Invasive group B streptococcal infection in infants, Malawi

Astrocyte-derived complement C3 facilitated microglial phagocytosis of synapses in Staphylococcus aureus-associated neurocognitive deficits

The presence of pathogens is a significant challenge in causing brain infections and tissue damage. There is growing evidence that pathogen infections are commonly associated with cognitive dysfunction and mental health problems, but the underlying mechanisms are not yet fully understood. Here, we found microglia and astrocyte activation, neuronal damage, synapse loss, and cognitive impairment in a Staphylococcus aureus (S. aureus) induced mouse model. An unbiased transcription profile of isolated microglia derived from S. aureus-infected mice identified the involvement of microglial phagosome and regulation of neurogenesis. Our findings indicate that the complement C1q and C3 are upregulated, and astroglial release of C3 activates microglia to phagocytose synapses. Blocking the C3-C3aR axis can improve microglial phagocytosis, thus rescuing synapse loss and cognitive impairment in infected mice. These results indicate that S. aureus induces synapse elimination and cognitive impairment by activating microglia and astrocytes through C3-C3aR signaling. This suggests a mechanism of complement signaling bridged crosstalk between astrocyte and microglia in the S. aureus-associated post-infectious synapse loss and cognitive dysfunction, and provide potential therapeutic targets for managing pathogen-associated brain infections.

Diversity in Naturally Acquired Immunity to Group B Streptococcus: A Comparative Study of Women From Bangladesh, Malawi, and the United Kingdom

BACKGROUND

Significant disparities in group B Streptococcus (GBS) colonization and neonatal disease rates have been documented across different geographic regions. For example, Bangladesh reports notably lower rates as compared with the United Kingdom and Malawi. This study investigates whether this epidemiologic variability correlates with the immune response to GBS in these regions.

METHODS

Qualitative and quantitative analyses of naturally acquired immunoglobulin G (IgG) antibodies against GBS capsular polysaccharide and the Alp protein family were conducted in serum samples from women of childbearing age in the United Kingdom, Bangladesh, and Malawi. The efficacy of these antibodies in clearing vaginal colonization or protecting newborns from GBS infection was assessed with humanized mouse models.

RESULTS

Bangladeshi women displayed the highest diversity in serotype distribution, with elevated IgG levels in the serum against GBS capsular polysaccharides Ia, Ib, II, III, IV, and V, as well as Alp family proteins. In contrast, Malawian sera demonstrated the weakest antibody response. Bangladeshi sera also showed heightened IgG-mediated complement deposition, opsonophagocytic killing, and neonatal Fc receptor binding while tested against capsular polysaccharide Ib. In a humanized neonatal Fc receptor mouse model, Bangladeshi sera led to faster clearance of GBS virulent serotype Ib vaginal colonization. Additionally, offspring from dams passively immunized with Bangladeshi sera demonstrated notably increased survival rates.

CONCLUSIONS

This study demonstrates significant variability in the immune response to GBS across different geographic regions. These findings underscore the importance of understanding GBS-induced immune response in diverse populations, which may significantly affect vaccine efficacy in these regions.

Group B streptococcal prevalence in internal organs and placentas of deceased neonates and stillbirths in South Asia

OBJECTIVE

Group B streptococcus (GBS) has been associated with adverse pregnancy outcomes, but few prospective studies have assessed its prevalence in low- and middle-income country settings. We sought to evaluate the prevalence of GBS by polymerase chain reaction (PCR) in internal organ tissues and placentas of deceased neonates and stillbirths.

DESIGN

This was a prospective, observational study.

SETTING

The study was conducted in hospitals in India and Pakistan.

POPULATION

Pregnant women with stillbirths or preterm births were recruited at delivery, as was a group of women with term, live births, to serve as a control group.

METHODS

A rectovaginal culture was collected from the women in Pakistan to assess GBS carriage. Using PCR, we evaluated GBS in various tissues of stillbirths and deceased neonates and their placentas, as well as the placentas of live-born preterm and term control infants.

MAIN OUTCOME MEASURES

GBS identified by PCR in various tissues and the placentas; rate of stillbirths and 28-day neonatal deaths.

RESULTS

The most obvious finding from this series of analyses from India and Pakistan was that no matter the country, the condition of the subject, the tissue studied or the methodology used, the prevalence of GBS was low, generally ranging between 3% and 6%. Among the risk factors evaluated, only GBS positivity in primigravidae was increased.

CONCLUSIONS

GBS diagnosed by PCR was identified in <6% of internal organs of stillbirths and neonatal deaths, and their placentas, and control groups in South Asian sites. This is consistent with other reports from South Asia and is lower than the reported GBS rates from the USA, Europe and Africa.

The effect of group B streptococcus on maternal and infants' prognosis in Guizhou, China

Group B Streptococcus (GBS) is a kind of opportunistic pathogenic bacteria and mainly strikes the lower digestive tract and genitourinary tract. It is a major risk factor for neonatal babies, seriously threatening their lives. In the present study, we aimed to detect the GBS colonization in late pregnant women, and to study the effect of GBS on maternal and infants’ prognosis. Pregnant women with a gestational age of 35–37 weeks were enrolled in the study. Real-time polymerase chain-reaction (RT-PCR) was used to detect the colonization of GBS in the vaginal and rectal secretions for late pregnant women according to the screening guidelines. Chi-square test was applied to analyze the relationship between GBS colonization and clinical characteristics. A follow-up of 6 weeks was performed on the puerpera and infants after delivery. The positive rate of GBS was 12.6% in late pregnant women. GBS carrier state was positively related to several pregnancy outcomes, including intrauterine infection, premature rupture of membranes, postpartum hemorrhage, fetal distress and puerperal infection, as well as to part neonatal outcomes, containing neonatal infection, neonatal pneumonia and neonatal sepsis (all P < 0.05). GBS infection in late pregnant women results in adverse effects on maternal and neonatal outcomes.

Pathogen Analysis of Central Nervous System Infections in a Chinese Teaching Hospital from 2012-2018: A Laboratory-based Retrospective Study

Central nervous system (CNS) infections are associated with high mortality rates. The clinical presentation of many CNS infections by different pathogens is difficult to distinguish, but the definite diagnosis of the etiology is critical for effective therapy and prognosis. The aim of this study was to explore the etiology of CNS infections with definite diagnoses based on data from a clinical microbiology laboratory in Tongji Hospital, a teaching hospital in China, obtained over a six-year period. We conducted a retrospective study on all cerebrospinal fluid (CSF) specimens submitted to our clinical microbiology laboratory from September, 2012 to December, 2018. The etiology of CNS infections caused by Cryptococcus neoformans, Mycobacterium tuberculosis and common bacteria was analyzed. Antimicrobial susceptibility testing was conducted on all isolates. The results showed that 1972 cases of CNS infections were identified from 18 300 CSF specimens. Common bacterial meningitis (BM), cryptococcal meningitis (CM) and tuberculous meningitis (TM) accounted for 86.3% (677/785), 9.4% (74/785) and 4.3% (34/785) respectively of cases over the six-year period. BM was the most common among the different age groups, followed by CM. Of the TM cases, 44.1% (15/34) were distributed within the age group of 15-34 years, whereas for CM cases, 52.7% (39/74) occurred within the 35-54-year age group, and the age distribution of BM cases was fairly even. Among the bacterial pathogens isolated, Staphylococcus epidermidis was the most common, accounting for 12.5% (98/785), followed by Acinetobacter baumannii (ABA) and Staphylococcus aureus (SAU), accounting for 11.8% (93/785) and 7.6% (60/785) respectively. The resistance rates to antibiotics were >75%, with the exception of the resistance rate of ABA to tegafycline, which was <3%. More than 60% of SAU strains displayed resistance to penicillin, oxacillin, ampicillin/sulbactam, cefazolin, cefuroxime, gentamycin, tobramycin, erythromycin and levofloxacin, whereas more than 90% of SAU strains showed susceptibility to trimethoprim/sulfamethoxazole, tegafycline, vancomycin, teicoplanin and linezolid. For C. neoformans, the susceptibility rates to amphotericin B, 5-fluorocytosine, fluconazol and voriconazole were >95%. Analysis of samples from patients with CNS infection in a clinical microbiology laboratory at a teaching hospital in China over a six-year period indicated that the most common etiological agents were the bacteria ABA and SAU. The antibiotic resistance levels of ABA were found to be high and of concern, whereas isolates of C. neoformans were found to be sensitive to antifungal antibiotics.

Prevalence and capsular type distribution of Streptococcus agalactiae isolated from pregnant women in Namibia and South Africa

Background

Streptococcus agalactiae or Group B Streptococcus (GBS) is the leading cause of neonatal morbidity and mortality resulting in septicaemia, bacteraemia and meningitis. Long term problems in children range from loss of hearing to mental retardation. While Intrapartum Antibiotic Prophylaxis (IAP) has reduced the incidence of S. agalactiae infection, it still remains the leading cause of disease in neonates. GBS has ten capsular types whose distribution varies across the world. Therefore, this study sought to determine the prevalence of GBS in Namibia and South Africa amongst pregnant women between 35 and 37 weeks gestation and elucidate the capsular types.

