Prevalence of occult hepatitis B virus infection among patients receiving haemodialysis in Sana'a city.

Background: Occult hepatitis B virus infection (OBI) is a challenging entity. Due to the increase in invasive procedures, blood transfusions, and difficulties in diagnosing OBI, patients are more likely to acquire OBI. This cross-sectional study was conducted to assess the prevalence of OBI by hepatitis B virus (HBV)-DNA detection, the prevalence of HBV infection by total hepatitis B core antibody (HBcAb) detection, and the potential risk factors for HBV infection in patients receiving haemodialysis regularly. Methods: This study included 80 patients receiving haemodialysis regularly, without acute or chronic HBV infection. They were selected from the dialysis units in Sana'a city, Yemen from June 2016 to June 2017. Patients who were positive for hepatitis B surface antigen and hepatitis B surface antibody were excluded from this study. Blood samples were taken prior to each haemodialysis session, and serological markers of HBV were included. HBcAb was measured by enzyme-linked immunosorbent assay, and HBV-DNA was measured by polymerase chain reaction. Results: HBV-DNA was detected in four patients (5%) and HBcAb was detected in 38 patients (47.5%). There was a significant association between HBV-DNA and HBcAb in patients receiving haemodialysis regularly. Conclusions: Patients who test positive for HBcAb should undergo additional HBV-DNA testing to allow accurate HBV screening and prevent infection of other patients.

Streptomyces sp. 1S1 isolated from Southern coast of the Red Sea as a renewable natural resource of several bioactive compounds.

Red Sea represents one of the most remarkable marine ecosystems. However, it is also one of the world's least explored areas of marine biodiversity. The aims of this investigation were therefore, to isolate marine microorganisms from the seashore sediments and water in shallow region from west Yemen coast, to assess their antimicrobial potential, to identify the highly active isolate, and to purify and identify the bioactive compounds from it. In this regard, twenty-five bacterial strains have been isolated from twenty samples and tested for their antimicrobial ability against some pathogenic bacteria and yeast by using the agar disk diffusion and agar well diffusion assay. Out of the total 25 marine actinomycetes isolates only 13 exhibited interesting antimicrobial activity. The morphological, biochemical, and phylogenetic characteristics of the potential isolate 1S1 were compatible with their classification in the genus Streptomyces. The 16S rRNA gene sequences have shown that the isolate 1S1 clustered with Streptomyces longisporoflavus. The strain Streptomyces sp. 1S1 was cultivated and extracted with ethyl acetate. The GC-MS study of the extract indicated the presence of certain fatty acyl compounds e.g., tetradecanoic acid, 9-octadecenoic acid, hexadecanoic acid, and 9,12,15-octadecatrienoic acid. Using chromatographic techniques, three compounds were isolated and by spectroscopic methods e.g., IR, MS and NMR structurally elucidated. The three compounds were identified as a triacylglyceride, 9-octadecenoic acid, and hexadecanoic acid. The study reinforces the evidence of the potential of Streptomyces sp and the ability to produce several antimicrobial compounds.

Class 1 Integrons in Clinical Multi Drug Resistance E. coli, Sana'a Hospitals, Yemen.

BACKGROUND AND OBJECTIVES: The occurrence of multi-drug resistance (MDR) Escherichia coli is one responsible for raised mortality and morbidity and was reported as major health problem. Class 1 integrons has crucial role in distributing antibiotic resistance genes among bacteria. Present work was aimed to determine the prevalence of class 1 integrons and its association with antibiotic resistance in MDR E. coli isolated from patient's body fluid and tissues from 6 health centers in Sana'a, Yemen. MATERIALS AND METHODS: A cross-sectional study a total of 198 E. coli from patients diagnosed with infection that had been referred to 6 hospitals and medical diagnostic from July, 2017 to August, 2017 in Sana'a, Yemen. Susceptibility of E. coli isolates to 15 antibiotics using the disc diffusion method. Conventional polymerase chain reaction was used for detection of class 1 of integrons in 100 randomly selected MDR E. coli. RESULTS: Overall 174 (87.9%) of 198 E. coli isolates were MDR. Class 1 integrons were detected in 67% of the randomly selected 100 of 198 MDR E. coli. A significant range (p<0.05-p<0.0001) was identified between presence of class 1 integrons and resistance to ceftriaxone, aztreonam, cefepime, amoxicillin-clavulanic acid, cefotoxime, cefepime-clavulanic acid, ceftazidime-clavulanic acid, ciprofloxacin, ceftazidime, norfloxacin and trimethoprim-sulfamethoxazole, while no significant difference were identified between integron class 1 and resistance to gentamicin, amikacin, nitrofurantoin and imipenem. CONCLUSION: High MDR E. coli isolates were detected in this study, among them the prevalence of class 1 integrons is the most common. The significant association between class 1 integrons and resistance to common prescribed antibiotics in hospitals in Sana'a, Yemen.

