HIV patients dying on anti-tuberculosis treatment: are undiagnosed infections still a problem in French Guiana?

OBJECTIVE: Despite scaling-up testing and antiretroviral treatment in Latin America, advanced HIV remains a significant public health problem. The objective of the present study was look for historical risk factors for death in French Guiana's HIV cohort taking into account the immunological status, the main opportunistic infections, and their treatment. A retrospective cohort study was conducted on data collected between 1992 and 2008 to identify factors associated with death in a cohort 2323 patients. RESULTS: There were 370 deaths for a total 9608 patient-years. Being on tuberculosis treatment was associated with a greater hazard of death. The diagnosis of confirmed tuberculosis, of histoplasmosis, of toxoplasmosis, and pneumocystosis were independently associated with death. Interactions terms between cotrimoxazole treatment and pneumocystosis, or between confirmed tuberculosis and tuberculosis treatment showed a protective treatment-effect. All patients having received anti-tuberculosis treatment (n = 347) did not have a final diagnosis of tuberculosis (n = 93). For histoplasmosis, 199 patients received antifungal treatment while 141 were diagnosed as having histoplasmosis. The number of patients on anti-tuberculosis drugs was far greater that the number of patients with confirmed tuberculosis, and these patients on treatment without confirmed tuberculosis had a twofold greater risk of dying.

Clinical Features, Diagnosis, and Outcome of Encephalitis in French Guiana.

The aim of our study was to describe the clinical features, the etiologies, and the factors associated with poor outcome of encephalitis in French Guiana. Our study was retrospective, including all cases of encephalitis hospitalized in the Cayenne General Hospital, from January 2007 to July 2017. Patients were included through the 2013 encephalitis consortium criteria and the outcome was evaluated using the Glasgow outcome scale at 3 months from the diagnosis of encephalitis. We included 108 patients, giving an approximate incidence rate of four cases/100,000 inhabitants/year. The origin of the encephalitis was diagnosed in 81 cases (75%), and 72 of them (66.7%) were from an infectious origin. The most common infectious causes were Cryptococcus sp. (18.5%) independently of the immune status, Toxoplasma gondii (13.9%), and Streptococcus pneumoniae (5.5%). In the follow-up, 48 patients (46.6%) had poor outcome. Independent risk factors associated with poor outcome at 3 months were "coming from inside area of the region" (P = 0.036, odds ratio [OR] = 4.19; CI 95% = 1.09-16.06), need for mechanical ventilation (P = 0.002, OR = 5.92; CI 95% = 1.95-17.95), and age ≥ 65 years (P = 0.049, OR = 3.99; CI 95% = 1.01-15.89). The most identified cause of encephalitis in French Guiana was Cryptococcus. The shape of the local epidemiology highlights the original infectious situation with some local specific pathogens.

Human impact on the diversity and virulence of the ubiquitous zoonotic parasite Toxoplasma gondii.

A majority of emerging infectious diseases in humans are zoonoses. Understanding factors that influence the emergence and transmission of zoonoses is pivotal for their prevention and control. Toxoplasma gondii is one of the most widespread zoonotic pathogens known today. Whereas only a few genotypes of T. gondii dominate in the Northern Hemisphere, many genotypes coexist in South America. Furthermore, T. gondii strains from South America are more likely to be virulent than those from the Northern Hemisphere. However, it is not clear what factor(s) shaped modern-day genetic diversity and virulence of T. gondii Here, our analysis suggests that the rise and expansion of farming in the past 11,000 years established the domestic cat/mouse transmission cycle for T. gondii, which has undoubtedly played a significant role in the selection of certain linages of T. gondii Our mathematical simulations showed that within the domestic transmission cycle, intermediately mouse-virulent T. gondii genotypes have an adaptive advantage and eventually become dominant due to a balance between lower host mortality and the ability to superinfect mice previously infected with a less virulent T. gondii strain. Our analysis of the global type II lineage of T. gondii suggests its Old World origin but recent expansion in North America, which is likely the consequence of global human migration and trading. These results have significant implications concerning transmission and evolution of zoonotic pathogens in the rapidly expanding anthropized environment demanded by rapid growth of the human population and intensive international trading at present and in the future.

Inflammatory early events associated to the role of P2X7 receptor in acute murine toxoplasmosis.

