Epidemiology of Taenia solium infection in the Russian Federation in the last 20 years: a systematic review.

Taenia solium is a zoonotic parasite that causes taeniasis and cysticercosis in humans (as final hosts) and cysticercosis in pigs (as intermediate hosts). The Russian Federation (RF) is traditionally considered as endemic for this zoonosis. However, the epidemiological data on T. solium infection have not been reviewed for the past 20 years, in which time dynamic economical and societal changes have occurred in the RF. The aim of this systematic review was to analyse the status of T. solium infection in RF in the 2000-2019 period. A literature search was conducted, which collected published articles, grey literature and official data on the epidemiology of T. solium taeniasis and cysticercosis in the RF published from 2000. From a total of 2021 articles and 24 official reports originally returned by the search, data were extracted from 12 full text articles and 11 official reports. Taenia solium taeniasis was continuously reported in the RF between 2000 and 2019, with a tenfold decrease in the incidence, from 0.2 per 100,000 population in 2000 to 0.023/100,000 in 2019. Also, the number of administrative units where taeniasis was detected continuously decreased. Cysticercosis in pigs had a declining trend after 2006. In conclusion, although decreasing, T. solium infection is still endemic in several regions and suspected to be endemic in most of the RF.

Factors associated with Toxoplasma gondii infection in confined farrow-to-finish pig herds in western France: an exploratory study in 60 herds.

BACKGROUND: Infection by Toxoplasma gondii postnatally can occur after ingestion of contaminated meat or water (tissue cysts/oocysts). In Europe, percentage of meat borne infections is estimated between 30 and 63 %, out of which pork makes the most important source. The aim of this study was to (i) investigate the seroprevalence of T. gondii in intensive pig farms from western France; and (ii) identify the risk factors associated with seropositivity. METHODS: Data were collected between November 2006 and February 2008 in 60 intensive farrow-to-finish farms, where sera were taken from 3595 fattening pigs, weaned and suckling piglets. Information about three classes of potential seropositivity risk factors were obtained through a questionnaire concerning: (i) breeding characteristics; (ii) farm management; and (iii) husbandry and hygiene. The modified agglutination test (MAT) was used for detection of specific anti T. gondii antibodies in pig sera, starting from 1/6 dilution. RESULTS: The overall proportion of seropositive animals was 6.9 %, but the proportion of herds with at least one positive pig was 100 %. Multivariate logistic mixed model showed an increased seropositivity risk in weaned compared to suckling piglets, and a decreasing risk for mid-sized and large farms. The presence of a Danish entry facility, that clearly separates clean and dirty areas, had a protective effect on T. gondii seropositivity as well. CONCLUSIONS: The observed proportion of herds with at least one T. gondii seropositive animal provides further evidence that even in confined conditions of pig breeding, infection occurs, and is common. The highest risk for acquiring T. gondii is at the end of weaning period. Smaller confined pig farms demonstrate higher T. gondii seropositivity levels. This study also showed that Danish entry on farm buildings provides effective protection against T. gondii.

Toxoplasma gondii infection in pork produced in France.

The aim of this study was to assess the seroprevalence of the Toxoplasma gondii parasite in pork produced in France, and to determine infection risk factors. An innovative survey was designed based on annual numbers of slaughtered pigs from intensive and outdoor farms in France. A total of 1549 samples of cardiac fluids were collected from pig hearts to determine seroprevalence using a Modified Agglutination Test. Of those, 160 hearts were bio-assayed in mice to isolate live parasites. The overall seroprevalence among fattening pigs was 2·9%. The adjusted seroprevalence in pigs from intensive farms was 3·0%; the highest in sows (13·4%); 2·9% in fattening pigs and 2·6% in piglets. Adjusted seroprevalence in fattening animals from outdoor farms was 6·3%. Strains were isolated from 41 animals and all were genotyped by Restriction Fragment Length Polymorphism as type II. Risk-factor analysis showed that the risk of infection was more than three times higher for outdoor pigs, and that sows' risk was almost five times higher than that of fattening animals. This study provides further evidence of extensive pork infection with T. gondii regardless of breeding systems, indicating that farm conditions are still insufficient to guarantee 'Toxoplasma-free pork'.

