Radiolabelled monoclonal antibodies (McAb): an alternate approach to the conventional methods for the assessment of cardiomyocyte damage in an experimental brain-death pig model

BACKGROUND: According to the Ministry of Health and Welfare AIDS Surveillance Committee's report on vertically transmitted human immunodeficiency virus (HIV) infection, there have been eight children with acquired immune deficiency syndrome (AIDS) and 18 children with HIV infection in Japan, totalling 26 in all as of February 1997. A search of the literature fails to reveal any report that deals with many cases of vertically transmitted HIV infection in Japan. METHODS: A primary questionnaire survey was taken of the main medical institutions across the country, followed by a secondary questionnaire survey of physicians and pediatricians who treated the disease. A clinical review was made of 19 children with vertically transmitted HIV infection (including eight AIDS children) according to the 1994 Revised Classification System for HIV Infection in Children. RESULTS: The mean age at diagnosis was 14.5 months and the diagnosis was made at less than 18 months of life in approximately 70% of infected children. In the mean observation period of 16 months, six of eight AIDS children (75%), and one child of group B died. The mean period of observation for the seven dead children was 7 months, and six of seven children died by 36 months of life. The survival period after the diagnosis of AIDS was 15 months. The diagnosis of HIV infection was made based on the clinical symptoms of all children with AIDS. Of 11 children, six (45%) presented with symptoms of HIV infection by 6 months of life, and 10 of 11 children (91%) presented with symptoms by 26 months of life. The noteworthy clinical findings included hepatomegaly, splenomegaly, recurrent respiratory tract infection, lymph node swelling, oral candidiasis, hepatitis, wasting syndrome, HIV encephalopathy and severe pneumonia. The favored age for the start of complications and the magnitude of decrease in the HIV helper cell count varied with each case of complications of HIV infection (wasting syndrome, HIV encephalopathy) or opportunistic infections (cytomegalovirus infection, Mycobacterium avium complex infection). Anti-HIV drugs (mainly zidovudine) had been used in five of eight children with AIDS and were effective in two long survivors alone. CONCLUSIONS: Children who are diagnosed with HIV infection, based on their clinical symptoms, carry a poor prognosis. In this respect, early diagnosis and progress in anti-HIV therapy are necessary.     

Cancer in human immunodeficiency virus-infected children: a case series from the Children's Cancer Group and the National Cancer Institute

PURPOSE: To describe the spectrum of malignancies in human immunodeficiency virus (HIV)-infected children and the clinical outcome of patients with these tumors. METHODS: We retrospectively surveyed the Children's Cancer Group (CCG) and the National Cancer Institute (NCI) for cases of cancer that occurred between July 1982 and February 1997 in children who were HIV seropositive before or at the time of cancer diagnosis. We used Kaplan-Meier survivorship curves, hazard function estimates, and Cox proportional hazards models to evaluate survival. RESULTS: Sixty-four children (39 boys, 25 girls) with 65 tumors were reported. Thirty-seven children (58%) acquired HIV infection vertically (median age at cancer diagnosis, 4.3 years); 22 children (34%) acquired HIV through transfusion of blood or blood products (median age at cancer diagnosis, 13.4 years). Forty-two children (65%) had non-Hodgkin's lymphoma (NHL). Eleven children (17%) had leiomyosarcomas (or leiomyomas), which are otherwise exceptionally rare in children. Other malignancies included acute leukemia (five children), Kaposi's sarcoma (KS; three children), Hodgkin's disease (two children), vaginal carcinoma in situ (one child), and tracheal neuroendocrine carcinoma (one child). Median survival after NHL diagnosis was 6 months (range, 1 day to 89 months) and after leiomyosarcoma was 12 months (range, 10 days to 19 months). The average monthly death rate after NHL diagnosis was 12% in the first 6 months, which decreased to about 2% thereafter. In contrast, the monthly death rate after leiomyosarcoma diagnosis increased from 5% in the first 6 months to about 20% thereafter. CONCLUSION: After NHL, leiomyosarcoma is the second leading cancer in children with HIV infection. Both cancers have high mortality rates; improved outcome for NHL, in particular, may depend on earlier diagnosis and therapy.     

