower in low-income countries than in high-income countries. Rwanda was one of the first low-income countries in sub-Saharan Africa to introduce rotavirus vaccine into its national immunization program. We sought to evaluate rotavirus vaccine effectiveness (VE) in this setting.

METHODS

VE was assessed using a case-control design. Cases and test-negative controls were children who presented with a diarrheal illness to 1 of 8 sentinel district hospitals and 10 associated health centers and had a stool specimen that tested positive (cases) or negative (controls) for rotavirus by enzyme immunoassay. Due to high vaccine coverage almost immediately after vaccine introduction, the analysis was restricted to children 7-18 weeks of age at time of rotavirus vaccine introduction. VE was calculated as (1 - odds ratio) × 100, where the odds ratio was the adjusted odds ratio for the rotavirus vaccination rate among case-patients compared with controls.

RESULTS

Forty-eight rotavirus-positive and 152 rotavirus-negative children were enrolled. Rotavirus-positive children were significantly less likely to have received rotavirus vaccine (33/44 [73%] unvaccinated) compared with rotavirus-negative children (81/136 [59%] unvaccinated) (P= .002). A full 3-dose series was 75% (95% confidence interval [CI], 31%-91%) effective against rotavirus gastroenteritis requiring hospitalization or a health center visit and was 65% (95% CI, -80% to 93%) in children 6-11 months of age and 81% (95% CI, 25%-95%) in children ≥12 months of age.

CONCLUSIONS

Rotavirus vaccine is effective in preventing rotavirus disease in Rwandan children who began their rotavirus vaccine series from 7 to 18 weeks of age. Protection from vaccination was sustained after the first year of life.

Impact and Effectiveness of Monovalent Rotavirus Vaccine Against Severe Rotavirus Diarrhea in Ghana

BACKGROUND

Ghana was among the first African nations to introduce monovalent rotavirus vaccine (RV1) into its childhood immunization schedule in April 2012. We aimed to assess the impact of vaccine introduction on rotavirus and acute gastroenteritis (AGE) hospitalizations and to estimate vaccine effectiveness (VE).

METHODS

Using data from 2 teaching hospitals, monthly AGE and rotavirus admissions by age were examined 40 months before and 31 months after RV1 introduction using interrupted time-series analyses. From January 2013, we enrolled children <2 years of age who were eligible for RV1 from a total of 7 sentinel sites across the country. To estimate VE, we fit unconditional logistic regression models to calculate odds ratios of vaccination by rotavirus case-patient status, controlling for potential confounders.

RESULTS

Vaccine coverage ranged from 95% to 100% for dose 1 and 93% to 100% for dose 2. In the first 3 years after vaccine introduction, the percentage of hospital admissions positive for rotavirus fell from 48% in the prevaccine period to 28% (49% adjusted rate reduction; 95% confidence interval [CI], 32%-63%) postvaccination among <5-year-olds. With high vaccine coverage, it was not possible to arrive at robust VE estimates; any-dose VE against rotavirus hospitalization was estimated at 60% (95% CI, -2% to 84%;P= .056).

CONCLUSIONS

Results from the first 3 years following RV1 introduction suggest substantial reductions of pediatric diarrheal disease as a result of vaccination. Our VE estimate is consistent with the observed rotavirus decrease and with efficacy estimates from elsewhere in sub-Saharan Africa.

Effect of pentavalent rotavirus vaccine introduction on hospital admissions for diarrhoea and rotavirus in children in Rwanda: a time-series analysis

BACKGROUND

In May, 2012, Rwanda became the first low-income African country to introduce pentavalent rotavirus vaccine into its routine national immunisation programme. Although the potential health benefits of rotavirus vaccination are huge in low-income African countries that account for more than half the global deaths from rotavirus, concerns remain about the performance of oral rotavirus vaccines in these challenging settings.