Methods

Lower vaginal and rectal swabs were collected from pregnant women between 35 and 37 weeks gestation. Five hundred and thirty pregnant women were recruited into the study in Windhoek, Namibia while one hundred pregnant women were recruited in the Eastern Cape, South Africa. The swabs were cultured on 5% sheep blood agar (Biomerieux, New Jersey, USA) for isolation of GBS. Presumptive isolates were confirmed using both the Vitek (2) and molecular techniques targeting the scpB gene. Capsular typing was performed in a multiplex PCR with capsular specific primer pairs.

Results

The prevalence of GBS in Namibia was 13.6 and 37% in South Africa respectively. In both countries most women were dually colonised with GBS. Capsular types II, III and V were the most prevalent.

Conclusions

The prevalence of GBS in Namibia was lower than in South Africa in this study. The prevalence in both countries was not different from those reported in other African countries and around the world. The predominant capsular types in this study are the ones commonly associated with adverse maternal outcomes.

The activity of commercial antimicrobials, and essential oils and ethanolic extracts of Olea europaea on Streptococcus agalactiae isolated from pregnant women

BACKGROUND

Streptococcus agalactiae also known as Group B Streptococcus (GBS) is a major cause of disease in pregnant women and new born babies where it causes early and late onset disease characterised by sepsis, pneumonia and meningitis. Ten to 37 % of pregnant women in the world are colonised with GBS while intrapartum antibiotic prophylaxis has led to significant reduction in early onset disease. The increase in drug resistant microorganisms has become a major threat. Development of vaccines is still in progress so there is need for new and safer alternatives to treatment.

METHODS

Benzyl penicillin, Ampicillin, Cefotaxime, Ceftriaxone, Levofloxacin, Erythromycin, Clindamycin, Linezolid, Vancomycin, Tetracycline and Cotrimoxazole, Olea europaea leaf extracts and essential oil were tested against GBS isolates from South Africa and Namibia.

RESULTS

The isolates showed 100% sensitivity to benzyl penicillin, ampicillin, ceftriaxone, levofloxacin, linezolid, vancomycin, O. europaea leaf extracts and essential oils. Only one isolate (0.6%) was resistant to cefotaxime and 23.4 and 10.4% were resistant to clindamycin and erythromycin respectively.

CONCLUSION

GBS isolates showed sensitivity to O. europaea extracts at low minimum inhibitory concentrations. Β lactams are still the drugs of choice for treatment of GBS disease but O. europaea extracts potent as an alternative source of antimicrobials.

Epidemiological characterization of serotype group B Streptococci neonatal infections associated with interleukin-6 level as a sensitive parameter for the early diagnosis

Group B streptococcal infection (Streptococcus agalactiae) is one of the leading causes of life-threatening disease in the early neonatal period, resulting in sepsis, pneumonia, and meningitis. During invasive infections, an excessive release of pro-inflammatory cytokine, such as interleukin-6 (IL-6), thus IL-6 gene is significant, as a diagnostic marker of systemic infection of the newborns. The present study aimed to describe the epidemiology diagnostic of GBS disease in neonatal by phenotypic and genotypic methods. Nine hundred and ninety-six samples were taken at Maternity and Children Hospital, Jeddah, Saudi Arabia for a period of one year (2011-2012). Results indicated that out of 217 infected samples, twenty (9.23.0%) were positive for group B Streptococci bacteria. This study also shows that female infants are more susceptible than males. The level of IL-6 was higher in mothers above 30 years. Twenty positive Streptococci group B isolates showed bands with the cylE gene primers in the border between 228 bp, 267 bp and 50 bp. Molecular detection by Real time polymerase chain reaction was also done to detect the target (Sip gene) encoding the Sip surface immunogenic protein. Specific primers and TaqMan probe were chosen for this purpose. A Real-time PCR method targeting the sip gene of GBS in neonates after delivery has been evaluated.

Maternal Carriage of Group B Streptococcus and Escherichia coli in a District Hospital in Mozambique

BACKGROUND

In low-income countries, data on prevalence and effects of group B Streptococcus (GBS) and Escherichia coli (E. coli) colonization among pregnant women are scarce, but necessary to formulate prevention strategies. We assessed prevalence of GBS and E. coli colonization and factors associated among pregnant women, its effect in newborns and acceptability regarding the utilized sampling methods in a semirural Mozambican hospital.

METHODS

Pregnant women were recruited from June 2014 to January 2015, during routine antenatal clinics at gestational age ≥ 34 weeks (n = 200); or upon delivery (n = 120). Maternal risk factors were collected. Vaginal and vagino-rectal samples for GBS and E. coli determination were obtained and characterized in terms of antimicrobial resistance and serotype. Anti-GBS antibodies were also determined. Neonatal follow-up was performed in the first 3 months after birth. Semistructured interviews were performed to investigate acceptability of sample collection methods.

RESULTS

In total, 21.3% of women recruited were GBS carriers, while 16.3% were positive for E. coli. Prevalence of HIV was 36.6%. No association was found between being colonized by GBS and E. coli and maternal risk factors. GBS isolates were fully susceptible to penicillin and ampicillin. Serotypes V (32.4%), Ia (14.7%) and III (10.3%) were the most commonly found and 69.2% of the women tested had immunoglobuline G antibodies against GBS. E. coli isolates showed resistance to ampicillin in 28.9% and trimethoprim/sulfamethoxazole in 61.3% of the cases.

CONCLUSION

Prevalence of GBS and/or E. coli colonization among pregnant women is high in this semirural community and comparable with those reported in similar settings. Four serotypes accounted for nearly 70% of all isolates of GBS. Population-based data on infant GBS infections would enable the design of prevention strategies for GBS disease in Mozambique.

Aetiology of neonatal sepsis in Nigeria, and relevance of Group b streptococcus: A systematic review

BACKGROUND

Group B Streptococcus (GBS) causes invasive infections in neonates and has been implicated as a cause of prelabour rupture of membranes, preterm delivery and stillbirths. The success of phase II trials of polyvalent polysaccharide GBS vaccines indicates that these infections are potentially preventable. Nigeria is the most populous country in Africa with one of the highest birth rates, one of the highest neonatal sepsis incidence rates and one of the highest mortality rates in the world. Therefore, before the possible introduction of preventive strategies such as intrapartum antibiotic prophylaxis or GBS vaccine into Nigeria, it is vital that there is accurate data on the aetiology of neonatal sepsis and on the incidence of GBS neonatal sepsis in particular. The objective of this study was to determine the incidence and aetiology of neonatal sepsis in Nigeria with a focus on GBS sepsis and also to assess the potential impact of a GBS vaccine.

METHODS

A literature search was conducted on the databases of African journals online, PubMed and Google Scholar for works conducted between 1987 to 2017. Case reports, reviews, and studies not stating specific culture methods or specific bacteria isolated were excluded. Data extracted included; incidence of neonatal sepsis, method of blood culture, blood volume, sample size, bacterial agents isolated and history of antibiotic use. PRISMA guidelines were followed and modified Down's and Black criteria used to evaluate the quality of studies.

RESULTS

A total of 5,114 studies were reviewed for neonatal sepsis out of which 24 consisting of a total of 2,280 cases were selected for final review. Nine studies met criteria for assessment of hospital based incidence of neonatal sepsis representing 31,305 hospital births. The incidence of neonatal sepsis was 18.2/1000 livebirths with range from 7-55/1000 livebirths while the GBS incidence was 0.06/1000 livebirths with range from 0-2/1000 live births. We discovered various limitations such as identification techniques that could result in underestimation of the true incidence of GBS sepsis. Pathogens such as Klebsiella pneumoniae and Staphylococcus aureus were more commonly isolated than GBS.

IMPLICATIONS OF KEY FINDINGS

The hospital based incidence of neonatal sepsis was high at 18.2/1000 live births while that due to GBS was 0.06/1000 live births. The burden of neonatal sepsis, including that attributable to GBS is substantial and could be reduced by preventive strategies such as intrapartum antibiotic prophylaxis or GBS vaccine. There is however very sparse meaningful data currently. Well planned prospective studies with larger sample sizes, more advanced isolation and identification techniques and those following up invasive disease cases for possible short and long term sequelae are needed-not only prior to possible introduction of the vaccine to determine the baseline epidemiology, but also thereafter to monitor its impact on the population. Strategies need to be developed to also reduce the morbidity and mortality attributable to other bacteria that have an incidence even greater than that of GBS.

Risk of Early-Onset Neonatal Group B Streptococcal Disease With Maternal Colonization Worldwide: Systematic Review and Meta-analyses

Background

Early-onset group B streptococcal disease (EOGBS) occurs in neonates (days 0-6) born to pregnant women who are rectovaginally colonized with group B Streptococcus (GBS), but the risk of EOGBS from vertical transmission has not been systematically reviewed. This article, the seventh in a series on the burden of GBS disease, aims to estimate this risk and how it varies with coverage of intrapartum antibiotic prophylaxis (IAP), used to reduce the incidence of EOGBS.

