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Toll-like receptors (TLRs) are essential elements of the innate immune response to different infections including the infection with human immunodeficiency virus (HIV). Single nucleotide polymorphisms (SNPs) in TLRs such as TLR4 1063A/G and 1363C/T have been found to be associated with changes in CD4 count, viral load (VL), and disease progression during HIV infection. However, the association of these SNPs with the pathogenesis during HIV infection is controversial. We investigated the frequency of TLR4 1063A/G and 1363C/T SNPs in 168 Omani donors [68 HIV-infected patients (>3% of Omani HIV-infected patients) and 100 healthy controls] and the association of these SNPs with the VL, CD8 and CD4 counts, and the immune recovery after cART as observed by CD4 T cell increase. SNPs were analyzed after the amplification of the regions that contain them by polymerase chain reaction (PCR) and sequencing of the PCR products. The TLR4 1063GG genotype was detected in the HIV-infected group only. No association was found between the studied SNPs and the average VL during 1 year of infection, the average CD4 and CD8 count during 1 year of viremia, the nadir CD4 count, the CD4 count when the patient reached VL < 50 copies/mL due to cART, and the ratio of the CD4 count 3 and 6 months after reaching VL < 50 copies/mL after cART to the last CD4 count before reaching VL < 50 copies/mL. Our study suggests that TLR4 (1063A/G and 1363C/T) SNPs have no association with the VL or the CD4 and CD8 counts during HIV infection.

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Routine HIV testing of all pregnant women in Oman has been introduced without prior knowledge of women's attitudes towards testing or their behaviour in the event of a positive test. This study recruited 1000 Omani pregnant women from antenatal clinics to explore their knowledge of HIV/AIDS, attitudes towards HIV testing and intended behaviours in the event of a positive test. Mother-to-child transmission was recognized by 86.6% of the women but only 21.0% knew that it was preventable and a few acknowledged the important role of antiviral drugs. Half of the women (51.9%) reported having been tested for HIV and 75.8% agreed about routine HIV testing for all pregnant women. A higher level of knowledge was significantly associated with a favourable intended behaviour related to voluntary testing, disclosure and seeking professional assistance in the event of a positive HIV test. The results are discussed in relation to opt-in and opt-out approaches to voluntary testing during pregnancy.

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Infected aneurysm is a life threatening clinical condition that is associated with significant morbidity and mortality. Early detection is essential for a rapid and efficacious initial treatment for better prognosis. Since the introduction of antibiotic therapy and concomitant decline of endocarditis, true mycotic aneurysms are rarely seen. The usual treatment consists of antibiotics along with aggressive surgical debridement of the infected tissue and vascular reconstruction, if needed. We here describe an infected aneurysm presenting as pyrexia of unknown origin and discuss the clinical features and challenges encountered in the treatment.

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BACKGROUND: Toll-like receptors (TLRs) are essential elements of the innate immune response to different infections including HIV-1 infection. The single-nucleotide polymorphisms (SNPs) in TLRs have been associated with CD4T cell count and HIV disease progression. The TLR7 (Gln11Leu) SNP was shown to be associated with a rapid decline of CD4T cell count. A relation between TLR9 (1635A/G) SNP and CD4T cells count in HIV-infected patients is suggested, although the outcome associated with this SNP is still controversial. OBJECTIVES: To determine the relation of the TLR7 (Gln11Leu) and TLR9 (1635A/G) SNPs with the damage to the immune system during HIV infection as reflected by the average CD4T cell count. METHODS: A total of 63 HIV-infected patients and 100 healthy individuals (controls) were enrolled in this study. The above named SNPs were analyzed after amplification of the regions that potentially contain the SNPs by polymerase chain reaction (PCR) and sequencing of the PCR products. The frequency of these SNPs and their relation with the CD4T cell count were investigated. RESULTS: The TLR7 (AA) genotype 'Gln' had a trend toward being associated with a CD4T cell count >400cells/µl after controlling viremia via HAART. Additionally, the TLR9 1635 (GG) genotype was associated with a low average CD4T cell count and the TLR9 1635 (AG) genotype was significantly related to a higher average CD4T cell count during the viremic period in HIV-infected patients. CONCLUSION: The results of this longitudinal study supports the presence of an association between the TLR9 (1635A/G) genotype and the CD4T cell count, which helps clarifying the controversial results regarding this association. It also suggests that the CD4T cell count during the viremic period might be linked to the combination of both TLR7 (Gln11Leu) and TLR9 (1635A/G) genotypes. These results may help predicting the damage to the immune system, and thus impacting the planning for novel anti-HIV strategies.