Pork as a source of human parasitic infection.

Foodborne zoonoses have been estimated to annually affect 10% of the global population, among which zoonotic parasites constitute an important class of aetiological agents. The major meatborne parasites include the protozoa Toxoplasma gondii and Sarcocystis spp., and the helminths Trichinella spp. and Taenia spp., all of which may be transmitted by pork. The significance of zoonotic parasites transmitted by pork consumption is emphasized by the prediction by the Food and Agriculture Organization of an 18.5% increase in world pork production over the next 10 years. Of all the porkborne parasites, the three 'T' parasites have been responsible for most porkborne illness throughout history; they are still endemic, and therefore are important public-health concerns, in developing countries. Although the risk of porkborne parasites, particularly helminths, may currently be considered insignificant in developed countries, the modern trend of consuming raw meat favours their re-emergence. This paper overviews the main parasites transmitted to humans by pork, and outlines the main lines of prevention.

Clinical pattern of ocular toxoplasmosis treated in a referral centre in Serbia.

PURPOSE: To analyze the clinical pattern of ocular toxoplasmosis (OT) in a referral centre in Serbia. PATIENTS AND METHODS: The medical records of consecutive patients admitted for OT to the single referral centre for uveitis in Serbia between 2006 and 2010 were retrospectively analyzed. OT was diagnosed on the basis of typical fundus lesions and positive serology for Toxoplasma. RESULTS: In a total of 457 uveitis patients, OT was the third leading cause, with 59 patients (12.9%). Most OT cases (73%) were monocular. An active primary retinal lesion was observed in 36% and recurrent OT in 64% patients. Localization of lesions was central/paracentral (44%), juxtapapillar (27%), peripheral (19%), and multifocal (10%). Other ocular manifestations of inflammation included vitritis (44%), anterior uveitis (19%), and retinal vasculitis (10%). Complications included choroidal neovascularization in two and exudative retinal detachment with cataract, glaucoma, and cystoid macular oedema in one patient each. The detection of Toxoplasma-specific IgM antibodies in a single patient indicates a low rate of OT concomitant with acute infection. After treatment, the mean best-corrected visual acuity (BCVA) increased significantly. However, 14 (24%) patients ended up legally blind in the affected eye, of which 2 (3%) with bilateral blindness, all with a very poor BCVA (0.047 ± 0.055) at presentation. Visual impairment and treatment outcome were both associated with central localization of lesions (P<0.0001 and P=0.006, respectively). CONCLUSION: OT is a significant cause of posterior uveitis in Serbia. Patients should be aware of the recurring nature of OT and react immediately if symptoms occur.

Human giardiasis in Serbia: asymptomatic vs symptomatic infection.

Despite the public health importance of giardiasis in all of Europe, reliable data on the incidence and prevalence in Western Balkan Countries (Serbia, Bosnia and Herzegovina, Croatia, Montenegro and FYR Macedonia) are scarce, and the relative contribution of waterborne and food-borne, or person-to-person and/or animal-to-person, transmission of human giardiasis is not yet clear. To provide baseline data for the estimation of the public health risk caused by Giardia, we here review the information available on the epidemiological characteristics of asymptomatic and symptomatic human infection in Serbia. Although asymptomatic cases of Giardia represent a major proportion of the total cases of infection, high rates of Giardia infection were found in both asymptomatic and symptomatic populations. No waterborne outbreaks of giardiasis have been reported, and it thus seems that giardiasis mostly occurs sporadically in our milieu. Under such circumstances, control measures to reduce the high prevalence of giardiasis in Serbia have focused on person-to-person transmission, encouraging proper hygiene, but for more targeted intervention measures, studies to identify other risk factors for asymptomatic and symptomatic infections are needed.

