Prevalence and molecular characterization of hepatitis D virus in Saudi Arabia: A single-center study.

BACKGROUND/AIMS: Hepatitis D virus (HDV) is a defective RNA virus that is dependent on hepatitis B surface antigen (HBsAg) for transmission and replication. HDV significance arises from the possibility of poor prognosis of hepatitis B virus (HBV) infection. In Saudi Arabia, HDV prevalence varied from 8 to 32% before the HBV vaccination program and ranged from 0 to 14.7% after the vaccination program was started. The last study, performed in 2004, showed a prevalence of 8.6% in hospital-based HBV cases and 3.3% in healthy donors. The aim of this study was to investigate the prevalence and molecular characterization of HDV in chronic hepatitis B (CHB) patients at the King Abdulaziz University Hospital in Jeddah, Saudi Arabia by molecular and serological techniques. To the best of our knowledge, this is the first study to detect HDV at the molecular level in Saudi Arabia. PATIENTS AND METHODS: The study included samples from 182 CHB patients from Jeddah; 13 samples with HBsAg negative were excluded. Samples were tested for HDV-Ab, viral RNA by reverse transcriptase-polymerase chain reaction (RT-PCR) in the HDV L-Ag region and sequence analysis. RESULTS: The mean age of the participants was 44.36 years; 75.1% of the participants were Saudi nationals, 58% were males. Nine samples were positive for HDV-Ab and four were borderline; all were subjected to RT-PCR amplification. Three of the positive HDV-Ab cases and 1 borderline case were positive by RT-PCR. All the positive cases had HBV genotype D, and the positive RT-PCR cases were positive for HBV DNA. One of the HDV viremic samples was of genotype 1 by sequencing. The prevalence of HDV in the study was 7.7%, which was lower in Saudis (6.3%) than in non-Saudis (11.9%). CONCLUSION: HDV coinfection does not seem to have an effect on the clinical status of the recruited CHB cases in this study. More studies are needed to investigate the genetic diversity in other areas such as the southern parts of the Kingdom.

Evidence for a role of hemozoin in metabolism and gametocytogenesis.

Hemozoin is generally considered a waste deposit that is formed for the sole purpose of detoxification of free heme that results from the digestion of hemoglobin by Plasmodium parasites. However, several observations of parasite multiplication, both in vertebrate and invertebrate hosts are suggestive of a wider, but overlooked, metabolic role for this product. The presence of clinical peripheral blood samples of P. falciparum with high parasitemia containing only hemozoin-deficient (non-pigmented) asexual forms has been repeatedly confirmed. Such samples stand in contrast with other samples that contain mostly pigmented circulating trophozoites and gametocytes, indicating that pigment accumulation is a prominent feature of gametocytogenesis. The restricted size, i.e. below detection by light microscopy, of hemozoin in asexual merozoites and ringforms of P. falciparum implies its continuous turnover, supporting a role in metabolism. The prominent interaction of hemozoin with several antimalarial drugs, the involvement of proteins in hemozoin formation, and the finding of plasmodial genes coding for a heme-oxygenase-like protein argue for a wider and more active role for hemozoin in the parasite's metabolism. The observed association of hemozoin with crystalloids during ookinete development is consistent with a useful function to it during parasite multiplication in the invertebrate host. Finally, alternative mechanisms, other than hemozoin formation, provide substitute or additional routes for heme detoxification.

Seroepidemiology of Asymptomatic Dengue Virus Infection in Jeddah, Saudi Arabia.