Urinary Tract Infection among Renal Transplant Recipients in Yemen.

Urinary tract infection (UTI) is the most common complication following kidney transplantation (KT), which could result in losing the graft. This study aims to identify the prevalence of bacterial UTI among KT recipients in Yemen and to determine the predisposing factors associated with post renal transplantation UTI. A cross sectional study included of 150 patients, who underwent KT was conducted between June 2010 and January 2011. A Morning mid-stream urine specimen was collected for culture and antibiotic susceptibility test from each recipient. Bacterial UTI was found in 50 patients (33.3%). The prevalence among females 40.3% was higher than males 29%. The UTI was higher in the age group between 41-50 years with a percentage of 28% and this result was statistically significant. Predisposing factors as diabetes mellitus, vesicoureteral reflux, neurogenic bladder and polycystic kidney showed significant association. High relative risks were found for polycystic kidney = 13.5 and neurogenic bladder = 13.5. The most prevalent bacteria to cause UTI was Escherichia coli represent 44%, followed by Staphylococcus saprophyticus 34%. Amikacin was the most effective antibiotic against gram-negative isolates while Ciprofloxacin was the most effective antibiotic against Staphylococcus saprophyticus. In conclusion, there is high prevalence of bacterial UTI among KT recipients in Yemen. Diabetes mellitus, vesicoureteral reflux, neurogenic bladder, polycystic kidney and calculi were the main predisposing factors.

The Association between Human Leukocyte Antigens and Hypertensive End-Stage Renal Failure among Yemeni Patients.

OBJECTIVES: Many studies have attempted to locate a connection between various genetic factors and the pathogenesis of certain diseases. A number of these have found human leukocyte antigens (HLAs) to be the most significant genetic factors affecting the susceptibility of an individual to a certain disease. The present case-control study aimed to determine the connection between class I and class II HLAs and cases of hypertensive end-stage renal failure (HESRF), as contrasted with healthy controls, in Yemen. METHODS: The study was carried out between March 2013 and March 2014 and included 50 HESRF patients attending the Urology & Nephrology Center at Al-Thawra University Hospital in Sana'a, Yemen, and 50 healthy controls visiting the same centre for kidney donation. Among both patients and controls, HLA class I (A, B and C) and class II (DRB1) genotypes were determined by polymerase chain reactions. RESULTS: There was an association (odds ratio: 4.0) with HLA-A9(24) and HESRF, although this was not statistically significant. A significant protective function was found for the HLA-CW3 and DRB1-8 genes against the development of HESRF. Although HLA-B14 was present in some patients (0.06) and not in the controls, this difference was not statistically significant enough to conclude that HLA-B14 plays a role in the genetic predisposition for end-stage renal disease development. There was a high frequency of HLA-A2, B5, CW6, DRB1-3, DRB1-4 and DRB1-13 in both patients and controls. CONCLUSION: Although no HLAs were found to play a highly significant role in genetic predisposition to HESRF, certain HLA genes could be considered as protective genes against HESRF development.

Clinical and laboratory manifestations of yemeni patients with systemic lupus erythematosus.

OBJECTIVES: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterised by multi-systemic involvement. This is the first study undertaken to determine the relationships between serological marker positivity and age, gender, signs and symptoms, risk factors and the treatment of SLE in Yemen. METHODS: We investigated the cases of 149 patients with SLE admitted to Al-Thawra Hospital in Sana'a city between November 2009 and November 2010. Of the 149 patients, females represented 75.2% and males, 24.8%. RESULTS: The most frequent presenting signs and symptoms were fatigue (84.6%), fever (81.9%), arthropathy (81.2%), anaemia (64.4%), photosensitivity (54.4%), renal involvement (53%), malar rash (52.3%), and alopecia (49%). Antinuclear antibodies (ANA) were detected in 95.3% of the patients and were associated significantly with most clinical presentations, except weight loss, hypertension and serositis. Anti-ds deoxyribonucleic acid (anti-dsDNA) was detected in 59.7% of the patients, and was associated significantly with fever and fatigue. Anti-Smith (anti-Sm) antibodies were detected in 27.5% of the patients, but were not significantly associated with all clinical presentations. Social stress was the most important risk factor for inducing SLE, with an odds ratio (OR) of 6.0, followed by common exposure to sunlight (OR = 2.2). CONCLUSION: In this study, SLE was more prevalent among females and young adults. The clinical presentation was characterised by a high incidence of fatigue and fever, and a low incidence of oral ulcers and serositis. ANA was associated with most clinical presentations except weight loss, hypertension, and serositis. Anti-dsDNA antibodies were most frequently associated with fever, fatigue and hypertension. There was no significant association of the anti-Sm antibodies with any clinical presentations.