Methods

We conducted systematic reviews (Pubmed/Medline, Embase, Latin American and Caribbean Health Sciences Literature (LILACS), World Health Organization Library Information System [WHOLIS], and Scopus) and sought unpublished data from investigator groups on maternal GBS colonization and neonatal outcomes. We included articles with ≥200 GBS colonized pregnant women that reported IAP coverage. We did meta-analyses to determine pooled estimates of risk of EOGBS, and examined the association in risk of EOGBS with IAP coverage.

Results

We identified 30 articles including 20328 GBS-colonized pregnant women for inclusion. The risk of EOGBS in settings without an IAP policy was 1.1% (95% confidence interval [CI], .6%-1.5%). As IAP increased, the risk of EOGBS decreased, with a linear association. Based on linear regression, the risk of EOGBS in settings with 80% IAP coverage was predicted to be 0.3% (95% CI, 0-.9).

Conclusions

The risk of EOGBS among GBS-colonized pregnant women, from this first systematic review, is consistent with previous estimates from single studies (1%-2%). Increasing IAP coverage was linearly associated with decreased risk of EOGBS disease.

Infant Group B Streptococcal Disease Incidence and Serotypes Worldwide: Systematic Review and Meta-analyses

Background

Group B Streptococcus (GBS) remains a leading cause of neonatal sepsis in high-income contexts, despite declines due to intrapartum antibiotic prophylaxis (IAP). Recent evidence suggests higher incidence in Africa, where IAP is rare. We investigated the global incidence of infant invasive GBS disease and the associated serotypes, updating previous estimates.

Methods

We conducted systematic literature reviews (PubMed/Medline, Embase, Latin American and Caribbean Health Sciences Literature [LILACS], World Health Organization Library Information System [WHOLIS], and Scopus) and sought unpublished data regarding invasive GBS disease in infants aged 0–89 days. We conducted random-effects meta-analyses of incidence, case fatality risk (CFR), and serotype prevalence.

Results

We identified 135 studies with data on incidence (n = 90), CFR (n = 64), or serotype (n = 45). The pooled incidence of invasive GBS disease in infants was 0.49 per 1000 live births (95% confidence interval [CI], .43–.56), and was highest in Africa (1.12) and lowest in Asia (0.30). Early-onset disease incidence was 0.41 (95% CI, .36–.47); late-onset disease incidence was 0.26 (95% CI, .21–.30). CFR was 8.4% (95% CI, 6.6%–10.2%). Serotype III (61.5%) dominated, with 97% of cases caused by serotypes Ia, Ib, II, III, and V.

Conclusions

The incidence of infant GBS disease remains high in some regions, particularly Africa. We likely underestimated incidence in some contexts, due to limitations in case ascertainment and specimen collection and processing. Burden in Asia requires further investigation.

Seroprevalence of Opsonophagocytic Antibodies against Serotype Ia, Ib, II, III, and V Group B Streptococcus among Korean Population

BACKGROUND

Invasive Streptococcus agalactiae (group B streptococcus, GBS) infection most commonly occurs in infants; however, cases of GBS infection in adults, particularly in the elderly with significant underlying diseases, are being increasingly reported. We analyzed the serotype specific opsonophagocytic antibodies (the major mechanism of protection against GBS) in infants, adults, and the elderly.

METHODS

The opsonization indices (OIs) of antibodies against serotype Ia, Ib, II, III, and V GBS were studied in 89 infants, 35 adults (age, 30-50 years), and 62 elderly individuals (age, 65-85 years) according to the University of Alabama at Birmingham GBS opsonophagocytic killing assay protocol (www.vaccine.uab.edu).

RESULTS

In infants, adults, and elderly groups respectively, geometric mean of OI against GBS serotype Ia were 3, 7, and 32; against GBS serotype Ib were 7, 242, and 252; against serotype II were 93, 363, and 676; against serotype III were 8, 212, and 609; and against serotype V were 4, 639, and 610. The seropositive rate (% of subjects with OI ≥ 4) increased significantly in older age group for all five serotypes.

CONCLUSION

During infancy, only a limited proportion of infants have functional immunity against serotype Ia, Ib, II, III, and V GBS. Furthermore, a lack of opsonic activities against GBS observed in some adults and the elderly might predispose such individuals to the risk of invasive GBS infection. Epidemiological monitoring and development of suitable vaccine for these populations are needed.

Cost-effectiveness of maternal GBS immunization in low-income sub-Saharan Africa

BACKGROUND

A maternal group B streptococcal (GBS) vaccine could prevent neonatal sepsis and meningitis. Its cost-effectiveness in low-income sub-Saharan Africa, a high burden region, is unknown.

METHODS

We used a decision tree model, with Markov nodes to project infants' lifetimes, to compare maternal immunization delivered through routine antenatal care with no immunization. 37 countries were clustered on the basis of economic and health resources and past public health performance. Vaccine efficacy for covered serotypes was ranged from 50% to 90%. The model projected EOGBS (early-onset) and LOGBS (late-onset) cases and deaths, disability-adjusted life years (DALYs), healthcare costs (2014 US$), and cost-effectiveness for a representative country in each of the four clusters: Guinea-Bissau, Uganda, Nigeria, and Ghana. Maximum vaccination costs/dose were estimated to meet two cost-effectiveness benchmarks, 0.5 GDP and GDP per capita/DALY, for ranges of disease incidence (reported and adjusted for under-reporting) and vaccine efficacy.

RESULTS

At coverage equal to the proportion of pregnant women with≥4 antenatal visits (ANC4) and serotype-specific vaccine efficacy of 70%, maternal GBS immunization would prevent one-third of GBS cases and deaths in Uganda and Nigeria, where ANC4 is 50%, 42-43% in Guinea-Bissau (ANC4=65%), and 55-57% in Ghana (ANC4=87%). At a vaccination cost of $7/dose, maternal immunization would cost $320-$350/DALY averted in Guinea-Bissau, Nigeria, and Ghana, less than half these countries' GDP per capita. In Uganda, which has the lowest case fatality ratios, the cost would be $573/DALY. If the vaccine prevents a small proportion of stillbirths, it would be even more cost-effective. Vaccination cost/dose, disease incidence, and case fatality were key drivers of cost/DALY in sensitivity analyses.

CONCLUSION

Maternal GBS immunization could be a cost-effective intervention in low-income sub-Saharan Africa, with cost-effectiveness ratios similar to other recently introduced vaccines. The vaccination cost at which introduction is cost-effective depends on disease incidence and vaccine efficacy. Clinical Trial registry name and registration number: Not applicable.

Group B streptococcus colonization and HIV in pregnancy: A cohort study in Nigeria

BACKGROUND

Group B streptococcus (GBS) is a leading cause of maternal and neonatal infectious morbidity. HIV is prevalent among pregnant women in Nigeria.

AIM

To determine the rates of anogenital GBS colonization in our institution and compare GBS colonization rates between HIV positive and negative pregnant women.

METHODS

A cross-sectional comparative study was conducted over 6 months. Patients were separated according to their HIV status: positive and negative. GBS colonization was assessed by vaginal and anal swabs collected at 35-37 weeks of gestation and cultured in Todd-Hewitt broth, followed by a confirmatory test. Socio-demographic characteristics and CD4 count were extracted from patient medical records. Secondary outcomes were identification of risk factors for GBS colonization, antibiotic sensitivity, and any association between CD4 count and GBS colonization. Appropriate statistical analysis was done.

RESULTS

A total of 200 patients attended the clinic; 67 HIV positive and 133 negative. Analyzed samples were 198; the overall prevalence of GBS was 18.2%. No significant difference in GBS colonization was noted between HIV positive (19.4% [13]) and negative patients (17.6% [23/131]). Most GBS isolates were susceptible to ampicillin (87%) and penicillin (81%). A high body mass index (BMI) was independently associated with GBS colonization (OR = 1.25, 95% CI: 1.04-1.51). No association was observed between CD4 counts and GBS colonization.

CONCLUSION

A high prevalence of GBS colonization was observed in our institution. Colonization rates were independent of the HIV status but associated with a high BMI in HIV positive women.

Antimicrobial resistance among children in sub-Saharan Africa

Antimicrobial resistance is an important threat to international health. Therapeutic guidelines for empirical treatment of common life-threatening infections depend on available information regarding microbial aetiology and antimicrobial susceptibility, but sub-Saharan Africa lacks diagnostic capacity and antimicrobial resistance surveillance. We systematically reviewed studies of antimicrobial resistance among children in sub-Saharan Africa since 2005. 18 of 1075 articles reviewed met inclusion criteria, providing data from 67 451 invasive bacterial isolates from inconsistently defined populations in predominantly urban tertiary settings. Among neonates, Gram-negative organisms were the predominant cause of early-onset neonatal sepsis, with a high prevalence of extended-spectrum β-lactamase-producing organisms. Gram-positive bacteria were responsible for a high proportion of infections among children beyond the neon atal period, with high reported prevalence of non-susceptibility to treatment advocated by the WHO therapeutic guidelines. There are few up-to-date or representative studies given the magnitude of the problem of antimicrobial resistance, especially regarding community-acquired infections. Research should focus on differentiating resistance in community-acquired versus hospital-acquired infections, implementation of standardised reporting systems, and pragmatic clinical trials to assess the efficacy of alternative treatment regimens.