Activation of the purinergic P2X7 receptor by extracellular ATP (eATP) potentiates proinflammatory responses during infections by intracellular pathogens. Extracellular ATP triggers an antimicrobial response in macrophages infected with Toxoplasma gondii in vitro, suggesting that purinergic signaling may stimulate host defense mechanisms against toxoplasmosis. Here, we provide in vivo evidence in support of this hypothesis, by showing that P2X7-/- mice are more susceptible than P2X7+/+ mice to acute infection by the RH strain of T. gondii, and that this phenomenon is associated with a deficient proinflammatory response. Four days post-infection, peritoneal washes from infected P2X7-/- mice had no or little increase in the levels of the proinflammatory cytokines IL-12, IL-1ß, IFN-γ, and TNF-α, whose levels increased markedly in samples from infected P2X7+/+ mice. Infected P2X7-/- mice displayed an increase in organ weight and histological alterations in some of the 'shock organs' in toxoplasmosis - the liver, spleen and mesenteric lymph nodes. The liver of infected P2X7-/- mice had smaller granulomas, but increased parasite load/granuloma. Our results confirm that the P2X7 receptor is involved in containing T. gondii spread in vivo, by stimulating inflammation.

Genotyping of Toxoplasma gondii: DNA extraction from formalin-fixed paraffin-embedded autopsy tissues from AIDS patients who died by severe disseminated toxoplasmosis.

This study investigated the genetic features of Toxoplasma gondii isolated directly in autopsies of HIV-infected patients who died with severe disseminated toxoplasmosis. This retrospective analysis was conducted in a cohort of 15 HIV-infected patients with clinical and laboratory data. They had previous cerebral toxoplasmosis at least 6 months before the disseminated toxoplasmosis episode. The hypothesis was that they were infected with highly virulent parasites due to the condition in which they died. T. gondii genotyping was done directly in DNA extracted from 30 autopsy brain and lung samples (2 per patient) and mutilocus PCR-RFLP genotyping was done using 12 molecular markers. The 30 clinical samples were genotyped successfully in 8 or more loci and six suggestive genotypes were identified. One of them was Toxo DB #11, previously identified in different domestic animals and virulent in experimental animals. The other five suggestive genotypes identified in 14 patients were not described. TgHuDis1 was the most frequent and was determined in 8 patients. TgHuDis3 and TgHuDis5 were identified in two patients each. TgHuDis2 and TgHuDis4 have been identified in one patient each. These suggestive genotypes could be considered as virulent, since they caused severe tissue damage and had similar characteristics as Toxo # DB 11.

Depletion of CD25⁺ cells during acute toxoplasmosis does not significantly increase mortality in Swiss OF1 mice.

The interleukin (IL)-2R alpha chain (CD25) is expressed on regulatory T cells (Treg), which constitute more than 85% of the CD25+ T cell population in a naïve mouse. CD25 is also expressed on effector T cells in mice suffering from an acute infection by the obligate intracellular protozoan parasite, Toxoplasma gondii. Lethal toxoplasmosis is accompanied by a significant loss of Treg in mice naturally susceptible to toxoplasmosis. The present study was done to explore the role of Treg cells using an anti-CD25 antibody-mediated depletion in mice naturally resistant to toxoplasmosis. Although a significant decrease in the percentage of Treg cells was observed following anti-CD25 monoclonal antibody injections, the depletion of CD25+ cells during acute toxoplasmosis did not significantly increase the mortality of Swiss OF1 mice and no significant difference was observed in the brain parasitic load between the mice in the depleted-infected and isotype-infected groups. We found no significant difference between the titres of total IgG in the sera of the mice from the two groups in the chronic phase. However, CD25+ cells depletion was followed by significantly higher levels of IL-12 in the serum of depleted mice than in that of mice injected with the isotype control antibody.

