Biomedical subjects
M C Croxson
Publications and source records attributed to M C Croxson.
Hepatitis C infection by needlestick?
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Recurrent aseptic meningitis.
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Demonstration of herpes simplex type 2 in the cerebrospinal fluid of two patients with recurrent lymphocytic meningitis.
AIMS: To investigate the aetiology of recurrent lymphocytic meningitis in two patients with a past history of recurrent genital herpes simplex infection. METHODS: Cerebrospinal fluid (CSF) obtained from two patients during an acute recurrent episode of lymphocytic meningitis was analysed by polymerase chain reaction for the presence of herpes simplex DNA. RESULTS: In both patients, the acute CSF was positive for herpes simplex type 2 DNA. A second CSF obtained 2 weeks later from one patient was negative for HSV DNA: CONCLUSIONS: Herpes simplex type 2 may be an important cause of recurrent lymphocytic meningitis. Available evidence suggests that viral DNA is cleared from the CSF between episodes and supports active viral replication as the pathological mechanism. The recurrences of meningitis need not coincide with clinical recurrences of genital herpes.
Identification of human immunodeficiency virus type 2 in a New Zealand resident.
AIMS: To determine the human immunodeficiency virus (HIV) types infecting a West African immigrant to New Zealand. To develop an HIV type 2 specific polymerase chain reaction (PCR). METHODS: The HIV antibody status of the patient was determined using both HIV-1 and dual HIV-1 and 2 enzyme immuno assays (EIA). Western blot with HIV-2 and HIV-1 and 2 strips was used as a confirmatory assay. DNA from white blood cells was extracted and HIV proviral DNA amplified using either primers specific to the HIV-2 gag region (VB305 and VB312) or to HIV-1 gag (SK38/39) and env (SK68/69) regions. Amplified products were electrophoretically resolved, southern blotted and probed with specific oligonucleotide probes. RESULTS: The patient serum was strongly reactive for HIV antibodies by EIA and showed multiple reactivity when tested by western blot against both HIV-1 and HIV-2 proteins. DNA was only amplified with primers specific to HIV-2 and the 298 bp product hybridized with an HIV-2 specific probe. No HIV-1 DNA was amplified from the patient. CONCLUSION: This individual is infected with HIV-2 and has most likely developed antibodies that cross-react with HIV-1. We believe this is the first report of an HIV-2 infected individual in New Zealand.
Unlinked anonymous monitoring of HIV prevalence at sexually transmitted disease clinics.
AIM: To determine the prevalence of HIV infection among patients attending the four sexually transmitted disease (STD) clinics in two metropolitan areas of New Zealand. METHODS: The population studied comprised everyone who attended between August 1991 and August 1992 because of concern about a possible new episode of an STD and who had a blood specimen taken for hepatitis B (or syphilis) serology. The study involved unlinked anonymous testing of left-over blood specimens, following ethical guidelines that have been proposed internationally. RESULTS: Among 8478 specimens tested, 23 (2.7 per 1000) were found to be HIV positive. The seroprevalence rates per 1000 among women, heterosexual men, and homosexual or bisexual men were 1.1, 1.3, and 44, respectively. All but five of the infected people were either known to be HIV positive or had an identifiable test during their clinic attendance. CONCLUSIONS: The seroprevalence rates are similar to those reported from STD clinics in England, and suggest that heterosexual transmission of HIV infection has not yet been extensive in New Zealand.
A polymerase chain reaction assay of cerebrospinal fluid in patients with suspected herpes simplex encephalitis.
A polymerase chain reaction (PCR) was used to detect herpes simplex virus (HSV) deoxyribonucleic acid (DNA) in CSF of 109 patients with possible herpes simplex encephalitis. HSV DNA was found in 20/109 patients. In 14 of these patients the diagnosis was confirmed by a rise in CSF antibodies, isolation of HSV from the brain, or both. In 3 patients CSF antibodies did not rise and 3 patients did not have a follow up lumbar puncture or a brain biopsy. In 19/20 patients HSV DNA was present in the first CSF specimen. The virus was identified as HSV I in 15 patients and HSV II in 4; the virus was not typed in the other patient. A possible diagnosis of herpes simplex encephalitis was not confirmed in the 89 PCR-negative patients. HSV DNA was present in CSF of 3 patients who had meningitis with herpetic genital infections but it was not found in 24 patients with other neurological diseases. The results suggest that the detection of HSV DNA in CSF using a PCR assay will be an accurate method of early diagnosis of herpes simplex encephalitis.
Identification of cytomegalovirus in vitreous using the polymerase chain reaction.
A presumptive clinical diagnosis of cytomegalovirus (CMV) retinitis was made in two patients presenting with atypical ophthalmologic findings. The diagnosis was confirmed by finding specific CMV DNA sequences in sampled vitreous fluid using a polymerase chain reaction (PCR) based assay. Neither of these patients yielded CMV on culture or PCR of peripheral blood leucocytes, nor was CMV present in tears or urine of either patient. Serum antibody titres were stable and did not help in establishing the diagnosis. This report suggests that CMV retinitis can occur in the absence of disseminated CMV disease.
Polymerase chain reaction in detection of CMV DNA in renal allograft recipients.
