Rift Valley fever in Egypt 1986. Surveillance of sheep flocks grazing in the northeast Nile Delta

From October 1985 through November 1986, 1714 presumably unvaccinated sheep in 13 nomadic flocks located in four provinces in Dakahliya Governorate, in the northeast Nile Delta, were ear tagged and monitored for acquisition of Rift Valley fever virus (RVFV) antibodies. Sheep were bled at approximately 3 month intervals and sera were tested for haemagglutination inhibition (HI) antibodies to RVFV. HI reactors were tested for RVFV specific IgM antibody by enzyme-linked immunosorbent assay (ELISA) and neutralizing antibody to RVFV by plaque reduction neutralization (PRN) tests. Base line results showed 1.2% prevalence of HI antibody to RVFV with titres from 1:20 to 1:320. All HI positive sera were PRN positive through PRN titres were generally higher than HI titres. No RVFV specific IgM antibody was detected in the HI and PRN positive sera. Throughout the study, no initially seronegative sheep became positive and no HI positive sheep showed an appreciable increase above initial antibody titre. These data indicate absence of RVFV transmission to sheep in Dakahliya Governorate during the period of the study.

Segmental spinal dysgenesis

Segmental spinal dysgenesis is characterized by focal agenesis or dysgenesis of the lumbar or thoracolumbar spine, with focal abnormality of the underlying spinal cord and nerve roots. Children are symptomatic at birth with lower limb deformities and neurological deficits that may be segmental. Myelography and computed tomography disclose hypoplastic or absent vertebrae and atrophic or absent neural elements adjacent to the bony deformity; the spinal column distal to the abnormality may be partially bifid, but is otherwise normal. Spinal ultrasonography was a helpful diagnostic adjunct in one patient. Surgery may be helpful in decompressing partially functioning spinal cord or nerve roots, but may exaggerate the tendency toward spinal instability. The embryology of this abnormality is not clear, but two children had other anomalies suggesting a spinal dysraphic syndrome, and its cause is probably related to a segmental maldevelopment of the neural tube.

Antigenic variation of wild and vaccine rabies strains of Egypt

Nineteen street rabies virus strains, isolated in Egypt from humans (two), dogs (nine), cats (two), farm animals (two), gerbils (three), and a jackal were antigenically analyzed. The Pasteur strain used for the preparation of human rabies vaccine, the Flury high and low egg passage stains (HEP, LEP) used for animal vaccines, and the challenge virus standard (CVS) strain were also assayed. All were examined by the indirect fluorescent antibody test, using a panel of 20 monoclonal antibodies against the nucleocapsid of rabies and rabies-related viruses. The rabies isolates demonstrated patterns of reactivity with the antinucleocapsid panel different from those of the Pasteur, HEP, and CVS strains. Representative human, dog, and rodent isolates were analyzed by neutralization tests in mice, with a second panel of 19 monoclonal antibodies against rabies and Mokola envelope glycoproteins. With this panel, the isolates demonstrated patterns of reactivity different from the vaccine strains. These data indicate antigenic variation between wild virus and vaccine strains.

The clinical significance of hindbrain herniation and deformity as shown on MR images of patients with Chiari II malformation

This study investigates whether the degree of brainstem herniation and the nature of the cervicomedullary deformity seen on sagittal plane MR images correlates with the clinical syndrome in patients with the Chiari II malformation. The amount of brainstem herniation was assessed by relating the position of the midbrain and pons to the sella turcica and the anterior lip of the foramen magnum, respectively. The cervicomedullary deformity was graded into degrees of increasing severity. We found that the neurologic status of these children was not affected by either the amount of herniation or the characteristics of the cervicomedullary deformities. Because of these findings, we believe that other factors, such as disorganization of the brainstem nuclei, may be the likely cause for the breathing and swallowing difficulties experienced by children with the Chiari II malformation.

MR evaluation of neurovascular lesions after endovascular occlusion with detachable balloons

Three patients with surgically inaccessible giant carotid aneurysms/pseudoaneurysms and one patient with carotid cavernous fistula had endovascular occlusion with detachable silicone balloons filled with Cholografin. MR was performed before the procedures in three cases and again 18 hr to 44 days after embolization in all four cases. The age-related changes of arterial thrombi, as well as the optimal timing and value of different pulse sequences in the noninvasive follow-up, were evaluated. Arterial thrombi have some characteristics in common with intracerebral hematomas, being isointense on T1-weighted spin-echo images during acute phase and subsequently acquiring hyperintense signals on both T1- and T2-weighted spin-echo images during the subacute and chronic phases. Additional observations are that (1) hyperacute (less than 24 hr old) thrombus is hyperintense on T2-weighted spin-echo sequences; (2) hemosiderin is less conspicuous in chronic intraluminal thrombi than in intracerebral hematomas of comparable size; and (3) thrombosis is initiated at a site remote from the apex of the aneurysm and then progresses centripetally. The Cholografin-filled balloon is hypointense to gray matter on T1-weighted spin-echo images and isointense to both hyperacute and chronic thrombus on T2-weighted spin-echo images. The optimal timing and sequence for MR follow-up of a thrombosed aneurysm with conventional spin-echo technique is beyond 7 days on T1-weighted spin-echo images. The in vivo appearance of Cholografin-filled silicone balloons does not change appreciably on T1- and T2-weighted spin-echo sequences up to 6 weeks if filled according to the manufacturer's specification.