Depletion of CD25+ cells during acute toxoplasmosis does not significantly increase mortality in Swiss OF1 mice

The interleukin (IL)-2R alpha chain (CD25) is expressed on regulatory T cells (Treg), which constitute more than 85 percent of the CD25+ T cell population in a naïve mouse. CD25 is also expressed on effector T cells in mice suffering from an acute infection by the obligate intracellular protozoan parasite, Toxoplasma gondii. Lethal toxoplasmosis is accompanied by a significant loss of Treg in mice naturally susceptible to toxoplasmosis. The present study was done to explore the role of Treg cells using an anti-CD25 antibody-mediated depletion in mice naturally resistant to toxoplasmosis. Although a significant decrease in the percentage of Treg cells was observed following anti-CD25 monoclonal antibody injections, the depletion of CD25+ cells during acute toxoplasmosis did not significantly increase the mortality of Swiss OF1 mice and no significant difference was observed in the brain parasitic load between the mice in the depleted-infected and isotype-infected groups. We found no significant difference between the titres of total IgG in the sera of the mice from the two groups in the chronic phase. However, CD25+ cells depletion was followed by significantly higher levels of IL-12 in the serum of depleted mice than in that of mice injected with the isotype control antibody.

Acute toxoplasmoses in immunocompetent patients hospitalized in an intensive care unit in French Guiana.

Atypical Toxoplasma gondii strains, unrelated to archetypal clonal lineages (I, II, III), have been reported more frequently over the last decade in areas other than Europe and North America. A newly described form of toxoplasmosis, 'Amazonian toxoplasmosis' (AT), has been reported since 2002 in French Guiana. It is characterized by severe cases and atypical strains linked to a neotropical forest-based cycle. We report on the cases of AT that required intensive care management. We performed a prospective observational study on hospitalized adults in the Intensive Care Unit (ICU) from 2002 to 2008. Clinical and laboratory data, microbiological findings and outcomes were recorded. Data, including the ICU simplified acute physiology score and the pneumonia severity index, were calculated. Epidemiological risk factors for AT were assessed through questionnaires. Eleven non-immunodeficient patients were admitted to the ICU in Cayenne for life-threatening pneumonia associated with disseminated toxoplasmosis. Mechanical ventilation was necessary in seven patients, four of whom required immediate orotracheal intubation. Cardiac and ophthalmological abnormalities were found in five and four patients, respectively. One patient died from multiple organ failure. The genetic characterization of Toxoplasma DNA using six microsatellite markers revealed unique and atypical genotypes in eight patients. All patients presented epidemiological risk factors for AT. In French Guiana, significant T. gondii-related infectious syndrome associated with the lungs, a high level of LDH activity and the reported risk factors for AT was strongly suggestive of disseminated toxoplasmosis with a possible trend toward life-threatening pneumonia.

Effects of synbiotic-based Bifidobacterium animalis in female rats experimentally infected with Toxoplasma gondii.

The aim of this study was to assess the effects of a synbiotic composed of Bifidobacterium animalis and fructooligosaccharides on female rats infected with Toxoplasma gondii. Female Wistar rats, treated or not with dexamethasone, were daily supplemented with synbiotics for 21 days. After 15 days of supplementation, the rats were orally infected with 10(4)T. gondii bradyzoites. Blood samples were collected to measure the levels of IFN-γ, IL-10 and T. gondii antibodies. All synbiotic-supplemented rats survived until the end of the experiment; however, non-supplemented dexamethasone-treated rats died between the fifth and the eighth days after T. gondii infection. Dexamethasone-treated rats supplemented with synbiotics (P<0.05) were capable of synthesizing IFN-γ, and this immunological response was essential to ensure their survival. In addition, brain cysts were found in one rat not supplemented with synbiotics. Results suggest that the synbiotic composed of B. animalis and fructooligosaccharides may be beneficial to toxoplasmosis control.

Diagnosis of disseminated toxoplasmosis by polymerase chain reaction in bronchoalveolar lavage fluid of a patient with aids / Diagnóstico de toxoplasmose disseminada através de técnica de reação em cadeia da polimerase realizada no lavado bronco-alveolar de paciente com sida

Pulmonary toxoplasmosis is a challenging diagnosis in immunosuppressed patients with nonspecific clinical picture and radiologic findings. We present a case of pneumonia due to Toxoplasma gondii diagnosed by polymerase chain reaction (PCR) in the bronchoalveolar lavage (BAL) fluid of a patient with acquired immunodeficiency syndrome (AIDS). Coinfection with Pneumocystis jirovecii was found in the same specimen. Direct examination and culture for bacteria, mycobacteria and other fungus were negative. Despite the intensive management, respiratory compromise evolved rapidly, with the need for ventilatory support. Acute respiratory distress syndrome developed, and the patient died of multiple organ failure. This case illustrates that a high index of suspicion is necessary for diagnosis of pulmonary toxoplasmosis, a potentially fatal condition. Due to high diagnostic performance, PCR in BAL fluid should be included in the evaluation of immunosuppressed patients with nonspecific pulmonary diseases.

