Bridging the Gap: Conference Record [Abstract book, International Conference on AIDS (12th: 1998: Geneva, Switzerland)]

12th World AIDS Conference

Abstracts 22234-22238 309

sporadic in non-HIV patients. In HIV patients, risk factors were low CD4 cells,
diarrhea and male homo/bisexuality. An outbreak occurred from May 1995 to
November 1995, with attack rate reaching 0.9% per month in July-August. The
occurrence of microsporisiosis during the outbreak was significantly associated
with living in an area corresponding to 1 of the 3 water distribution systems of the
town. According to usual markers (turbidity, total coliform, fecal streptococcus),
no significant water contamination occurred during follow up, either during the
outbreak or outside the outbreak. No reason could explain the end of the outbreak,
which was ended several months before antiprotease era.
Conclusions: Intestinal microsporidiosis should not be restricted to HIVinfected patients but may represent a public health problem for all immunodepressed and immunocompetent patients. The link with water/feces transmission
stressed up for recommendations for the prevention of transmission, and for the
redefinition of safety criteria for water.
22234 Incidence and risk factors of toxoplasmosis in a French
cohort of HIV-infected patients between 1988 and 1995
Francois Belanger1, Francis Derouin2, L. Grangeot-Keros3, L. Meyer1. 11nserm
U292 H6pital De Bicetre, 82 Rue Du Gal Leclerc 94276 Kremlin Bicetre; 2H6pital
Saint Louis, Paris; 3H6pital Antoine Beclere, Clamart, France
Background: To study incidence and risk factors of toxoplasmosis, including the
prognostic value of high toxoplasma antiboby titres, in a cohort of HIV-infected
patients.
Methods: 1699 HIV+ subjects were followed in the French SEROCO/HEMOCO
cohorts between 1988 and 1995. Toxoplasma antibody titres were quantified at
each 6-month follow-up visit. A validation committee revised cases of toxoplasmosis (cerebral or extra-cerebral). Risk factors for toxoplasmosis were assessed
using a Cox model.
Results: 116 toxoplasmosis were diagnosed during follow-up, including 3 cases
in subjects whose serology was persistently negative. The incidence of toxoplasmosis increased from 0.7/100 persons-years (p-y) in 1988 to 2.1/100 p-y in 1992
due to the increasing number of patients below 200 CD4/il: incidence among
patients <200//pl was stable during 1988-1992. Incidence decreased thereafter to
0.2/100 p-y in 1995, while the proportion of patients on specific prophylaxis was
increasing. Risk factors for toxoplamosis included a high toxoplasma antibody
titre (>150 IU/ml), independently of a fall in CD4+ cells <200//il (time-dependent variables): adjusted RRs were respectively 3.6 [95% CI: 2.1-6.0]) and 21.1
[8.3-53.9], after taking into account the protective effect of specific prophylaxis
(aRR: 0.2 [0.1-0.3]). Median CD4+ counts at the time of the increase in antibodies
>150 IU/ml was 389//lI and the median delay until the occurrence of toxoplasmosis was 25 months (range 10 days to 74 months). The follow-up of patients
who were seronegative for T. gondii at enrolment (28%) showed an incidence of
seroconversion of 1.6/100 p-y. None of these seroconverters developed cerebral
or extra-cerebral toxoplasmosis.
Conclusion: The widespread use of specific prophylaxis probably explains the
dramatic decrease in toxoplasmosis incidence observed since 1992 in this large
cohort. A fall in CD4+ counts below 200//il remains an important predictor of
toxoplasmosis, the risk being increased when toxoplasma antibody titre is >150
IU/ml. This finding reinforces the need for these patients of prescription and good
compliance to specific prophylaxis.
22235 Determination of genotypes of enterocytozoon bieneusi
strains isolated from patients with intestinal
microsporidiosis
Olivier Liguory, F. David, F. Derovin, J.M. Molina. Hopital Saint-Louis, 1 Avenue
Claude Vellefaux, 75010 Paris, France
Objectives: To study genetic diversity among Enterocytozoon bieneusi strains
isolated from patients with intestinal microsporidiosis.
Methods: We developed a rapid and efficient approach for typing parasites
obtained from stool specimens using a PCR-restriction fragment length polymorphism (PCR-RFLP) method. Typing was based on DNA polymorphism of the
rDNA internal transcribed spacer (ITS) region of E. bieneusi. RFLPs generated
with two restriction enzymes (Nlalll and Fnu4HI) in PCR-amplified ITS products
were used to classify strains into different lineages of E. bieneusi.
Results: This approach was successfully used to differentiate 78 strains that
had been obtained from the stools of 65 patients with intestinal microsporidiosis.
Among the 78 strains, we found 4 genetically unrelated lineages, showing the
genetic diversity of E. bieneusi. Type I strains of E. bieneusi were found in a
majority of the samples, accounting for 51 (78%) of the 65 microsporidiosis cases.
In contrast, type II, III and IV strains were only found in 8 (12%), 3 (5%) and 3
(5%) cases, respectively
Conclusions: The results of this study show that it is possible to classify all
strains of E. bieneusi into 4 different lineages, and that human intestinal microsporidiosis is most often associated with type I strains. PCR-RFLP analysis of
the ITS region of E. bieneusi should be useful for epidemiological studies.