Group B streptococcus and respiratory syncytial virus immunisation during pregnancy: a landscape analysis

Group B streptococcus and respiratory syncytial virus are leading causes of infant morbidity and mortality worldwide. No licensed vaccines are available for either disease, but vaccines for both are under development. Severe respiratory syncytial virus disease can be prevented by passively administered antibody. The presence of maternal IgG antibody specific to respiratory syncytial virus is associated with reduced prevalence and severity of respiratory syncytial virus disease in the first few weeks of life, whereas maternal serotype-specific anticapsular antibody is associated with protection against both early-onset and late-onset group B streptococcus disease. Therefore, vaccination in pregnancy might protect infants against both diseases. This report describes what is known about immune protection against group B streptococcus and respiratory syncytial virus, identifies knowledge gaps regarding the immunobiology of both diseases, and aims to prioritise research directions in maternal immunisation.

Prevalence of pregnancy-relevant infections in a rural setting of Ghana

BACKGROUND

Although infectious diseases still account for a high burden of morbidity and mortality in sub-Saharan Africa, simultaneous investigations on multiple infections affecting maternal and child health are missing.

METHODS

We conducted a cross-sectional, single-centre pilot study in a rural area of Ghana to assess the infectiological profile during pregnancy. Screening of 180 expectant mothers was done by vaginal swabs and serology to detect the most common pregnancy-relevant infections. They were also interviewed for potential risk factors, outcome of previous pregnancies, and socio-economic aspects.

RESULTS

We found a high prevalence of infections caused by hepatitis B virus (16.7% HBs antigen positive). In contrast, infections caused by hepatitis C virus (1.1% anti-HCV) and HIV (0.6%) were rare. Maternal malaria was frequent (10.6%), despite increasing acceptance of intermittent preventive treatment during pregnancy (IPTp). Group B streptococci were present in 10.6% of all pregnant women. Absence of antibodies against varicella zoster virus in 43.2%, Toxoplasma gondii in 26.8%, parvovirus B19 in 20.0%, and rubella virus in 15.7% makes a significant proportion of pregnant women susceptible for acquiring primary infections. Whereas all study participants had specific IgG antibodies against human cytomegalovirus, infections with Listeria, Brucella, or Neisseria gonorrhoeae as well as active syphilis were absent.

CONCLUSIONS

Our pilot study in a rural community in Ghana indicates an urgent need for action in dealing at least with high-prevalent pregnancy-relevant infections, such as hepatitis B, malaria and those caused by group B streptococci. In addition, the resulting prevalence rates of various other infections may offer guidance for health officials to prioritize possible future intervention schemes.

Group B Streptococcus among Pregnant Women and Newborns in Mirzapur, Bangladesh: Colonization, Vertical Transmission, and Serotype Distribution

Group B streptococcus (GBS) infection is a leading cause of death among newborns in developed countries. Data on the burden of GBS in Asian countries are lacking. This study aimed to understand (i) the rate of maternal rectovaginal GBS carriage, (ii) the rate of vertical transmission of GBS, as determined by culturing ear, umbilicus, and nasal swabs, and (iii) the distribution of GBS serotypes. This prospective observational study was conducted between September 2012 and November 2013 at Kumudini Women's Medical College Hospital, a secondary-level hospital in Mirzapur, Bangladesh. The study enrolled pregnant women who visited the outpatient clinic for antenatal care (ANC) and/or delivered a child in the inpatient department of Kumudini Women's Medical College Hospital and the babies born to those mothers. Among 1,151 enrolled pregnant women, 172 (15% [95% confidence interval [CI], 13 to 17%]) carried GBS; among 68 babies born to mothers with carriage, 26 (38% [95% CI, 27 to 51%]) had GBS on their body surfaces, indicating vertical transmission. Typing of the isolates (n = 172) identified all 10 GBS serotypes, most commonly types Ia (40% [69/172 isolates]), V (23% [40/172 isolates]), II (14% [24/172 isolates]), and III (12% [20/172 isolates]). This study shows that Bangladesh has all of the ingredients for invasive GBS disease, including colonization of mothers by invasive serotypes and vertical transmission to babies.

Challenges in reducing group B Streptococcus disease in African settings

Group B Streptococcus (GBS) is a leading cause of neonatal sepsis and meningitis in high-income settings and is associated with high rates of neonatal mortality and morbidity. There is now increasing evidence to suggest that there is a high GBS disease burden in resource-limited countries, and it is therefore critically important to identify suitable and practical preventive strategies. In Europe and North America, intrapartum antibiotic prophylaxis (IAP) has led to a dramatic reduction of early-onset GBS disease. However, the methods for identifying pregnant women who should receive IAP and how to reduce late-onset GBS disease are not without controversy and are challenging for most sub-Saharan African countries. GBS vaccines are approaching phase III trials but are still under development. This review aims to explore the current evidence related to strategies for reducing invasive GBS disease in an African setting, the development of a GBS vaccine and whether preventative measures against GBS disease can be practically implemented.

Group B Streptococcus vaccine development: present status and future considerations, with emphasis on perspectives for low and middle income countries

Globally, group B Streptococcus (GBS) remains the leading cause of sepsis and meningitis in young infants, with its greatest burden in the first 90 days of life. Intrapartum antibiotic prophylaxis (IAP) for women at risk of transmitting GBS to their newborns has been effective in reducing, but not eliminating, the young infant GBS disease burden in many high income countries. However, identification of women at risk and administration of IAP is very difficult in many low and middle income country (LMIC) settings, and is not possible for home deliveries. Immunization of pregnant women with a GBS vaccine represents an alternate pathway to protecting newborns from GBS disease, through the transplacental antibody transfer to the fetus in utero. This approach to prevent GBS disease in young infants is currently under development, and is approaching late stage clinical evaluation. This manuscript includes a review of the natural history of the disease, global disease burden estimates, diagnosis and existing control options in different settings, the biological rationale for a vaccine including previous supportive studies, analysis of current candidates in development, possible correlates of protection and current status of immunogenicity assays. Future potential vaccine development pathways to licensure and use in LMICs, trial design and implementation options are discussed, with the objective to provide a basis for reflection, rather than recommendations.

Disease Burden of Group B Streptococcus Among Infants in Sub-Saharan Africa: A Systematic Literature Review and Meta-analysis

BACKGROUND

Group B streptococcus (GBS) is a leading neonatal sepsis pathogen globally. Investment in GBS disease prevention, such as maternal vaccination, requires evidence of disease burden, particularly in high infant mortality regions like sub-Saharan Africa. We aimed to provide such evidence by conducting a systematic literature review and meta-analysis to estimate maternal colonization proportion, GBS disease incidence and GBS serotype distribution.

METHODS

MEDLINE, MEDLINE in process and Cochrane Library were searched for studies published during 1990-2014, pertaining to sub-Saharan Africa. Eligible studies were used to estimate the proportion of pregnant women colonized with GBS, early-onset GBS disease incidence, late-onset GBS disease incidence and respective serotype distributions. Random effects meta-analysis was conducted to estimate weighted means and confidence intervals (CIs).

RESULTS

We identified 17 studies of colonization, 9 of disease incidence, and 6 of serotype distribution meeting inclusion criteria. 21.8% (95% CI: 18.3, 25.5) of expectant women were colonized with GBS. The incidence of early-onset GBS disease was 1.3 per 1000 births (95% CI: 0.81, 1.9), that of late-onset GBS disease 0.73 per 1000 births (95% CI: 0.48, 1.0). The most common disease-causing serotype was 3, followed by 1a. Serotypes 1b, 2 and 5 were next most common in frequency.

CONCLUSION

Despite methodological factors leading to underestimation, GBS disease incidence appears high in sub-Saharan Africa. A small number of GBS serotypes cause almost all disease. GBS disease burden in sub-Saharan Africa suggests that safe, effective and affordable GBS disease prevention is needed.

Comparison Between Pathogen Associated Laboratory and Clinical Parameters in Early-Onset Sepsis of the Newborn

OBJECTIVES

To identify laboratory and clinical characteristics of different pathogens associated with early-onset sepsis (EOS) of the newborn.

METHODS

Newborns with EOS were retrospectively analyzed regarding laboratory and clinical parameters associated with the identified pathogen.

RESULTS

We identified 125 newborns having diagnosis of culture proven EOS between 1993 and 2011. One hundred cases had diagnosis of group B streptococci (GBS) infection (80%), 11 had Escherichia coli (8.8%), eight enterococci (6.4%), and six other pathogens (4.8%). White blood cell count (WBC), immature to total neutrophil (IT) ratio, and C-reactive protein (CRP) values did not differ between groups within the first 72 hours of life. Presence of high (>30000/µL) and low (<9000/µl) WBC was significantly less found compared with IT-ratio >0.2 in GBS and E.coli EOS. High WBC were more common found than low WBC in all groups. Gram positive pathogens were more common found in late preterm and term infants (84%), and gram negative pathogens more common in very low birth weight infants (64%). E. coli was significantly associated with lower gestational age and birth weight, respectively.

