Molecular Characterization of the Fecal Microbiota in Patients with Nonalcoholic Steatohepatitis – A Longitudinal Study

Background

The human gut microbiota has profound influence on host metabolism and immunity. This study characterized the fecal microbiota in patients with nonalcoholic steatohepatitis (NASH). The relationship between microbiota changes and changes in hepatic steatosis was also studied.

Methods

Fecal microbiota of histology-proven NASH patients and healthy controls was analyzed by 16S ribosomal RNA pyrosequencing. NASH patients were from a previously reported randomized trial on probiotic treatment. Proton-magnetic resonance spectroscopy was performed to monitor changes in intrahepatic triglyceride content (IHTG).

Results

A total of 420,344 16S sequences with acceptable quality were obtained from 16 NASH patients and 22 controls. NASH patients had lower fecal abundance of Faecalibacterium and Anaerosporobacter but higher abundance of Parabacteroides and Allisonella. Partial least-square discriminant analysis yielded a model of 10 genera that discriminated NASH patients from controls. At month 6, 6 of 7 patients in the probiotic group and 4 of 9 patients in the usual care group had improvement in IHTG (P = 0.15). Improvement in IHTG was associated with a reduction in the abundance of Firmicutes (R² = 0.4820, P = 0.0028) and increase in Bacteroidetes (R² = 0.4366, P = 0.0053). This was accompanied by corresponding changes at the class, order and genus levels. In contrast, bacterial biodiversity did not differ between NASH patients and controls, and did not change with probiotic treatment.

Conclusions

NASH patients have fecal dysbiosis, and changes in microbiota correlate with improvement in hepatic steatosis. Further studies are required to investigate the mechanism underlying the interaction between gut microbes and the liver.     

Case–Case Comparison of Candida auris Versus Other Candida Species Bloodstream Infections: Results of an Outbreak Investigation in Colombia

Background

Candida auris is an emerging multidrug-resistant yeast that causes outbreaks in healthcare settings around the world. In 2016, clinicians and public health officials identified patients with C. auris bloodstream infections (BSI) in Colombian healthcare facilities. To evaluate potential risk factors and outcomes for these infections, we investigated epidemiologic and clinical features of patients with C. auris and other Candida species BSI.

Methods

We performed a retrospective case-case investigation in four Colombian acute care hospitals, defining a case as Candida spp. isolated from blood culture during January 2015–September 2016. C. auris BSI cases were compared to other Candida species BSI cases. Odds ratio (OR), estimated using logistic regression, was used to assess the association between risk factors and outcomes.

Results

We analyzed 90 patients with BSI, including 40 with C. auris and 50 with other Candida species. All had been admitted to the intensive care unit (ICU). No significant demographic differences existed between the two groups. The following variables were independently associated with C. auris BSI:?≥?15 days of pre-infection ICU stay (OR: 5.62, CI: 2.04–15.5), evidence of severe sepsis (OR: 3.70, CI 1.19–11.48), and diabetes mellitus (OR 5.69, CI 1.01–31.9).

Conclusion

Patients with C. auris BSI had longer lengths of ICU stay than those with other candidemias, suggesting that infections are acquired during hospitalization. This is different from other Candida infections, which are usually thought to result from autoinfection with host flora.

     

Fetal Growth and Risk of Stillbirth: A Population-Based Case–Control Study

Background

Stillbirth is strongly related to impaired fetal growth. However, the relationship between fetal growth and stillbirth is difficult to determine because of uncertainty in the timing of death and confounding characteristics affecting normal fetal growth.

Methods and Findings

We conducted a population-based case–control study of all stillbirths and a representative sample of live births in 59 hospitals in five geographic areas in the US. Fetal growth abnormalities were categorized as small for gestational age (SGA) (<10th percentile) or large for gestational age (LGA) (>90th percentile) at death (stillbirth) or delivery (live birth) using population, ultrasound, and individualized norms. Gestational age at death was determined using an algorithm that considered the time-of-death interval, postmortem examination, and reliability of the gestational age estimate. Data were weighted to account for the sampling design and differential participation rates in various subgroups. Among 527 singleton stillbirths and 1,821 singleton live births studied, stillbirth was associated with SGA based on population, ultrasound, and individualized norms (odds ratio [OR] [95% CI]: 3.0 [2.2 to 4.0]; 4.7 [3.7 to 5.9]; 4.6 [3.6 to 5.9], respectively). LGA was also associated with increased risk of stillbirth using ultrasound and individualized norms (OR [95% CI]: 3.5 [2.4 to 5.0]; 2.3 [1.7 to 3.1], respectively), but not population norms (OR [95% CI]: 0.6 [0.4 to 1.0]). The associations were stronger with more severe SGA and LGA (<5th and >95th percentile). Analyses adjusted for stillbirth risk factors, subset analyses excluding potential confounders, and analyses in preterm and term pregnancies showed similar patterns of association. In this study 70% of cases and 63% of controls agreed to participate. Analysis weights accounted for differences between consenting and non-consenting women. Some of the characteristics used for individualized fetal growth estimates were missing and were replaced with reference values. However, a sensitivity analysis using individualized norms based on the subset of stillbirths and live births with non-missing variables showed similar findings.