METHODS

We conducted a time-series analysis to examine trends in admissions to hospital for non-bloody diarrhoea in children younger than 5 years in Rwanda between Jan 1, 2009, and Dec 31, 2014, using monthly discharge data from the Health Management Information System. Additionally, we reviewed the registries in the paediatric wards at six hospitals from 2009 to 2014 and abstracted the number of total admissions and admissions for diarrhoea in children younger than 5 years by admission month and age group. We studied trends in admissions specific to rotavirus at one hospital that had undertaken active rotavirus surveillance from 2011 to 2014. We assessed changes in rotavirus epidemiology by use of data from eight active surveillance hospitals.

FINDINGS

Compared with the 2009-11 prevaccine baseline, hospital admissions for non-bloody diarrhoea captured by the Health Management Information System fell by 17-29% from a pre-vaccine median of 4051 to 2881 in 2013 and 3371 in 2014, admissions for acute gastroenteritis captured in paediatric ward registries decreased by 48-49%, and admissions specific to rotavirus captured by active surveillance fell by 61-70%. The greatest effect was recorded in children age-eligible to be vaccinated, but we noted a decrease in the proportion of children with diarrhoea testing positive for rotavirus in almost every age group.

INTERPRETATION

The number of admissions to hospital for diarrhoea and rotavirus in Rwanda fell substantially after rotavirus vaccine implementation, including among older children age-ineligible for vaccination, suggesting indirect protection through reduced transmission of rotavirus. These data highlight the benefits of routine vaccination against rotavirus in low-income settings.

FUNDING

Gavi, the Vaccine Alliance and the Government of Rwanda.

An outbreak of pneumococcal meningitis among older children (≥5 years) and adults after the implementation of an infant vaccination programme with the 13-valent pneumococcal conjugate vaccine in Ghana

BACKGROUND

An outbreak of pneumococcal meningitis among non-infant children and adults occurred in the Brong-Ahafo region of Ghana between December 2015 and April 2016 despite the recent nationwide implementation of a vaccination programme for infants with the 13-valent pneumococcal conjugate vaccine (PCV13).

METHODS

Cerebrospinal fluid (CSF) specimens were collected from patients with suspected meningitis in the Brong-Ahafo region. CSF specimens were subjected to Gram staining, culture and rapid antigen testing. Quantitative PCR was performed to identify pneumococcus, meningococcus and Haemophilus influenzae. Latex agglutination and molecular serotyping were performed on samples. Antibiogram and whole genome sequencing were performed on pneumococcal isolates.

RESULTS

Eight hundred eighty six patients were reported with suspected meningitis in the Brong-Ahafo region during the period of the outbreak. In the epicenter district, the prevalence was as high as 363 suspected cases per 100,000 people. Over 95 % of suspected cases occurred in non-infant children and adults, with a median age of 20 years. Bacterial meningitis was confirmed in just under a quarter of CSF specimens tested. Pneumococcus, meningococcus and Group B Streptococcus accounted for 77 %, 22 % and 1 % of confirmed cases respectively. The vast majority of serotyped pneumococci (80 %) belonged to serotype 1. Most of the pneumococcal isolates tested were susceptible to a broad range of antibiotics, with the exception of two pneumococcal serotype 1 strains that were resistant to both penicillin and trimethoprim-sulfamethoxazole. All sequenced pneumococcal serotype 1 strains belong to Sequence Type (ST) 303 in the hypervirulent ST217 clonal complex.

CONCLUSION

The occurrence of a pneumococcal serotype 1 meningitis outbreak three years after the introduction of PCV13 is alarming and calls for strengthening of meningitis surveillance and a re-evaluation of the current vaccination programme in high risk countries.

Selective Estrogen-Receptor Modulators and Aromatase Inhibitors: Promising New Medical Therapies for Endometriosis?

