Cases Of Dual Infection Research Articles

Reappraising the value of urine leukocyte esterase testing in the age of nucleic acid amplification.

The leukocyte esterase (LE) test has a limited role in determination of empiric therapy for male patients screened for urethritis because of its poor positive predictive value in low (< 5%) prevalence settings. The recent advent of nucleic acid amplification testing of first-void urine (FVU) has dramatically increased the ease with which widespread screening for Chlamydia trachomatis and Neisseria gonorrhoeae can be performed, but the costs of such testing may be prohibitive. The LE test may therefore have a role in management of urethritis because of its high negative predictive value. To determine the sensitivity, specificity, and positive and negative predictive value of LE testing for the diagnosis of N. gonorrhoeae and C. trachomatis in male FVU specimens in a low-prevalence urban setting using a commercial polymerase chain reaction (PCR) as the gold standard. Data were obtained on men presenting to an urban sexually transmitted disease clinic over a 16-month period. Patients were included if an FVU had been tested for the presence of LE using a rapid dipstick, read by an automated urine analyzer, and the sample (either an FVU or urethral swab) had then been processed for the detection of N. gonorrhoeae and C. trachomatis by PCR. Of 301 assessable patients, there were 14 cases of gonorrhoea, 21 cases of chlamydia, and 1 case of dual infection detected by PCR. Most men (245/301; 81.4%) were asymptomatic, of whom 12 of 245 (4.9%) had an infection detected compared with 24 of 56 (42.9%) in the symptomatic men (P < 0.001). Using a "< or = trace" cutoff, the overall value for the sensitivity of the LE test was 77.8% (95% confidence interval, 60.4-89.3), specificity 80.8% (75.4-85.2), positive predictive value 35.4% (25.2-47.1), and negative predictive value 96.4% (92.8-98.3). The negative predictive value of the LE test may be of use in determining which patients should proceed to specific diagnosis by nucleic amplification methods (e.g., PCR or ligase chain reaction). By limiting testing to patients with positive LE results, cost savings may be made, enabling the technology to be used in a wider community setting. The value of the LE test in higher prevalence populations with access to nucleic amplification testing remains to be established.

Meningitis due to a combined infection with Cryptococcus neoformans and Streptococcus pneumoniae in an AIDS patient

We report on a case of dual infection with Cryptococcus neoformans and Streptococcus pneumoniae in the cerebrospinal fluid of a patient with AIDS. To our knowledge this represents the first case to be reported in the English literature. In immunocompromised patients the importance of performing both the Gram- and India-ink stain and cryptococcal antigen test on CSF specimens with completely normal biochemical and cellular parameters is emphasized.

Lymphatic filariasis and malaria: concomitant parasitism in Orissa, India

Concomitant parasitism with Plasmodium spp. and Wuchereria bancrofti was examined in Orissa, India, to study the influence of one parasite infection on the other in human communities. A survey of 1815 nocturnal blood films in 11 villages indicated an overall prevalence of 9·6% for malaria and 8·5% for microfilaraemia. Only 0·3% of the population harboured both parasites. Analysis of the expected and observed distribution of cases of dual infection in each village did not indicate any significant interaction between the 2 infections. The malarial vector density in 3 selected villages correlated well with the prevalence rate of malaria.

Relative frequency of human rotavirus VP4 (P) genotypes recovered over a ten-year period from South African children with diarrhea.

The relative frequency and distribution of the VP4 (P) genotypes of 227 human rotavirus field strains were investigated in South Africa. The stool samples were collected between 1984-1993 from infants and young children with diarrhea at Ga-Rankuwa Hospital, Pretoria, South Africa. The RNA was extracted from stools, heat denatured, and dot blotted onto nylon membranes. The blots were hybridized to PCR-generated, 32P radio-labelled VP4-specific probes (corresponding to the hyperdivergent region of the VP4 gene) of the following human rotavirus VP4 genotypes: P4, P6, P8, P9, P10, and P12. Of the 157 rotavirus strains typed by the probes, the P8 genotype was identified most frequently in 63.7% (n = 100) of the samples. The P4 and P6 genotypes were detected less frequently in 22.3% (n = 35) and 8.3% (n = 13) of the samples, respectively. Five cases of dual infection between P8 and P4 genotypes occurred, indicating the potential for reassortment between members of different rotavirus genogroups. The P9 genotype could not be confirmed in 3 cases (1.9%), while the P10 genotype was not observed at all, indicating the scarcity or absence of these VP4 genotypes in this region. Interestingly, we identified the newly-described P12 VP4 genotype in 6 cases (3.8%), suggesting a wide geographical distribution. Furthermore, several samples with sufficient RNA by gel electrophoresis remained untyped by the probes used in this study, and may represent putative "new" human VP4 genotype(s).