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The objective of the study is to investigate the anti-snake venom activities of a local plant, Hibiscus aethiopicus L. The H. aethiopicus was dried and extracted with ethanol. Different assays were performed according to standard techniques, to evaluate the plant's acute toxicity and its antivenom activities. The results of evaluating the systemic acute toxicity of the H. aethiopicus extract using "oral and intra-peritoneal" route were normal even at the highest dose (24 g/kg) tested. All guinea pigs (n = 3) when treated with venoms E. c. sochureki (75 µg) alone induced acute skin haemorrhage. In contrast, all guinea pigs (n = 18) treated with both venom and the plant extract at a concentration between 500 and 1000 mg/kg showed no signs of haemorrhage. Moreover, all guinea pigs (n = 18) treated with venom and the plant extract below 400 mg/kg showed acute skin haemorrhage. All guinea pigs treated with venom E. c. sochureki (75 µg) alone induced acute skin haemorrhage after both 24 and 32 hours. In contrast, all guinea pigs treated with both venom and the plant extract (administered independently) at concentrations between 500 and 1000 mg/kg showed no signs of haemorrhage after 32 hours. However, after 24 hours all tested guinea pigs showed less inhibition (<60%) compared to that obtained after 32 hours. The outcome of this study reflects that the extract of H. aethiopicus plant may contain an endogenous inhibitor of venom induced local haemorrhage.

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INTRODUCTION: Quality drinking water should be free from harmful levels of impurities such as heavy metals and other inorganic elements. METHODS: Samples of tap water collected from 24 locations in Peninsular Malaysia were determined for inorganic element content. Minerals and heavy metals were analysed by spectroscopy methods, while non-metal elements were analysed using test kits. RESULTS: Minerals and heavy metals determined were sodium, magnesium, potassium, calcium, chromium, manganese, iron, nickel, copper, zinc, arsenic, cadmium and lead while the non-metal elements were fluoride, chloride, nitrate and sulphate. Most of the inorganic elements found in the samples were below the maximum permitted levels recommended by inter-national drinking water standard limits, except for iron and manganese. Iron concentration of tap water from one of the locations was higher than the standard limit. CONCLUSION: In general, tap water from different parts of Peninsular Malaysia had low concentrations of heavy metals and inorganic elements.

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This paper analyzed, experimentally, the influences of pattern of exposure, parasite genetic diversity, and parasite sex on the degree of protection against reinfection with Schistosoma mansoni in the mouse. The results show that, (1) in infections with one male parasite genotype, successive infections induced a significant decrease in the infectivity of the parasite and significant increases in the spleen and liver weights compared to mass infections, (2) successive infections with one male genotype induced a significant decrease in the infectivity of the parasite compared to successive infections with five male genotypes, and (3) genotype infectivities were determined by the order at which they were used in the successive infections. These results are discussed in terms of protective effect and concomitant immunity and provide an ecological explanation of the natural sex-biased dispersal toward the male schistosomes.

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The historical phylogeography of the two most important intermediate host species of the human blood fluke Schistosoma mansoni, B. glabrata in the New World, and B. pfeifferi in the Old World, was investigated using partial 16S and ND1 sequences from the mitochondrial genome. Nuclear sequences of an actin intron and internal transcribed spacer (ITS)-1 were also obtained, but they were uninformative for the relationships among populations. Phylogenetic analyses based on mtDNA revealed six well-differentiated clades within B. glabrata: the Greater Antilles, Venezuela and the Lesser Antilles, and four geographically overlapping Brazilian clades. Application of a Biomphalaria-specific mutation rate gives an estimate of the early Pleistocene for their divergence. The Brazilian clades were inferred to be the result of fragmentation, due possibly to climate oscillations, with subsequent range expansion producing the overlapping ranges. Within the Venezuela and Lesser Antilles clade, lineages from each of these areas were estimated to have separated approximately 740 000 years ago. Compared to B. glabrata, mitochondrial sequences of B. pfeifferi are about 4x lower in diversity, reflecting a much younger age for the species, with the most recent common ancestor of all haplotypes estimated to have existed 880 000 years ago. The oldest B. pfeifferi haplotypes occurred in southern Africa, suggesting it may have been a refugium during dry periods. A recent range expansion was inferred for eastern Africa less than 100 000 years ago. Several putative species and subspecies, B. arabica, B. gaudi, B. rhodesiensis and B. stanleyi, are shown to be undifferentiated from other B. pfeifferi populations.

