Monica Grandien

Serum Antibody Responses to Individual Viral Polypeptides in Human Rotavirus Infections

A radioimmunoprecipitation assay (RIPA) was used to study the serum antibody responses to individual polypeptides that developed after infection with viruses from human rotavirus subgroups I and II. Paired sera from eight children (1 to 8.5 years of age) were used in the study. Although all of the eight acute sera were negative by the complement fixation test, four of them were positive by RIPA, indicating a previous infection by rotavirus. A significant difference in the number of polypeptides immunoprecipitated was seen among the convalescent sera. The number of polypeptides immunoprecipitated was found to be related to previous infection experience. At most, ten different polypeptides were immunoprecipitated: seven structural polypeptides VP1 to VP7 and three non-structural polypeptides, NS1, NS2 and NS3. No sera immunoprecipitated VP8 or VP9. Acute sera positive by RIPA immunoprecipitated up to five polypeptides, VP1, VP2, VP3, VP4 and VP6. One of the non-structural proteins (NS2) was found to be particularly immunogenic, since antibodies to this polypeptide were detected in several convalescent sera. Among the structural proteins VP2 and VP6 were found to be the two immunodominant polypeptides which were recognized by all convalescent sera. Only three convalescent sera immunoprecipitated VP7, the major type-specific antigen responsible for inducing neutralizing antibodies. Three of four originally seronegative children with no reactivity in the convalescent sera to VP7 developed neutralizing antibodies to a single serotype. One child developed antibodies to two serotypes.

Detection of Specific IgM Antibodies for the Diagnosis of Mycoplasma pneumoniae Infections: A Clinical Evaluation

The diagnostic value of detection of specific IgM antibodies was analysed in Mycoplasma pneumoniae infections. In a retrospective clinical and serological study, M. pneumoniae IgM antibodies were determined by a mu-capture ELISA using enzyme-labelled antigen. The study group consisted of 91 patients with significantly raised titers in paired sera or a single high titer of complement fixation antibodies. About 40% of the patients had been treated with antibiotics ineffective against M. pneumoniae infections prior to admission to hospital. Treatment with erythromycin or tetracycline was shown to give a shorter period of fever compared to if no or ineffective therapy was given. Specific IgM antibodies were detected in about 80% of sera sampled 9 days or more after onset of symptoms. In sera sampled at 7-8 days after onset IgM antibodies were found in about 40% of the sera but only occasionally in sera sampled earlier. In the age group 0-20 years 88% of the patients developed an IgM response. In the higher ages (greater than 60 years) a significantly lower rate of IgM responders was observed.

Prevalence of herpes simplex virus types 1 and 2, cytomegalovirus, and varicella-zoster virus infections in Eritrea

BACKGROUND Herpesviruses establish latent infections in their hosts for life. The scarcity of data that exists in regard to herpesvirus infections in many African regions, could partly be due to the mild nature of their primary infections and the lack of means for their proper diagnosis. However, in recent decades the alarming spread of HIV infection in Africa and associated frequent reactivation of herpesvirus infections is leaving less room for neglect. This seroprevalence study is intended to help in the evaluation of the prevalence of herpesvirus infections in Eritrea. OBJECTIVE To evaluate the spread of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), cytomegalovirus (CMV), and varicella-zoster virus (VZV) infections. STUDY DESIGN The study population groups comprise female sex workers (FSW), former guerrilla fighters, truck drivers, port workers, a tribe called Rashaida, pregnant women, children under 5 years of age, and children over 5 years of age. The groups of pregnant women and children under and over 5 years of age were included to form a background for the evaluation of groups considered at risk for sexually transmitted or blood borne infections. RESULTS All study groups had a high seroprevalence of HSV-1 infections ( > 80%), except for the children under 5 years of age. The FSW had the highest prevalence of HSV-2 infections, 80%, followed by guerrilla fighters, truck drivers, port workers, pregnant women, children, and the Rashaidas. Positivity for antibodies against CMV was > 90% in all studied populations. The prevalence of VZV infections was surprisingly low in the tribe of Rashaida, 44% compared to more than 90% in the other adult groups tested for VZV (P = 0.0001). CONCLUSION The study shows that the prevalence of HSV-2 in the risk group of FSW was high, which could partly be explained by their sexual behaviours. HSV-2 was particularly low in the Rashaida group and, as expected, in the children. The low prevalence of VZV observed in the Rashaida is of importance since it makes them vulnerable to infection with varicella during their inevitable integration with the other tribes in their society.