O diagnóstico de toxoplasmose pulmonar em pacientes imunossuprimidos é difícil, devido ao quadro clínico e aos achados radiológicos inespecíficos. Neste artigo, relatamos o caso de uma paciente com síndrome da imunodeficiência adquirida (SIDA), que apresentou pneumonia por Toxoplasma gondii diagnosticada através de reação em cadeia da polimerase (PCR) no lavado bronco-alveolar (LBA). A paciente apresentava co-infecção com Pneumocystis jirovecii. Os demais exames microbiológicos, como bacterioscópico, cultural para bactérias, micobactérias e fungos, foram negativos. Apesar do manejo intensivo, a paciente evoluiu com síndrome do desconforto respiratório agudo e óbito por falência múltipla dos órgãos. Este caso demonstra que um alto índice de suspeita clínica é necessário para o diagnóstico de pneumonia por Toxoplasma gondii. Devido ao seu desempenho diagnóstico, o PCR para Toxoplasma gondii no LBA deve ser incluído na avaliação de pacientes imunossuprimidos com quadros pulmonares inespecíficos.

BALB/c mice resistant to Toxoplasma gondii infection proved to be highly susceptible when previously infected with Myocoptes musculinus fur mites.

The immune response induced by Toxoplasma gondii is characterized by Th1 immune mechanisms. We previously demonstrated that C57BL/6 mice infested with Myocoptes musculinus and infected with T. gondii by intraperitoneal route undergo accelerated mortality according to Th2 immune mechanisms induced by the acarian. To evaluate whether infection with M. musculinus influences T. gondii-induced Th1 response in a resistant mouse lineage, BALB/c, which develops latent chronic toxoplasmosis in a way similar to that observed in immunocompetent humans, this study was done. The animals were infected with T. gondii ME-49 strain 1 month after M. musculinus infestation, being the survival and the immune response monitored. The double-infected displayed higher mortality rate if compared with the mono-infected mice. In addition, infection with M. musculinus changed the T. gondii-specific immune response, converting BALB/c host to a susceptible phenotype. Spleen cells had increased the levels of IL-4 in double-infected mice. This alteration was associated with severe pneumonia, encephalitis and wasting condition. In addition, a higher tissue parasitism was observed in double-infected animals. It can be concluded that infection with these two contrasting parasites, M. musculinus and T. gondii, may convert an immunocompetent host into a susceptible one, and such a host will develop severe toxoplasmosis.

Fatal outbreak of human toxoplasmosis along the Maroni River: epidemiological, clinical, and parasitological aspects.

BACKGROUND: Well-documented outbreaks of human toxoplasmosis infection are infrequently reported. Here, we describe a community outbreak of multivisceral toxoplasmosis that occurred in Patam, a Surinamese village near the French Guianan border. METHODS: From the end of December 2003 through the middle of January 2004, 5 adult patients in Patam, including 2 pregnant women, were initially hospitalized for multivisceral toxoplasmosis. A French-Surinamese epidemiological investigation was conducted in the village; inquiries and clinical examinations were performed, and blood and environmental samples were obtained. For all serologically confirmed cases of toxoplasmosis, molecular analysis and mouse inoculations were performed for diagnosis and genetic characterization of Toxoplasma gondii. RESULTS: The hospitalized patients, who did not have any immunodeficiencies, presented with an infectious disease with multivisceral involvement. Serological examination confirmed acute toxoplasmosis. One adult died, and a neonate and a fetus with congenital toxoplasmosis also died. During the investigation, 4 additional acute cases of toxoplasmosis were diagnosed among the 33 villagers. Only 3 inhabitants had serological evidence of previous T. gondii infection. In total, we reported 11 cases of toxoplasmosis: 8 multivisceral cases in immunocompetent adults, resulting in 1 death; 2 cases of lethal congenital toxoplasmosis in a neonate and a fetus; and 1 symptomatic case in a child. Molecular analysis demonstrated that identical isolates of only 1 atypical strain were responsible for at least 5 of the 11 cases of toxoplasmosis in the outbreak. No epidemiological sources could be linked to this severe community-wide outbreak of toxoplasmosis. CONCLUSION: This report is in agreement with the particular features of toxoplasmosis involving atypical strains that were recently described in French Guiana.

