Immunogenicity of recombinant hepatitis B vaccine among infants of mothers with active schistosomiasis.

A study of the immunogenicity of a recombinant hepatitis B vaccine was conducted among 385 Egyptian infants, 191 (49.6%) of whom were born to mothers with moderately active Schistosoma mansoni infection (mean egg count = 224 eggs/g of feces). All mothers were seronegative for hepatitis B surface antigen (HBsAg) and hepatitis B e antigen. Infants were vaccinated with a 2.5-microg dose of this vaccine, given along with diphtheria, tetanus, and pertussis (DTP) vaccine, at the ages of two, four, and six months. Serum samples taken from each infant at nine months of age were tested for HBsAg, antibody to hepatitis B core antigen, and quantitatively for antibody to hepatitis B surface antigen (anti-HBs). There was no significant difference (P = 0.1) between anti-HBs titers in infants of S. mansoni-infected mothers (mean = 539 mIU/ml) and in infants of noninfected mothers (mean = 377 mIU/ml). This study shows that there was no apparent effect of maternal schistosomiasis infection on the immune response of these infants to vaccination.

Hepatitis C antibody prevalence in blood donors in different governorates in Egypt.

Markers of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections were sought in serum samples from 2644 blood donors in 24 of Egypt's 26 governorates. Of the 2644 samples, 656 (24.8%) were shown to contain anti-HCV immunoglobulin G antibody by Abbott second generation enzyme immunoassays (EIA). Of 85 EIA-positive samples tested by recombinant immunoblot assay, 72 (85%) were positive. HCV seroprevalence in the governorates ranged from zero to 38%; 15 governorates (62%) had an HCV antibody prevalence greater than 20%, and 6 (25%) greater than 30%. Governorates with higher sero-prevalences were located in the central and north-eastern Nile river delta, and south of Cairo in the Nile river valley. Subjects from areas in and adjoining the Sinai peninsula, in the eastern and western desert, and in southernmost Egypt, had the lowest prevalence of HCV antibody. The large urban governorates of Cairo and Alexandria had antibody prevalences of 19% and 11%, respectively. A total of 39.4% subjects had evidence of HBV infection (and-HBV core antigen total antibody). HCV infections were detected more frequently in donors with markers for HBV infections than in uninfected subjects (36% versus 18%, P < 0.001).

Comparative study of the immunogenicity and safety of two dosing schedules of hepatitis B vaccine in neonates.

Healthy Egyptian neonates born to hepatitis B surface antigen (HBsAg)-seronegative mothers were randomly enrolled in one of three vaccination schedules. A dose of 2.5 micrograms of recombinant HB vaccine was given at birth, two, and six months of age (group A) or two, four, and nine months of age (group B). These two groups and a third control group (group C) also were given the other routine childhood vaccines (BCG, DPT, polio, and measles). Blood samples were taken one month after the third vaccine dose in groups A (seven months of age) and B (10 months of age), and a second follow-up blood sample was taken at the age of 18 months for all three groups. Sera were tested for HBsAg and antibody to hepatitis B core antigen, and quantitatively for antibody to hepatitis B surface antigen (anti-HBs) using commercial enzyme immunoassay kits. The vaccine was well tolerated and side effects were limited to local soreness, redness, or temporary swelling. Among 590 infants who were followed-up, good (51-300 mIU anti-HBs/ml) or excellent (> 300 mIU/ml) immune responses occurred in 85% of the infants in group A and in 96% in group B. Geometric mean titers of anti-HBs at the first and second follow-up were 306 and 55 mIU/ml in group A, and 1,492 and 147 mIU/ml in group B. The recombinant HB vaccine is safe and immunogenic when given in three doses of 2.5 micrograms in either regimen, but delay of the booster dose of the vaccine until nine months after birth produced a higher immune response.

Recurrence of Rift Valley fever in Egypt.

Rift Valley fever (RVF) has been recorded in man and in domestic animals in Egypt after a 12-year absence. Human infections were first noted in the Aswan Governorate in late May, 1993. Only cases of ocular disease, an infrequent and late manifestation, were reported. Of 41 cases, 35 were tested serologically and 27 (77%) had RVF virus-specific IgM antibodies. An estimated 600-1500 infections occurred in the region. Abortions in cattle and buffalo were seen concurrently and antibodies to RVFV were present in 39% of domestic livestock, presumably unvaccinated. RVFV was isolated from an aborted water buffalo fetus.

Acute sporadic hepatitis E in an Egyptian pediatric population.