Risk factors for Toxoplasma infection in pregnant women in FYR of Macedonia.

The aim of the study was to identify risk factors for Toxoplasma gondii infection in pregnant women in FYR of Macedonia. Retrospective analysis of serological and epidemiological data in a series of 235 pregnant women from Macedonia, tested for Toxoplasma infection between January 2004 and December 2005, showed an overall prevalence of infection of 20.4%. Exposure to transmission factors significantly increased the risk of infection (RR = 1.989, 95 % CI = 1.041-3.800, p = 0.037). The single infection transmission factor that was a predictor of infection in the whole series was exposure to soil (RR = 1.946, 95% CI = 1.026-3.692, p = 0.041). Based on prevalence and the established risk factors for Toxoplasma infection in Macedonia, the health education programme as a sustainable measure for the prevention of congenital toxoplasmosis should focus on educating women of generative age to avoid contact with soil (farming, gardening), and/to adhere to strict hygienic practices afterwards.

Toxoplasmosis in Serbia: time for an action plan.

Known for a century, Toxoplasma gondii has been studied in Serbia half this time, ever since the introduction of the Sabin-Feldman test at the Institute for Medical Research (IMR) in 1959. However, despite 50 years of continuous efforts, exact data on the frequency of acute clinical disease, acute infections in pregnancy and congenital infection in the offspring are still lacking, due to the vague regulatory provision that toxoplasmosis is subject to reporting "in case of epidemiological indications". It is, however, clear that the major Toxoplasma-induced public health issue in Serbia, like elsewhere in Europe, is congenital toxoplasmosis (CT). Continuous monitoring of particular patient groups showed a dramatic decrease in the prevalence of infection over the past two decades, and a consequently increased proportion of women susceptible to infection in pregnancy, suggesting a potential increase in the incidence of CT. Studies of risk factors for infection transmission have provided data to guide national health education campaigns. It is expected that the recent appointment of the National Reference Laboratory for Toxoplasmosis as the focal point for the collection of data from the primary level, will provide the means for accurate assessment of the measure of the problem, which is a prerequisite of an evidence-based nation-wide prevention program. In the meantime, health education of all pregnant women, focused at risk factors of major local significance, is advocated as a sound and financially sustainable option to reduce congenital toxoplasmosis.

Seasonality of trichinellosis in patients hospitalized in Belgrade, Serbia.

A retrospective study of the course and outcome of trichinellosis in a series of 50 patients hospitalized at the Institute for Infectious and Tropical Diseases in Belgrade between 2001 and 2008 was performed. Clinical diagnosis of trichinellosis was based upon the patients' clinical history, symptoms and signs, and eosinophilia. The occurrence of cases showed a strong seasonality (P < 0.0001). The incubation period ranged between one and 33 days. The mean time between onset of symptoms and admission was nine days. Family outbreaks were the most frequent. Smoked pork products were the dominant source of infection (76%). Fever was the most frequent clinical manifestation (90%), followed by myalgia (80%) and periorbital edema (76%). 43 patients were examined serologically and 72% of them had anti-Trichinella antibodies. Eosinophilia and elevated levels of serum CK and LDH were detected in 94, 50 and 56% of the patients, respectively. All patients responded favorably to treatment with mebendazole or albendazole, but eight developed transient complications. Trichinellosis remains a major public health issue in Serbia.

The prognosis of patients with dissociated virological and immunological responses to HAART.