CONCLUSION

An abnormal IT-ratio was a more common finding than an abnormal WBC in GBS and E. coli EOS. E. coli was significantly associated with prematurity.

Maternal colonization with Streptococcus agalactiae and associated stillbirth and neonatal disease in coastal Kenya

Streptococcus agalactiae (group B streptococcus, GBS) causes neonatal disease and stillbirth, but its burden in sub-Saharan Africa is uncertain. We assessed maternal recto-vaginal GBS colonization (7,967 women), stillbirth and neonatal disease. Whole-genome sequencing was used to determine serotypes, sequence types and phylogeny. We found low maternal GBS colonization prevalence (934/7,967, 12%), but comparatively high incidence of GBS-associated stillbirth and early onset neonatal disease (EOD) in hospital (0.91 (0.25-2.3)/1,000 births and 0.76 (0.25-1.77)/1,000 live births, respectively). However, using a population denominator, EOD incidence was considerably reduced (0.13 (0.07-0.21)/1,000 live births). Treated cases of EOD had very high case fatality (17/36, 47%), especially within 24 h of birth, making under-ascertainment of community-born cases highly likely, both here and in similar facility-based studies. Maternal GBS colonization was less common in women with low socio-economic status, HIV infection and undernutrition, but when GBS-colonized, they were more probably colonized by the most virulent clone, CC17. CC17 accounted for 267/915 (29%) of maternal colonizing (265/267 (99%) serotype III; 2/267 (0.7%) serotype IV) and 51/73 (70%) of neonatal disease cases (all serotype III). Trivalent (Ia/II/III) and pentavalent (Ia/Ib/II/III/V) vaccines would cover 71/73 (97%) and 72/73 (99%) of disease-causing serotypes, respectively. Serotype IV should be considered for inclusion, with evidence of capsular switching in CC17 strains.

Group B Streptococcus Colonization among Pregnant Women Attending Antenatal Care at Tertiary Hospital in Rural Southwestern Uganda

Objectives. This study sought to determine the prevalence and factors associated with group B streptococcal anogenital colonization among pregnant women attending antenatal care at Mbarara Regional Referral Hospital, a tertiary hospital. Methods. Cross-sectional study where 309 pregnant women ≥ thirty-five weeks of gestation attending antenatal clinic were consecutively recruited between January and March 2015. Anovaginal swabs were collected and tested qualitatively using rapid visual immunoassay GBS test kits for presence of GBS antigens. Data was analyzed using STATA version 12. In univariate analysis, GBS colonized mothers were presented as percentages and numbers, and in multivariate analysis logistic regression analysis was applied to determine the associations of exposure variable and GBS colonization; a value of less than 0.05 was considered significant. Results. Mothers' median age was 25 years, 14.6% mothers being obese. GBS prevalence was 28.8%, 95% CI: 23.7-33.9. Obesity was the only significant factor associated with anogenital GBS colonization with odds ratio of 3.78, 95% CI: 1.78-8.35, a p value of 0.001. Maternal ages, educational level, residence, and gravidity were not associated with GBS anogenital colonization. Conclusion. Group B streptococcal anogenital colonization among pregnant women attending antenatal care at tertiary hospital, in Southwestern Uganda, is high.

Invasive Group B Streptococcal Disease in South Africa: Importance of Surveillance Methodology

Data on neonatal group B streptococcal (GBS) invasive disease burden are needed to refine prevention policies. Differences in surveillance methods and investigating for cases can lead to varying disease burden estimates. We compared the findings of laboratory-based passive surveillance for GBS disease across South Africa, and for one of the provinces compared this to a real-time, systematic, clinical surveillance in a population-defined region in Johannesburg, Soweto. Passive surveillance identified a total of 799 early-onset disease (EOD, <7 days age) and 818 LOD (late onset disease, 7-89 days age) cases nationwide. The passive surveillance provincial incidence varied for EOD (range 0.00 to 1.23/1000 live births), and was 0.03 to 1.04/1000 live births for LOD. The passive surveillance rates for Soweto, were not significantly different compared to those from the systematic surveillance (EOD 1.23 [95%CI 1.06-1.43] vs. 1.50 [95%CI 1.30-1.71], respectively, rate ratio 0.82 [95%CI 0.67-1.01]; LOD 1.04 [95% CI 0.90-1.23] vs. 1.22 [95%CI 1.05-1.42], rate ratio 0.85 [95% CI 0.68-1.07]). A review of the few cases missed in the passive system in Soweto, suggested that missing key identifiers, such as date of birth, resulted in their omission during the electronic data extraction process. Our analysis suggests that passive surveillance provides a modestly lower estimate of invasive GBS rates compared to real time sentinel-site systematic surveillance, however, this is unlikely to be the reason for the provincial variability in incidence of invasive GBS disease in South Africa. This, possibly reflects that invasive GBS disease goes undiagnosed due to issues related to access to healthcare, poor laboratory capacity and varying diagnostic procedures or empiric antibiotic treatment of neonates with suspected sepsis in the absence of attempting to making a microbiological diagnosis. An efficacious GBS vaccine for pregnant women, when available, could be used as a probe to better quantify the burden of invasive GBS disease in low-middle resourced settings such as ours. From our study passive systems are important to monitor trends over time as long as they are interpreted with caution; active systems give better detailed information and will have greater representivity when expanded to other surveillance sites.

Status of vaccine research and development of vaccines for GBS

Streptococcus agalactiae (group B streptococcus (GBS)) is the leading cause of neonatal sepsis and meningitis in many countries. Intrapartum antibiotic strategies have reduced the incidence of early-onset neonatal GBS in a number of countries but have had no impact on late onset GBS infection (LOD). In low/middle income settings, the disease burden remains uncertain although in several countries of Southern Africa appears comparable to or higher than that of high-income countries. As disease may be rapidly fulminating cases can be missed before appropriate samples are obtained and this may lead to underestimation of the true burden. Given the rapid onset and progression within hours of birth as well as the deficiencies in IAP strategies and absence of a solution for preventing LOD, it is clear that administration of a suitable vaccine in pregnancy could provide a better solution in all settings; it should also be cost effective. The current leading vaccine candidates are CPS-protein conjugate vaccines but protein-based vaccines are also in development and one has recently commenced clinical trials.

'Tweaking' the model for understanding and preventing maternal and neonatal morbidity and mortality in Low Income Countries: "inserting new ideas into a timeless wine skin"

Background

Maternal and neonatal morbidity and mortality in Low Income Countries, especially in sub-Saharan Africa involves numerous interrelated causes. The three-delay model/framework was advanced to better understand the causes and associated

Contextual factors. It continues to inform many aspects of programming and research on combating maternal and child morbidity and mortality in the said countries. Although this model addresses some of the core areas that can be targeted to drastically reduce maternal and neonatal morbidity and mortality, it potentially omits other critical facets especially around primary prevention, and pre- and post-hospitalization continuum of care.

Discussion

The final causes of Maternal and Neonatal mortality and morbidity maybe limited to a few themes largely centering on infections, preterm births, and pregnancy and childbirth related complications. However, to effectively tackle these causes of morbidity and mortality, a broad based approach is required. Some of the core issues that need to be addressed include:-i) prevention of vertically transmitted infections, intra-partum related adverse events and broad primary prevention strategies, ii) overall health care seeking behavior and delays therein, iii) quality of care at point of service delivery, and iv) post-insult treatment follow up and rehabilitation. In this article we propose a five-pronged framework that takes all the above into consideration. This frameworks further builds on the three-delay model and offers a more comprehensive approach to understanding and preventing maternal and neonatal morbidity and mortality in Low Income Countries

Conclusion

In shaping the post 2015 agenda, the scope of engagement in maternal and newborn health need to be widened if further gains are to be realized and sustained. Our proposed five pronged approach incorporates the need for continued investment in tackling the recognized three delays, but broadens this to also address earlier aspects of primary prevention, and the need for tertiary prevention through ongoing follow up and rehabilitation. It takes into perspective the spectrum of new evidence and how it can be used to deepen overall understanding of prevention strategies for maternal and neonatal morbidity and mortality in LICS.

Improving the outcome of bacterial meningitis in newborn infants in Africa: reflections on recent progress

PURPOSE OF REVIEW

There has been a reduction in overall under fives mortality (UFM) but neonatal mortality has not fallen at the same rate as for older children. Bacterial meningitis remains a common, often unrecognized and devastating illness in many African newborns with high mortality and morbidity. Further progress in reducing UFM has to focus on quality of care for neonates. Recent efforts to improve diagnosis, treatment and outcome are reviewed.

RECENT FINDINGS

Diagnosis is often unsupported by laboratory tests and efforts have been made to improve the clinical diagnosis of bacterial meningitis. Simpler, robust bedside tests are being devised. The cause of bacterial meningitis is changing and first-line antimicrobial therapy and adjuvant therapies are evaluated. Programmes to reduce risk factors and prevent neonatal infections are identified.