Spread of HIV-1 to children in Cambodia

Beginning November 1, 1995, children under 5 years of age, who were admitted to Kantha Bopha Hospitals and who were suspected tuberculosis cases, were screened for human immunodeficiency virus 1 (HIV-1) using enzyme-linked immunosorbent assay (ELISA). By January 31, 1997, 9026 children, 83% of the under 5-year-olds admitted, had been tested; 290 (3.2%) were positive. Serum samples from 205 children of the 236 seropositive children under the age of 18 months were tested for p24 antigen; 51 (25%) were positive. Mothers of 173 of the seropositive children were tested for antibodies to HIV; 170 were positive, which suggests that the main mode of acquisition of HIV-1 in the children was vertical transmission. If HIV-1 infection occurred only in the 54 seropositive children older than 18 months and in the 51 children younger than 18 months with detectable p24 antigen, the calculated prevalence of HIV-1 in children under 5 years old who were suspected of having tuberculosis when admitted to Kantha Bopha Children's Hospitals would be 1.2%. If the 17% not included in the test were all negative, the prevalence would be 1%. This is an underestimate because some of the children not tested could be positive and because some of the children tested had indeterminate HIV status. HIV testing was extended to all children admitted to the hospital; 715 were younger than 5 years of age, 596 of whom were suspected of having tuberculosis, and 119 of whom were not. The seroprevalences for the 2 subgroups were 3.2% and 0.8%, respectively. None of the 369 older children was seropositive. In 1996, the World Health Organization estimated a seroprevalence of 1.97% in adults 15-49 years old in Cambodia, the highest among Asian countries. The blood bank at Kantha Bopha found 211 (6.6%) HIV-1 seropositives among 3197 donors in 1995 and 211 (7.5%) among 2834 donors in 1996. Similar figures were seen at the National Transfusion Centre in Phnom Penh. A 1996 survey in Cambodia found an HIV-1 seroprevalence of 40.9% in prostitutes and 1.7% in pregnant women. The vertical transmission of HIV-1 to children may increase because the virus appears to have been introduced recently to Cambodia; this is indicated by lack of seropositivity in children older than 5 years of age.     

How to prevent stroke recurrence in patients with patent foramen ovale: anticoagulants, antiaggregants, foramen closure, or nothing?

A study on how to apply PCR as a diagnostic test for the infants born to HIV-1 infected mothers is described. All steps including clinical care, blood sampling, specimen processing and PCR analysis were carried out using native facilities and personnel. An open cohort of 130 children was evaluated at birth, 1, 6, 9, 15, and 18 months of age. Definite infection status was assessed by clinical and serological data during an 18 months of follow up period. PCR results were reported as positive or negative when at least 2 concordant data were denoted. This in-house PCR, compared to known infection status, gave 100% sensitivity and 94.4% specificity within 6 months after birth. On the other hand, clinical diagnosis could identify only the infected infants at 9 months of age. The HIV-1 transmission rate from mother to infant was 23.2%. Though this PCR was not at an optimal level of specificity, it was still beneficial to identify uninfected infants in the first year of their lives and avoid unnecessary medical care. Here, we report an in-house PCR that offers good performance at low cost for the diagnosis of HIV-1 vertical transmission.     

Culture-positive tuberculosis in human immunodeficiency virus type 1-infected children

BACKGROUND: Adults infected by HIV have increased susceptibility to Mycobacterium tuberculosis and progress more rapidly to disease. HIV and tuberculosis (TB) coinfection in children has been reported but often lacks bacterial confirmation. We report on the clinical picture, special investigations, clinical course and outcome of 14 children with HIV infection and culture-confirmed TB from a developing country. METHODS: The clinical records of all children, from 1992 to 1997, with HIV infection and culture-proved TB were reviewed. RESULTS: Fourteen (10.4%) of 135 children with vertically transmitted HIV infection, 93% <2 years of age, fit the criteria. Nonresolving pneumonia (4) and otorrhoea (6) were common complaints. A Mantoux test was positive (> or =15 mm) in 6 of 11 children. Extrapulmonary TB was present in 5 cases. Ear swabs were the source of M. tuberculosis culture in 3. Chest radiographs were abnormal in all with hilar and paratracheal lymphadenopathy present in 7. A source case with pulmonary TB was identified for 10. Susceptibility tests were done on 9 strains of which 1 was drug-resistant. Four children were culture-positive 4 to 10 months after initiation of TB treatment. Mortality was 21% and 3 were lost to follow-up. CONCLUSIONS: In HIV-infected children the Mantoux skin test remains useful and culture specimens should be obtained from all sources. Response to treatment is unpredictable, and for this reason repeated cultures should be taken during treatment and a 9-month course of treatment considered.     