Conclusions

Stillbirth is associated with both growth restriction and excessive fetal growth. These findings suggest that, contrary to current practices and recommendations, stillbirth prevention strategies should focus on both severe SGA and severe LGA pregnancies. Please see later in the article for the Editors'' Summary     

A Prospective Study of Selenium Concentration and Risk of Preeclampsia in Pregnant Iranian Women: a Nested Case–Control Study

Preeclampsia remains a leading cause of maternal and perinatal mortality and morbidity worldwide; however, its specific etiology still remains obscure. Some studies implicate poor maternal selenium status predisposing the mother to preeclampsia. This study was designed to determine changes in plasma selenium levels in women having preeclampsia as compared with those with normal pregnancy. In a nested case–control study, 650 normal primigravida in their first 24–28 weeks participated in the study. After 3 months of follow-up of all subjects, blood selenium levels were measured in 38 women presenting consecutively with preeclampsia and in 38 women having a normal pregnancy by atomic absorption spectrophotometry. Birth outcomes were recorded, such as gestational age at delivery, height, weight, birth head circumflex and 1-min Apgar score. Preeclampsia affects about 5.84 % of pregnancies, and in our study, there were no significant differences in age, anthropometric indices, and family history of preeclampsia between the preeclamptic and control groups. The selenium concentrations in plasma in women with preeclampsia were significantly lower as compared with those in women with normal pregnancy (70.63?±?21.41 versus 82.03?±?15.54 μg/L, p?<?0.05). Being in the bottom tertile of selenium concentration (less than 62.2 μg/L) was associated with greater risk of preeclampsia in pregnant women. The reduced selenium in the maternal circulations observed in the preeclamptic mothers support the hypothesis that insufficient selenium concentration may be a contributing factor to the pathophysiological mechanisms associated with preeclampsia, and optimizing the dietary selenium intake through supplementation could produce demonstrable clinical benefits.     

Concerns Expressed by Parents of Children with Pervasive Developmental Disorders for Different Time Periods of the Day: A Case–Control Study

Background/Aim

The Questionnaire: Children with Difficulties (QCD) is a parent-assessed questionnaire designed to evaluate child’s difficulties in functioning during specific periods of the day. This study aimed to evaluate difficulties in daily functioning of children and adolescents with pervasive developmental disorder (PDD) using the QCD. Results were compared with those for a community sample.

Methods

A case–control design was used. The cases comprised elementary school students (182 males, 51 females) and junior high school students (100 males, 39 females) with PDD, whereas a community sample of elementary school students (568 males, 579 females) and junior high school students (180 males, 183 females) was enrolled as controls. Their behavior was assessed using the QCD, the Tokyo Autistic Behavior Scale (TABS), the ADHD-rating scale (ADHD-RS), and the Oppositional Defiant Behavior Inventory (ODBI) for elementary and junior high school students, respectively. Effects of gender and diagnosis on the QCD scores were analyzed. Correlation coefficients between QCD and TABS, ADHD-RS, and ODBI scores were analyzed.

Results

The QCD scores for the children with PDD were significantly lower compared with those from the community sample (P < 0.001). Significantly strong correlations were observed in more areas of the ADHD-RS and ODBI scores compared with the TABS scores.

Conclusions

Children with PDD experienced greater difficulties in completing basic daily activities; moreover, their QCD scores revealed stronger associations with their ADHD-RS and ODBI scores in comparison with their TABS scores. The difficulties of PDD, ADHD and OBDI symptoms combined in children makes it necessary to assess all diagnoses before any therapy for PDD is initiated in order to be able to evaluate its results properly.     