SUMMARY

Neonatal care needs to improve in first referral hospitals with simple, low-cost, validated measures provided as bundles of care for both mother and child. First-line antibiotic therapy must be reconsidered in the light of increased infections by multiresistant and Gram-negative bacteria. Studies are needed for effective and safe lengths of antimicrobial therapy, the role of adjuvant therapy and the best anticonvulsants to use.

Antigenic distribution of Streptococcus agalactiae isolates from pregnant women at Garankuwa hospital - South Africa

INTRODUCTION

Streptococcus agalactiae (group B streptococcus; GBS) is globally recognised as one of the leading causes of neonatal sepsis and meningitis. It also causes adverse pregnancy outcomes such as stillbirth and miscarriages. Incidence of invasive disease is increasing in non-pregnant adults with underlying medical conditions (e.g., diabetes mellitus). Epidemiological studies of GBS infections are based on capsular serotyping. Genotyping of the surface anchored protein genes is also becoming an important tool for GBS studies. Currently ten different GBS serotypes have been identified. This study was performed to determine the prevalence of GBS capsular types (CTs) and surface anchored protein genes in isolates from colonized pregnant women attending antenatal clinic, at Dr George Mukhari Academic Hospital, Garankuwa, Pretoria, South Africa.

METHODS

The samples were collected over 11 months and cultured on selective media. GBS was identified using different morphological and biochemical tests. Capsular typing was done using latex agglutination test and conventional PCR. Multiplex PCR with specific primers was used to detect the surface anchored protein genes.

RESULTS

Of the 413 pregnant women recruited, 128 (30.9%) were colonized with GBS. The capsular polysaccharide (CPS) typing test showed that CPS type III (29.7%) was the most prevalent capsular type followed by CPS type Ia (25.8%), II (15.6%), IV (8.6%), V (10.9%) and Ib (8.6%); 0.7% of the isolates were nontypeable. Multiplex PCR revealed that the surface proteins genes were possessed by all the capsular types: rib (44.5%), bca (24.7%), alp2/3 (17.9%), epsilon (8.6%) and alp4 (4.7%).

CONCLUSION

The common capsular types found in this study are Ia, III, and II. The most common protein genes identified were rib and bca, and the distribution of the surface protein genes among the isolates of different capsular types showed similar trends to the distribution reported from previous studies.

Global research priorities for infections that affect the nervous system

Infections that cause significant nervous system morbidity globally include viral (for example, HIV, rabies, Japanese encephalitis virus, herpes simplex virus, varicella zoster virus, cytomegalovirus, dengue virus and chikungunya virus), bacterial (for example, tuberculosis, syphilis, bacterial meningitis and sepsis), fungal (for example, cryptococcal meningitis) and parasitic (for example, malaria, neurocysticercosis, neuroschistosomiasis and soil-transmitted helminths) infections. The neurological, cognitive, behavioural or mental health problems caused by the infections probably affect millions of children and adults in low- and middle-income countries. However, precise estimates of morbidity are lacking for most infections, and there is limited information on the pathogenesis of nervous system injury in these infections. Key research priorities for infection-related nervous system morbidity include accurate estimates of disease burden; point-of-care assays for infection diagnosis; improved tools for the assessment of neurological, cognitive and mental health impairment; vaccines and other interventions for preventing infections; improved understanding of the pathogenesis of nervous system disease in these infections; more effective methods to treat and prevent nervous system sequelae; operations research to implement known effective interventions; and improved methods of rehabilitation. Research in these areas, accompanied by efforts to implement promising technologies and therapies, could substantially decrease the morbidity and mortality of infections affecting the nervous system in low- and middle-income countries.

Group B Streptococci serotype distribution in pregnant women in Ghana: assessment of potential coverage through future vaccines

OBJECTIVE

Group B streptococcal (GBS) colonization of pregnant women can lead to subsequent infection of the new-born and potentially fatal invasive disease. Data on GBS colonization prevalence and serotype distribution from Africa are scarce, although GBS-related infections are estimated to contribute substantially to infant mortality. In recent years, GBS vaccine candidates provided promising results in phase I and II clinical trials. We aimed to assess the prevalence and serotype distribution of GBS in Ghana since this knowledge is a prerequisite for future evaluation of vaccine trials.

METHODS

This double-centre study was conducted in one rural and one urban hospital in central Ghana, West Africa. Women in late pregnancy (≥35 weeks of gestation) attending the antenatal care clinic (ANC) provided recto-vaginal swabs for GBS testing. GBS isolates were analysed for serotype and antibiotic susceptibility. GBS-positive women were treated with intrapartum antibiotic prophylaxis (IAP) according to current guidelines of the Center for Disease Control and Prevention (CDC).

RESULTS

In total, 519 women were recruited at both study sites, recto-vaginal swabs were taken from 509. The overall prevalence of GBS was 19.1% (18.1% in rural Pramso and 23.1% in urban Kumasi, restrospectively). Capsular polysaccharide serotype (CPS) Ia accounted for the most frequent serotype beyond all isolates (28.1%), followed by serotype V (27.1%) and III (21.9%). No resistance to Penicillin was found, resistances to second line antibiotics clindamycin and erythromycin were 3.1% and 1%, respectively.

DISCUSSION

Group B Streptococcus serotype distribution in Ghana is similar to that worldwide, but variations in prevalence of certain serotypes between the urban and rural study site were high. Antibiotic resistance of GBS strains was surprisingly low in this study.

Isolation and anti-microbial susceptibility pattern of group B Streptococcus among pregnant women attending antenatal clinics in Ayder Referral Hospital and Mekelle Health Center, Mekelle, Northern Ethiopia

Background

Vaginal colonization with group B Streptococcus (GBS) is the predominant risk factor for the development of invasive neonatal GBS diseases and puts newborns at increased risk for morbidity and mortality. This study is aimed to determine the colonization rate and antimicrobial susceptibility pattern of group B Streptococcus among pregnant women.

Methods

Hospital based cross-sectional study was conducted from August to December 2014 at selected health facilities. A total of 139 antenatal clinics attendees, proportionally allocated, were recruited consecutively. Socio-demographic and clinical factors were collected using a structured questionnaire. Vaginal swabs were collected and cultured on Todd Hewitt broth and in 5 % sheep blood agar. Antimicrobial susceptibility test was done using Kirby-Bauer disk diffusion test. Statistical analysis was performed using Pearson’s Chi square test.

Results

Among the 139, 19 (13.7 %) were positive for GBS. All the GBS isolates were susceptible (100 %) to penicillin G, vancomycin, ampicillin, erythromycin and gentamicin. Two of the GBS isolates showed multidrug resistance against norfloxacin and ciprofloxacin. No statistically significant difference was observed for GBS colonization with any independent variables.

Conclusion

Vaginal colonization of GBS for the present study put emphasis on further investigation and accomplishment of routine GBS screening practices. The recovery of resistant strains to antimicrobial agents recommended in cases of penicillin allergic mothers indicates the importance of susceptibility test.

A high burden of late-onset sepsis among newborns admitted to the largest neonatal unit in central Vietnam

OBJECTIVE

The objective of this study is to determine the prevalence, causes and outcome of sepsis in hospitalized neonates in the largest neonatal unit in central Vietnam.

STUDY DESIGN

A 1-year prospective cohort study of newborns admitted to the neonatal unit in Da Nang. A sepsis work-up including blood culture was undertaken before commencing antibiotics for neonates with suspected sepsis.

RESULT

Of 2555 neonatal admissions, 616 neonates had 729 episodes of suspected invasive sepsis. A pathogen was isolated from blood in 115 (16%) episodes in 106 neonates. The prevalence of early-onset sepsis (EOS) was 8 (95% confidence interval (CI): 4 to 11) per 1000 admissions, and of late-onset sepsis (LOS) was 34 (95% CI: 27 to 41) per 1000 admissions. Of 86 neonates with LOS, 69 (80%) also fulfilled the criteria for nosocomial sepsis. The commonest bacterial causes of EOS were coagulase-negative Staphylococcus (CoNS) and Staphylococcus aureus, and of LOS were Acinetobacter, CoNS and Klebsiella pneumoniae. Fungal sepsis occurred in 35 neonates of which most were nosocomial sepsis. In vitro resistance to multiple antibiotics was common among Gram-negative bacteria. Antibiotics were prescribed and given to 68% of all admissions, and 14% of all admissions received four or more different antibiotics. The case fatality rate for confirmed sepsis was 46%.

CONCLUSION

Late-onset, nosocomial sepsis was common and associated with a high mortality in hospitalized newborns in the largest neonatal unit in central Vietnam. These findings highlighted the need for improved infection control measures and antibiotic stewardship, which have since been implemented.

Antibiotic resistance of Streptococcus agalactiae isolated from pregnant women in Garankuwa, South Africa

Background

This study was undertaken to determine the susceptibility profile and the mechanism of antibiotic resistance in Group B streptococcus (GBS) isolates detected in vaginal and rectal swabs from pregnant women attending Dr George Mukhari Academic Hospital, a University Teaching Hospital in Pretoria, South Africa.