Causes of chronic persistent cough in adult patients: the results of a systematic management protocol

BACKGROUND AND METHODS: In Japan, 26 children who vertically acquired human immunodeficiency virus (HIV) infection had been reported as at February 1997. Little information was published about their epidemiological backgrounds and the rate of perinatal HIV transmission in Japan remains unknown. To learn the epidemiological features of perinatal HIV infection in Japan, we examined the medical records of five perinatally infected children. RESULTS: Three of five mothers were Japanese and two others were South East Asian. Four of them acquired HIV infection abroad and one became infected through her spouse who had acquired infection abroad. Therefore, HIV infection in these five cases can be regarded as an imported infectious disease. None of the five mothers noticed their HIV infection before their pregnancy. One mother was found to be HIV seropositive during her pregnancy, but the others did not notice their HIV infection until their delivery. CONCLUSIONS: To reduce the incidence of perinatally HIV-infected children it is necessary to lower the incidence of mother-to-infant HIV transmission. In Western countries they have succeeded in reducing the risk for perinatal HIV transmission with perinatal zidovudine therapy. To prescribe the preventive therapy against perinatal HIV transmission, it is essential to know if pregnant women are infected with HIV or not. Therefore, women of childbearing age should accept voluntary prenatal HIV testing. At the same time, they should be offered such programs that can enable them to receive timely counseling, besides medical treatment, if they are found to be HIV infected.     

Absence of pericentromeric heterochromatin (9qh-) in a patient with bilateral retinoblastoma

The diagnosis of HIV infection is based on screening of HIV antibodies and confirmed by a more specific supplementary test. The most common confirmation test is Western blot, which is expensive, time consuming and subject to technical skill. The present study was carried out to evaluate whether the anti-HIV-1 antibody titer is valid as a supplementary test for diagnosis of HIV-1 infection. Anti-HIV-1 antibody titers of 2,414 anti-HIV-1 positive sera determined by the particle agglutination (PA) method were analysed in comparison with the Western blot analysis. The Western blot negative result was found in 11 of 2,414 (0.46%) anti-HIV-1 positive sera, these sera also gave negative anti-HIV by ELISA. The PA titers of these sera were found in the range of 16 to 64. Seventeen samples (0.70%) with anti-HIV-1 in the titer range of 16 to 256 showed indeterminate Western blot analysis. The rest, 2,386 of these 2,414 sera (98.84%), were shown to be positive by Western blot. However, all of the 2,356 sera with antibody titers > or = 512 (97.6%) demonstrated positive Western blot results. Five cases among the 17 (29.4%) indeterminate sera were examples of early seroconversion of HIV infection, which were confirmed in follow up specimens. The results suggest that only the samples with antibody titers < 512 are required to be confirmed for HIV infection by Western blot. It is possible that early seroconversion may be inferred from anti-HIV titers. Therefore, in order to reduce time and cost, the PA anti-HIV titer can be used as an alternative supplementary test for diagnosis of HIV-1 infection in most positive screened anti-HIV samples. Western blot is needed for testing in only a few cases.     

New systems of cardiac mapping or life to the electrophysiologist may become complicated

We report the case of an infant with progressive human immunodeficiency virus (HIV) infection and persistent seronegativity. The child had Pneumocystis carinii pneumonia at 4 months of age and was documented to be HIV-infected by HIV-1 deoxyribonucleic acid (DNA) polymerase chain reaction (PCR), but enzyme-linked immunosorbent assay (ELISA) and Western blot tests for HIV-1 and HIV-2 specific antibodies remained negative until the infant was 10 months old. This case should increase awareness about the possibility of seronegative HIV infection in infants and stress the fact that in questionable cases, even if the screening serology is negative, additional methods of diagnosis (ie, PCR, viral culture, and p24 antigen) should be considered.     