Infectivity of cysts of the ME-49 Toxoplasma gondii strain in bovine milk and homemade cheese.

OBJECTIVE: Analyze the infectivity and storage resistance of cysts of the ME-49 strain of Toxoplasma gondii in artificially infected bovine milk and homemade fresh cheese. METHODS: Pasteurized bovine milk was infected with 10 cysts/ml of the ME-49 strain of T.gondii and inoculated in different groups of mice, immediately or after storage at 4 degrees C for 5, 10 and 20 days. Homemade fresh cheese was prepared with artificially infected milk, and also tested in groups of mice, using the same storage process. Infection was identified by the presence of cysts in the brain or serological testing in challenged mice after 5 weeks, confirmed by Western Blot and histology. RESULTS: The infectivity of cysts of the ME-49 strain of T.gondii was maintained in the milk even after storage for 20 days at refrigerator temperatures. Cysts were also able to survive the production process of homemade fresh cheese and storage for a period of 10 days in the same conditions. CONCLUSIONS: These data demonstrated that milk and dairy products could be an important source of T.gondii in human contamination, reinforcing the importance of milk pasteurization before any processing or ingestion.

Central nervous system infections following bone marrow transplantation: an autopsy report of 27 cases.

The authors retrospectively assess the autopsy findings of central nervous system (CNS) infections in marrow transplant recipients. From July 1987 to June 1998, 845 patients at our institution were submitted to bone marrow transplantation (BMT). The CNS of 180 patients was studied through autopsy and these patients had their medical records reviewed. Twenty-seven (15%) patients presented brain parenchyma infection. Fungi were isolated in approximately 60% of the cases. Mean survival time was 153 days (0-1,264 days) and the majority of the patients died during the first 3 months after BMT (18 cases; 67%). Aspergillus sp. were the most prevalent fungi (approximately 30%), followed by Candida sp. infection (approximately 18%). There was one case of Fusarium sp. infection and two cases of unidentified fungus. All patients with fungal infections had documented involvement at widespread sites. Toxoplasma gondii encephalitis was demonstrated in 8 patents (approximately 30%). Bacterial abscesses were responsible for approximately 11% of the findings. Eleven (41%) of the 27 patients died secondary to cerebral causes. These results show that infectious compromise of the CNS following BMT is a highly fatal event, caused mainly by fungi and T. gondii. Furthermore, they provide a likely guide to the possible causes of brain abscesses following BMT.

Age influence in the natural resistance of white rat and mice to the protozoan Toxoplasma gondii

Groups of 1, 5, 10, 15 and 30 day old rats (Sprague Dawley) and Wistar mice were infected per os with different inocula of Toxoplasma gondii oocysts from an avirulent strain. Infection pattern was followed by determination of survival time, tissue lesions, parasite presence and serology. Although all the animals survived the total experimental period (30 day), there were important differences between both rodents regarding to Toxoplasma natural resistance. Brain cysts, as well as tachyzoites in other organs were regularly present in mice but not in rats. On the other hand, most of the organs from mice presented characteristic T. gondii lesions, while in rats a normal tissues were observed, with the exception of an acute reaction found in the brain of a 15d old animal

Age influence in the natural resistance of white rat and mice to the protozoan Toxoplasma gondii.

Groups of 1, 5, 10, 15 and 30 day old rats (Sprague Dawley) and Wistar mice were infected per os with different inocula of Toxoplasma gondii oocysts from an avirulent strain. Infection pattern was followed by determination of survival time, tissue lesions, parasite presence and serology. Although all the animals survived the total experimental period (30 day), there were important differences between both rodents regarding to Toxoplasma natural resistance. Brain cysts, as well as tachyzoites in other organs were regularly present in mice but not in rats. On the other hand, most of the organs from mice presented characteristic T. gondii lesions, while in rats a normal tissues were observed, with the exception of an acute reaction found in the brain of a 15d old animal.

