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Biomedical subjects

D M Thea

Publications and source records attributed to D M Thea.

28 records · Page 2Linked to original sources
PubMed1996

Benefit of primary prophylaxis before 18 months of age in reducing the incidence of Pneumocystis carinii pneumonia and early death in a cohort of 112 human immunodeficiency virus-infected infants. New York City Perinatal HIV Transmission Collaborative Study Group.

OBJECTIVE: To determine the effectiveness of primary prophylaxis in preventing Pneumocystis carinii pneumonia (PCP) in children with perinatally acquired human immunodeficiency virus 1 (HIV-1) infection. METHODS: We conducted a retrospective analysis of a cohort of infants followed from birth at six metropolitan hospitals and one outpatient clinic for pregnant, drug-using women in New York City. Outcomes measured were histologically confirmed PCP and/or death. The potential confounding effect of the infant's stage of illness, as determined by CD4 count, was controlled by including all CD4 determinations as time-dependant covariates in a Cox proportional hazards analysis. Cases were censored at PCP onset, death, loss to follow-up, and 18 months of age. RESULTS: One hundred twelve HIV-infected children were enrolled at birth between 1986 and 1993. Sixty of these were tracked beyond 18 months of age; of the others, 21 died before this age, 4 were considered lost to follow-up, and 27 had not reached 18 months of age at the last visit. Only 3 cases (4%) of confirmed PCP occurred among the 70 children who received primary PCP prophylaxis before 18 months of age, compared with 12 cases (28%) among 42 children not receiving PCP prophylaxis at any point before 18 months of age. The Kaplan-Meier estimated incidence of PCP in the first year among children not receiving prophylaxis was 25% (95% confidence interval [CI], 12 to 39). Using Cox methods, the unadjusted risk of PCP among infants not receiving prophylaxis, relative to those receiving it, was 4.1 (95% CI, 1.1 to 15); the relative risk was 4.4 (95% CI, 1.2 to 17) adjusting for the percentage of CD4-positive lymphocytes and 5.1 (95% CI, 1.3 to 20) adjusting for the absolute number of CD4-positive cells. Eight of 26 deaths were caused by PCP, and the likelihood of early death was significantly diminished if PCP prophylaxis was given (relative risk controlling for absolute CD4 cells, 2.57; 95% CI, 1.1 to 6.1). CONCLUSIONS: We report evidence that primary antimicrobial PCP prophylaxis is highly effective in decreasing the frequency of PCP and early death in infants with perinatal HIV infection. These findings support the revised National Pediatric HIV Resource Center and Centers for Disease Control and Prevention guidelines for PCP prophylaxis in children.

AIDS-Related Opportunistic Infections↗
PubMed1995

Efficacy of antenatal zidovudine in reducing perinatal transmission of human immunodeficiency virus type 1. The New York City Perinatal HIV Transmission Collaborative Study Group.

New York City women (321) enrolled during 1986-1993 in an observational cohort study were analyzed retrospectively to determine the effectiveness of antenatal zidovudine in reducing perinatal transmission of human immunodeficiency virus type 1 (HIV-1) in women with various CD4+ lymphocyte counts (< 200, 200-499, > 499/microL). When CD4+ lymphocyte level was controlled for, women prescribed zidovudine during pregnancy were less likely to transmit HIV-1 to their infants (adjusted odds ratio, 0.36; 95% confidence interval, 0.14-0.92). There was no conclusive evidence that efficacy of zidovudine depended on CD4+ lymphocyte level, suggesting that women with severe CD4+ cell depression, who are at highest risk of transmitting HIV-1, may also benefit from zidovudine. Antenatal zidovudine treatment alone may substantially lower the risk of perinatal HIV-1 transmission. These data are consistent with the results of AIDS Clinical Trial Group protocol 076 and suggest that a substantial portion of zidovudine's protective effect may occur when used during the antenatal period.

CD4-CD8 Ratio↗
PubMed1995

Neonatal predictors of infection status and early death among 332 infants at risk of HIV-1 infection monitored prospectively from birth. New York City Perinatal HIV Transmission Collaborative Study Group.