Vertical transmission of hepatitis C virus in New Zealand

AIMS: To investigate the transmission of hepatitis C virus from viraemic mothers to infants. METHODS: The study group comprised 54 hepatitis C ribonucleic acid (RNA) positive, human immunodeficiency virus (HIV) negative women attending antenatal clinic, their infants when born, 12 previous children and 44 children of 29 additional nonpregnant, viraemic women. During the study period there were 60 live births (1 set of twins, 5 sequential pregnancies). All infants were tested at birth for hepatitis C virus (HCV) RNA. Thirty infants were retested at 6 months or later. Breast milk from 30 mothers was tested for HCV RNA. The 56 other children were tested for antibody to HCV and HCV RNA. RESULTS: Of the 60 infants tested at birth, 30 failed to attend a 6 month or later followup, 2 infants were HCV viraemic by six months of age, 2 infants had one episode of possible HCV RNA positivity followed by loss of detectable HCV RNA and 26 have shown no evidence of HCV infection. Five of the 30 breast milk samples tested were positive for HCV RNA. Four older children of viraemic mothers were HCV RNA positive. CONCLUSIONS: In this study, 2 of 30 (6.6%) of infants born to HIV negative, HCV viraemic mothers acquired HCV infection. Breast milk remains a possible contributory source of infant HCV infection. Management of babies born to HCV viraemic mothers should include retesting of baby for HCV RNA at 3 to 6 months of age.     

Human immunodeficiency virus (HIV) antigen testing to detect HIV infection in female sex workers in Singapore

Human immunodeficiency virus (HIV) infection is characterised by seroconversion after a ?window? period of 2 to 3 months. After this period antibodies are usually detectable by screening tests (enzyme immunoassay or particle agglutination) confirmed by Western blot analysis. We studied 1000 newly enrolled female sex workers who had not been previously tested for HIV to assess the usefulness of HIV antigen testing to improve the efficacy of HIV infection detection. Blood was taken at enrollment for HIV antigen and HIV antibody testing. The Abbott HIVAG-1 test was used to detect antigen; antibody detection was by the Abbott recombinant HIV-1/HIV-2 3rd generation enzyme immunoassay (EIA) test, the Fujirebio Serodia-HIV particle agglutination (PA) test for screening, and the Diagnostic Biotechnology HIV Blot 2.2 Western blot (WB) test for antibody confirmation. Of the 1000 samples, 26 were positive for HIV antibody testing (26/26 for EIA, 25/25 for PA, 26/26 for WB), giving a prevalence rate of 2.6%, Of these 26 seropositive samples 1 was positive on HIV antigen testing. There were no samples which were antigen-positive and antibody-negative. HIV antigen testing does not add to increased efficacy of HIV detection among female sex workers in Singapore.     

CD44 plays a role in adhesive interactions between glioma cells and extracellular matrix components

To evaluate how individuals infected with the human immunodeficiency virus (HIV) became aware of their infection, when they first suspected they were infected with HIV and factors associated with suspecting HIV infection, we surveyed 227 patients at an urban outpatient HIV clinic. Though nearly all patients acknowledged risk factors for HIV, 60% reported that they did not suspect that they were infected until they received a positive HIV antibody test result. Non-white patients were less likely to suspect HIV infection prior to testing than white subjects (p < 0.03). Subjects not suspecting infection more often received HIV testing through a screening program or during a medical encounter (p = 0.02) and were less likely to be told by others that they might be infected (p = 0.001) than patients suspecting infection prior to testing. Forty-eight percent of subjects who suspected HIV infection prior to testing waited one year or more before obtaining their HIV antibody test. Interventions to reduce faulty personal HIV risk perception are needed to promote earlier HIV diagnosis.     