BACKGROUND: While HAART allows for the reconstitution of immune functions in most treated HIV patients, failure to achieve a significant increase in circulating CD4+ T cells despite undetectable viremia occurs. METHODS: A retrospective study was conducted to evaluate the treatment outcome in a subgroup of 232 patients who after 3.1 years of treatment had not achieved desirable immune reconstitution despite a good virological response to HAART. RESULTS: After a further 3.6 ± 2.4 years of HAART, 82 (35.3%) patients achieved immune reconstitution (565.2 ± 174.6 CD4 cells/µl), while 149 (64.2%) patients did not (268.8 ± 91.1 cells/µl); the difference in the achieved CD4 counts between these subgroups was significant (P<0.01). One patient experienced treatment failure. Eleven patients died to the end of follow-up, of which 10 with a continuously dissociated response. Factors associated with immune recovery included clinical AIDS at HAART initiation (OR: 0.4, 95% CI: 0.24-0.81, P<0.01), usage of PIs and of drugs from all three classes (OR: 1.7, 95% CI: 1.0-3.0, P=0.046 and OR: 4.5, 95% CI: 1.15-18.19, P=0.03, respectively), and a rise in CD4 count to over 200 cells/µl after the first 3.1 years of treatment (OR: 5.3 95% CI: 2.6-11.0, P<0.01). Achievement of a rise in CD4 count to over 200 cells/µl after the first 3.1 years of treatment was an independent predictor of immune reconstitution in the following period. CONCLUSION: If patients on HAART reach CD4 cell counts of above 200 cells/µl in the first 3 years, immune recovery is possible after at least 6 years of treatment.

The metabolic syndrome, an epidemic among HIV-infected patients on HAART.

BACKGROUND: HAART has dramatically changed the prognosis of AIDS, but has led to long-term toxicities of antiretroviral drugs. A major chronic complication is the metabolic syndrome (MS), including hyperlipidemia, lipodystrophy (LD), and impaired glucose metabolism. METHODS: A cross-sectional study of a series of 582 patients from the Serbian HIV/AIDS cohort, treated with HAART for a mean period of 3.3+/-2.1 years (range 1-10), was performed to evaluate the prevalence and risk factors for MS during HAART. RESULTS: The prevalence of LD was 29.1%, with a 100% probability of development after 10 years of treatment. Risk factors for LD included female gender (OR 1.7, 95% CI 1.0-2.7, P=0.02), age>40 (OR 1.7, 95% CI 1.1-2.7, P=0.01) and AIDS at HAART initiation (OR 1.9, 95% CI 1.2-2.2, P<0.01), as well as prolonged usage of NRTIs (OR 2.7, 95% CI 1.6-4.5, P<0.01). The NNRTI-based regimens were less likely to induce LD than those PI-based (OR 1.87, 95% CI 1.2-2.9 vs. OR 3.7, 95% CI 2.3-6.1, respectively). Hyperlipidemia occurred in 47% of the patients, and was associated with male gender (OR 2.2, 95% CI 1.4-3.5, P<0.01) and prolonged usage of PI+NNRTI HAART (OR 3.0, 95% CI 1.8-4.9, P<0.01). In contrast, regimens composed of 2 NRTI+NNRTI were less likely to induce hyperlipidemia (OR 0.4, 95% CI 0.3-0.7, P=0.03). Glucose intolerance and/or diabetes mellitus was recorded in 9.6%, if with AIDS at HAART initiation (OR 3.7, 95% CI 1.2-11.4, P<0.01), male gender (OR 5.2, 95% CI 1.8-15.1, P<0.01) and age>40 (OR 2.6, 95% CI 1.1-6.3, P=0.02). CONCLUSION: MS seems an inevitable consequence of long-term successful HAART.

Serum beta2-microglobulin as a marker of congenital toxoplasmosis and cytomegalovirus infection in preterm neonates.