Short Report: Relative Risk of Hepatitis A and E among Foreigners in Nepal

Sera from two groups of patients in Nepal with acute hepatitis were examined for the presence of antibodies to the hepatitis A, B, C, and E viruses to determine the etiology of viral hepatitis. The first group consisted of 43 consecutive acute hepatitis patients presenting at a clinic for tourists and foreign residents in Kathmandu from January 1987 to June 1988. The other group consisted of 95 consecutive acute hepatitis patients admitted during the same period at a hospital used predominantly by adult Nepalese residents of Kathmandu. Hepatitis A was diagnosed in 39 (91%) of the foreign patients and in one of the 95 Nepalese patients, whereas hepatitis E was diagnosed in four of the 43 foreign patients and in 90 (95%) of the Nepalese patients. No cases of hepatitis B or C were identified in either group, nor were any cases of dual infection with the hepatitis A virus (HAV) and hepatitis E virus (HEV) identified. These results suggest that in the Kathmandu Valley, hepatitis A is the predominant form of hepatitis among foreigners, hepatitis E is the predominant form of hepatitis among adult Nepalese, and both HAV and HEV are endemic to the Kathmandu Valley.

Virological Study on Dengue Epidemic in Vientiane Municipality, Lao PDR, 1994.

In May 1994, an epidemic of dengue fever (DF) / dengue hemorrhagic fever (DHF) was reported in Ban Horn commune in Vientiane municipality. This was after a six-year period of non-epidemic DF/ DHF in the municipality. In early June, we collected 81 serum specimens from children with fever of unknown origin (FUO) in the commune. Of 81 specimens, 48 were taken from children within 5 days after the onset of FUO and subjected to dengue (DEN) virus isolation. Four strains of DEN-1 and 12 strains of DEN-2 viruses were isolated from 15 serum specimens (31.3%). A case of dual infection with DEN-1 and DEN-2 viruses was detected by enzyme antibody method using type-specific monoclonal antibodies and reverse transcription polymerase chain reaction (RT-PCR). The percentage incidences of the positive virus isolation from the serum specimens taken on the second and the third day of fever were 41.8% and 21.1%, respectively, and no virus was isolated from the specimens other than those from these two days. All the specimens were examined by the IgM-capture ELISA. Thirty-two specimens (39.5%) were positive for DEN IgM antibody.

Disease due to the Legionellaceae (other than Legionella pneumophila). Historical, microbiological, clinical, and epidemiological review.

More than 20 species of the Legionellaceae family of bacteria have been discovered since the discovery of Legionella pneumophila. Thirteen have been implicated as causative agents of pneumonia including the Pittsburgh pneumonia agent (Tatlockia micdadei, Legionella micdadei). Although outbreaks of nosocomial pneumonia in immunosuppressed hosts have been well-described, most cases have occurred sporadically in the community. The spectrum of disease ranges from severe life-threatening pneumonia to a self-limiting febrile illness (Pontiac fever). Isolation from the natural aquatic environment has preceded its discovery as agents of human disease in 6 species, while environmental isolation has not yet been obtained for 3 species implicated in disease. The mode of transmission is uncertain, but cases of dual infection by L. pneumophila and the newer species suggests that the epidemiology of these new organisms will be similar to that of L. pneumophila. The antibiotic of choice appears to be erythromycin. The historical background, epidemiology, microbiology, and clinical manifestations of these newly-discovered organisms are reviewed in comparative fashion.

CONCURRENT INFECTION WITH HISTOPLASMA CAPSULATUM AND BLASTOMYCES DERMATITIDIS.

DESPITE an increasing volume of literature concerning systemic mycotic infections caused by Histoplasma capsulatum and Blastomyces dermatitidis only 3 cases of dual infection have been reported in recent years.1 2 3 Two of these cases were in human beings, and 1 in a dog. Culture results of specimens from large numbers of patients suspected of having mycotic pulmonary disease indicate that dual infections may be far more prevalent than is generally recognized. Although these patients respond to the same treatment as those with single infections2 there is a definite problem in the identification of the two fungi when they are cultured together . . .