Human immunodeficiency virus seropositivity in adolescents with syphilis

OBJECTIVE: The purpose of this study was to assess the relationship between syphilis and human immunodeficiency virus (HIV) infection among inner-city, minority group adolescents. METHODS: From August 1989 through June 1990, serum from all positive serologic tests for syphilis, obtained from patients attending a comprehensive adolescent health center in an acquired immunodeficiency syndrome epicenter and its two school-based clinics, were frozen without patient identifiers and were subsequently screened for HIV by enzyme-linked immunosorbent assay with confirmatory Western blot for positives. In addition, a retrospective chart review was performed for all patients with a positive serologic test for syphilis during the study period. RESULTS: Of the 59 specimens with a positive syphilis serologic test, 9 (15.3%) were HIV seropositive. Of the patients with syphilis, 57.4% were black and 42.6% were Hispanic; 16.4% were male (mean age 18.1) and 83.6% were female (mean age 17.8). Only 1 subject (female) was an injection drug user; 4 of the male subjects self-identified as having had sex with other males. Of the subjects, 27.8% had primary, 19.7% had secondary, and 52.5% had latent syphilis at the time of diagnosis. A prior or concurrent sexually transmitted disease was present in 90% of the males and 80% of the females; gonorrhea was the most prevalent sexually transmitted disease in the males (89%) and chlamydia was most prevalent in the females (35%). A history of chancroid and/or herpes was present in 16.4% of the subjects. CONCLUSIONS: It is concluded that the diagnosis of syphilis in an adolescent is a risk factor for HIV infection. All sexually active adolescents should be routinely screened for syphilis, regardless of sexual practices. Those with syphilis should be specifically counseled about their increased risk for HIV infection and the importance of consistent condom use, and they should be referred for formal HIV pretest counseling.     

Pneumolysin PCR-based diagnosis of invasive pneumococcal infection in children

Blood-based pneumolysin PCR was compared to blood culture and detection of pneumolysin immune complexes, as well as to detection of antibodies to pneumolysin and to C polysaccharide, in the diagnosis of pneumococcal infection in 75 febrile children. Invasive pneumococcal infection was suspected on clinical grounds in 67 of the febrile children, and viral infection was suspected on clinical grounds in 8 of the febrile children. In addition, 15 healthy persons were examined to test the specificity of the PCR assay. Plasma, serum, and leukocyte fractions were analyzed by PCR. The combination of all test results led to the diagnosis of pneumococcal infection in 25 patients. Pneumolysin PCR was positive in 44% of these children, an increase occurred in the pneumolysin antibodies in 39% and in the C polysaccharide antibodies in 30% of the patients; pneumolysin immune complexes were found in convalescent serum in 30%, pneumolysin immune complexes occurred in acute-phase serum samples in 16%, and a positive blood culture was found in 20% of the patients. None of the healthy controls had positive results by PCR. The results suggest that the diagnosis of Streptococcus pneumoniae infection from blood samples necessitates the use of several different assays. Pneumolysin PCR was the most sensitive assay, but its clinical value is reduced by the fact that three blood fractions are needed.     

Risk factors and clinical presentation of acute primary HIV infection in India

CONTEXT: Most previous studies of clinical presentation and risk factors in early human immunodeficiency virus (HIV) infection have relied on retrospective analyses and referred seroconverters, and thus were subject to possible bias. OBJECTIVES: To apply a method based on measurement of prevalent HIV-1 p24 antigenemia for identification of risk factors for newly acquired HIV infection and to describe the signs and symptoms of acute HIV infection. DESIGN AND SETTING: Nested case-control study in Pune, India. PARTICIPANTS: HIV antibody-negative persons attending 2 sexually transmitted disease (STD) clinics between May 1993 and June 1996. OUTCOME MEASURES: Prevalent p24 antigenemia, risk factors for HIV infection, and clinical symptoms of acute primary HIV infection. RESULTS: Of 3874 HIV antibody-negative persons tested, 58 (1.5%) were p24 antigen positive at initial presentation to the clinics. Unprotected sexual contact with a commercial sex worker (CSW) was reported by 39 (77%) of the 51 p24 antigenemic men, compared with 131 (51 %) of 255 control men (adjusted odds ratio [AOR], 3.4; 95% confidence interval [CI], 1.2-9.6; P=.02). The presence of an active genital ulcer at the time of screening was found in 46 (79%) of the 58 p24 antigenemic men and women, compared with 137 (47%) of the 290 control subjects (AOR, 4.2; 95% CI, 2.0-9.0; P<.001). Signs and symptoms independently associated with p24 antigenemia in HIV antibody-seronegative persons included fever, which was reported by 28 (48%) of the 58 p24 antigenemic subjects, but only 52 (18%) of the 290 control subjects (AOR, 4.7; 95% CI, 2.4-9.0; P<.001). Joint pain was reported by 10% of subjects recently HIV infected, compared with 2% of the control subjects (AOR, 6.5; 95% CI, 1.7-24.8; P=.006). Night sweats were reported by 9% of the p24 antigenemic, but only 1% of the control subjects (AOR, 9.1; 95% CI, 1.7-47.6; P=.009). Overall, fever, joint pain, and/or night sweats were reported in 27 (47%) of the 58 subjects with recent HIV infection. CONCLUSIONS: This systematic case-control study of p24 antigen screening in HIV-seronegative patients attending STD clinics in India identified unprotected sex with a CSW and a genital ulcer as independent risk factors associated with newly acquired HIV infection. In addition, p24 antigen positivity identified recent fever, night sweats, and arthralgias as symptoms that may be predictive of recent HIV infection. In a study of patients attending STD clinics in India, screening for p24 antigen in HIV antibody-negative persons was found to be a reliable and effective research method for determining recent risk behavior and identifying clinical signs of acute primary HIV infection.     