Endometriosis is an estrogen-dependent disease and estrogen-related pathways are imbalanced in women with endometriosis. One of the key enzymes in estrogen synthesis is aromatase. Inhibiting this pathway at several points is a promising idea for the treatment of endometriosis. The third generation of aromatase inhibitors is becoming more potent in efficacy, with fewer side effects than previous generations, but cotreatment with other hormones is needed to inhibit ovarian stimulation. Other components that promote estrogen synthesis such as COX-2 can also be potentially targeted. Selective estrogen-receptor modulators could also be interesting in view of their tissue-specific effect. However, all these new drugs are still in an early phase of development. At present, it is too early to conclude that aromatase inhibitors, COX-2 inhibitors or selective estrogen-receptor modulators really present any added value compared with the existing drugs that can be used to achieve hormonal suppression in the medical treatment of endometriosis.

The Economic Burden Attributable to a Child's Inpatient Admission for Diarrheal Disease in Rwanda

Background

Diarrhea is one of the leading causes of childhood morbidity and mortality. Hospitalization for diarrhea can pose a significant burden to health systems and households. The objective of this study was to estimate the economic burden attributable to hospitalization for diarrhea among children less than five years old in Rwanda. These data can be used by decision-makers to assess the impact of interventions that reduce diarrhea morbidity, including rotavirus vaccine introduction.

Methods

This was a prospective costing study where medical records and hospital bills for children admitted with diarrhea at three hospitals were collected to estimate resource use and costs. Hospital length of stay was calculated from medical records. Costs incurred during the hospitalization were abstracted from the hospital bills. Interviews with the child’s caregivers provided data to estimate household costs which included transport costs and lost income. The portion of medical costs borne by insurance and household were reported separately. Annual economic burden before and after rotavirus vaccine introduction was estimated by multiplying the reported number of diarrhea hospitalizations in public health centers and district hospitals by the estimated economic burden per hospitalization. All costs are presented in 2014 US$.

Results

Costs for 203 children were analyzed. Approximately 93% of the children had health insurance coverage. Average hospital length of stay was 5.3 ± 3.9 days. Average medical costs for each child for the illness resulting in a hospitalization were $44.22 ± $23.74 and the total economic burden was $101, of which 65% was borne by the household. For households in the lowest income quintile, the household costs were 110% of their monthly income. The annual economic burden to Rwanda attributable to diarrhea hospitalizations ranged from $1.3 million to $1.7 million before rotavirus vaccine introduction.

Conclusion

Households often bear the largest share of the economic burden attributable to diarrhea hospitalization and the burden can be substantial, especially for households in the lowest income quintile.

c-Jun NH2-terminal kinase inhibitor bentamapimod reduces induced endometriosis in baboons: an assessor-blind placebo-controlled randomized study

OBJECTIVE

To test the hypothesis that the c-Jun NH2-terminal kinase (JNK) inhibitor (JNKI) bentamapimod (AS602801/PGL5001) can reduce induced endometriosis in baboons.

DESIGN

Prospective randomized placebo-controlled study.

SETTING

Nonhuman primate research center.

ANIMAL(S)

Twenty baboons each underwent four laparoscopies. Initial screening laparoscopy (L1) was followed after one rest cycle by an endometriosis-induction laparoscopy (L2). Fifty days after L2, the baboons were randomized just before staging laparoscopy (L3). Treatment lasted for 60 days, followed by a post-treatment staging laparoscopy (L4).

INTERVENTION(S)

Randomization before a 60-day treatment in four groups: daily placebo (n = 5), daily oral administration of 20 mg/kg JNKI (n = 5), concomitant daily oral administration of 20 mg/kg JNKI and 10 mg medroxyprogesterone acetate (MPA; n = 5), or subcutaneous administration of 3 mg cetrorelix every 3 days (n = 5).

MAIN OUTCOME MEASURE(S)

Type, surface area and volume of endometriotic lesions, and revised American Society for Reproductive Medicine score and stage were recorded during L3 and L4. Menstrual cycle length and serum hormonal concentration were recorded before and after treatment.

RESULT(S)

Compared with placebo, treatment with JNKI, JNKI + PMA, or cetrorelix resulted in lower total surface area and volume of endometriotic lesions. Remodeling of red active lesions into white lesions was observed more frequently in baboons treated with JNKI + MPA than in baboons treated with JNKI only. Menstrual cycle length and serum hormonal concentration were similar between placebo and JNKI groups.