BACKGROUND AND METHODS: Differences in newborn outcome measures for human immunodeficiency virus (HIV)-1-infected and HIV-1-exposed but uninfected infants have been found in several studies, but not in others. Eighty-four infected and 248 uninfected children born to HIV-1-seropositive mothers followed prospectively in a multicenter, perinatal HIV-1 transmission cohort study were compared for differences in maternal demographics, health status, and newborn outcome measures, including delivery complications, physical examination findings, neonatal complications, and laboratory results. RESULTS: Mothers of HIV-1-infected infants were more likely than those of uninfected infants to have acquired immunodeficiency syndrome (AIDS) diagnosed through 2 weeks postpartum (21% vs 11%, P = .04); the transmission rate for the 38 women with AIDs was 37% compared with 22% for the 245 women without AIDS. Two of 27 (7%) women receiving zidovudine during pregnancy had infected infants compared with 73 (27%) of 275 women who did not receive zidovudine (P = .033). Mean gestational age was significantly lower among HIV-1-infected (37 weeks) than among uninfected infants (38 weeks; P < .001). Infected infants had significantly higher rates of prematurity (gestational age less than 37 weeks) (33% vs 19%, P = .01) and extreme prematurity (gestational age less than 34 weeks) (18% vs 6%, P = .001) than uninfected infants. Infection was associated with lower birth weight (2533 g vs 2862 g, P < .001) and smaller head circumference (32.0 cm vs 33.1 cm, P = .001). HIV-1-infected infants were significantly more likely to be small for gestational age (26% vs 16%, P = .04) and low birth weight (less than 2500 g) (45% vs 29%, P = .006) than infants who were uninfected. Twenty-two (26%) HIV-1-infected children died during a median follow-up of 27.6 months (range 1.9 to 98.3 months). Prematurity was predictive of survival: by Kaplan-Meier, an estimated 55% (95% confidence interval, 31% to 72%) of preterm infected children survived to 24 months compared with 84% (95% confidence interval, 70% to 92%) of full-term infected children (P = .005). CONCLUSION: Infants born to women with AIDS are at higher risk for HIV-1 infection than are infants born to HIV-1-infected women with AIDS not yet diagnosed. Women receiving zidovudine appear less likely to transmit HIV-1 to their infants. Significantly higher rates of prematurity and intrauterine growth retardation were found among HIV-1-infected infants than among those in the uninfected, HIV-1-exposed control group. Prematurity was associated with shortened survival in HIV-1-infected infants. Measures of intrauterine growth and gestation appear to be important predictors of HIV-1 infection status for seropositive infants and of prognosis for the infected infant.

Acquired Immunodeficiency Syndrome↗
PubMed1993

A prospective study of diarrhea and HIV-1 infection among 429 Zairian infants.

BACKGROUND: Persistent diarrhea is a prominent feature of the acquired immunodeficiency syndrome in adults, but its cause and its effect on children with human immunodeficiency virus (HIV) infection are largely unknown, particularly in Africa. METHODS: We studied a birth cohort of 429 infants born to HIV-positive or HIV-negative mothers in Zaire to determine the incidence of acute, recurrent (> or = 2 episodes), and persistent (> or = 14 days) diarrhea; outcome; and risk factors. RESULTS: Of the 238 infants whose mothers were HIV-positive, 53 were infected, 139 were uninfected, and the HIV status of 46 could not be determined. As compared with uninfected infants, infected infants had higher incidence rates for acute diarrhea (170 vs. 100 episodes per 100 child-years, P = 0.003), recurrent diarrhea (21 vs. 11, P = 0.12), and persistent diarrhea (19 vs. 4, P < 0.003). Persistent diarrhea developed in 11 HIV-infected infants; all but 1 died. It also developed in 19 uninfected infants; all but 1 survived. The prevalence of stool pathogens was similar in the two groups. In a multivariate model, persistent diarrhea in an infant was independently associated with symptomatic HIV type 1 infection in the mother (relative hazard, 1.5; P = 0.08). The incidence of persistent diarrhea in the uninfected infants of seropositive mothers was nearly double that in the uninfected infants of seronegative mothers (4.9 vs. 2.7 episodes per 100 child-years), and the risk increased if the mother died (relative hazard, 10.4). Significant growth impairment and severe immunosuppression occurred in the six to eight weeks before the onset of persistent diarrhea. CONCLUSIONS: In Zaire, infants with HIV infection have an 11-fold increased risk of death from diarrhea, largely persistent diarrhea, which is often preceded by recurrent episodes of acute diarrhea, malnutrition, or immunosuppression. Illness and death of the mother increase that risk, even among her uninfected infants.