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After 4 years of mass chemotherapy with a single annual dose of albendazole 400 mg, health education and promotion of environmental health, the prevalence of Necator americanus in Wilayat Tagah, Dhofar, Oman was reduced from 40 to 1.3% and from 6 to 0%, respectively, among rural and urban school children. Stool samples with egg load >1000 egg/gm were reduced from 28 to 0% after the first year of intervention and maintained as such in subsequent years.

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Glycosphingolipids from the parasitic liver flukes Fasciola gigantica and Fasciola hepatica were isolated and their carbohydrate moieties were structurally analysed by methylation analysis, exoglycosidase treatment, on-target exoglycosidase cleavage and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. For both liver fluke species, the ceramide monohexosides Gal1-ceramide and Glc1-ceramide were found in relative amounts of 1.0 to 0.1, respectively. From F. gigantica, the ceramide dihexoside was isolated in sufficient amounts to be structurally determined as lactosylceramide, Gal beta4-Glc1-ceramide, while for both liver fluke species the ceramide trihexoside was shown to be Gal alpha4Gal beta4-Glc1-ceramide, which is designated as either globotriaosylceramide, Pk-blood group antigen or CD77 leucocyte cluster of differentiation antigen. To our knowledge, this is the first report on the expression of globo-series glycosphingolipids in non-mammalian species. Ceramide analysis of ceramide monohexosides yielded as major components octadecanoic and 2-hydroxyoctadecanoic fatty acids together with C18- and C20-phytosphingosines. By the use of an anti-CD77 monoclonal antibody and the Escherichia coli Shiga toxin B1 subunit, globotriaosylceramide could be immunolocalised to the tegument of F. hepatica cryosections. The sharing of CD77 between liver flukes and their mammalian hosts fits in with the concept of molecular mimicry, which is closely parallel to the established imitation of host CD15 (Lewis X) displayed by the blood fluke Schistosoma mansoni.

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OBJECTIVES: To assess the efficacy of the Kato-Katz technique and to re-evaluate other routine procedures conducted in the Microbiology Clinical Laboratory at Sultan Qaboos University Hospital (SQUH) and to throw light on the prevalence of intestinal parasitic infections among a small group of food handlers in Muscat. METHOD: Faecal samples collected from food handlers were examined using five parasitological techniques. RESULTS: Out of 100 faecal samples, 53 were positive for one or more of 11 intestinal parasites. The Kato-Katz and trichrome stain methods were found superior to the other techniques in detecting helminthic and protozoan infections, respectively. The auramine stain was useful only in detecting Cryptosporidium parvum oocysts. CONCLUSION: A combination of trichrome stain and Kato-Katz techniques for stool examination is sufficient and recommended for busy laboratories; auramine stain should be applied only to samples with suspected cryptosporidal infections.