Methods

The samples were collected over an 11-month period, cultured on selective media (colistin and nalidixic acid agar and Todd-Hewitt broth), and GBS positively identified by using different morphological and biochemical tests. The susceptibility testing was done using the Kirby–Bauer and E test methods according to CLSI guidelines 2012. The D test method was used for the detection of inducible clindamycin resistance. Multiplex PCR with specific primers was used to detect different genes coding for resistance.

Results

Out of 413 samples collected, 128 (30.9 %) were positive with GBS. The susceptibility testing revealed that 100 % of isolates were sensitive to penicillin, ampicillin, vancomycin and high level gentamicin. Erythromycin and clindamycin resistance was 21.1 and 17.2 %, respectively, in which 69 % had harboured constitutive macrolide, lincosamide and streptogramin B (MLS_B), 17.4 % had inducible MLS_B. The M and L phenotypes were present in 6.8 % each. The methylation of target encoded by ermB genes was the commonest mechanism of resistance observed in 55 % of isolates, 38 % of isolates had both ermB and linB genes and efflux pump mediated by mefA genes was also distributed among the isolates.

Conclusions

The study reaffirmed the appropriateness of penicillin as the antibiotic of choice for treating GBS infection. However it identified the challenges of resistance to macrolides and lincosamides used as alternative drugs for individuals allergic to penicillin. More GBS treatment options for penicillin allergic patients need to be researched on.

Neonatal group B streptococcus disease in developing countries: are we ready to deploy a vaccine?

Group B streptococcus (GBS) disease is the leading cause of neonatal sepsis in developed countries and has high case fatality rates. In developing countries, however, the burden of GBS is less clear; this is due to a lack of studies using optimal diagnostic, clinical and laboratory techniques and is complicated by the wide availability of non-prescription antibiotics to the general population and in peripartum patients. There is an urgent need for prospective, population-based surveillance to provide an accurate assessment of neonatal GBS disease burden in developing countries, which remains largely unrecognized, and consequently obscures the potential relevance of GBS vaccination in these populations. Preliminary data on GBS vaccines are promising as a preventive tool for neonatal GBS infection, more so than any other currently available public health initiative. However, how do we assess the true impact of a GBS vaccine without accurate surveillance data on the real burden of disease?

Rational development of guidelines for management of neonatal sepsis in developing countries

PURPOSE OF REVIEW

This review discusses the rational development of guidelines for the management of neonatal sepsis in developing countries.

RECENT FINDINGS

Diagnosis of neonatal sepsis with high specificity remains challenging in developing countries. Aetiology data, particularly from rural, community-based studies, are very limited, but molecular tests to improve diagnostics are being tested in a community-based study in South Asia. Antibiotic susceptibility data are limited, but suggest reducing susceptibility to first-and second-line antibiotics in both hospital and community-acquired neonatal sepsis. Results of clinical trials in South Asia and sub-Saharan Africa assessing feasibility of simplified antibiotic regimens are awaited.

SUMMARY

Effective management of neonatal sepsis in developing countries is essential to reduce neonatal mortality and morbidity. Simplified antibiotic regimens are currently being examined in clinical trials, but reduced antimicrobial susceptibility threatens current empiric treatment strategies. Improved clinical and microbiological surveillance is essential, to inform current practice, treatment guidelines, and monitor implementation of policy changes.

Burden of bacterial resistance among neonatal infections in low income countries: how convincing is the epidemiological evidence?

Background

Antibiotic resistance is a threat in developing countries (DCs) because of the high burden of bacterial disease and the presence of risk factors for its emergence and spread. This threat is of particular concern for neonates in DCs where over one-third of neonatal deaths may be attributable to severe infections and factors such as malnutrition and HIV infection may increase the risk of death. Additional, undocumented deaths due to severe infection may also occur due to the high frequency of at-home births in DCs.

Methods

We conducted a systematic review of studies published after 2000 on community-acquired invasive bacterial infections and antibiotic resistance among neonates in DCs. Twenty-one articles met all inclusion criteria and were included in the final analysis.

Results

Ninety percent of studies recruited participants at large or university hospitals. The majority of studies were conducted in Sub-Saharan Africa (n = 10) and the Indian subcontinent (n = 8). Neonatal infection incidence ranged from 2.9 (95% CI 1.9–4.2) to 24 (95% CI 21.8–25.7) for 1000 live births. The three most common bacterial isolates in neonatal sepsis were Staphylococcus aureus, Escherichia coli, and Klebsiella. Information on antibiotic resistance was sparse and often relied on few isolates. The majority of resistance studies were conducted prior to 2008. No conclusions could be drawn on Enterobacteriaceae resistance to third generation cephalosporins or methicillin resistance among Staphylococcus aureus.

Conclusions

Available data were found insufficient to draw a true, recent, and accurate picture of antibiotic resistance in DCs among severe bacterial infection in neonates, particularly at the community level. Existing neonatal sepsis treatment guidelines may no longer be appropriate, and these data are needed as the basis for updated guidelines. Reliable microbiological and epidemiological data at the community level are needed in DCs to combat the global challenge of antibiotic resistance especially among neonates among whom the burden is greatest.

Evaluation of intermittent preventive treatment of malaria against group B Streptococcus colonization in pregnant women: a nested analysis of a randomized controlled clinical trial of sulfadoxine/pyrimethamine versus mefloquine

OBJECTIVES

Streptococcus agalactiae constitutes an important cause of neonatal infections in sub-Saharan Africa. Sulfadoxine/pyrimethamine-the current intermittent preventive treatment of malaria in pregnancy (IPTp)-has proven in vitro activity against group B Streptococcus (GBS). Because of specific drug resistance to sulfadoxine/pyrimethamine, mefloquine-an antimalarial without in vitro activity against GBS-was evaluated as a potential alternative. This study assessed the potential of sulfadoxine/pyrimethamine-IPTp to reduce the prevalence of GBS colonization in pregnant women in Gabon when compared with the inactive control mefloquine-IPTp.

METHODS

Pregnant women participating in a randomized controlled clinical trial evaluating mefloquine-IPTp versus sulfadoxine/pyrimethamine-IPTp were invited to participate and recto-vaginal swabs were collected at delivery for detection of GBS colonization. Prevalence of recto-vaginal GBS colonization was compared between IPTp regimens and risk factor and birth outcome analyses were computed.

RESULTS

Among 549 participants, 106 were positive for GBS colonization at delivery (19%; 95% CI = 16%-23%). Prevalence of maternal GBS colonization showed no significant difference between the two IPTp regimens (mefloquine-IPTp: 67 of 366 women = 18%; 95% CI = 14%-22%; sulfadoxine/pyrimethamine-IPTp: 39 of 183 women = 21%; 95% CI = 15%-27%). Risk factor analysis for GBS colonization demonstrated a significant association with illiteracy (adjusted OR = 2.03; 95% CI = 1.25-3.30). GBS colonization had no impact on birth outcome, anaemia at delivery, gestational age and birth weight.

CONCLUSIONS

Sulfadoxine/pyrimethamine did not reduce colonization rates when used as the IPTp drug during pregnancy. Illiteracy was associated with GBS colonization.

HIV-1 Is Associated With Lower Group B Streptococcus Capsular and Surface-Protein IgG Antibody Levels and Reduced Transplacental Antibody Transfer in Pregnant Women

BACKGROUND

Human immunodeficiency virus (HIV)-exposed infants are at increased risk of invasive Group B Streptococcus (GBS) disease; however, the reason for this increased susceptibility has not been characterized.

METHODS

We compared GBS capsular and surface-protein maternal immunoglobin G antibody concentrations and cord-maternal ratios between HIV-infected and HIV-uninfected mother-newborn dyads.

RESULTS

Median capsular antibody concentrations (µg/mL) were lower in HIV-infected than HIV-uninfected women for serotypes Ib (P = .033) and V (P = .040); and for pilus island (PI)-1 (P = .016), PI-2a (P = .015), PI-2b (P = .015), and fibrinogen-binding protein A (P < .001). For serotypes Ia and III, cord-maternal ratios were 37.4% (P < .001) and 32.5% (P = .027) lower in HIV-infected compared to HIV-uninfected mother-newborn dyads. The adjusted odds of having capsular antibody concentration ≥2 µg/mL when comparing HIV-infected to -uninfected women were 0.33 (95% confidence interval [CI], .15-.75) and 0.34 (95% CI, .12-1.00) for serotypes Ia and III, respectively. Antibody levels and cord-maternal ratios were independent of CD4(+) lymphocyte counts or HIV-1 viral load.

CONCLUSIONS

The lower GBS antibody concentrations and reduced transplacental antibody transfer in HIV-infected women, which likely contribute to their infants being at heightened susceptibility for invasive GBS disease, could possibly be mitigated by vaccination with a GBS conjugate vaccine currently under clinical development.

Anti-group B Streptococcus antibody in infants born to mothers with human immunodeficiency virus (HIV) infection

BACKGROUND

HIV-exposed uninfected infants have increased infection risk and mortality compared to HIV-unexposed infants. HIV-exposed infants may be at increased risk of invasive GBS disease due to reduced maternal antibody against GBS.