A prospective study of dengue infections in Bangkok

Dengue infections were prospectively studied among 4- to 16-year-old students at a Bangkok school. Blood samples were obtained from 1,757 students in June 1980, before the dengue season, and in January 1981, after the season, and tested for dengue antibodies by the hemagglutination inhibition method. Classrooms were monitored daily for school absences. Fifty percent of the children had antibodies to, and were presumably immune to, at least 1 dengue serotype by the age of 7 years. Most (90/103, 87%) students who became infected by dengue viruses during the study period were either asymptomatic or minimally symptomatic (absent only 1 day). Most (7/13, 53%) of the symptomatic dengue infections (absent with fever for greater than or equal to 2 days) were clinically recognized as cases of dengue hemorrhagic fever which required hospitalization. None of 47 primary dengue infections required hospitalization, whereas 7 of 56 secondary infections did (P = 0.012). Preexistent dengue immunity, as detected by conventional serologic techniques, was a significant (odds ratio greater than or equal to 6.5) risk factor for development of dengue hemorrhagic fever.

Arboviral causes of non-specific fever and myalgia in a fever hospital patient population in Cairo, Egypt

Fever and myalgia are non-specific clinical manifestations of illness which commonly occur in patients with arboviral disease. In Egypt, such illness is often mis-diagnosed as "influenza". To determine arboviral aetiology in patients admitted with fever and myalgia, acute and convalescent sera samples were obtained from 55 patients admitted with these clinical manifestations to the Imbaba Fever Hospital, Giza, Egypt, during October and November 1984. Based on viral isolation, and a comparison of acute and convalescent sera, 4 patients (7%) had acute arboviral infections. Haemagglutination inhibition and indirect immunofluorescence tests showed that one had West Nile virus (WNV) infection, 2 had sandfly fever virus-Naples (SFN), and 1 had sandfly fever virus-Sicilian (SFS) infection. SFN was isolated from the acute serum sample of 1 of the 2 patients with SFN infection.

Chiari II malformation: MR imaging evaluation

The purpose of this study was to explore the value of high-detail MR imaging in the diagnosis of the Chiari II malformation. Twenty-four patients with known Chiari II malformation as diagnosed by CT scanning were evaluated with cranial MR scans. Two patients also had spine scans. The sagittal-plane images were the most informative, and abnormalities of the telencephalon, diencephalon, mesencephalon, rhomboencephalon, upper spinal cord, and mesencephalon were shown extremely well. We found MR to be an easy and accurate method for demonstrating the abnormalities of the Chiari II malformation, and it is our procedure of choice.

Sand fly fever-Naples infection in Egypt

Two Egyptian male patients with sand fly fever-Naples virus infection are presented. The virus was isolated from one patient while both patients had diagnostic rises in indirect fluorescent antibody titers to the virus. The viral isolate, SFN 85055, grows to much higher titers and plaques more efficiently than the prototype sand fly fever-Naples virus and should facilitate work with this virus.

Antibody responses to Fermi antirabies vaccine in 21 patients bitten by a rabid jackal

In a village in Upper Egypt, 21 persons were bitten by a rabid jackal. All received antirabies vaccine of the Fermi type within a few hours after the exposure. Antirabies hyperimmune serum was not administered. Three of the 21 victims died on days 16, 17 and 27 after exposure. Blood samples were obtained from 19 of the 21 bitten persons 5 days after completion of a series of 20 vaccine doses. Sera were tested for rabies antibodies by the indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA) test. All 19 persons developed rabies antibodies detectable by these techniques. IFAT titres ranged from 128 to greater than or equal to 1024. ELISA antiglycoprotein titres were generally low, ranging from 0.7 to 18 iu/ml of serum.

Difficulties in diagnosing congenital posterior fossa fluid collections after shunting procedures

The differential diagnosis of retrocerebellar fluid collections in infants is important because of the prognostic implications. Usually the diagnoses are easy; however, shunting of the lateral ventricles or of the fluid collections may alter the appearance of the lesions, precluding accurate diagnosis. Under such circumstances a careful study of all the sequential radiologic studies is necessary.

Dermoid tumors occurring at the site of previous myelomeningocele repair

Four children with previously repaired myelomeningoceles presented toward the end of the first decade or early in the second decade of life with deteriorating lower-extremity and bladder function. Myelography and computerized tomography scanning demonstrated irregular filling defects at the area of the myelomeningocele repair, and surgical exploration disclosed dermoid tumors that were adherent to the placode and adjacent roots. Dermoid tumors should be considered in the differential diagnosis of neurological deterioration in children with a repaired myelomeningocele.