BACKGROUND: Fetal serum beta(2)-microglobulin (beta(2)M) has been reported as a reliable indicator of fetal infectious diseases. OBJECTIVES: To evaluate serum beta(2)M as a marker of congenital toxoplasmosis or cytomegalovirus (CMV) infection in neonates. METHODS: beta(2)M was retrospectively measured in 72 neonatal serum samples from preterm neonates. Of these, 32 originated from neonates with serological evidence of congenital toxoplasmosis (n = 12) and CMV infection (n = 20), while 40 samples from neonates in which both infections were serologically excluded served as controls. beta(2)M levels were compared between the infection and control groups. RESULTS: Mean (+/-SEM) beta(2)M levels were significantly higher in the groups of neonates infected with Toxoplasma (5.64 +/- 0.61 mg/l) (p = 0.014) and CMV (6.06 +/- 0.66 mg/l) (p < 0.0001) than in the control group (3.80 +/- 0.2). Against the cut-off level of 5 mg/l, beta(2)M was normal in 36 of the 40 uninfected neonates examined, indicating a specificity of 90%. In contrast, it was elevated in 66.7% (8/12) and 65% (13/20) of the Toxoplasma and CMV-infected neonates, respectively, indicating an overall sensitivity of 66%. CONCLUSIONS: In the absence of urogenital disorders, an increase in beta(2)M in neonates is likely to be infection-induced. We showed that serum beta(2)M is increased in congenital toxoplasmosis and CMV infection in the first weeks of life.

The prognosis of CMV retinitis among patients with AIDS in Serbia.

BACKGROUND: Cytomegalovirus (CMV) end-organ diseases, including CMV retinitis, are major opportunistic events in terminal AIDS patients. METHODS: A retrospective study of 30 AIDS patients with CMV retinitis treated between 1997 and 2007 in Serbia was conducted to examine the prognosis and factors associated with survival. RESULTS: Eighteen (60%) patients survived the mean follow-up period of 46.4+/-36 months. Patients' sex, mode of HIV transmission or previous AIDS diagnosis did not affect survival. Bilateral CMV retinitis predicted dissemination of CMV disease and poor prognosis (OR 7.8, 95% CI 1.3-47.0, P=0.012), but was not associated with blindness (P=0.33). Among patients treated with HAART and CMV therapy the probability of surviving 10 years was 70%, while in those on CMV therapy alone, the median survival was 10 months (log rank P=0.00). However, HAART itself was not sufficient to prevent blindness and the major predictor of blindness was a baseline CD4 cell count of less than 50/microL (OR 6.8, 95% CI 1.1-41.8, P=0.03). After CMV disease, most patients suffered other opportunistic events regardless of HAART introduction. CONCLUSION: Even in the HAART era patients with advanced immunodeficiency and CMV retinitis may not escape from the high risk mortality group, while survivors commonly lose sight.

The prevalence and risk of hepatitis flares in a Serbian cohort of HIV and HCV co-infected patients treated with HAART.

Despite substantial benefits of HAART treatment of HIV-infected patients, cumulative long-term toxicity, including drug-induced hepatotoxicity, has emerged as an important complication. Thus, to examine the prevalence and risk of developing severe hepatic injury during HAART, we conducted a retrospective study in a cohort of 364 HIV-infected patients treated with HAART between January 1998 and May 2006, for whom data on alanine aminotransferase activity were available both before and during HAART. HCV co-infection was recorded in 35.4% of the series, but was found not to influence either the efficacy of HAART or survival (P>0.05). Severe hepatotoxicity occurred in a total of 24 patients (6.6%). Multivariate logistic regression defined HCV co-infection (OR 16.6, 95% CI 3.8-46.0, P<0.0001), and the use of SQV/RTV and d4T (OR 3.1, 95% CI 1.2-8.16, P=0.02, and OR 7.1, 95% CI 1.0-54.5, P=0.05, respectively) as independent risk factors for aggravation of hepatitis. In addition, there was a significant increase in the probability of developing liver damage over years of treatment (Log rank, P<0.01). Conversely, the probability of developing hepatotoxicity was not associated with an increase in the CD4 cell count to values greater than 350/microL (Log rank, P=0.59). In conclusion, in the setting of chronic viral hepatitis, hepatotoxicity during HAART may be attributed to the cumulative toxicity of drugs that induce mitochondrial toxicity, along with particular PIs and/or NNRTIs. Furthermore, our data suggest prudent use of D-drugs, still common in resource-limited countries, in HCV co-infected patients.

Comparison of a commercial ELISA with the modified agglutination test for the detection of Toxoplasma gondii infection in naturally exposed sheep.