Levels of Heavy Metals and Essential Minerals in Hair Samples of Children with Autism in Oman: a Case–Control Study

Toxic levels of heavy metals and low levels of essential minerals have been suggested to play a critical role in the pathogenesis of autism spectrum disorders (ASD). This study documents the levels of heavy metals and essential minerals in hair samples of children with ASD in Muscat, the urbanized capital of Oman, Muscat. The study included 27 children with ASD and 27 matched non-ASD controls. Parental interviews were held and dietary intake questionnaires completed in conjunction with the collection of hair samples. Analysis of heavy metals and essential minerals was carried out by inductively coupled plasma mass spectrometry. Chi-square analysis and non-parametric Fisher’s exact tests were used to assess statistical significance. Children with ASD had significantly higher levels of all 11 analyzed heavy metals in their hair samples (P?<?0.05), ranging from 150 to 365 % of control levels. ASD children also had significantly higher levels of essential minerals sulfur, sodium, magnesium, potassium, zinc, and iron, but lower levels of calcium and copper in their hair samples. This study corroborates data from previous studies in different parts of the world indicating the presence of elevated levels of heavy metals and selective depletion of essential minerals in the hair of children with ASD.     

Ethnic Variations in Severe Maternal Morbidity in the UK– A Case Control Study

Background

Previous studies showed a higher risk of maternal morbidity amongst black and other minority ethnic (BME) groups, but were unable to investigate whether this excess risk was concentrated within specific BME groups in the UK. Our aim was to analyse the specific risks and to investigate reasons for any disparity.

Methods

Unmatched case-control analysis using data from the United Kingdom Obstetric Surveillance System (UKOSS), February 2005-January 2013. Cases were 1,753 women who experienced severe morbidity during the peripartum period. Controls were 3,310 women who delivered immediately before the cases in the same hospital. Multivariable logistic regression modelling was used to adjust for known confounders and to understand their effects.

Results

Compared with white European women, the odds of severe maternal morbidity were 83% higher among black African women (adjusted odds ratio (aOR) = 1.83; 95% Confidence Interval (CI) = 1.39–2.40), 80% higher among black Caribbean (aOR = 1.80; 95% CI = 1.14–2.82), 74% higher in Bangladeshi (aOR = 1.74; 95% CI = 1.05–2.88), 56% higher in other non-whites (non-Asian) (aOR = 1.56; 95% CI = 1.05–2.33) and 43% higher among Pakistani women (aOR = 1.43; 95% CI = 1.07–1.92). There was no evidence of substantial confounding. Anaemia in current pregnancy, previous pregnancy problems, inadequate utilisation of antenatal care, pre-existing medical conditions, parity>3, and being younger and older were independent risk factors but, the odds of severe maternal morbidity did not differ by socioeconomic status, between smokers and non-smokers or by BMI.

Discussion

This national study demonstrates an increased risk of severe maternal morbidity among women of ethnic minority backgrounds which could not be explained by known risk factors for severe maternal morbidity.     

Virulence Factors and Antifungal Susceptibility of Candida albicans Isolates from Oral Candidosis Patients and Control Individuals

Sixty isolates of Candida albicans, 30 obtained from the oral cavity of denture wearers presenting signs of candidosis and 30 obtained from the oral cavity of denture wearers with normal palatal mucosa were assayed for phospholipase and proteinase production, as well as for adherence to buccal epithelial cells. Likewise, susceptibility of the isolates to antifungals was determined by the NCCLS reference method and the E-test method. Proteinase activity was increased among the strains obtained from oral candidosis patients. In contrast, no significant differences between the two groups of isolates were observed in their adherence ability in vitro, in phospholipase production, and susceptibility to antifungal drugs.     

Farmer’s Lung Disease and Microbiological Composition of Hay: A Case–Control Study

Previous studies performed in France have suggested that handling hay contaminated with high amounts of moulds, and especially Absidia corymbifera and Eurotium amstelodami, may favour farmer’s lung disease. The circumstances favouring farmer’s lung disease and the distinctive microbiological composition of hay samples that provoke attacks need to be specified. We present a case–control study which investigates the agricultural practices and the microbiological composition of hay handled in patients with farmer’s lung disease as compared to those of a representative control population. Ten cases identified the hay they were handling at the onset of symptoms. The location, type of farm and working conditions were similar to those of the control farms. Conversely, the microbiological composition of hay differed, with significantly higher amounts of E. amstelodami (P < 0.01), A. corymbifera (P = 0.003), mesophilic Streptomyces (P < 0.01), thermophilic Streptomyces (P < 0.01) and Saccharomonospora viridis (P < 0.01) than in the control population. Our results demonstrate that hay identified by patients as having a harmful effect is characterized by a higher total amount of microorganisms, notably five microorganisms that seem discriminative. Mean concentrations are 2- to 115-fold higher in hay suspected to cause symptoms than in hay from a representative panel of farms. Handling hay with high amounts of these five microorganisms constitutes a risk factor for farmer’s lung disease that should be considered for the development of prophylactic measures.     