Poor outcome after lateral medullary infarcts

In two patients, lateral medullary infarcts were followed by repeated brainstem ischemia. One patient had posturally sensitive vertebrobasilar TIAs, and the other had TIAs followed by quadriparesis. Both had angiographic evidence of intracranial vertebral artery occlusion on one side and severe stenosis of the contralateral vertebral artery. Propagation or embolization of clot from the occluded vertebral artery or decreased blood flow caused by stenosis of the contralateral vertebral artery can cause a bad outcome.

Serological tests for detecting Rift Valley fever viral antibodies in sheep from the Nile Delta

To determine the accuracy of serological methods in detecting Rift Valley fever (RVF) viral antibodies, we examined serum samples obtained from 418 sheep in the Nile Delta by using five tests. The plaque reduction neutralization test (PRNT) was considered the standard serological method against which the four other tests were compared. Twenty-four serum samples had RVF viral antibodies detected by PRNT. Hemagglutination inhibition and enzyme-linked immunosorbent assay antibodies to RVF virus were also present in the same 24 serum samples. Indirect immunofluorescence was less sensitive in comparison with PRNT, and complement fixation was the least sensitive. These results extend observations made with laboratory animals to a large field-collected group of Egyptian sheep.

Rift Valley fever surveillance in mobile sheep flocks in the Nile Delta

Rift Valley fever (RVF) surveillance was carried out in the Nile Delta by monitoring mobile and stationary sheep flocks for antibodies to RVF virus. Sheep are known to be susceptible to RVF virus infection and experienced severe morbidity in 1977 and 1978 when RVF was epidemic in Egypt. Four hundred six sheep in 32 flocks were surveyed during 1984. Twenty-four sheep from 7 flocks had antibodies to RVF virus detected by hemagglutination inhibition and plaque reduction neutralization tests. Antibodies were found primarily in sheep greater than 3 years of age, although 1- and 2-year-old sheep were included in the sample. No seroconversion was observed among 177 seronegative sheep that were bled successively for a period of 10 months. These results indicate that epizootic RVF was probably not present in the Nile Delta during 1984.

Osteoid osteoma of the cervical spine

Osteoid osteoma is a benign tumor of bone that occurs in children and adolescents, particularly in the femur and tibia. Osteoid osteoma of the spine accounts for approximately 10% of these lesions. There frequently is a delay in diagnosis because of its difficult visual appearance. Pain in the spine occurring at night that is relieved by aspirin, or painful scoliosis, should alert the physician to the possibility of its presence. Bone scan and tomograms are essential in making the diagnosis. Complete surgical excision of the lesion is the procedure of choice for immediate, lasting pain relief.

Evaluation of febrile patients in Port Sudan, Sudan: isolation of dengue virus

One hundred consecutive patients admitted to the Port Sudan Hospital with a temperature greater than or equal to 100 degrees F were evaluated. Enteric fever was diagnosed in 19 patients and malaria in 13. Virologic studies identified 21 cases of dengue infection. One dengue 1 and 17 dengue 2 infections were diagnosed by viral isolation. Three untyped dengue infections were identified serologically. The clinical presentation and course of patients infected with dengue virus were most consistent with classic dengue fever. There was no evidence of hemorrhagic phenomena or shock in any of the dengue-infected patients. Both dengue 1 and 2 must be considered causes of acute fever in East Africa.

Clinical and angiographic features of carotid circulation thrombus

We studied five patients with intraluminal carotid thrombus visualized by angiography. The distinctive clinical features included the following: thrombus formation without significant atherostenosis; peripheral and cerebral arterial thrombosis; step-wise evolution of cerebral and/or peripheral signs over a period of days to several weeks; clotting tendency despite heparin anticoagulation; and carotid or iliac artery thrombosis after thrombo-endarterectomy. These unusual features serve to identify an uncommon subgroup of stroke patients with large artery thrombosis. Pathogenesis was not established. Coagulopathy with elevated factor VIII levels was the suspected mechanism.

Comparison of whole pelvis versus small-field radiation therapy for carcinoma of prostate

One hundred thirty-six patients with adenocarcinoma of the prostate gland Stage A2 (12 patients), Stages B1 and B2 (26), Stage C (64), and Stages D1 and D2 (34 patients) were evaluated clinically and treated in a similar fashion at three hospitals. Megavoltage radiation therapy units were employed to deliver 4,600-5,000 cGy to the whole pelvis, and the prostatic area was treated for an additional 2,000 cGy (boost). Local recurrence was infrequent (8/136 = 6%), and the five-year actuarial survival and disease-free survival rates were 85 and 42 per cent, respectively. Adverse clinical parameters included poor histologic differentiation, age younger than sixty years, and diagnosis by transurethral resection of the prostate rather than needle biopsy in Stage C patients. Severe acute reactions occurred in only 2 patients, and only 2 patients were hospitalized for severe chronic (late) reactions. Whole pelvis radiation yielded a statistically significant improved five-year survival and three-year disease-free survival for similarly evaluated patients for Stage C but not for Stages A and B when compared with 116 patients treated with small-volume radiation (prostate area), previously reported from these three hospitals.