A study was conducted to determine the etiology of acute hepatitis among 261 children (age range 1-11 years) living in Cairo, Egypt. A blood sample was obtained from each subject when initially evaluated and a questionnaire was used to collect demographic and risk factor data. Sera were tested by enzyme immunoassay for acute hepatitis A (anti-hepatitis A virus IgM), hepatitis B (anti-hepatitis B core antigen IgM and hepatitis B surface antigen [HBsAg]), hepatitis C (total anti-HCV), delta hepatitis (total anti-delta), and cytomegalovirus infection (anti-CMV IgM). In addition, hepatitis E virus (HEV) infection was diagnosed using a new Western blot technique to test patients with non-A, non-B hepatitis for anti-HEV IgM. Among 261 children, acute hepatitis A was diagnosed in 85 (32.6%) patients, acute hepatitis B in 19 (7.3%), delta hepatitis in 3 (1.1%), mixed hepatitis A and B infection in 2 (0.8%), CMV infection in 1 (0.4%), hepatitis E in 58 (22.2%), and non-A, non-B hepatitis of unknown type in 51 (19.5%). Forty-two (16.1%) subjects had HBsAg without other markers of acute infection. Risk factor analysis indicated that patients living in homes not connected to a municipal source of water were at increased risk of hepatitis E infection. These data provide additional evidence that hepatitis E virus is a common cause of acute sporadic hepatitis in children living in Egypt.

Antibodies to lymphocytic choriomeningitis virus in wild rodent sera in Egypt.

Specific antibodies to lymphocytic choriomeningitis (LCM) virus were detected in sera of wild rodents trapped in different regions of Egypt. The highest proportion of positive sera (11.5%) was found in Sinaa Governorate of the Asian Continent, followed by Sharkia Governorate (5.6%) adjacent to Sinaa and Giza Governorate (1.8%). In Upper Egypt, however all 610 rodent sera collected in Aswan, Red sea Pernees and New Valley adjacent to Sudan were negative. The highest percentage of positive sera was in Rattus rattus frugivorus and Mus musculus species.

Acute sporadic non-A, non-B hepatitis in a pediatric population living in Cairo, Egypt.

One-hundred and four cases of acute viral hepatitis and 100 controls 13 years of age and less were entered into a study of acute hepatitis in children in Cairo, Egypt. Study subjects, who were mainly from a lower socioeconomic level, were selected from a public pediatric clinic. Acute non-A, non-B hepatitis was diagnosed in 51 (49%) patients, hepatitis A in 46 (44%), possible hepatitis B in three (3%), and EBV hepatitis in four (4%) patients. Contact with a family member with jaundice was found to be significantly associated with hepatitis A. A history of a blood transfusion, a medical injection, and knowledge of an individual outside of the household with jaundice during the prior six months were significantly associated with non-A, non-B hepatitis. A significant association was not found between the type of hepatitis and the age and gender of study subjects and the extent of household crowding. In this pediatric population living in an urban area of a developing country, non-A, non-B hepatitis was found to be a major cause of acute sporadic hepatitis.

Serological evidence of Crimean-Congo haemorrhagic fever viral infection among camels imported into Egypt.

A serosurvey was conducted during 1986-87 to determine evidence of prior Crimean-Congo haemorrhagic fever (CCHF) viral infection among camels imported into Egypt from Sudan and Kenya. Sera obtained from camesl arriving at the Aswan quarantine station, southern Egypt, were tested for CCHF antibody by the agar gel diffusion (AGD) and the indirect fluorescent antibody (IFA) techniques. CCHF viral antibody was demonstrated in 14% (600/4301) of the camels, with both techniques yielding similar results. CCHF viral antibody prevalence among camels imported from Sudan was lower (12%) than among camels imported from Kenya (26%). Ganjam and Qalyub viral antibody was not detected among the 600 CCHF viral antibody positive sera, but 7% (44/600) were positive for Dugbe viral antibody. CCHF viral antibody was not demonstrated in 400 sheep and 200 cows of native animals. These data indicate that camels imported from Sudan and Kenya had previous CCHF viral infection, but evidence of transmission to animals of Egypt was not obtained. Further studies are needed to assess the possible role of imported animals in the ecology and epidemiology of CCHF virus in Egypt.

Maternal-infant transmission of hepatitis B in Egypt.

In order to determine whether maternal-infant (vertical) transmission of hepatitis B is a common route of infection leading to chronic antigenemia in Egypt, 901 asymptomatic women in labor were evaluated. Forty-three women (4.8 percent) were positive for HBsAg, but only one woman was positive for HBeAg. From one year of observation of children born to 13 of the HBsAg-positive mothers, vertical transmission of hepatitis B was estimated to have occurred in approximately 1.7% of births, with chronic antigenemia resulting from 0.6% of births. It was also possible to observe 29 children born to women negative for HBsAg. Horizontal transmission of hepatitis B occurred in 17.2 percent of these children during the first year of life. Maternal-infant transmission of hepatitis B at birth does not appear to be the predominant mechanism of hepatitis B transmission or a common cause of chronic antigenemia in Egypt. The first year after birth appears to be a more important period of hepatitis B transmission. Therefore, vaccination of all children at birth with hepatitis B vaccine could be an effective vaccine strategy despite a low incidence of vertical hepatitis B transmission.

The detection of enteropathogens in acute diarrhea in a family cohort population in rural Egypt.