Defective Mitochondrial Function In Vivo in Skeletal Muscle in Adults with Down’s Syndrome: A 31P-MRS Study

Down’s syndrome (DS) is a developmental disorder associated with intellectual disability (ID). We have previously shown that people with DS engage in very low levels of exercise compared to people with ID not due to DS. Many aspects of the DS phenotype, such as dementia, low activity levels and poor muscle tone, are shared with disorders of mitochondrial origin, and mitochondrial dysfunction has been demonstrated in cultured DS tissue. We undertook a phosphorus magnetic resonance spectroscopy (³¹P-MRS) study in the quadriceps muscle of 14 people with DS and 11 non-DS ID controls to investigate the post-exercise resynthesis kinetics of phosphocreatine (PCr), which relies on mitochondrial respiratory function and yields a measure of muscle mitochondrial function in vivo. We found that the PCr recovery rate constant was significantly decreased in adults with DS compared to non-DS ID controls (1.7±0.1 min⁻¹ vs 2.1±0.1 min⁻¹ respectively) who were matched for physical activity levels, indicating that muscle mitochondrial function in vivo is impaired in DS. This is the first study to investigate mitochondrial function in vivo in DS using ³¹P-MRS. Our study is consistent with previous in vitro studies, supporting a theory of a global mitochondrial defect in DS.     

Molecular Characterization of a Deletion in the HPRT1 Gene in a Patient with Lesch–Nyhan Syndrome

Lesch–Nyhan syndrome is caused by a deficiency of hypoxanthine phosphoribosyltransferase (HPRT) encoded by HPRT1. About 20% of patients have a deletion of HPRT1 and large deletions of HPRT1 are not always fully characterized at the molecular level. Here, we report on a case of Lesch–Nyhan syndrome with a 33-kb deletion involving exon 1 of HPRT1. This novel mutation is caused by a nonhomologous recombination between different classes of interspersed repetitive DNA.     

Molecular Identification and Echinocandin Susceptibility of Candida parapsilosis Complex Bloodstream Isolates in Italy, 2007–2014

The Candida parapsilosis group encompasses three species: C. parapsilosis, C. orthopsilosis, and C. metapsilosis. Here, we describe the incidence and echinocandin susceptibility profile of bloodstream isolates of these three species collected from patients admitted to an Italian university hospital from 2007 to 2014. Molecular identification of cryptic species of the C. parapsilosis complex was performed using polymerase chain reaction amplification of the gene encoding secondary alcohol dehydrogenase, followed by digestion with the restriction enzyme BanI. Minimum inhibitory concentrations were determined using the broth microdilution method according to European Committee for Antimicrobial Susceptibility Testing (EUCAST EDef 7.2) and Clinical Laboratory Standards Institute (CLSI M27-A3) guidelines, and the results were compared with those obtained using the E-test and Sensititre methods. Of the 163 C. parapsilosis complex isolates, 136 (83.4%) were identified as C. parapsilosis, and 27 (16.6%) as C. orthopsilosis. The species-specific incidences were 2.9/10,000 admissions for C. parapsilosis and 0.6/10,000 admissions for C. orthopsilosis. No resistance to echinocandins was detected with any of the methods. The percent essential agreement (EA) between the EUCAST and E-test/Sensititre methods for anidulafungin, caspofungin, and micafungin susceptibility was, respectively, as follows: C. parapsilosis, 95.6/97.8, 98.5/88.2, and 93.4/96.3; C. orthopsilosis, 92.6/92.6, 96.3/77.8, and 63.0/66.7. The EA between the CLSI and E-test/Sensititre methods was, respectively, as follows: C. parapsilosis, 99.3/100, 98.5/89.0, and 96.3/98.5; C. orthopsilosis, 96.3/92.6, 100/81.5, and 92.6/88.9. Only minor discrepancies, ranging from 16.9% (C. parapsilosis) to 11.1% (C. orthopsilosis), were observed between the CLSI and E-test/Sensititre methods. In conclusion, this epidemiologic study shows a typical C. parapsilosis complex species distribution, no echinocandin resistance, and it reinforces the relevance of using commercially available microbiological methods to assess antifungal susceptibility. These data improve our knowledge of the national distribution of species of the psilosis group, as there are very few studies of these species in Italy.     