Surprisingly few commercial ELISAs are available for the detection of Toxoplasma gondii infection in animals, and none for use in sheep have been evaluated. We thus compared the Bommeli Diagnostics ELISA Toxotest for the detection of T. gondii antibodies in ruminants with the reference modified agglutination test (MAT) in a series of 180 sheep sera. ELISA results were analysed at two cut-off levels (30%, comprising both weakly positive and positive results, and 100%, comprising only positive results), and compared with MAT at three cut-off levels (titre of 1 : 25, 1 : 50 and 1 : 100). The results showed a moderate agreement of ELISA at both cut-offs (kappa = 0.46 and 0.51) with MAT at a cut-off titre of 1 : 100. However, the specificity and positive predictive value were above 95% only at an ELISA cut-off of 100%, indicating its potential as a diagnostic test, particularly in areas with a high prevalence of infection. On the other hand, lower sensitivity and negative predictive value limit its value as a screening test. Thus, the ELISA Toxotest may be used for quick diagnosis of T. gondii infection in sheep in the field, i.e. for the differential diagnosis of ovine abortion storms.

Long-term survival of HIV-infected patients treated with highly active antiretroviral therapy in Serbia and Montenegro.

BACKGROUND: Highly active antiretroviral therapy (HAART) has dramatically changed the prognosis of HIV disease, even in terminally ill patients. Although these patients may survive many years after the diagnosis of AIDS if treated with HAART, some still die during treatment. METHODS: A retrospective study in a cohort of 481 HIV-infected patients treated with HAART between January 1998 and December 2005 was conducted to compare subgroups of long-term survivors (LTSs) and patients who died during treatment. RESULTS: A total of 48 patients survived for more than 72 months (mean 83.8+/-standard deviation 5.6 months). Thirty patients died during treatment (mean 35.3+/-25.0 months), of whom nine died from non-AIDS-related causes, 18 died from AIDS-related causes, and three died as a result of HAART toxicity. Although LTSs were significantly (P=0.015) younger at HAART initiation, age below 40 years was not a predictor of long-term survival. The subgroups did not differ in the proportion of clinical AIDS cases at HAART initiation, in the prevalence of hepatitic C virus (HCV) coinfection, or in pretreatment and end-of-follow-up CD4 cell counts. In contrast, the viral load achieved during treatment was lower in the survivors (P=0.03), as was the prevalence of hepatitis B virus (HBV) coinfection (P=0.03). Usage of either protease inhibitor (PI)-containing regimens [odds ratio (OR) 9.0, 95% confidence interval (CI) 2.2-35.98, P<0.001] or all three drug classes simultaneously (OR 7.4, 95% CI 2.2-25.1, P<0.001) was associated with long-term survival. Drug holidays incorporated in structured treatment interruption (STI) were also associated with a good prognosis (OR 14.9, 95% CI 2.9-75.6, P<0.001). CONCLUSIONS: Long-term survival was associated with PI-based HAART regimens and lower viraemia, but not with the immunological status either at baseline or at the end of follow up. STI when CD4 counts reach 350 cells/microL, along with undetectable viraemia, was a strong predictor of long-term survival.

Undercooked meat consumption remains the major risk factor for Toxoplasma infection in Serbia.

Toxoplasma gondii infection prevalence and infection risk factors were analyzed in a series of 765 women of generative age from throughout Serbia tested at the Institute for Medical Research Toxoplasmosis Laboratory between 2001 and 2005. The infection risk factors were additionally analyzed in a group of 53 women with acute infection (cases) compared to a group of seronegative women matched for age and education level (controls). The overall prevalence of infection was 33%. Infection risk factors in the whole series were undercooked meat consumption (RR = 1.77, 95% CI = 1.16-2.7, P = 0.008) and exposure to soil (RR = 1.63, 95% CI = 1.17-2.29, P = 0.004), particularly in less educated women. Moreover, undercooked meat consumption was the single predictor of infection in women with acute infection, with an 11-fold increased risk of infection in women who acknowledged consumption of undercooked meat (RR = 11.21, 95% CI = 3.10-40.53, P = 0.000). These data prompted us to analyze the significance of consumption of particular meat types as sources of infection. Of all the meat types mostly consumed in Serbia, only consumption of beef (RR = 1.006, 95% CI = 1.001-1.011, P = 0.027) was shown to influence Toxoplasma infection rates.

