[Malaria attacks after returning from endemic areas. Failure or inadequate chemoprophylaxis?]

OBJECTIVE

Determine the causes of malaria attacks in subjects who have returned from endemic areas by assessing prescriptions for chemical prophylaxis and compliance.

PATIENTS AND METHODS

All patients who developed a paroxysmal episode of malaria diagnosed at the University of Nice hospital in 1995 answered specific questions concerning their anti-malaria prophylaxis.

RESULTS

Thirty-three patients were hospitalized for paroxysmal episodes of malaria in 1995. In 32 cases (97%) the attack resulted from either the lack of any prophylaxis (17 cases, 52%), inadequate prescription (11 cases, 12%) or poor compliance (4 cases, 12%). The prescribed chemical prophylaxis was not adapted to the chloroquinone-resistant area in 8 cases (24%) and medical recommendations concerning administration rules were inadequate in 3 cases (9%). Only one patient developed a paroxysmal episode despite correct compliance to a chloroquine-resistant zone-adapted well-conducted prescription. The cost of poor prophylaxis in terms of human suffering and financial cost was high for this preventable disease. Four patients had to be hospitalized in the intensive care unit and one died during hospitalization. The cumulative cost of hospitalization for these 33 cases was evaluated at 660,000 FF.

CONCLUSION

Preventive measures for malaria must include better information for physicians on changing recommendations for chemical prophylaxis as well as better information for travelers provided by all those involved in organizing travel to endemic areas.

Pneumococcal resistance patterns in Europe

The emergence of Streptococcus pneumoniae strains with decreased susceptibility to penicillin has been reported worldwide over the past 20 years. However, there are striking discrepancies in penicillin susceptibility among various European countries, suggesting that local conditions may affect clonal propagation or de novo selection of resistant strains. In the present study, data on penicillin resistance patterns, antibiotic use and mode of administration, and treatment compliance in five European countries (France, Spain, Germany, Italy, and the UK) were compared. High prevalence rates of penicillin-resistant pneumococci have been reported in Spain and France, where antibiotics are widely prescribed, and overall in Europe, patient compliance with more than 50% of oral antimicrobial prescriptions is inadequate. The low prevalence of penicillin resistance in Germany and the UK coincides with lower antibiotic consumption and better treatment compliance in these countries. Recent attempts to raise public awareness and to restrict and improve indications for antimicrobial agents have resulted in decreased pneumococcal resistance in Hungary and Iceland, suggesting that pneumococcal resistance can be reversed.

[Community-acquired and nosocomial septicemias in patients with human immunodeficiency virus infection]

OBJECTIVES

Study the characteristics of community and nosocomial-acquired bacteremia in HIV-infected patients in order to improve curative, and if possible, preventive therapy.

METHODS

We analyzed retrospectively 47 cases of community-acquired and 31 cases of nosocomial bacteremia identified in 63 of 436 patients hospitalized between January 1992 and December 1993 with HIV infection (53 men, 10 women, mean age 34.3 years, stage A: 1, stage B: 20, stage C: 42). The portal was identified for 68 episodes (40 in the community acquired and 28 in the nosocomial groups). The main portal was pulmonary infection (42.5% vs 17.8%; p = 0.03) and digestive tract infection due to Streptococcus pneumoniae (70%) and Salmonella spp (60%). Nosocomial bacteremia following intravenous infusions included Staphylococcus epidermidis (oxacillin-resistant in 57%) and Staphylococcus (oxacillin-sensitive) infections. Bacteremia was the immediate cause of death in 18% of the deaths occurring in the 436 patients hospitalized during the study period.

CONCLUSION

These findings confirm the gravity of community-acquired and nosocomial bacteremia in advanced stage HIV-infected patients. Antibiotics should be adapted on the basis of probability of the infectious agent obtained from epidemiologic data and the effectiveness of prophylaxis measures validated.

Blood pressure and arterial lactate level are early indicators of short-term survival in human septic shock

OBJECTIVE

To identify early prognostic markers of septic shock among catheterization-derived hemodynamic and metabolic data.

DESIGN

Prospective cohort study.

SETTING

A medical intensive care unit in a university hospital.