130*/22236 Falciparum malaria and its association with
immune status in a cohort of HIV-1 infected adults
in Entebbe, Uganda
Neil French1, E. Lugadda1, C. Watera1, J. Nakiyingi1, L. Carpenter1, C.F. Gilks2.
1Medical Research Council, PO. Box 49, Entebbe, Uganda, Uganda, 2Liverpool
School of Tropical Medicine, Liverpool, UK
Objective: To prospectively compare rates of malaria in a cohort of well characterised HIV-1 infected adults at different levels of immunosuppression.
Method: Study population; 1,213 members of a pneumococcal vaccine efficacy
trial enrolled between October 95 and November 97 in Entebbe, Uganda. Case
ascertainment; Febrile episodes (axillary temperature >37.5) are investigated
according to standard rigorous protocols. Malaria is defined by a clinically compatible febrile presentation, negative blood culture, parasite positive blood smear
with an appropriate response to anti-malarials. CD4 counts are measured at enrollment and six monthly, when participants are "well". End points; First episode of
falciparum malaria or any febrile event. Statistics; Participants contribute PYO's
from the time of their first visit up until first event, death, default or end of follow-up.
Results: The overall rate of malaria was 53/1000PYO (16% of all febrile events
investigated, 331/1000PYO), the most important single identifiable cause of fever.
breakdown by CD4 group, rates are per 1000PYO.

CD4 group
1-199
200-499
500+
x2 test for trend

Malaria
Events Rate (95%CI)

33
20
10
(df = 1)

73.5 (52-103)
50.6 (32-78)
31.7 (17-58)
5.93 p = 0.015

All febrile events
Events Rate (95% CI)
200 597.0 (520-686)
95 292.7 (239-358)
40 139.7 (102-190)
87.5 p - 0.001

Discussion: We have shown a significant trend towards increased rates of
Falciparum malaria with decreasing CD4 count. It is possible that the increasing
rate of malaria is reflecting the increased rate of fever and hence sampling and
co-incidental parasitaemia. Preliminary data shows a 6% asymptomatic parasitaemia rate irrespective of CD4 count. This finding will not wholly explain the
trend. Further work is required on the interaction of these two important diseases.
14*/22237 Sustained disappearance of human
cytomegalovirus (HCMV) in blood of AIDS patients
following HAART
Giuseppe Gernal, F. Baldanti1, A. D'Arminio Monforte2, M. Zavattoni1,
R. Maserati3, L. Testa2, G Gorini1. Servizio di Virologia IRCCS Policlinico, San
Matteo 27100 Pavia; 21st. Mal. Inffetive Univ. di Milano, Milano; 31st. Mal. Inffet.
IRCCS Policlin. S. Matteo, Italy
Objectives: To verify the presence of HCMV infections in HIV-infected patients
with a nadir of <100 CD4+ cells/l I following treatment with highly active antiretroviral therapy (HAART) consisting of two reverse transcriptase and one protease
inhibitor compared to baseline and archived control data.
Design: Two groups of patients were investigated in the absence of antiHCMV treatment: group A, consisting of 33 patients monitored every 3 months
for 12-24 months of HAART; and group B, consisting of 57 patients examined
cross-sectionally after 0-18 months of HAART.
Methods: Plasma HIV RNA, CD4+ cells as well as HCMV leukoDNAemia and
pp65-antigenemia were quantified. In parallel clinical controls were performed.
Results: In group A, 8/33 (24.2%) patients were positive for HCMV DNA
in blood at baseline, whereas after 6 months only 1/33 (3.0%), and at 9, 12
and 15-24 months 0/29, 0/23 and 0/9, respectively, were DNA-positive. Similar
results were obtained by determination of HCMV pp65 antigenemia. Median
CD4+ cell levels/lil increased from 18 (range 1-62) at baseline to 145 (range
11-437) after 6 months, 221 (range 70-478) after 12 months and 241 (range
136-461) after 15-24 months, while plasma median HIV RNA levels dropped
from 1.66 x 105 (range 6.74 x 103-7.73 x 106) copies/ml to undetectable levels.
In group B, similar trends were observed for CD4+ cells and plasma HIV RNA
as well as HCMV leukoDNAemia and pp65 antigenemia. In fact 9/23 (39.1%)
and 4/19 (21.0%) patients were DNA- and pp65 antigenemia-positive, respectively, after 0-3 months of HAART, while only 2/34 (5.9%) were DNA-positive and
1/22 (4.5%) pp65-positive after 3-6 months. 0/57 patients were HCMV-positive
after >6 months of treatment. In no patient a new HCMV syndrome or organ
involvement was observed folloving HAART initiation.
Conclusions: Compared to baseline and archived control data, HAART appears to drastically reduce till abolishing HCMV infections and diseases in HIVinfected patients. In parallel, plasma HIV RNA tends to reach undetectable levels
and CD4+ cells progressively increase in number. Such an effect appears to be
sustained, since no patient was found to be DNA-positive or affected by HCMV
disease after 9-24 months of HAART.
18*/22238 Lack of effect of long-term HAART on hepatitis C
(HCV) viremia
Olivier T. Rutschmann', B. Hirschel', F. Negro2, L.H. Perrin3. 1Division of
Infections Diseases, 2Division of Gastroenterology 3Laboratory of Virology.
University Hospital, Geneva, Switzerland
Background: HCV infection is common in HIV-infected patients. HAART has
been shown to increase temporarily HCV viremia. We explored the long-term
impact of HAART on HCV viremia.