Acute Disease↗
PubMed1993

Malnutrition in AIDS.

Malnutrition, weight loss, and chronic diarrhea are common findings in patients infected with human immunodeficiency virus (HIV), and many traditional and nontraditional dietary approaches have been suggested. This article examines the mechanisms and pathophysiology of wasting in HIV, and the evidence for malnutrition of protein, energy, and micronutrients in patients with the acquired immunodeficiency syndrome (AIDS). The article concludes with a review of dietary therapy in AIDS patients.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Persistent diarrhea associated with AIDS.

Chronic diarrhea and wasting are very common manifestations of AIDS in adults in developing countries. Etiologic studies show that protozoa (including Cryptosporidium parvum, Isospora belli, and Enterocytozoon bieniusi) and Mycobacterium avium-intracellulara are the most frequently identified pathogens. Limited data in children suggest that common enteric pathogens are equally as likely in HIV+ and HIV- babies. Preliminary analysis of an ongoing longitudinal study of 469 babies born to mothers with known HIV serostatus in Kinshasa, Zaire, reveals progression of acute to persistent diarrhea is six times greater in HIV+ compared to HIV- babies, and 3.5 times greater in HIV- babies born of HIV+ mothers in comparison to HIV- babies with HIV- mothers. HIV+ babies were also at greater risk than HIV- babies to have recurrent episodes of diarrhea (RR = 2.3). Fifty percent of the deaths were due to acute or persistent diarrhea, and were strongly associated with HIV infection. Efforts to improve child survival in AIDS infected populations will need to address HIV infections in both mothers and infants.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Identification and partial purification of a lectin on the surface of the sporozoite of Cryptosporidium parvum.

A human-derived isolate of Cryptosporidium parvum from a symptomatic patient with the acquired immunodeficiency syndrome was expanded in vivo by infecting a neonatal calf with 10(8) oocysts. Sporozoites were isolated from 4 x 10(10) oocysts harvested from this single infection, and the characteristics of mixed hemagglutination (HA) with rabbit erythrocytes were determined. Sporozoite HA was inhibited by bovine submaxillary mucin (BSM), hog gastric mucin, and orosomucoid, but not by simple sugars, including sialic acid. Carbohydrate-inhibitable HA (lectin) activity increased with sporozoite lysis and was associated with the sporozoite membrane fractions. The ability of intact sporozoites to form rosettes around erythrocytes indicates that the HA (lectin) is, at least in part, present on the parasite surface. Hemagglutination (lectin) activity was partially purified from sporozoite lysates by affinity chromatography with BSM coupled to Sepharose-4B. Best elution was obtained with ethylene glycol and NaCl, which resulted in enrichment of 6 bands compared to the crude starting lysate (Mr = 60, 24, 22, 20, and 15 kDa and a 40-kDa doublet). Our results indicate that an HA (lectin) activity is present on the surface of intact sporozoites where it could play a role in cell-to-cell interactions with eukaryotic targets.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Prevalence of enteric viruses among hospital patients with AIDS in Kinshasa, Zaire.

Diarrhoea is the most common manifestation of acquired immunodeficiency syndrome (AIDS) in Africa. Numerous parasitic or bacterial agents have been implicated, but a pathogen-specific aetiology has not been found. Enteric viruses (i.e., rotavirus, small round structured viruses, coronavirus, and adenovirus) were detected by enzyme-linked immunosorbent assay or electron microscopy in faecal specimens of 17% of 198 consecutive adult admissions to a general medical ward of an urban hospital in Kinshasa, Zaire. Overall, 57% of patients were seropositive for infection with human immunodeficiency virus (HIV) 1; of these, 50% were classified as World Health Organization AIDS stage IV. The prevalence of enteric viruses in stool specimens did not differ significantly between patients with and without HIV infection, and was not associated with acute or chronic diarrhoea, or constitutional symptoms. However, a trend (P = 0.14) towards greater frequency of virus in stools from patients in the lower 3 quintiles of the CD4/CD8 T cell ratio was seen. This trend approached statistical significance (P = 0.07) with stratification by HIV infection. Although we found no evidence in this population to support a major pathogenic role for these viruses alone in the enteropathy of AIDS, increased viral shedding was weakly associated with immunodeficiency.

Acquired Immunodeficiency Syndrome↗