CONCLUSION(S)

JNKI alone was as effective as JNKI + MPA or cetrorelix in reducing induced endometriosis in baboons, but without severe side effects or effect on cycle length or serum reproductive hormones.

Strengthening laboratory capacity through the surveillance of rotavirus gastroenteritis in Central Africa: the Surveillance Épidémiologique en Afrique Centrale (SURVAC) Project

OBJECTIVES

The goal of the SURVAC pilot project was to strengthen disease surveillance and response in three countries; Cameroon (CAE), Democratic Republic of the Congo (DRC) and Central African Republic (CAR).

METHODS

Seven laboratories involved in rotavirus surveillance were provided with equipment, reagents and supplies. CDC and WHO staff provided on-site classroom and bench training in biosafety, quality assurance, quality control (QC), rotavirus diagnosis using Enzyme Immunoassay (EIA) and genotyping of rotavirus strains using the Reverse Transcription Polymerase-chain reaction (RT-PCR). All laboratory data were reported through WHO/AFRO.

RESULTS

Twenty-three staff members were trained on RT-PCR for rotavirus genotyping which was introduced for the first time in all three countries. In CAE, the number of samples analysed by EIA and RT-PCR increased tenfold between 2007 and 2013. In DRC, this number increased fivefold, from 2009 to 2013 whereas in CAR, it increased fourfold between 2011 and 2013. All laboratories passed WHO proficiency testing in 2014.

CONCLUSION

Laboratory capacity was strengthened through equipping laboratories and strengthening a subregional laboratory workforce for surveillance of rotavirus gastroenteritis. Each of the three countries generated rotavirus surveillance and genotyping data enabling the mapping of circulating genotypes. These results will help monitor the impact of rotavirus vaccination in these countries.

Whole genome detection of rotavirus mixed infections in human, porcine and bovine samples co-infected with various rotavirus strains collected from sub-Saharan Africa

Group A rotaviruses (RVA) are among the main global causes of severe diarrhea in children under the age of 5years. Strain diversity, mixed infections and untypeable RVA strains are frequently reported in Africa. We analysed rotavirus-positive human stool samples (n=13) obtained from hospitalised children under the age of 5years who presented with acute gastroenteritis at sentinel hospital sites in six African countries, as well as bovine and porcine stool samples (n=1 each), to gain insights into rotavirus diversity and evolution. Polyacrylamide gel electrophoresis (PAGE) analysis and genotyping with G-(VP7) and P-specific (VP4) typing primers suggested that 13 of the 15 samples contained more than 11 segments and/or mixed G/P genotypes. Full-length amplicons for each segment were generated using RVA-specific primers and sequenced using the Ion Torrent and/or Illumina MiSeq next-generation sequencing platforms. Sequencing detected at least one segment in each sample for which duplicate sequences, often having distinct genotypes, existed. This supported and extended the PAGE and RT-PCR genotyping findings that suggested these samples were collected from individuals that had mixed rotavirus infections. The study reports the first porcine (MRC-DPRU1567) and bovine (MRC-DPRU3010) mixed infections. We also report a unique genome segment 9 (VP7), whose G9 genotype belongs to lineage VI and clusters with porcine reference strains. Previously, African G9 strains have all been in lineage III. Furthermore, additional RVA segments isolated from humans have a clear evolutionary relationship with porcine, bovine and ovine rotavirus sequences, indicating relatively recent interspecies transmission and reassortment. Thus, multiple RVA strains from sub-Saharan Africa are infecting mammalian hosts with unpredictable variations in their gene segment combinations. Whole-genome sequence analyses of mixed RVA strains underscore the considerable diversity of rotavirus sequences and genome segment combinations that result from a complex evolutionary history involving multiple host species.