PATIENTS

Thirty-two consecutive patients with septic shock, separated into two groups according to short-term (10-day) evolution: 18 acute survivors and 14 fatalities.

MEASUREMENTS

Usual hemodynamic and metabolic variables were measured at the onset of shock, i.e., when the catheter was inserted (T0), and 24 h later (T24). The values collected for each group at T0 and T24 and their 24-h changes were compared.

RESULTS

On admission, no difference was found between acute survivors and eventual fatalities. After 24 h, fatalities presented with significantly lower mean arterial pressure (p <0.01), left ventricular stroke work index (p <0.05) and higher lactate levels (p <0.01) than acute survivors. Moreover, the 24-h changes of lactate and blood pressure were also of prognostic value (p <0.05). Oxygen delivery and oxygen consumption did not differ statistically between the two groups. At T24, a mean arterial pressure of less than 85 mmHg and a lactate level equal to or greater than 3.5 mmol/l were independently associated with poor survival (37.5% and 30.7%, respectively). Day 10 survival was only 12.5% when both criteria were present at T24.

CONCLUSIONS

Changes in mean arterial pressure and arterial blood lactate within the first 24 h of treatment are strong prognostic indicators of short-term survival in patients with septic shock. After 24 h of treatment, maintenance of a mean blood pressure equal to or greater than 85 mmHg correlates with survival at day 10. Data suggest that early reductions in both cardiac function and vascular tone play a determining role in the hypotension observed in fatalities. Persistence of hyperlactatemia in hypotensive patients bodes particularly ill. Blood pressure and lactate level are simple bedside parameters that can enable the clinician to identify patients with a high risk of mortality.

In-vitro development of resistance to beta-lactam antibiotics in Streptococcus pneumoniae

Selection of resistant mutants was induced in broth by exposing pneumococci to serial sub-inhibitory concentrations of various beta-lactam antibiotics. Aminopenicillins selected for resistance to themselves and to cephalosporins although cephalosporins tended to select for resistance to their own class, with the exception of cefixime which seems to select cross-resistant organisms.

[Persistent diarrhea in HIV infected patients: role of Enterocytozoon bieneusi]

OBJECTIVES

To determine the epidemiologic, clinical and aetiologic features of chronic diarrhoea in patients with human immunodeficiency virus (HIV) infection.

METHODS

Between January 1992 and April 1993, all HIV positive patients with chronic diarrhoea were enrolled in a prospective study. There were 46 patients in the study group including 33 (22 homosexuals) in stage C according to the 1993 Centers for Disease Control classification.

RESULTS

Thirty-four pathogenic agents were isolated in 26 of the patients (57%). Enterocytozoon bieneusi was the most frequently found pathogen (11 patients, 24%) followed by Cryptosporidium sp (8 patients). Enterocytozoon bieneusi was found in association with other pathogens in 7 patients. All patients with microsporidiosis were in stage C (p = 0.04) and had a longer duration of diarrhoea (19.6 vs 9.8 weeks, p = 0.03), greater weight loss (9.6 vs 2.1 kg, p = 0.0003) and a lower Karnofsky index (48% vs 67%, p = 0.01). Prophylaxy with dapsone or pyrimethamine during the 3 months prior to inclusion had been more frequent (p = 0.04 and p = 0.05 respectively) in patients without microsporidiosis.

CONCLUSION

Microsporidiosis should be suspected as a probable cause of chronic diarrhoea in HIV positive patients with a CD4 count < 100/mm3. Multiple infections may be a factor leading to treatment failure. Microsporidiosis seems to be linked to homosexual intercourse.

Possible prevention of in vitro selection of resistant Streptococcus pneumoniae by beta-lactamase inhibitors

The development of resistance in vitro in five strains of Streptococcus pneumoniae (3 with full susceptibility and 2 with intermediate susceptibility to penicillin) was investigated by serial passages in the presence of subinhibitory concentrations of amoxicillin and ampicillin. At the end of passaging, MICs of antibiotics for all the strains increased by a factor of four or more, reaching at least intermediate levels. MICs of cephalosporins, ampicillin and amoxicillin increased for almost all variants obtained. Similar results were obtained with amoxicillin plus clavulanic acid at a ratio of 2:1 and at a constant concentration of 2 micrograms/ml, and with ampicillin plus sulbactam at a ratio 2:1. In contrast, no significant modification of MIC was seen with ampicillin plus sulbactam at a constant concentration of 4 micrograms/ml sulbactam. These results suggest interaction of sulbactam with penicillin binding proteins as described previously for other bacterial species, and merit further investigation.