Prevalencia da Encefalite por Toxoplasma em pacientes com SIDA no Hospital de Clinicas de Porto Alegre / Prevalence of toxoplasmic encephalitis in patients eith AIDS in Hospital de Clinicas de Porto Alegre

Com o objetivo de determinar a prevalencia da encefalite por toxoplasma (ET) em pacientes com SIDA, em nosso meio, bem como descrever o perfil sorologico antitoxoplasma desta populacao, revisaram-se 313 prontuarios de pacientes portadores do virus da imunodeficiencia humana (VIH) internados entre maio/85 e dezembro/89. A prevalencia presuntiva (por achados tomograficos) foi de 8,9% (28 casos). Em 192 pacientes foram dosados anticorpos antitoxoplasma (IgG) no sangue; destes 65,6% foram reagentes. Vinte e sete pacientes com ET tinham dosagem de anticorpos antitoxoplasma no sangue, sendo 26 reagentes. Quinze pacientes com ET tinham dosagem de anticorpos antitoxoplasma no sangue, sendo 26 reagentes. Quinze pacientes com ET tinham dosagem de anticorpos antitoxoplasma no liquor sendo 14 reagentes. Concluimos que a prevalencia da ET, em pacientes com SIDA, em nosso meio, e semelhante a descrita na literatura, e que maiores esforcos se devem empregar para a obtencao de material (por biopsia ou necropsia)a fim de firmar o diagnostico definitivo

Immediate causes of death in acquired immunodeficiency syndrome.

We evaluated the immediate causes of death in 54 adults who underwent an autopsy and were diagnosed as having died of the acquired immunodeficiency syndrome between April 1980 and October 1983. The study group included 25 Haitians, 19 homosexual men, five intravenous drug abusers, two hemophiliacs (type A), and three with no known risk. Fourteen died of central nervous system diseases: 11 of Toxoplasma encephalitis, one of progressive multifocal leukoencephalopathy, one of viral encephalitis, and one of intracerebral hemorrhage. Thirty died of respiratory failure; 16 of Pneumocystis carinii pneumonia, ten of cytomegalovirus pneumonia, one of multiple infections, one of interstitial pneumonia, and two of bacterial pneumonia. Two died of overwhelming generalized infections: one of Mycobacterium avium-intracellulare and one of listeriosis. Six died of disseminated Kaposi's sarcoma, while the remaining two persons died of Toxoplasma myocarditis (one) and one of shock resulting from a percutaneous liver biopsy, respectively. There were differences in the immediate causes of death between Haitians and homosexuals as follows: 63% of homosexual men died of either P carinii pneumonia or Kaposi's sarcoma vs 20% of Haitians. In contrast, 72% of Haitians died of other opportunistic infections as compared with 21% of homosexuals. There has not been an increase in the proportion of cases diagnosed premortem since 1982 and overall, only 32 (58%) were diagnosed premortem; the rest were diagnosed only at autopsy. This study provided evidence that 42% died of currently untreatable diseases.

Unusual causes of death in Haitians residing in Miami. High prevalence of opportunistic infections.

Twenty-one (100%) Haitians and 42 (21.5%) of 192 native black Americans autopsied in a 33-month period at Jackson Memorial Hospital, Miami, were included in this review. All autopsied materials were examined. Among the Haitians autopsied, infectious diseases accounted for 11 (52%) of 21 deaths. Toxoplasma encephalitis was the leading cause of death (five cases). Other infectious causes of death included disseminated cryptococcosis (one), disseminated cytomegalovirus diseases (one), Pneumocystis carinii pneumonia (one), chronic active hepatitis B (two), and bacterial pneumonia (one). Malignant neoplasms were also found to be causes of death and these included a single cases of each of the following: adenocarcinoma of the lung, multiple myeloma, diffuse histiocytic lymphoma, hepatoma, and Kaposi's sarcoma. Deaths of the remaining cases were due to hypertensive cardiovascular diseases (two), rheumatic heart disease (one), glomerulonephritis (one), and intimal fibroplasia of coronary arteries (one). Seven Haitian cases fulfilled the Centers for Disease Control case definition for the acquired immune deficiency syndrome (AIDS). For comparison, autopsies of black Americans were chosen from conditions that would most likely predispose them to opportunistic infections. Among the autopsies on black Americans there were no cases of opportunistic infections or Kaposi's sarcoma that were considered to be consistent with the AIDS.