Normalized real-time PCR for diagnosis of H. pylori infection.

OBJECTIVES: There is increasing interest in the use of quantitative PCR (q-PCR) for diagnosis of H. pylori infection. However, the assay remains largely unstandardized, making comparison between studies unreliable. The objective of this study was to assess accuracy of a normalized q-PCR assay for diagnosis of the infection. SUBJECTS AND METHODS: Seventy-six fresh gastric biopsy specimens were collected from patients undergoing upper gastrointestinal tract endoscopy and examined by rapid urease test (RUT), culture, and a commercial TaqMan q-PCR assay targeting the ureA gene. Counts obtained from the latter assay were normalized to the human ACTB gene. A subject was considered to be infected if two or more assays were positive. RESULTS: The detection rates were 42.1%, 52.6%, and 78.9% by culture, RUT and q-PCR, respectively. Bacterial density ranged 0.005 to 4800 bacteria per 100 human cells. Because q-PCR showed low initial specificity (45.7%), the cutoff value for the assay was recalculated as 1 bacterium per 100 human cells, using ROC curve analysis. Accordingly, the sensitivities and specificities were 79.5% and 97.3%, respectively, for culture; 94.9% and 91.9%, respectively, for RUT; and 94.9% and 94.6%, respectively, for q-PCR. By gold standard, 39 of the dyspeptic patients (51.3%) were found to be infected. CONCLUSIONS: With the identified cutoff value, the q-PCR assay diagnosed H. pylori infection with an accuracy slightly superior to that of RUT. However, the possibility that low counts detected only by q-PCR represent true infections warrants further investigation. Normalization of bacterial counts for standardization of q-PCR H. pylori assays is recommended.

Prevalence of rabies in various species in yemen and risk factors contributing to the spread of the disease.

OBJECTIVES: This study aimed to describe for the first time the prevalence of the passively-reported rabies virus among different domestic and wild animals submitted to the Central Veterinary Laboratory from various areas in Yemen, and to study prevalence proportion ratios (PPR) that contributed to the spread of rabies among animals, and its transmission to humans. METHODS: A brain sample was obtained from each of the 180 animals and tested for rabies virus by a direct fluorescent antibody test. RESULTS: Out of the total number of animals involved in attacks on humans, 63.3 % were positive for rabies. Of these, dogs were the main animal involved in attacks with a percentage of 92%, of which 62.7% were positive for rabies. Of animals involved in attacks, 70.6% were males of which 60.6% were positive, and 29.4% were females of which 69.8% were positive. Males comprised 68.9% of the total human individuals attacked, of whom 62.9% were attacked by rabies-positive animals. The significant risk factors that contributed to the spread of rabies in general included the presence of poultry carcasses and other waste in the vicinity of the attacks (PPR = 9.5) with a percentage of 84.8%, followed by the time of year, in particular school vacations (PPR = 3.8) with a percentage of 78%. CONCLUSION: Rabies is endemic in Yemen with a very high rabies-positive rate for animals involved in attacks, particularly for stray male dogs. Male children were most often involved in attacks by rabies-positive animals. The presence of food waste (particularly poultry carcasses) and school vacation periods were found to correlate significantly with increased risk for human exposure to rabies.

Types of Bacteria associated with Neonatal Sepsis in Al-Thawra University Hospital, Sana'a, Yemen, and their Antimicrobial Profile.