[Mechanisms of lymphopenia in HIV infection]

Blood counts of CD4 cells remain the best prognostic factor in patients infected with human immunodeficiency virus (HIV). However, the small number of infected cells contrasts with the importance of lymphocyte depletion. Several mechanisms might explain this depletion including: antibody-dependent cytotoxicity. Twenty to 50% of the antibodies produced in vitro by B lymphocytes are directed against HIV antigens, especially the gp120 and gp41 viral envelope antigen. If this cytotoxicity effect occurs in vivo, it could reduce of lymphocytes carrying the viral genome and partially explain the major lymphopenia in HIV-infected patients. It is not yet known whether the long-term effect of these antibodies is immunoprotective or deleterious, but they may play a protective role at least in the initial stages of the disease. autoimmunity. Sequence homology between the HLA II molecules and the glycoproteins of the viral envelope has been clinically and biologically documented in many manifestations of HIV infection. It has been suggested that alloreactivity, similar to the graft-versus-host reaction could be involved. In addition, programmed cell-death of the CD4 lymphocytes appears to be overactivated in HIV-positive subjects, possibly because the gp120 viral antigen perturbs the CD4-dependent signal for cell death. deleterious effects of cytokines. Tumour necrosis factor, for example, is known to play a role in the regulation of viral replication; it may favour the destruction of contaminated cells but also the initiation of provirus replication and integration into the cell genome. supra-antigens and/or infectious factors. Supra-antigenes, which can link with HLA molecules, are capable of oligoclonal activation without being "processed" in the cell presenting the antigen. This activation might affect cell death. Certain germ toxins could also play a role as cofactors. Cohort studies of asymptomatic HIV patients are needed to improve our understanding of these mechanisms. A therapeutic approach tailored to the stage reached by HIV-infected subjects will then be possible.

HIV prenatal screening in south-eastern France: differences in seroprevalence and screening policies by pregnancy outcome

Two complementary surveys were carried out in the 89 hospital units of South-Eastern France which deal with pregnant women. Firstly, in November 1991, medical chiefs of these units were interviewed face-to-face about their current HIV screening policy. Secondly, between Jan 27 and March 22, 1992, all women at the end of their pregnancy attending these units were included in an anonymous unlinked seroprevalence survey, irrespective of pregnancy outcome (n = 11,056). The goal of the research was to compare HIV prenatal screening policies and seroprevalences by pregnancy outcomes in order to contribute to the public debate initiated on that issue by the French health authorities. The seroprevalence survey showed a global prevalence rate of 0.43% (CI 95% = 0.32-0.54) with the prevalence among women who had an elective abortion (0.56%) being more than twice that among women who delivered (0.22%). However, routine HIV screening was more frequent toward women coming for regular prenatal care than for women seeking abortion. A systematic procedure for obtaining women's consent for HIV testing only existed in a minority of units. Only 23 out of the 62 units offering both antenatal and termination services to women had the same screening policy for women attending the different services. The research confirmed that a mandatory requirement would not improve HIV screening policy during prenatal care. However, less emphasis on women who have opted for termination of pregnancy, an absence of appropriate counselling and information procedures, and pressures on HIV-infected women to terminate current pregnancies and discourage future ones strongly suggest that HIV prenatal screening in French hospitals remains mainly focussed on fetal concerns, without sufficient attention towards the needs of women at risk of HIV infection.