Injectable and Oral Contraceptive Use and Cancers of the Breast,Cervix, Ovary,and Endometrium in Black South African Women: Case–Control Study

Background

Oral contraceptives are known to influence the risk of cancers of the female reproductive system. Evidence regarding the relationship between injectable contraceptives and these cancers is limited, especially in black South Africans, among whom injectable contraceptives are used more commonly than oral contraceptives.

Methods and Findings

We analysed data from a South African hospital-based case–control study of black females aged 18–79 y, comparing self-reported contraceptive use in patients with breast (n = 1,664), cervical (n = 2,182), ovarian (n = 182), and endometrial (n = 182) cancer, with self-reported contraceptive use in 1,492 control patients diagnosed with cancers with no known relationship to hormonal contraceptive use. We adjusted for potential confounding factors, including age, calendar year of diagnosis, education, smoking, alcohol, parity/age at first birth, and number of sexual partners. Among controls, 26% had used injectable and 20% had used oral contraceptives. For current and more recent users versus never users of oral or injectable contraceptives, the odds ratios (ORs) for breast cancer were significantly increased in users of oral and/or injectable contraceptives (OR 1.66, 95% CI 1.28–2.16, p<0.001) and separately among those exclusively using oral (1.57, 1.03–2.40, p = 0.04) and exclusively using injectable (OR 1.83, 1.31–2.55, p<0.001) contraceptives; corresponding ORs for cervical cancer were 1.38 (1.08–1.77, p = 0.01), 1.01 (0.66–1.56, p = 0.96), and 1.58 (1.16–2.15, p = 0.004). There was no significant increase in breast or cervical cancer risk among women ceasing hormonal contraceptive use ≥10 y previously (p = 0.3 and p = 0.9, respectively). For durations of use ≥5 y versus never use, the ORs of ovarian cancer were 0.60 (0.36–0.99, p = 0.04) for oral and/or injectable contraceptive use and 0.07 (0.01–0.49, p = 0.008) for injectable use exclusively; corresponding ORs for endometrial cancer were 0.44 (0.22–0.86, p = 0.02) and 0.36 (0.11–1.26, p = 0.1).

Conclusions

In this study, use of oral and of injectable hormonal contraceptives was associated with a transiently increased risk of breast and cervical cancer and, for long durations of use, with a reduced risk of ovarian and endometrial cancer. The observed effects of injectable and of oral contraceptives on cancer risk in this study did not appear to differ substantially. Please see later in the article for the Editors'' Summary     

Microbiota Composition of the Intestinal Mucosa: Association with Fecal Microbiota?

The fecal and mucosal microbiota of infants with rectal bleeding and the fecal microbiota of healthy age-matched controls were investigated by fluorescent in situ hybridization. Bifidobacteria were the main genus in both the feces and mucosa. The other genera tested, Bacteroides, Clostridium, Escherichia coli and lactobacilli/enterococci, represented only minor constituents. No differences in fecal microbiota were observed between patients and controls. In the patients, however, four times greater numbers of bifidobacteria were observed in the feces when compared to the mucosa. Notwithstanding this difference, a strong positive correlation prevailed for bifidobacteria in feces and mucosal samples. The genera assessed accounted for 16% of total bacterial counts on mucosal samples and for 47% of total bacterial counts in feces. This indicates that the unidentified part of the microbiota, especially on the mucosa, deserves more attention.     

Comparative Assessment of Cytokines and Other Inflammatory Markers for the Early Diagnosis of Neonatal Sepsis–A Case Control Study

Objective

Cytokines (IL-6, IL-8 and TNF-α), sCD163, and C-reactive protein were serially measured in an attempt to identify a set of tests which can reliably confirm or refute the diagnosis of neonatal sepsis at an early stage.

Methods

One hundred neonates suspected to have sepsis on clinical grounds and who met the inclusion criteria were enrolled for the study. Based on the positive or negative blood culture reports they were classified as infected (n = 50) and non-infected (n = 50) neonates respectively. Fifty healthy neonates without any signs of sepsis were also included in the study as control group. The initial blood sample was taken on day 0 (at the time of sepsis evaluation) and two further samples were taken on days 1 and 2 for monitoring the clinical progress and response to treatment. In the control group the cord blood and 48 hours venous sample was collected. Plasma CRP (ng/ml), IL-6 (pg/ml), IL-8 (pg/ml), TNF-α (ng/ml) and sCD163 (ng/ml) were determined by double antibody method Enzyme Linked Immunosorbent Assay in all the three blood samples.