Vertical transmission of human immunodeficiency virus: six years of development 1987-1992)

BACKGROUND: According to World Health Organization estimates, from the beginning of the epidemics to the end of 1994, the number of children infected by human immunodeficiency virus (HIV) was 1.5 million. This paper describes the evolution of some clinical and epidemiologic characteristics of vertically transmitted HIV infection. PATIENTS AND METHODS: All children born to HIV-infected mothers who delivered at a university hospital in Barcelona, Spain, between 1987 and 1992, were included in the study. Rates of HIV vertical transmission, HIV infection incidence and mortality due to HIV were estimated, and trends for the study period analyzed. Odds ratios were used to assess associations between variables. RESULTS: 192 newborns were identified and allocated, with respect to the year of birth, in three cohorts of 71, 58 and 63 children. Overall HIV vertical transmission rate was 16.5% and did not differ between cohorts. Infection incidence density rates increased over time (0.2, 4.9 and 8.1 cases/100 child-years, respectively; p = 0.016), while incubation periods decreased significantly (248, 103 and 114 days; p = 0.0004). There were no changes in mortality density rates (2.2 deaths/100 child-years). Regarding mothers' characteristics, a significant temporal trend (p < 0.001) for being older at delivery, belonging to the heterosexual transmission group and having symptomatic infection was observed over time. CONCLUSIONS: Certain clinical and epidemiologic aspects of HIV vertical transmission have changed over time, however the number of new cases has remained fairly constant. In our setting, both early diagnosis and clinical management of these children have improved, but primary prevention for HIV vertical transmission has not been effective. Better counselling for HIV-infected women of childbearing age is needed.     

The utility of IgA antibody to human immunodeficiency virus type 1 in early diagnosis of vertically transmitted infection. National Institute of Allergy and Infectious Diseases and National Institute of Child Health and Human Development Women and Infants Transmission Study Group

OBJECTIVE: To determine the sensitivity and specificity of anti-human immunodeficiency virus (HIV) IgA in identifying infected infants at or before 6 months of age among the offspring of HIV-infected mothers. DESIGN: Prospective comparison of anti-HIV IgA measurement performed in 2 different laboratories by 2 different methods with the criterion standard of blood culture. SETTING: Five centers in the United States and Puerto Rico. PATIENTS: Population-based sample of 156 infants of HIV-infected mothers in the Women and Infants Transmission Study. MAIN OUTCOME MEASURES: Results of anti-HIV IgA test in relation to the infection status of the infants as measured by blood culture. RESULTS: Six-month plasma or serum samples were first tested in the 2 laboratories. The sensitivity and specificity of anti-HIV IgA in detecting infected infants at this age by laboratories 1 and 2 were 69% and 63% and 100% and 99%, respectively. A look-back study of samples obtained at birth, 1, 2, and 4 months was then performed on all infected children and a matched set of uninfected children. The performance of the test at birth was unsatisfactory in both laboratories (sensitivity 44% and 33%, specificity 43% and 60%), whether peripheral or cord blood was examined. At 1, 2, and 4 months, the sensitivity of the test was lower than at 6 months, but specificity was high. A modest correlation of absent anti-HIV IgA antibody and low percentage of CD4 cells in peripheral blood was seen at 6 months of age. CONCLUSIONS: The anti-HIV IgA test has moderate sensitivity and high specificity for the diagnosis of HIV infection at 6 months of age in the offspring of infected mothers.     

