Studies on West Nile virus infection in Egypt.

We conducted a prospective cohort study to determine prevalence and incidence of West Nile virus (WNV) in Egypt. Cohorts were established in Upper (UE), Middle (ME), and Lower (LE) Egypt. Additionally, a cross-sectional serosurvey was performed in the North (NS) and South (SS) Sinai. Cohorts were bled initially and 1 year later. Sera were tested for WNV-IgG by ELISA and positive sera were confirmed by plaque reduction neutralization test (PRNT). Sentinel chicken flocks placed in the above sites were bled monthly for virus isolation and serology. Mosquitoes were collected monthly from the above sites and tested for WNV. Human seroprevalence rates were 35%, 27%, 14%, 1% and 7% in UE, ME, LE, NS and SS, respectively. Seroconversion rates were 18%, 17% and 7% in UE, ME and LE, respectively; 49% of the seroconverters reported undiagnosed febrile illness. Sentinel chickens showed seroconversion in all study sites. WNV was isolated from both sentinel chickens and mosquitoes in cohort sites. This study demonstrates that WNV was actively circulating during the study period in different areas in Egypt and causing febrile illness in a considerable proportion of individuals in the study sites.

Major outbreak of hepatitis A associated with orange juice among tourists, Egypt, 2004.

In 2004, a major outbreak of hepatitis A among tourists returning from Egypt involved 351 case-patients from 9 European countries who were infected with a single strain (genotype 1 b). The case-control study identified orange juice as the most likely infection vehicle. Vaccination against hepatitis A virus is strongly recommended before travel to disease-endemic areas.

Microbial study of meningitis and encephalitis cases.

Meningitis and/or encephalitis can pose a serious public health problem especially during outbreaks. A rapid and accurate diagnosis is important for effective earlier treatment. This study aimed to identify the possible microbial causes of meningitis and/or encephalitis cases. CSF and serum samples were collected from 322 patients who had signs and symptoms suggestive of meningitis and/or encephalitis. Out of 250 cases with confirmed clinical diagnosis, 83 (33.2%) were definitely diagnosed as bacterial meningitis and/or encephalitis cases (by using CSF culture, biochemical tests, latex agglutination test, and CSF stain), 17 (6.8%) were definitely diagnosed as having viral causes ( by viral isolation on tissue culture, PCR and ELISA), and one (0.4%) was diagnosed as fungal meningitis case (by India ink stain, culture, and biochemical tests). Also, there was one encephalitis case with positive serum ELISA IgM antibodies against Sandfly scilian virus. N. meningitidis, S. pneumonia and M. tuberculosis were the most frequently detected bacterial agents, while Enteroviruses, herpes simplex viruses and varicella zoster viruses were the most common viral agents encountered. Further studies are needed to assess the role of different microbial agents in CNS infections and their effective methods of diagnosis.

PCR analysis of egyptian respiratory adenovirus isolates, including identification of species, serotypes, and coinfections.

Eighty-eight adenovirus (Ad) isolates and associated clinical data were collected from walk-in patients with influenza-like illness in Egypt during routine influenza surveillance from 1999 through 2002. Respiratory Ad distributions are geographically variable, and serotype prevalence has not been previously characterized in this region. Serotype identity is clinically relevant because it predicts vaccine efficacy and correlates strongly with both clinical presentation and epidemiological pattern. Species and serotype identities were determined using several well-validated multiplex PCR protocols culled from the literature and supplemented with a few novel primer sets designed to identify rare types. The isolates included common species B1 serotypes (Ad3 and Ad7), common species C serotypes (Ad1, Ad2, and Ad5), the less common species B2 serotype Ad11, and three isolates of the rare species B1 serotype Ad16. Two isolates that appear to be variant Ad16 were also identified. Fifteen coinfections of multiple adenoviral types, primarily AdB/AdC and Ad3/Ad7 dual infections, were detected. The majority of these were verified using redundant PCR tests targeted at multiple genes. PCR is able to resolve coinfections, in contrast to traditional serum neutralization tests. PCR is also comparatively rapid and requires very little equipment. Application of the method allowed an inclusive determination of the serotypes found in the Egyptian respiratory sample set and demonstrated that coinfections are common and may play a previously unrecognized role in adenovirus pathogenesis, evolution, and epidemiology. In particular, coinfections may influence adenoviral evolution, as interserotypic recombination has been identified as a source of emerging strains.

Hospital-based surveillance for acute febrile illness in Egypt: a focus on community-acquired bloodstream infections.

Acute febrile illness (AFI) is a common syndrome in Egypt. However its etiologies are not well characterized. To determine the relative frequency of pathogen etiologies and possibly improve diagnostic, clinical management and public health measures, we implemented laboratory-based surveillance in a network of infectious disease hospitals throughout Egypt. Admitted patients with AFI provided background details and a blood sample for bacterial culture and serologic analysis. Case definitions were based on laboratory results. Of 10,130 patients evaluated between 1999 and 2003, 5% were culture positive for Salmonella enterica serogroup Typhi, 3% for Brucella, and 2% for other pathogens. An additional 18% of patients had positive serologic results for typhoid and 11% for brucellosis. Risk factor analysis identified availability of municipal water to be significantly (P < 0.05) associated with protection against typhoid. Animal contact and consumption of raw dairy products were significantly associated with brucellosis. The surveillance network identified typhoid fever and brucellosis as the most common bacterial causes of AFI in Egypt, allowed better description of their epidemiology, and may lead to the development of targeted prevention strategies.