The dissociation between virological and immunological responses to HAART.

While HAART allows for the reconstitution of immune functions in most treated HIV patients, discrepant responses including failure to achieve a significant increase in circulating CD4+ T cells despite undetectable plasma viral loads (pVL), or a good immunological response while not reaching undetectable viremia, may occur. Thus, to evaluate the incidence of and risk factors for discrepant responses to HAART, we conducted a retrospective study of all 446 patients treated with HAART between 1 January 1998 and 31 August 2004 in our HIV unit. CD4+ T cell counts and pVL values at baseline and end of study were parameters of the type of response. Within a mean follow-up period of 33 months, discrepant immunological and virological responses occurred in even 50% patients. Of these, 174 (39%) did not have a rise in CD4+ T cells to above 400 per microl despite a good virological response (type 1 dissociation), while 49 (11.0%) had a rise in the CD4+ T cell count to at least 200 per microl but their pVL was not undetectable (type 2 dissociation). The risk factors for immunological failure despite an undetectable pVL were baseline CD4+ T cells below 100 per microl (OR 1.44, 95%CI 1.02-2.03) and HAART composed of three NRTIs (OR 1.92, 95%CI 1.35-2.73), while usage of two NRTIs in combination with PI(s) (OR 0.36, 95%CI 0.26-0.49), as well as simultaneous usage of all three drug classes (OR 0.37, 95%CI 0.26-0.53) were shown to be protective. The usage of PI-containing HAART regimens was protective against type 2 dissociation (OR=0.40, 95%CI 0.19-0.83). Importantly, there were no differences in the survival of HAART-treated patients irrespective of the type of response.

The prevalence and risk of immune restoration disease in HIV-infected patients treated with highly active antiretroviral therapy.

BACKGROUND: It is becoming increasingly clear that, during successful highly active antiretroviral therapy (HAART), a proportion of treated patients develop opportunistic infections (OIs), referred to in this setting as immune restoration disease (IRD). We examined the risk of developing IRD in HAART-treated HIV-infected patients. METHODS: A retrospective study of a cohort including all 389 patients treated with HAART between 1 January 1998 and 31 May 2004 in our HIV unit was performed to evaluate the occurrence of and risk factors for IRD during HAART. Baseline and follow-up values of CD4 T-cell counts and plasma viral loads (pVLs) were compared to assess the success of HAART. RESULTS: During successful HAART (significant increase in CD4 T-cell counts and decrease in pVL), at least one IRD episode occurred in 65 patients (16.7%). The median time to IRD was 4.6 months (range 2-12 months). IRDs included dermatomal herpes zoster (26 patients), pulmonary tuberculosis (four patients), tuberculous exudative pericarditis (two patients), tuberculous lymphadenitis (two patients), cerebral toxoplasmosis (one patient), progressive multifocal leucoencephalopathy (PML) (one patient), inflamed molluscum (one patient), inflamed Candida albicans angular cheilitis (three patients), genital herpes simplex (two patients), tinea corporis (two patients), cytomegalovirus (CMV) retinitis (two patients), CMV vitritis (one patient) and hepatitis B (three patients) or C (fifteen patients). A baseline CD4 T-cell count below 100 cells/microL was shown to be the single predictor [odds ratio (OR) 2.5, 95% confidence interval (CI) 0.9-6.4] of IRD, while a CD4 T-cell count increase to >400 cells/microL, but not undetectable pVL, was a negative predictor of IRD (OR 0.3, 95% CI 0.1-0.8). CONCLUSIONS: To avoid IRD in advanced patients, HAART should be initiated before the CD4 T-cell count falls below 100 cells/microL.