Results

The cut of levels for CRP at >19,689 ng/ml had a sensitivity of 68%, specificity of 92%, for IL-6 at >95.32 pg/ml had a sensitivity of 54%, specificity of 96%, for IL-8 at >70.86 pg/ml had a sensitivity of 78%, specificity of 70%, for sCD163 at >896.78 ng/ml had a sensitivity of 100%, specificity of 88% for the diagnosis of infection before antibiotics. TNF-α levels of >12.6 ng/ml showed 100% sensitivity and 72% specificity for the diagnosis of inflammation.

Conclusion

The most powerful predictor to differentiate between the non-infected and infected neonates before antibiotics was sCD163. The most powerful indicator for evaluation of prognosis is IL-6. sCD163 can be used alone to screen for sepsis in neonates before the results of blood culture are received.     

Psychiatric Illness and Intellectual Disability in the Prader–Willi Syndrome with Different Molecular Defects - A Meta Analysis

Background and Objectives

Several studies have suggested a difference in clinical features of intellectual ability and psychiatric illness in the Prader–Willi syndrome (PWS) with the 15q11-q13 paternal deletion and maternal uniparental disomy (mUPD). Our objective was to appraise evidence on this association through a meta-analysis.

Methods

The electronic records PubMed and EMBASE from 1956 to 2012 were extracted for meta-analysis. Meta-analyses were performed by using fixed effect model. Mean difference, odds ratio, and 95% confidence interval were calculated.

Results

We retrieved a total of 744 PWS cases from 13 studies. These include 423 cases with paternal 15q11-q13 deletions and 318 cases of mUPD. Compare to the PWS cases with mUPD, PWS patients with the paternal 15q11-q13 deletion associated with significantly lower full scale IQ (FSIQ) [mean difference (MD), -2.69; 95%CI, -4.86 to -0.52; p=0.02] and verbal IQ (VIQ) (MD, -7.5; 95%CI, -9.75 to -5.26; p<0.00001) but higher performance IQ (PIQ) (MD, 4.02; 95%CI, 1.13 to 6.91; p=0.006). In contrast, PWS patients with mUPD are associated with significantly higher risk of psychiatric illness [odds rate (OR), 0.14; 95%CI, 0.08 to 0.23; p<0.00001] and higher risk of bipolar disorder (OR, 0.04; 95%CI, 0.01 to 0.23; p=0.0002).

Conclusions

Significant different clinical features of cognitive development and psychiatric illness are associated with PWS with different molecular defects. These findings provide support for evidence based practice to evaluate and manage the PWS syndrome with different molecular defects.     

Risk Factors for Buruli Ulcer in Ghana—A Case Control Study in the Suhum-Kraboa-Coaltar and Akuapem South Districts of the Eastern Region

Background

Buruli ulcer (BU) is a skin disease caused by Mycobacterium ulcerans. Its exact mode of transmission is not known. Previous studies have identified demographic, socio-economic, health and hygiene as well as environment related risk factors. We investigated whether the same factors pertain in Suhum-Kraboa-Coaltar (SKC) and Akuapem South (AS) Districts in Ghana which previously were not endemic for BU.

Methods

We conducted a case control study. A case of BU was defined as any person aged 2 years or more who resided in study area (SKC or AS District) diagnosed according to the WHO clinical case definition for BU and matched with age- (+/−5 years), gender-, and community controls. A structured questionnaire on host, demographic, environmental, and behavioural factors was administered to participants.

Results

A total of 113 cases and 113 community controls were interviewed. Multivariate conditional logistic regression analysis identified presence of wetland in the neighborhood (OR = 3.9, 95% CI = 1.9–8.2), insect bites in water/mud (OR = 5.7, 95% CI = 2.5–13.1), use of adhesive when injured (OR = 2.7, 95% CI = 1.1–6.8), and washing in the Densu river (OR = 2.3, 95% CI = 1.1–4.96) as risk factors associated with BU. Rubbing an injured area with alcohol (OR = 0.21, 95% CI = 0.008–0.57) and wearing long sleeves for farming (OR = 0.29, 95% CI = 0.14–0.62) showed protection against BU.

Conclusion

This study identified the presence of wetland, insect bites in water, use of adhesive when injured, and washing in the river as risk factors for BU; and covering limbs during farming as well as use of alcohol after insect bites as protective factors against BU in Ghana. Until paths of transmission are unraveled, control strategies in BU endemic areas should focus on these known risk factors.