OBJECTIVES: This study was undertaken to investigate the organisms causing sepsis in the Neonatal Unit at Al-Thawra Hospital, Sana'a, Yemen, determine their resistance to antibiotics, and recommend policy for empirical treatment. METHODS: A total of 158 neonates having one or more signs of sepsis, and aged from 0 to 28 days, were enrolled in this study. A blood sample was taken from each subject, cultured, and then antibacterial susceptibility tests were performed for isolates. RESULTS: 90 (57%) cases yielded positive cultures. Early-onset sepsis showed higher positive culture results (61.7%) than late-onset sepsis (32%). Significant positive culture results were found among the group with birth weight 0.9-2 Kg (78.6%). Gram negative bacteria constituted 97.8% of the total isolates, of which Klebsiella pneumoniae was the predominant pathogen (36.7%), followed by Pseudomonas species (30.0%). The commonest symptoms among the cases were respiratory distress (72.2%), jaundice (62.2%), cyanosis (51.1%), and lethargy (47.8%); the mortality rate was 27.8%. All Gram negative bacterial isolates were sensitive to imipenem and some isolates were sensitive to fourth-generation cephalosporins, but most isolates were highly resistant to the majority of other antibiotics tested. CONCLUSION: Gram negative organisms were the most frequent causative agents of bacterial sepsis, which is a significant cause of mortality and morbidity in the newborn, and particularly in those of very low birth weight. It can also be concluded that imipenem and fourth-generation cephalosporins can be used for empirical treatment of bacterial sepsis.

Hepatitis B Vaccine Coverage and the Immune Response in Children under ten years old in Sana'a, Yemen.

OBJECTIVES: The study was undertaken, first, to determine the coverage rate of hepatitis B (HB) vaccine and second to evaluate the immune response to HB vaccine among children under 10 years old by measuring the level of circulating anti-HB surface antigen (anti-HBs) antibodies after immunisation with three doses. METHODS: First, 840 children were randomly selected from 4 randomly selected sites in Sana'a city to study the coverage rate of the vaccine; of these, 504 children vaccinated against HBV prior to the study, were tested (56% males and 44% females). Sera were tested for anti-HBs antibodies by ELISA quantitative technique. Each individual's data was collected in a pre-designed questionnaire including: vaccination date, sex, and age at the time of the study. RESULTS: The coverage rate of HBV vaccine was only 69.9%, being slightly higher among male children (72.1%) than female children (66.8%). A total of 276 (54.8%) of the 504 children responded to the vaccine with anti-HBs antibody level ≥ 10 mIU/ml, while 228 (45.2%) of the 504 children had non-protective anti-HBs antibodies levels (<10IU/ml). Children of ages 3-5 years had the highest protective rate (63.6%), and the lowest protective rate was in the 9-10 years age group. CONCLUSION: This study revealed a low coverage rate of HBV vaccine and a low protective rate against HBV infection. A considerable proportion of vaccinated children should be considered for either revaccination or booster doses. There is also the need to complete HBV vaccine coverage among the child population in San'a, Yemen.

Assessment of antimalarial activity against Plasmodium falciparum and phytochemical screening of some Yemeni medicinal plants.

Developing countries, where malaria is one of the most prevalent diseases, still rely on traditional medicine as a source for the treatment of this disease. In the present study, six selected plants (Acalypha fruticosa, Azadirachta indica, Cissus rotundifolia, Echium rauwalfii, Dendrosicyos socotrana and Boswellia elongata) commonly used in Yemen by traditional healers for the treatment of malaria as well as other diseases, were collected from different localities of Yemen, dried and extracted with methanol and water successfully. The antiplasmodial activity of the extracts was evaluated against fresh clinical isolates of Plasmodium falciparum. The selectivity parameters to evaluate the efficacy of these medicinal plants were measured by in vitro micro test (Mark III) according to World Health Organization (WHO) 1996 & WHO 2001 protocols of antimalarial drug tests. Among the investigated 12 extracts, three were found to have significant antiplasmodial activity with IC(50) values less than 4 microg/ml, namely the water extracts of A. fruticosa, A. indica and D. socotrana. Six extracts showed moderate activity with IC(50) values ranging from 10 to 30 microg/ml and three appeared to be inactive with IC(50) values more than 30 microg/ml. In addition, preliminary phytochemical screening of the methanolic and aqueous extracts indicated the presence of saponins, tannins, flavonoids, terpenoids, polysaccharides and peptides.

The therapeutic efficacy of sulfadoxine/pyrimethamine against Plasmodium falciparum in Yemen.