Progressive rubella virus panencephalitis: synthesis of oligoclonal virus-specific IgG antibodies and homogeneous free light chains in the central nervous system.

The occurrence of oligoclonal IgG and homogeneous free lambda light chains in the cerebrospinal fluid (CSF) of a patient with progressive rubella virus panencephalitis is reported. Fractions of oligoclonal IgG corresponding to those of the CSF occurred also in the serum.

Seroprevalence of viral childhood infections in Eritrea.

BACKGROUND The seroprevalence of viral childhood infections in Africa has not been thoroughly investigated. The relatively recently discovered human parvovirus B19 (B19) and human herpesvirus 6 (HHV-6) have received particularly little attention. OBJECTIVE To investigate the seroprevalence of viral childhood infections in different Eritrean populations and to define groups at high risk for infection. STUDY DESIGN Five population groups in Eritrea have been examined to define the prevalence of specific antibodies to several childhood viruses. The study population of more than 400 persons consisted of children, pregnant women, female sex workers and members of a secluded tribe called Rashaida. RESULTS All groups showed a high prevalence of antibodies to measles and HHV-6 (> 85%). For rubella, the seroprevalence was very high in all adult groups (93-99%) except the Rashaida group (71%). The mumps prevalence was surprisingly low in the Rashaida group (29%) compared to 46-85% in the other adults. Late encounter of mumps and rubella was also observed among the Rashaidas. The pattern of antibodies to B19 showed a higher seroprevalence in all groups (56-91%) compared to what has been reported from the western world. CONCLUSION The findings represent what might be expected in an unvaccinated population. The exception was the Rashaidas, which had low seroprevalences and late encounter of mumps and rubella. This is of importance because it makes this tribe vulnerable to these infections, which are associated with complications when acquired in adult age. Also noteworthy is the high frequency of antibodies to HHV-6 and particularly B19 in all groups, indicative of an early encounter of both these viruses.

Effect of Zoster Immunoglobulin for Varicella Prophylaxis in the Newborn

Zoster immunoglobulin (ZIG) was given for prophylaxis to 95 neonates born to mothers with perinatal varicella. The treatment had no influence on the clinical attack rate; 48 (50%) of the children developed varicella. However, the ZIG treatment clearly influenced the course of the disease for newborns at particular risk, i.e. when maternal varicella developed within 4 days before and 2 days after delivery. Of 41 such neonates, 21 (51%) contracted varicella with an incubation mean time of 11 days. 13 of the 21 developed a very mild chickenpox (no fever, less than or equal to 20 pocks), 6 had a mild to normal disease, and 2 (10%) had more severe infections; none died or got sequelae after the disease. These results should be compared with the expected rate of complications in non-treated neonates in the defined risk group, where the mortality among those contracting varicella has been reported to be as high as about 30%.

Nested PCR for detection of BK virus and JC virus DNA

BACKGROUND A nested polymerase chain reaction (PCR) was developed to detect BK virus (BKV) and JC virus (JCV) DNA sequences. The unique clevage site for BamHI restriction enzyme was located in the JCV amplimer and cleavage was used to differentiate between BKV and JCV. STUDY DESIGN Twenty-three urine specimens from 17 bone marrow recipients with haemorrhagic cystitis and one liver transplant patient were tested for the presence of BKV and JCV DNA. Four brain tissue specimens (paraffin embedded brain tissues and a fresh frozen brain biopsy) and 5 cerebrospinal fluids from 3 AIDS patients and one liver transplant patient, all with progressive multifocal leukoencephalopathy (PML), were also examined by PCR. RESULTS The sensitivity of the PCR was 10 genomes for each virus. BKV DNA was detected in 15 urine specimens from 12 bone marrow transplant patients. JCV DNA was detected in 4 cerebrospinal fluids and 4 brain tissues from patients with PML. CONCLUSION Our results show that the nested PCR is a sensitive and rapid assay that can be used for diagnosis of BKV and JCV infections. The cerebrospinal fluid appears to be a suitable material for diagnosis of JC virus reactivation in the brain.