In 8 villages of rural northeastern Egypt, a 2-year study of the etiologic agents associated with episodes of diarrhea was carried out. Stool specimens (3,243) from 3,513 episodes of diarrhea were processed for enteropathogens. The most commonly identified agents in the group with diarrhea were Giardia lamblia (44%), heat stable enterotoxin (ST)-producing enterotoxigenic Escherichia coli (ETEC) (15%), heat labile toxin (LT)-producing ETEC (12%), enteropathogenic E. coli (EPEC) (4%), rotavirus (3%), Shigella (2%) and Salmonella (1%). Isolation rates were increased in cases compared to controls for all agents except G. lamblia and EPEC strains. Rotavirus, Salmonella and ST-producing ETEC were more frequently isolated during cooler months and Shigella and LT-ETEC occurred more commonly in warmer months. Campylobacter, EPEC, Giardia and E. histolytica did not show a discernable seasonal pattern. Rotavirus was primarily associated with diarrhea in infants only. Forty-four percent of children experienced at least 1 bout of rotavirus diarrhea by the age of 3 years. Vomiting was reported in 65% of cases of rotavirus infection. Dehydration was reported in greater than 40% of those with rotavirus-, Salmonella-, Campylobacter-, LT-ETEC- and EPEC-associated illness and in those without an identifiable agent. While rotavirus was implicated in 3% of cases overall, when vomiting or vomiting plus dehydration occurred, rotavirus was identified with a rate of 10% and 12%, respectively. Dysentery was common only in Shigella cases, occurring in 24%. A decrease in occurrence of rotavirus, Campylobacter and possibly EPEC illness was seen in the infants less than 6 months of age who were breast-fed when compared to those who were not.

Immunization and primary health care in Egypt.

PIP: The World Health organization's (WHO's) goal for its Expanded Program on Immunization (EPI) is the immunization of all children by 1990 against diphtheria, tetanus, whooping cough, tuberculosis, poliomyelitis, and measles. During the last 25-30 years considerable attention has been paid by the government of Egypt to aspects of primary health care, and immunization is being integrated into the country's basic health services. Precisely because of the principles of planning and implementation of this program, immunization has been made compulsory in Egypt for all children, and it is free of charge. This compulsory vaccination program was 1 of the reasons for the widespread establishment of basic health services in Egypt. The immunization program encourages the development of primary health care and the development of primary health care leads to better coverage and more perfection in the immunization of children against infectious diseases. An important element of any immunization program are the vaccines used. The vaccines must be potent, effective, safe, and readily available. The system of internal control of vaccines has been reorganized and strengthened in Egypt by the establishment of a national control laboratory for sera, vaccines, and biologicals. Another positive is the availability and production of vaccines. A country with a population of more than 20 or 30 million people may establish its own vaccine production facilities and thus become self-reliant in this respect. A prerequisite is the availability of well trained staff, suitable laboratories, and the presence of control laboratories. Egypt was fourtunate in this respect through the cooperation started in 1976 between the Netherlands government and the Egyptian government.^ieng

Cultivation and subgroup determination of human rotaviruses from Egyptian infants and young children.

Primary African green monkey kidney cells were more sensitive than primary cynomolgus monkey kidney and MA104 cells for supporting the growth of human rotaviruses detected in diarrheal stools of Egyptian infants and young children. In attempts to characterize these Egyptian rotaviruses, only 31% of the strains tested in the form of fecal suspensions were identified as subgroup 1 or 2. After one passage in African green monkey kidney cells, 80% of the strains were identified as subgroup 1 or 2. Of these 43 rotaviruses for which the subgroup was determined, 28% were subgroup 1 and 72% were subgroup 2. Thus, cultivation in African green monkey kidney cell cultures facilitated the antigenic characterization of rotaviruses by subgrouping; cultivation also represents an initial step in determining serotype and in developing potential vaccine candidates.

An epidemic of Rift Valley fever in Egypt. 1. Diagnosis of Rift Valley fever in man.

Rift Valley fever (RVF) virus was isolated from 53 of 56 sera collected from patients with a clinical picture of dengue-like illness during the peak of the epidemic of RVF in Egypt in the autumn of 1977. RVF virus was also isolated from the throat washings of two patients and the faeces of four, all of whom were positive for virus isolation from the serum. All the isolates were identified by the complement fixation (CF) test. Serological diagnosis of RVF, using paired sera from 16 patients, was made by both the haemagglutination-inhibition (HI) and CF tests. HI antibodies were demonstrated in all the acute sera, whereas CF antibodies, which seem to appear later, were detected in only seven acute and twelve convalescent sera. A longer period than the 12 days in this study must be allowed to elapse between the taking of the paired sera for a definite serological diagnosis to be obtained, especially when CF antibodies are taken into account.

An epidemic of Rift Valley fever in Egypt. 2. Isolation of the virus from animals.

During the epidemic of Rift Valley fever (RVF) that occurred in Egypt and other areas of North Africa in 1977, the virus was isolated from various species of domestic animal and rats (Rattus rattus frugivorus) as well as man. The highest number of RVF virus isolates were obtained from sheep; only one isolate was recovered from each of the other species tested, viz. cow, camel, goat, horse, and rat. RVF virus was reisolated from both camel and horse sera, apparently for the first time.