[HIV infection. Risky behavior in drug addicts using intravenous drugs. Experience in the Alpes-Maritimes region]

HIV risk behaviours among intravenous drug users (IVDUs) were studied in southeast France, where the prevalence of HIV infection is high. Data were collected from a self-reported questionnaire distributed to drug addicts admitted in the health care or social institutions of the Alpes Maritimes department during November 1991. Among the 195 IVDUs who answered the questionnaire, 142 (73 percent) were male and 53 (27 percent) were female. One hundred and seventeen (62 percent) were HIV positive, 21 (11 percent) had an unknown HIV status, and 51 (27 percent) where HIV negative. Significant differences in HIV risk behaviours were found between HIV negative, unknown HIV status and HIV positive IDVUs: 37 percent of unknown status and 47 percent of HIV negative IVDUs continued to lend their syringe, compared with less than 20 percent HIV positive IVDUs (P < 0.001). Conversely, 57 percent of unknown HIV status and 39 percent of HIV negative IVDUs borrowed used syringes in the previous 6 months, compared with 73 percent of HIV positive IVDUs (p < 0.001). Regarding sexual prevention behaviours of patients who had had sexual intercourse during the previous 6 months: less than 20 percent of HIV negative IVDUs used condoms regularly, as against 47 percent of HIV positive IVDUs (P < 0.001). More than 70 percent of HIV negative versus 46 percent of HIV positive reported sexual intercourse without condom (p < 0.001). Logistic regression showed that the systematic use of condom was associated with a reduction of needle sharing, which suggests that IVDUs who use condoms have the best perception of risk. But the only factor associated with an increase in condom use is a HIV positive serology. These results indicate that in southeast France more efforts should be devoted to specific programmes aimed at increasing the use of condoms in the IVDU population.

High prevalence of thyroid autoantibodies in a prospective series of patients with chronic hepatitis C before interferon therapy

After describing two cases of Hashimoto's thyroiditis associated with chronic hepatitis C, we set up a prospective study to assess the prevalence of thyroid autoantibodies (thyroglobulin and thyroid microsomal autoantibodies) in 72 chronic hepatitis C patients (43 men and 29 women; mean age = 51 +/- 2.1 yr) before interferon therapy admitted between January and December 1991 to our liver unit. Thyroid autoantibodies were systematically assayed in 60 chronic HBsAg-positive patients (34 men and 26 women; mean age = 50 +/- 2.2 yr), who served as controls. Antibody to hepatitis C virus was detected with a second-generation enzyme immunoassay and then confirmed with a recombinant immunoblot assay and a supplemental enzyme immunoassay using two beads. In chronic hepatitis C patients, no men had thyroid autoantibodies. Nine of 29 women (31%) had thyroid autoantibodies. Among them, six (20.7%) had high titers of thyroid autoantibodies, and two had hypothyroidism. In all nine of these women, hepatitis C virus viremia was detected on nested polymerase chain reaction (with primers located in the 5' untranslated region). One year later, titers of thyroid autoantibodies had increased in one patient. Three other patients progressed to hypothyroidism. We judged four of 29 patients (13.8%) to have Hashimoto's thyroiditis on the basis of their high titers of thyroid autoantibodies and biological features of hypothyroidism. In the control group, only one man had thyroid microsome autoantibodies, at a very low titer (1:100). The association between chronic hepatitis C and presence of thyroid autoantibodies is clearly confirmed (p = 0.021) by this study.

Effects of subinhibitory concentrations of vancomycin and teicoplanin on adherence of staphylococci to tissue culture plates

Bacterial adhesion is the first step in infection of medical devices. Staphylococcus aureus and Staphylococcus epidermidis are the pathogens recovered most often. The effects of subinhibitory concentrations of vancomycin and teicoplanin on the adherence of eight clinical strains of S. aureus and eight strains of S. epidermidis to tissue culture plates in vitro were tested. The mean relative inhibitions of adherence at one-fourth and one-eighth the MIC were statistically different for teicoplanin and vancomycin. Slime production seemed not to be involved in adherence.

[Non-typhoid salmonellosis in HIV infection]

Non-typhoid Salmonella infections associated with HIV infection are 20 times more frequent than those observed in the general population. Drug addicts and homosexuals are equally infected. Concerning physiopathology, a deficit in gastric acid secretion has been blamed as an etiological factor, together with T-cell deficit, except for reduction in the number of CD4 cells. This type of infection usually presents as fever; diarrhea is noted in only 20% of the cases. Several viscera can be involved. The best treatment seems to be fluoroquinones administered during 3 weeks, and several months in case of relapse. Patients under AZT therapy are less often affected with salmonellosis due to the antibiotic activity of this anti-retrovirus agent.