This study investigates the use of polymerase chain reaction (PCR) in comparison with viral culture and serology for monitoring of cytomegalovirus (CMV) infection in 21 consecutive renal allograft recipients treated with a quadruple immunosuppression protocol. In addition, an attempt is made to explore the significance of quantitation of CMV signals obtained from peripheral blood leucocytes. CMV infection developed in 16 patients with seven of these patients having organ involvement. All of these 16 patients had a fourfold rise in antibody titres as well as positive identification of CMV DNA in peripheral blood leucocytes by PCR. Blood viral cultures were negative in two of these patients. All five patients who remained PCR negative also remained culture negative with no antibody change. PCR detected CMV infection on average 15 days and 20 days earlier than viral culture and serology respectively. All except one of the patients with CMV organ involvement had an initial peak of CMV DNA followed by prolonged carriage of detectable CMV. The majority of patients with fever only or asymptomatic CMV infection had a transient peak of CMV DNA. A high incidence of CMV disease with organ involvement occurred in seronegative recipients of kidneys from seropositive donors (3/5) and in seropositive recipients of kidneys from seronegative donors (3/7). OKT3 was associated with a higher incidence of CMV organ involvement compared to Antilymphocytic globulin (3/5 v 4/16) but there was a higher incidence of CMV mismatched patients in the OKT3 treated group.(ABSTRACT TRUNCATED AT 250 WORDS)
Reactivation of hepatitis B virus infection with an unusual pattern of serological markers.
A 73-year-old man presented with acute hepatitis, judged to be a reactivation of hepatitis B virus infection. His serum samples during a follow-up time of 16 months showed an unusual pattern of serological markers. He was consistently HBeAg positive, HBsAg fluctuated just under the cut-off value and he had a low level of circulating anti-HBs. By electron microscopy numerous aggregates of surface antigen particles, but not complete virions were seen. He was HBV DNA positive by hybridization. The complete precore and core genes and a region of the surface gene were amplified from his serum by PCR. These findings emphasize the need for expanded serological testing in some patients with acute clinical hepatitis.
HIV-1 infection status in two HIV-1 antibody positive infants determined using the polymerase chain reaction.
The HIV-1 infection status of two HIV-1 antibody positive infants born to HIV-1 infected mothers was determined using the polymerase chain reaction. HIV-1 genomic sequences were not detected in the white blood cells of either infant suggesting that they were not infected. HIV-1 genomic sequences were detected in the white blood cells of the mothers of both infants and in cells from the one surviving father. These results confirm the value of the PCR detection method for assessing the HIV-1 infection status of infants born to HIV-1 antibody positive mothers.
Murine typhus in Kaukapakapa?
We report a patient who had not been outside New Zealand with a fever and maculopapular rash. Serology suggested acute murine typhus due to R typhi. This is the first reported case in New Zealand from a nontraveller.
Brain biopsy in the management of focal encephalitis.
The value of a brain biopsy in diagnosis and management of suspected herpes simplex encephalitis was studied in 29 patients (16 prospectively and 13 retrospectively). The biopsy showed herpes simplex encephalitis in eight, culture-negative encephalitis in 14, and was normal in three patients. It provided an alternative diagnosis in four patients, for two of whom curative treatment was available. The biopsy was complicated by a fatal intracranial haemorrhage in one patient. The low yield of alternative diagnoses suggests that a brain biopsy is not justified in the routine investigation of focal encephalitis.
Non-invasive diagnosis of herpes simplex encephalitis.
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Morbidity from acquired cytomegalovirus infection in a neonatal intensive care unit.
In a prospective study of transfused neonates, 32 of 262 infants were viruric at greater than 20 days of life. Of 212 neonates whose early status was known, postnatally acquired infection was proven in 21, two of whom were seronegative at birth and were thought to have transfusion-acquired cytomegalovirus (CMV). Maternal transmission of CMV is important in this population as there was 91% seropositivity for CMV at birth among the 21 babies who acquired CMV compared with 55% positivity among 150 babies who did not shed CMV (P less than 0.01). Significantly increased morbidity (increased length of stay in hospital, increased use of antibiotics, and longer duration of antibiotic administration) was found in babies with acquired CMV compared with matched controls who did not become viruric. Significant morbidity and mortality was not restricted to the two seronegative babies with transfusion-acquired CMV. The cost of providing CMV antibody negative blood for this neonatal unit would be less than the cost of providing the extended hospital care needed by the two babies with transfusion-acquired CMV found during this 3 year study.
Infantile gastroenteritis in Western Samoa.
Gastroenteritis has been identified traditionally as a major health problem in Western Samoa. In order to establish the extent of the problem, and to identify the viral and bacterial pathogens involved, stool specimens were collected from all children less than 2 years of age admitted to Apia Hospital, Western Samoa, over a 2 year period. Rotavirus was recovered from 5.5% of all admissions (20.5% of those labelled gastroenteritis) and bacterial pathogens were isolated from 2.1% of all admissions (0.9% of all those labelled gastroenteritis). Thus in Apia, as elsewhere, rotavirus is the most commonly identified enteric pathogen associated with infantile diarrhoea.
Idiopathic giant cell myocarditis: case report.
Idiopathic giant cell myocarditis has not been previously reported from Australasia; a typical case is presented, and the clinical and pathological findings discussed. Possible aetiologies are discussed in the light of positive serology to coxsackie B viruses.
A case of agammaglobulinaemia complicated by meningoencephalitis due to Echo virus 27.
A boy with agammaglobulinaemia diagnosed and treated from the age of 3 years 2 months developed encephalitis at 4 years 3 months. The illness showed a remitting but deteriorating course until death aged 6 years 5 months. Echo virus type 27 was isolated from the cerebrospinal fluid during the terminal illness. The virus was not isolated from five earlier cerebrospinal fluid samples nor was virus detected in a temporal lobe biopsy.