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BACKGROUND: Following an intensive public health eradication program, the focus of schistosomiasis mansoni at Salalah in Southern Oman (the only focus of schistosomiasis in Oman), appeared to have been eradicated in 1994. Since the vector snails for Schistosoma mansoni (and also for S. haematobium) were widely endemic in freshwater springs at Salalah, and reintroduction of infection (or introduction in the case of S. haematobium) was possible, we undertook a prospective study in 1995 for schistosomiasis in patients at the Sultan Qaboos University Hospital (SQUH), and to obtain evidence of visits by these patients to Salalah. PATIENTS AND METHODS: From May 1995 to May 2000, Omani and expatriate patients presenting at SQUH were evaluated for possible schistosomiasis (residence in an endemic region, suggestive clinical features) by a search for ova in stool, urine, or in tissue biopsies, or when ova were absent, by serodiagnosis. A retrospective survey of schistosomiasis patients diagnosed in SQUH from 1990 to April 1995 was also performed. Ministry of Health (MOH) data on reports of schistosomiasis (a notifiable disease) in Oman from 1991 to 2000, were obtained. RESULTS: Thirty patients with schistosomiasis were identified, 10 retrospectively and 20 in the prospective study. Patients were aged 9 to 60 years, and 25 of them (10 Omanis, 14 Egyptians, 1 Sudanese) contracted the infection in Africa, while 5 Omanis became infected in Salalah (3 in 1999). Twelve patients had schistosomiasis mansoni, 6 had schistosomiasis haematobia, and in the rest, infection by both parasites was confirmed or possible. The most common presentation (23%) was hepatosplenic schistosomiasis with portal hypertension. No patient admitted to contaminating freshwater with excreta in Salalah. MOH data revealed 3 to 14 cases of schistosomiasis were reported annually between 1991 and 2000, and that all schistosomiasis cases reported from 1994 to 1998 originated from Africa. CONCLUSION: Schistosomiasis remains an important health problem in Oman. Many doctors are unfamiliar with the clinical features and methods of diagnosis, thereby frequently causing delays in diagnosis. Because vector snails are endemic in Salalah, schistosomiasis patients must be detected and treated early. At infested freshwater sites at Salalah, mollusciciding should continue indefinitely, and notices should warn visitors not to contaminate the spring water.

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OBJECTIVE: To determine the extent of rickettsial infections prevalence of potential vector ticks in the rural population of Dhofar, Oman. METHOD: Human sera (n = 347) were obtained from six rural localities (school children, farmers, outpatients) in Dhofar, Sultanate of Oman. Sera were tested by immunofluorescence for the presence of antibodies reacting with Rickettsia conorii antigen. RESULTS: More than half the samples (59%) gave positive reactions (titres of at least 1:64). Ticks (n=707) were collected from cattle, camels and goats (n=102) and included Amblyomma variegatum, Hyalomma a. anatolicum, H. dromedarii, H. rufipes and Rhipicephalus spp., all of which can potentially transmit rickettsiae to humans. CONCLUSION: The results suggest that rickettsial infections are common among the rural population of Dhofar.

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The presence of antibodies against Echinococcus granulosus in sera from 306 humans and 390 camels in Oman was investigated by indirect haemagglutination assays. Only one of the human and five of the camel sera gave positive reactions. The reactivities of the human sera were confirmed by ELISA. These results, together with isolated reports of hydatid cysts, indicate that E. granulosus is endemic in Oman, although with a low prevalence.

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A sandwich enzyme-linked immunosorbent assay (ELISA) was developed to detect 31/32-kDa schistosome proteins as circulating antigens in sera from schistosomiasis patients. A monoclonal antibody was used as a capture antibody and rabbit antiserum raised against purified 31/32-kDa proteins was the detecting antibody. Positive results were obtained with patients infected with Schistosoma japonicum (88%; n = 69), S. mansoni (80%; n = 56), S. haematobium (100%; n = 40), or S. intercalatum (94%; n = 65). Sera from uninfected Chinese and African individuals and from Chinese patients with trichinosis, cysticercosis, or paragonimiasis did not react in the assay. This ELISA appears to be valuable in diagnosing infections by all major human schistosome species.

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The snail Biomphalaria arabica is apparently ubiquitous in the south of Oman (Dhofar province). Snails bred in the laboratory were susceptible to infection with miracidia of Schistosoma mansoni (Puerto Rican strain). The snail Bulinus wrighti, a potential intermediate host of S. haematobium, was found for the first time in Dhofar. Human sera from five localities had antibodies against adult worm antigens and in particular against Sm31/32. The prevalence of seropositive patients was 28% of 47 farm workers, 12% of 99 out-patients from a clinic and 1% of 389 children from four localities. Autochthonous transmission of schistosomiasis in Dhofar is discussed.

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