Identification of BK virus in a patient with acquired immune deficiency syndrome and bilateral atypical retinitis

OBJECTIVE To report the clinical and histopathologic characteristics of BK virus (BKV) retinitis. DESIGN Case report. TESTING The clinical features of bilateral retinitis in a 29-year-old homosexual white male with the acquired immune deficiency syndrome (AIDS) included focal, mottled fundus pigmentation, and haloes, as documented by fundus photography. After death of the patient, the left eye was studied by light microscopic and immunohistochemical examination. The nested polymerase chain reaction (PCR) was used to detect viral deoxyribonucleic acid (DNA) in the right eye and other nonocular tissues. The specificity was then confirmed by restriction enzyme analysis. RESULTS The retina of the left eye showed focal necrosis and contained cells with intranuclear staining for the BKV VP1 protein. In the right eye, BKV DNA was detected in the retina and other tissues by nested PCR. Autopsy showed that BKV infection was also present in the brain, kidneys, and peripheral blood mononuclear cells. CONCLUSIONS A number of pathogens may cause retinitis in patients with AIDS. The authors have shown that BKV should be included among those pathogens and that some clinical features may suggest the presence of BKV retinitis.

Seroprevalence of human herpes virus 8 in different Eritrean population groups

BACKGROUND Human herpesvirus 8 (HHV-8) is associated with Kaposis sarcoma. In the US and Europe, HHV-8 is believed to be mainly sexually transmitted, but reports from some African countries suggest non-sexual transmission. OBJECTIVES To find out more about HHV-8 seroprevalence and transmission in Eastern Africa. STUDY DESIGN In this study, 411 serum samples from different population groups in Eritrea (children, pregnant women, female sex workers and members of the isolated Rashaida tribe) were examined for HHV-8 antibodies with an immunofluorescence assay detecting antibodies to latent and lytic HHV-8 antigens. RESULTS Antibodies to HHV-8 latent antigen were found in 0-2% of Eritrean children, 5% of pregnant women, 8% of female sex workers and 26% of Rashaidas, respectively. No correlation was found between detectable HHV-8 antibodies and seropositivity to HIV or herpes simplex 2. CONCLUSIONS These results suggest that HHV-8 infection is relatively common in Eritrea and that viral transmission occurs predominantly through non-sexual route in this region.

Prevalence of infection with HIV, hepatitis B and C viruses, in four high risk groups in Eritrea

BACKGROUND Little is known about the prevalence of infections in different population groups in Africa, and about the influence of living conditions on the spread of infections. This study is the first of its kind in the state of Eritrea and is expected to serve as an evaluation of the situation in the country. OBJECTIVE A serosurvey for human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV) was carried out during the summer of 1995 in Massawa, a small sea port in Eritrea (East Africa) in four groups considered to be at risk for these infections. STUDY DESIGN The study subjects were former Guerrilla Fighters, Female Sex Workers, Truck Drivers, and Port Workers. Participants from a tribe called Rashaida were believed to be at low risk, and thus served as a control. RESULTS The Female Sex Workers had the highest incidence of HIV-1 infection, 29%, compared to 10% for Port Workers, and 3% for Guerrilla Fighters. On the other hand presence of HBsAg, indicating a high prevalence of hepatitis B carrier status, was highest in the Guerrilla Fighters, followed by the Rashaidas, and lowest in the Female Sex Workers. The Female Sex Workers were further tested for antibodies against HBV and the results revealed that 53% of them, 5%, had antibodies against HBcoreAg. Excluding the possibility of an acute infection at sampling time, three of them became HBsAg carriers. Surprisingly, our group of Truck Drivers did not show HIV-1 infection, and no HIV-2 infections were seen in the whole cohort. CONCLUSION The study shows that the described groups have different prevalences of infection with HIV, hepatitis B and C which can partly be explained by their living conditions.