BACKGROUND: Although virologically confirmed dengue fever has been recognized in Jeddah, Saudi Arabia, since 1994, causing yearly outbreaks, no proper seroepidemiologic studies on dengue virus have been conducted in this region. Such studies can define the extent of infection by this virus and estimate the proportion that may result in disease. The aim of this study was to measure the seroprevalence of past dengue virus infection in healthy Saudi nationals from different areas in the city of Jeddah and to investigate demographic and environmental factors that may increase exposure to infection. METHODS: Sera were collected from 1984 Saudi subjects attending primary health care centers in six districts of Jeddah. These included general patients of various ages seeking routine vaccinations, antenatal care or treatment of different illnesses excluding fever or suspected dengue. A number of blood donors were also tested. Serum samples were tested by enzyme immunoassay (EIA) for IgG antibodies to dengue viruses 1, 2, 3, 4. A questionnaire was completed for each patient recording various anthropometric data and factors that may indicate possible risk of exposure to mosquito bites and dengue infection. Patients with missing data and those who reported a history of dengue fever were excluded from analysis, resulting in a sample of 1939 patients to be analyzed. RESULTS: The overall prevalence of dengue virus infection as measured by anti-dengue IgG antibodies from asymptomatic residents in Jeddah was 47.8% (927/1939) and 37% (68/184) in blood donors. Infection mostly did not result in recognizable disease, as only 19 of 1956 subjects with complete information (0.1%) reported having dengue fever in the past. Anti dengue seropositivity increased with age and was higher in males than females and in residents of communal housing and multistory buildings than in villas. One of the six districts showed significant increase in exposure rate as compared to the others. Availability of public sewage was associated with lower infection at a nearly significant level. No other clear risk factors were identifiable. Infection was not related to travel abroad. CONCLUSIONS: Our results indicate a relatively high exposure of Jeddah residents to infection by dengue viruses, which must be considered endemic to this region. Infection largely remained asymptomatic or was only associated with minor illness for which patients did not seek treatment. These results call for continued vigilance for clinical cases of dengue that may arise from this wide exposure. They also call for more extensive control efforts to reduce exposure to and transmission of dengue viruses.

Detection of the Middle East respiratory syndrome coronavirus genome in an air sample originating from a camel barn owned by an infected patient.

Middle East respiratory syndrome coronavirus (MERS-CoV) is a novel betacoronavirus that has been circulating in the Arabian Peninsula since 2012 and causing severe respiratory infections in humans. While bats were suggested to be involved in human MERS-CoV infections, a direct link between bats and MERS-CoV is uncertain. On the other hand, serological and virological data suggest dromedary camels as the potential animal reservoirs of MERS-CoV. Recently, we isolated MERS-CoV from a camel and its infected owner and provided evidence for the direct transmission of MERS-CoV from the infected camel to the patient. Here, we extend this work and show that identical MERS-CoV RNA fragments were detected in an air sample collected from the same barn that sheltered the infected camel in our previous study. These data indicate that the virus was circulating in this farm concurrently with its detection in the camel and in the patient, which warrants further investigations for the possible airborne transmission of MERS-CoV. Importance: This work clearly highlights the importance of continuous surveillance and infection control measures to control the global public threat of MERS-CoV. While current MERS-CoV transmission appears to be limited, we advise minimal contact with camels, especially for immunocompromised individuals, and the use of appropriate health, safety, and infection prevention and control measures when dealing with infected patients. Also, detailed clinical histories of any MERS-CoV cases with epidemiological and laboratory investigations carried out for any animal exposure must be considered to identify any animal source.

Genotype and antiretroviral drug resistance of human immunodeficiency virus-1 in Saudi Arabia.

OBJECTIVE: To analyze antiretroviral drug resistance and determine the genotype of human immunodeficiency virus (HIV)-1 in Saudi patients by sequencing an amplified region of the viral pol gene. METHODS: This retrospective study analyzed data from plasma samples submitted for genotypic drug sensitivity monitoring. Samples were analyzed at the Special Infectious Agent Unit, King Fahd Medical Research Center of King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia from August 2004 to June 2009. The Viroseq2.5 kit (Celera/Abbott) was used with ABI Prism 3100 sequencer. All patients were Saudi nationals and were on antiretroviral therapy, some experiencing treatment failure. RESULTS: Based on protease region (PR), genotypes of 63 samples were as follows: C:22, G:21, B:9, CRF02_AG:5, D:3, A:1, F:1, and J:1. Based on reverse transcriptase region (RT), genotypes were as follows: C:23, G:24, B:9, CRF02_AG: 2, D:2, A:1, and F:1. Antiretroviral susceptibility testing results were as follows: 52% of the isolates were susceptible to all 3 major classes of antiretroviral drugs used, 41% had mutations known to confer high level resistance to one or more of the nucleoside analogue reverse transcriptase inhibitors, 16% had mutations known to confer high level resistance to non-nucleoside analogues reverse transcriptase inhibitors, 13% had mutations known to confer high level resistance to one or more of the protease inhibitors (PI). Most isolates were susceptible to 2 or at least one class of antiretroviral, and only 3% of the isolates had resistance to several members of all 3 classes. CONCLUSION: Antiretroviral resistance is not uncommon in Saudi patients on antiretroviral therapy.