Global invasive bacterial vaccine-preventable diseases surveillance--2008-2014

Meningitis and pneumonia are leading causes of morbidity and mortality in children globally infected with Streptococcus pneumoniae (pneumococcus), Neisseria meningitidis, and Haemophilus influenzae causing a large proportion of disease. Vaccines are available to prevent many of the common types of these infections. S. pneumoniae was estimated to have caused 11% of deaths in children aged <5 years globally in the pre-pneumococcal conjugate vaccine (PCV) era. Since 2007, the World Health Organization (WHO) has recommended inclusion of PCV in childhood immunization programs worldwide, especially in countries with high child mortality. As of November 26, 2014, a total of 112 (58%) of all 194 WHO member states and 44 (58%) of the 76 member states ever eligible for support from Gavi, the Vaccine Alliance (Gavi), have introduced PCV. Invasive pneumococcal disease (IPD) surveillance that includes data on serotypes, along with meningitis and pneumonia syndromic surveillance, provides important data to guide decisions to introduce PCV and monitor its impact.

Norovirus GII.17 Predominates in Selected Surface Water Sources in Kenya

In this study, the prevalence and genotypes of noroviruses (NoVs) in selected water sources from rural, urban and refugee settings in Kenya were investigated. Ten litres each of river, household and borehole water was collected in rural (Mboone River), urban (Nairobi and Mutoine River) and refugee (Dadaab refugee camp) settings. NoVs were recovered from the water samples by a glass wool adsorption-elution technique and/or PEG/NaCl precipitation. Nucleic acid was extracted using the automated MagNA Pure platform. NoVs were detected with singleplex real-time reverse transcription-polymerase chain reaction assays and characterised by nucleotide sequence analysis. NoVs were detected in 63% (25/40) of the selected water samples comprising GII (42.5%), GI (2.5%) and mixed GI/GII (17.5%) positive samples. The prevalence of NoVs in the Mutoine River (urban area) was higher than in the Mboone River (rural area) (P = 0.0013). Noroviruses GI.1, GI.3, GI.9, GII.4, GII.6, GII.12, GII.16 and GII.17 were identified, with GII.17 accounting for 76% (16/21) of the typed strains. The NoV GII.17 predominance differs to other studies in Africa and further surveillance of NoVs in clinical and environmental settings is required to clarify/elucidate this observation. As information regarding NoVs in Kenyan water sources is limited this report provides valuable new data on NoV genotypes circulating in environmental water sources and the surrounding communities in Kenya.

Whole-genome analyses of DS-1-like human G2P[4] and G8P[4] rotavirus strains from Eastern, Western and Southern Africa

Group A rotaviruses (RVAs) with distinct G and P genotype combinations have been reported globally. We report the genome composition and possible origin of seven G8P[4] and five G2P[4] human RVA strains based on the genetic evolution of all 11 genome segments at the nucleotide level. Twelve RVA ELISA positive stool samples collected in the representative countries of Eastern, Southern and West Africa during the 2007-2012 surveillance seasons were subjected to sequencing using the Ion Torrent PGM and Illumina MiSeq platforms. A reference-based assembly was performed using CLC Bio's clc_ref_assemble_long program, and full-genome consensus sequences were obtained. With the exception of the neutralising antigen, VP7, all study strains exhibited the DS-1-like genome constellation (P[4]-I2-R2-C2-M2-A2-N2-T2-E2-H2) and clustered phylogenetically with reference strains having a DS-1-like genetic backbone. Comparison of the nucleotide and amino acid sequences with selected global cognate genome segments revealed nucleotide and amino acid sequence identities of 81.7-100 % and 90.6-100 %, respectively, with NSP4 gene segment showing the most diversity among the strains. Bayesian analyses of all gene sequences to estimate the time of divergence of the lineage indicated that divergence times ranged from 16 to 44 years, except for the NSP4 gene where the lineage seemed to arise in the more distant past at an estimated 203 years ago. However, the long-term effects of changes found within the NSP4 genome segment should be further explored, and thus we recommend continued whole-genome analyses from larger sample sets to determine the evolutionary mechanisms of the DS-1-like strains collected in Africa.