OBJECTIVE: The aim of this study was to determine the sensitivities of Plasmodium falciparum clinical isolates to sulfadoxine/pyrimethamine (SP) using in vivo and in vitro methods. SUBJECTS AND METHODS: In vivo and Mark III in-vitro test techniques according to World Health Organization protocols of antimalarial drug tests were used to determine the SP susceptibility of the P. falciparum isolates from 100 malaria patients of both sexes between the ages of 3.5 and 45 years and living in Tihamah, Yemen. The study was conducted between 19 March and 12 May 2005. RESULTS: In vivo: no therapeutic failure occurred; the clinical outcome matched the parasitological response and all patients were parasite free by day 3 and remained so on days 7, 14 and 28. In vitro: all the P. falciparum isolates developed to schizonts in zero-drug-concentration wells, but were inhibited in 40 nmol/l of SP; the mean effective concentration (EC(99)) was 67.17 nmol/l. CONCLUSION: Our findings showed that the SP combination is still effective for the treatment of uncomplicated P. falciparum malaria in Yemen. It is recommended that further studies be carried out to address the importance of dihydropteroate synthetase/dihydrofolate reductase mutations as predictive markers of sulfadoxine/pyrimethamine resistance in Yemen.

Increasing single and multi-antibiotic resistance in Shigella species isolated from shigellosis patients in Sana'a, Yemen.

OBJECTIVE: The epidemiology and antibiotic susceptibility of Shigella species changes over time. Updated susceptibility knowledge is necessary for appropriate empirical antibiotic treatment. Thus, this research aimed to study these changes in 2 time periods with an interval of 10 years. METHODS: Two hundreds and three Shigella strains, isolated from stool samples of diarrheic patients at the Central Health Laboratory in Sana'a, Yemen in 2 time periods (1993 and 2003) with a 10-year interval, were examined for serotyping and drug resistance pattern. Resistance patterns of the strains to 12 commonly used antimicrobial agents and minimum inhibitory concentrations of the antibiotics were tested. RESULTS: Shigella flexneri (60%) was found to be the most common isolate of the total Shigella species, followed by Shigella dysenteriae (28.6%) and Shigella boydii (11.3%). In Shigella flexneri strains, Shigella flexneri 3 (30.5%) was the most prevalent serotype, followed by Shigella flexneri 6 (17.2%), and Shigella flexneri 1 (12.3%). All strains were found equally susceptible to cefotaxime, ceftriaxone, ciprofloxacin, and gentamicin, but more than 80% of the strains of 2003 were resistant to tetracycline, co-trimoxazole, and 52% of the same strains were resistant to ampicillin. Resistance to chloramphenicol was found in 61%, cefuroxime in 56.2%, and cephradine, 52% of the strains. Overall, Shigella species showed statistically significant increase in resistance against tetracycline, cephradine, trimethoprim/sulfamethoxazole, nalidixic acid, and aztreonam (p<0.05) over the 10 years period. This indicates decreased efficacy of co-trimoxazole and nalidixic acid for the empirical treatment of shigellosis in Sana'a, Yemen. Almost 55.2% of the strains were resistant to 4 drugs. CONCLUSION: This is one of the first studies reporting epidemiological pattern of Shigella species in Sana'a, Yemen with regard to serotypes and antibiotic resistance patterns. Based on these antibiotic resistance pattern findings, it is suggested that the commonly in use antibiotics including ampicillin, trimethoprim/sulfamethoxazole, tetracycline, and chloramphenicol should not be used for empirical treatment of shigellosis in Yemen.

Seroprevalence of Helicobacter pylori among children in Sana'a, Yemen.

BACKGROUND: Helicobacter pylori infection is primarily acquired in early childhood. Its transmission routes are debated. The aims of this study were to determine the seroprevalence of anti-H. pylori immunoglobulin G (IgG) in Yemeni children under 10 years of age, the potential risk factors for contracting H. pylori infection and co-infection of H. pylori with intestinal parasites. METHODS: Enzyme-labeled immunosorbent assay was used to determine the H. pylori prevalence rate among 572 healthy volunteers aged less than 10 years. Formalin ether concentration methods were used to test the prevalence of intestinal parasites (intestinal roundworms and tapeworms). In addition, we interviewed participants regarding potential risk factors for contracting H. pylori infection. RESULTS: The seroprevalence of H. pylori antibodies was 9%. The prevalence according to age varied from 0% in children under 2 years to 12.5% in age group 9-10 years. There was a correlation between the amounts of positive antibodies and increasing age. The prevalence rate of H. pylori antibodies was also significantly associated with the practice of drinking water from reused plastic jerry cans, with poor mouth hygiene and with co-infection by intestinal parasites. CONCLUSION: The prevalence of H. pylori antibodies in Yemen among children under 10 years of age is higher than that reported from other regions for the same age groups. Yemen shares some but not all potential risk factors for H. pylori infection with countries in which similar socioeconomic conditions are found. A possible way of eliminating H. pylori from the population would be via public health measures, i.e. preventing the reuse of plastic jerry cans, and improving sanitation and the standard of living.