Human immunodeficiency virus infection among high-risk seronegative prostitutes in Nairobi

To determine the frequency and duration of antibody-negative human immunodeficiency virus (HIV) infection among heterosexually exposed African women, 56 HIV-seronegative female prostitutes in Nairobi were studied. Polymerase chain reaction (PCR) was used to detect HIV DNA in peripheral blood at enrollment, and women were followed prospectively with serologic testing to determine HIV seroincidence. Six women (11%) were infected with HIV by PCR criteria at enrollment. Seroconversion occurred in 5 of these subjects within 1-12 months, while the sixth remained seronegative when last evaluated at 5 months. The cumulative annual seroconversion rate in the entire cohort was 38%. Using maximum likelihood analysis, the mean interval between HIV infection and seroconversion was estimated to be between 3 and 4 months, similar to that described for homosexual men and blood product recipients in the United States. Prolonged HIV infection in the absence of antibodies appears to be uncommon in this setting.     

Neuromagnetic activity in the human left cerebral hemisphere concerning logical processing during auditory oddball stimulation

PURPOSE: Acanthamoeba is an uncommon cause of corneal infection in which the best visual outcome follows prompt diagnosis and a long course of appropriate antimicrobial therapy. Because conventional detection techniques for Acanthamoeba have certain limitations, we investigated the ability of the polymerase chain reaction (PCR) to confirm the clinical diagnosis of Acanthamoeba keratitis, with the ultimate aim of achieving early diagnosis. METHODS: Using two different pairs of primers, PCR was performed on representative cultured Acanthamoeba isolates to confirm the assay's ability to amplify Acanthamoeba DNA from a wide range of acanthamoebae. Subsequently, corneal epithelial samples from 19 patients and tear samples from 12 patients with Acanthamoeba keratitis were analyzed by PCR for the presence of Acanthamoeba DNA. RESULTS: Acanthamoeba DNA was amplified by PCR from 16 (84%) of 19 corneal epithelial samples, whereas Acanthamoeba was cultured from 10 samples (53%), all of which were PCR positive. Tear samples from 8 (66%) of 12 patients were positive on PCR testing, and one tear sample was PCR positive, whereas the corresponding epithelial biopsy had yielded a negative PCR result. Samples from culture-positive patients were positive on PCR testing more frequently than those from culture-negative patients (10/10 culture-positive corneal epithelial and 5/7 [71%] culture-positive initial tear samples versus 6/9 [66%] culture-negative corneal epithelial and 2/5 [40%] culture-negative tear samples). All control epithelial (n = 15) and tear (n = 15) samples yielded negative results. CONcLUSIONS: PCR was a more sensitive diagnostic test than a culture for Acanthamoeba keratitis, and the use of two different primers achieved better sensitivity than a single set. A PCR of a tear sample also may be a useful complementary test and, in combination with PCR of epithelial samples, would prove particularly helpful in confirming the clinical diagnosis in culture-negative cases.     

Age of entry to day nursery and allergy in later childhood

BACKGROUND: Infections in early childhood may prevent allergies in later life. If this hypothesis is true, early exposure to childcare outside the home would protect against atopy by promotion of cross infections. We investigated whether children who attend a nursery at a young age have a lower rate of atopy and fewer allergies than children who attend from an older age. METHODS: In a cross-sectional study carried out in 1992-93, we examined 2471 children in three age-groups (5-7, 8-10, and 11-14 years) from the towns of Bitterfeld, Hettstedt, and Zerbst in eastern Germany. The children's parents answered a questionnaire about allergies and symptoms, attendance at day care, and related factors. Sensitisation was assessed by skin-prick tests and measurement of allergen-specific IgE antibodies in serum. FINDINGS: In 669 children from small families (up to three people), the prevalence of atopy was higher among children who started to attend day nursery at an older age than in those who started to attend at a younger age (p<0.05). Compared with children who first attended at age 6-11 months, the adjusted odds ratios for a positive skin-prick test were 1.99 (95% CI 1.08-3.66) for children who attended at age 12-23 months and 2.72 (1.37-5.40) for those who attended at age 24 months and older. In 1761 children from large families (more than three people), age of entry to day nursery had no effect on atopy. INTERPRETATION: Our findings accord with the hypothesis that early infection may protect against allergies in later life.