Human caliciviruses detected in HIV-seropositive children in Kenya

The human caliciviruses (HuCVs) are important causes of gastroenteritis worldwide. Norovirus (NoV) and sapovirus (SaV) have been detected in HIV-seropositive children but the genetic diversity of HuCVs circulating in these individuals is largely unknown. In this study the prevalence and genotype diversity of HuCVs circulating in Kenyan HIV-positive children, with or without diarrhea, from the year 1999 to 2000 was investigated. The overall prevalence of HuCVs was 19% with NoV predominating at 17% (18/105) and SaV present in 5.7% (6/105) of specimens. Human CVs were detected in both symptomatic (24%) and asymptomatic (16%) children. Co-infections with other enteric viruses were detected in 21.6% of children with diarrhea but only in 4.4% of children without diarrhea. Remarkable genetic diversity was observed with 12 genotypes (7 NoV, 5 SaV) being identified in 20 HuCV-infected children. NoV genogroup II (GII) strains predominated with GII.2 and GII.4 each representing 27% of the NoV-positive strains. The GII.4 strain was most closely related to the nonepidemic GII.4 Kaiso 2003 variant. Other NoV genotypes detected were GI.3, GII.6, GII.12, GII.14, and GII.17. Five different SaV genotypes (GI.2, GI.6, GII.1, GII.2, and GII.4) were characterized from six specimens. Diarrheal symptoms were not associated with any specific HuCV genotype. Overall the HuCV genotype distribution detected in this study reflects those in other studies worldwide. The strains detected are closely related to genotypes that have circulated on several continents since the year 2000.

Short-term effects of high-dose khat on sperm parameters and reproductive hormonal levels in olive baboons (Papio anubis)

The biological effects of khat (Catha edulis) on reproduction and fertility are inadequately investigated and controversial, hence we determined the effects of oral administration of high-dose khat on sperm parameters and male hormonal levels in olive baboons. In this study, 6 male baboons received a high dose of khat (500 g/week) during 1 month. Electroejaculation for sperm studies (concentration, motility and chromatin integrity) and plasma collection for hormonal analysis (testosterone, prolactin and cortisol) were done weekly during 1 month before and 1 month during khat administration as well as 2 weeks after the last dose of khat administration. Administration of khat extract induced a significant reduction in sperm motility (p = 0.008), sperm count (p = 0.041), sperm chromatin integrity (p = 0.0003), testosterone levels (p = 0.035) and prolactin levels (p = 0.0115), but not in cortisol levels and sperm volume (p > 0.05). The results suggest that high-dose khat decreases sperm quality and testosterone and hence may contribute to male infertility.

Baboon model for the study of endometriosis

Endometriosis is a benign, estrogen-dependent disease and is now recognized as an enigmatic disease owing to its various clinical manifestations and locations. The lack of a reliable and specific method for the early detection of endometriosis often results in delayed diagnosis. So far, research has born inadequate findings regarding understanding the basic etiology or pathophysiology of endometriosis. Animal models that accurately represent the cellular and molecular changes associated with the initiation and progression of human endometriosis have significant potential to facilitate the development of better methods for the early detection and treatment of endometriosis. A number of animal model systems have been developed for the study of this disease. These models replicate many of the known salient features of human endometriosis. This review provides an insight into the use of the baboon model for studies focused on understanding human endometriosis.

Endometriosis in African women

Endometriosis is a gynecological disorder characterized by the growth of endometrial tissue outside the uterine cavity. Although the prevalence of endometriosis is well documented in women living in developed countries, studies on the prevalence of this disease among African women are still wanting. The current view is that endometriosis rarely affects women of African descent. However, in African-American women in the USA, endometriosis is one of the common indications for major gynecological surgery and hysterectomy and is associated with a long hospitalization and high hospital charges. Endometriosis may be more commonly found in infertile Caucasian or African-American women than in African-Indigenous women, but it is likely that the true prevalence of endometriosis in African-Indigenous women is under reported owing to inadequate facilities and demands of specialized skills for adequate assessment of the pelvis and recognition of the various types and appearances of the disease. Understanding the prevalence of endometriosis among African women will be instrumental in proper management of this disease in the African continent.