METHODS

We quantified antibodies that bind to the surface of whole Group B Streptococcus (GBS) of serotypes Ia, Ib, II, III and V using novel flow cytometry assays in South African HIV-infected and non-infected mothers and their uninfected infants. Antibody-mediated complement C3b/iC3b deposition onto GBS of these serotypes was also quantified by a novel flow cytometry assay.

RESULTS

Geometric mean concentration (GMC) of both surface-binding anti-GBS antibody and antibody-mediated complement deposition onto GBS were reduced in HIV-infected women (n=46) compared to HIV-uninfected women (n=58) for ST1a (surface-binding: 19.3 vs 29.3; p=0.003; complement deposition: 2.9 vs 5.3 SU/mL; p=0.003), STIb (24.9 vs 47.6; p=0.003; 2.6 vs 4.9 SU/mL; p=0.003), STII (19.8 vs 50.0; p=0.001; 3.1 vs 6.2 SU/mL; p=0.001), STIII (27.8 vs 60.1; p=0.001; 2.8 vs 5.3 SU/mL; p=0.001) and STV (121.9 vs 185.6 SU/mL; p<0.001) and in their infants for STIa (complement deposition 9.4 vs 27.0 SU/mL; p=0.02), STIb (13.4 vs 24.5 SU/mL; p=0.02), STII (14.6 vs 42.7 SU/mL; p=0.03), STIII (26.6 vs 62.7 SU/mL; p=0.03) and STV (90.4 vs 165.8 SU/mL; p=0.04). Median transplacental transfer of antibody from HIV-infected women to their infants was reduced compared to HIV-uninfected women for GBS serotypes II (0.42 [IQR 0.22-0.59] vs 1.0 SU/mL [0.42-1.66]; p<0.001), III (0.54 [0.31-1.03] vs 0.95 SU/mL [0.42-3.05], p=0.05) and V (0.51 [0.28-0.79] vs 0.75 SU/mL [0.26-2.9], p=0.04). The differences between infants remained significant at 16 weeks of age.

CONCLUSIONS

Maternal HIV infection was associated with lower anti-GBS surface binding antibody concentration and antibody-mediated C3b/iC3b deposition onto GBS bacteria of serotypes Ia, Ib, II, III and V. This may render these infants more susceptible to early and late onset GBS disease.

Swine worker awareness and behavior regarding prevention of zoonotic influenza transmission

ABSTRACT A convenience survey of swine workers on large and small commercial farms in the Northeast and Midwest United States regarding zoonotic influenza awareness and precautions was conducted. Workers reported low levels of concern regarding the risk of contracting influenza from swine, and were generally not aware of national guidelines for influenza prevention. Use of personal protective equipment (PPE) varied by task, N95 respirator use was rare, and no workers were enrolled in respirator programs. Reported influenza vaccination coverage was greater than the national average in 2009-2010, but declined in 2010-2011. Workers on large farms were more likely to use PPE in some tasks and to report using more precautions when pigs appeared ill. Although reporting low levels of concern regarding zoonotic influenza and low adherence to national influenza guidelines, swine workers reported making task-based and risk-based decisions about use of PPE, suggesting opportunities for enhanced prevention of zoonotic disease transmission.

Breast milk and Group B streptococcal infection: vector of transmission or vehicle for protection?

Invasive Group-B streptococcal (GBS) disease is a leading cause of infant mortality and morbidity worldwide. GBS colonises the maternal rectum and vagina and transmission of bacteria from a colonized mother to her infant at birth is an important risk factor for GBS disease. GBS disease has also been associated with case reports of transmission via infected breast milk raising questions about mode of acquisition and transmission of this enteric pathogen and the development of neonatal disease. However, most breastfed infants remain unaffected by GBS in breast milk. Mechanisms associated with transmission of GBS in breast milk and potential factors that may protect the infant from transmission remain poorly understood. Understanding factors involved in protection or transmission of GBS infection via breast milk is important both for premature infants who are a high-risk group and for infants in the developing world where breastfeeding is the only sustainable infant feeding option. In this review we discuss the proposed mechanisms for GBS colonization in breast milk on one hand and its immune factors that may protect from transmission of GBS from mother to infant on the other. Innate and adaptive immune factors, including serotype-specific antibody and their significance in the prevention of infant disease are presented. We further report on the role of human oligosaccharides in protection from invasive GBS disease. Advances in our knowledge about breast milk and immunity in GBS disease are needed to fully appreciate what might mitigate transmission from mother to infant and protect neonates from this devastating disease and to contribute to the development of novel prevention strategies, including maternal immunization to prevent infant disease.

An overview of global GBS epidemiology

Streptococcus agalactiae (group B streptococcus (GBS)), remains the leading cause of neonatal sepsis and meningitis in many countries and an important cause of disease in pregnant women, immunocompromised adults and the elderly. Intrapartum antibiotic strategies have reduced the incidence of early-onset neonatal GBS where applied, but have had no impact on late onset GBS infection and only a limited impact on disease in pregnant women. In low/middle income settings, the disease burden remains uncertain although in several countries of Southern Africa appears comparable to that of high-income countries. Disease may be rapidly fulminating and cases therefore missed before appropriate samples are obtained. This may lead to significant underestimation of the true burden and be a particular issue in many African and Asian countries; comprehensive epidemiological data from such countries are urgently required. The available data suggest that the serotype distribution of GBS isolates is similar in Africa, Western Pacific, Europe, the Americas and the Eastern Mediterranean regions and has not changed over the past 30 years. Five serotypes (Ia, Ib, II, III, V) account for the majority of disease; conjugate vaccines including some or all of these serotypes therefore hold great promise for preventing this important disease.

Considerations for a phase-III trial to evaluate a group B Streptococcus polysaccharide-protein conjugate vaccine in pregnant women for the prevention of early- and late-onset invasive disease in young-infants

In 2010, an estimated 393,000 infection-related neonatal deaths occurred worldwide with Group B streptococcus (GBS) being a leading cause. Prevention of early-onset disease (0-6 days; EOD) is currently focused on intra-partum antibiotic prophylaxis to mothers identified as being at risk; such strategies reduce EOD by 75-80% but are resource-intensive and logistically-difficult to implement in developing countries. Vaccination of pregnant women is an alternate strategy for preventing both EOD and late-onset disease (7-89 days; LOD). A trivalent GBS polysaccharide-protein conjugate vaccine (GBS-CV) composed of capsular epitopes from serotypes Ia, Ib and III is undergoing phase-II evaluation among pregnant women in Europe, North America and Africa. These serotypes cause 70-80% of all invasive GBS disease in early-infancy. Maternal anti-GBS antibodies are associated with protection from EOD, however, since a correlate of efficacy has not been defined, a phase III efficacy trial may be required for licensure. Criteria for selecting appropriate sites include sufficiently high GBS incidence in large birth cohorts, as well as adequate clinical and microbiological diagnostic skills and capacities. Alternate pathways to licensure should be explored, e.g. identification of serological correlates of protection with subsequent phase IV studies establishing vaccine-effectiveness against invasive GBS disease. Conducting a randomized, placebo-controlled efficacy trial, however, has the additional advantage of also being able to evaluate the role of GBS contributing to neonatal culture-negative sepsis, stillbirths, prematurity and low-birth weight.

Epidemiology of Group B Streptococcus in developing countries

Group B Streptococcus (GBS) causes pneumonia, meningitis and sepsis in neonates. The current distribution pattern of GBS serotypes in developing countries such as India, China and Brazil is not clear. In order to appropriately plan for vaccination programs to address the burden of this disease in these countries, prospective population based studies are urgently needed. In our discussions, we focused on India, China and Brazil because of the membership of our workgroup, but data on other countries are also presented here. Further studies in developing countries are needed so as to better formulate appropriate public health interventions.

A three year descriptive study of early onset neonatal sepsis in a refugee population on the Thailand Myanmar border

BACKGROUND

Each year an estimated four million neonates die, the majority in the first week of life. One of the major causes of death is sepsis. Proving the incidence and aetiology of neonatal sepsis is difficult, particularly in resource poor settings where the majority of the deaths occur.

METHODS

We conducted a three year observational study of clinically diagnosed early onset (<7 days of age) neonatal sepsis (EONS) in infants born to mothers following antenatal care at the Shoklo Malaria Research Unit clinic in Maela camp for displaced persons on the Thailand-Myanmar border. Episodes of EONS were identified using a clinical case definition. Conventional and molecular microbiological techniques were employed in order to determine underlying aetiology.

RESULTS

From April 2009 until April 2012, 187 infants had clinical signs of EONS, giving an incidence rate of 44.8 per 1000 live births (95% CI 38.7-51.5). One blood culture was positive for Escherichia coli, E. coli was detected in the cerebrospinal fluid specimen in this infant, and in an additional two infants, by PCR. Therefore, the incidence of bacteriologically proven EONS was 0.7 per 1000 live births (95% CI 0.1-2.1). No infants enrolled in study died as a direct result of EONS.

CONCLUSION

A low incidence of bacteriologically proven EONS was seen in this study, despite a high incidence of clinically diagnosed EONS. The use of molecular diagnostics and nonspecific markers of infection need to be studied in resource poor settings to improve the diagnosis of EONS and rationalise antibiotic use.