Volume 20, Issue 1, 2012
Review
Plasmodium knowlesi: from Malaysia, a novel health care threat
Sabbatani Sergio,
Fiorino Sirio,
Manfredi Roberto
Epidemic foci of Plasmodium knowlesi malaria have been identified during the past ten years in Malaysia, in particular in the States of Sarawak and Sabah (Malaysia Borneo), and in the Pahang region (peninsular Malaysia). Based on a review of the available recent international literature, the authors underline the importance of molecular biology examinations, polymerase chain reactions (PCR), performed with primers specific for P. knowlesi, since the current microscopic examination (haemoscope) may fail to distinguish P. knowlesi from Plasmodium malariae, due to the very similar appearance of the two parasites. P. knowlesi has been described as the causal agent of life-threatening and lethal forms of malaria: its clinical picture is more severe when compared with that of P. malariae, since the disease is characterized by greater parasitaemia, as opposed to that documented in the course of P. malariae disease. The most effective carrier is Anopheles leucosphyrus: this mosquito is attracted by both humans and monkeys. Among primates, the natural hosts of P. knowlesi are Macaca fascicularis and Macaca nemestina, while Saimiri scirea and Macaca mulatta, which cannot become infected in nature, may be useful in experimental models. When underlining the potentially severe evolution, we note the key role played by prompt disease recognition, which is expected to be more straightforward in patients monitored in endemic countries at high risk, but should be carefully implemented for subjects being admitted to hospital in Western countries suffering from the typical signs and symptoms of malaria, after travelling in South-East Asia where they were engaged in excursions in the tropical forest (trekking, and similar outdoor activities). In these cases, the diagnosis should be prompt, and suitable treatment should follow. According to data in the literature, in non-severe cases chloroquine proves very effective against P. knowlesi, achieving the disappearance of signs and symptoms in 96% of cases after only 24 hours after treatment start. In the light of the emerging epidemiological data, P. knowlesi should be added to Plasmodium vivax, Plasmodium ovale, P. malariae, and Plasmodium falciparum, as the fifth aetiological agent of malaria. During the next few years, it will become mandatory to plan an appropriate surveillance program of the epidemiological evolution, paying also great attention to the clinical features of patients affected by P. knowlesi malaria, which are expected to worsen according to the time elapsed; some studies seem to point out greater severity according to increased parasitaemia, paralleling the increased interhuman infectious passages of the plasmodium.
Original article
Cytomegalovirus infection in immunocompetent patients. Clinical and immunological considerations
Colomba Claudia,
Lalicata Francesco,
Siracusa Lucia,
Saporito Laura,
Di Bona Danilo,
Giammanco Giovanni,
De Grazia Simona,
Titone Lucina,
Cytomegalovirus primary infection is considered dangerous for some kinds of patients: immunocompromised (HIV-infected and transplanted patients), newborns with congenital infection, and immunocompetent patients in critical condition. CMV infection is usually asymptomatic or only mildly symptomatic in immunocompetent hosts. We collected all cases of acute CMV infection that came to our attention during the period November 2009- May 2011 to analyze their clinical features. Immunoenzymatic methods (ELISA) were used for the detection of specific IgM and IgG antibodies in every case. We observed 73 cases of acute CMV infection. The male-female ratio was 1.5:1. The average age was 36.4. All the patients had fever, 16 (22%) pharyngitis, only 9 (12.3%) lymphadenopathy. The most common complications were hepatitis, encephalitis, pericarditis and pneumonia. Unknown genetic factors may greatly influence the clinical expression of the illness.
Diagnostic sensitivity of QuantiFERON-TB Gold In-Tube and tuberculin skin test in active tuberculosis: influence of immunocompromission and radiological extent of disease
Guglielmetti Lorenzo,
Conti Michela,
Cazzadori Angelo,
Lo Cascio Giuliana,
Sorrentino Annarita,
Concia Ercole
Tuberculosis (TB) is a pathology whose control is still unsatisfactory at global level. Traditional diagnostic techniques for active TB diagnosis are inadequate: the diagnostic gold standard is the cultural exam which suffers from lengthy processing and requires highly specialized laboratories. This study analyzed the diagnostic sensitivity of the tuberculin skin test (TST) and QuantiFERON-TB Gold In-Tube (QFT-IT) in 135 active, microbiologically confirmed TB cases. Sensitivity was 76% for both tests and reached cumulative levels close to 90%. QFT-IT revealed a statistically higher sensitivity than TST in a group of patients affected by various causes of immunosuppression, but was less sensitive in subjects with low levels of circulating CD4+ cells. The number of circulating CD4+ cells showed a direct correlation with the stimulated IFN-γ production. QFT-IT also demonstrated a decreased IFN-γ production, with a significant sensitivity reduction, in patients affected by advanced forms of pulmonary TB.
Study on in vitro susceptibility of Candida spp. isolated from blood culture
Grandesso Stefano,
Sapino Barbara,
Mazzucato Sandra,
Solinas Maria,
Bedin Maria,
D’Angelo Monica,
Gion Massimo
In recent years the incidence of bloodstream infections due to Candida species has progressively increased, partly due to the more critical conditions of hospitalized patients. There has been a significant increase in immune-compromised, diabetic and/or elderly patients, also with venous access, with a subsequent increase in Candida species isolated from bloodstream infections. In 2009-2010 in the hospitals of Mestre and Venice we isolated 123 Candida species from bloodstream infections: 59 Candida albicans, 28 Candida parapsilosis, 12 Candida glabrata, 9 Candida tropicalis, and 4 Geotrichum capitatum, while the 11 others belong to 8 different species. We calculated MIC for the following antifungal agents: fluconazole, itraconazole, voriconazole, 5-flucytosine, amphotericin B and caspofungin.
Liver biopsy in chronic hepatitis C: the experience of 15 Italian wards of infectious diseases
Sagnelli Evangelista,
Sagnelli Caterina,
Pisaturo Maria Antonietta,
Coppola Nicola,
Pasquale Giuseppe,
Piccinino Felice
To evaluate the impact of liver histology on the management of HCV-related chronic hepatitis, 281 patients with chronic HCV infection who consecutively underwent percutaneous liver biopsy (LB) at one of the 15 participating Italian Units of Infectious Diseases were investigated in 2005. Demographic, aetiological, laboratory and clinical data and information on methods applied to perform ultrasonography (US) and LB were recorded. Males predominated (61.6%), mean age was 47.5 years and the mean BMI 22.3. In each case LB was US-guided or US-assisted. An 18-gauge Menghini-type needle was used in 203 (72.2%) cases. The length of the specimen ranged between 1.5 and 5 cm in 279 (99.3%) cases, it was smaller in two cases, but the diagnosis was still possible. Haemoperitoneum was the only (0.4%) major unpredictable complication; minor complications were also infrequent (4%). Using both clinical and laboratory data and US examination the physician misdiagnosed liver histology in 25% of cases. After LB the physicians changed their opinion on whether to treat with PEG-INF plus ribavirin in 43 (15.5%) cases. Liver histology allows more accurate diagnosis and enables physicians to make the most appropriate choices regarding treatment.
Social and demographic determinants in the prescription of systemic antibiotics
Álvarez Montserrat,
Pastor Enrique,
María José
Spain presents a high level of systemic antibiotic consumption and subsequently shows important rates of bacterial resistance. Diverse parameters explain the uneven distribution of their consumption such as the epidemiology of infectious processes, population-dependent factors, and factors dependent on the prescribing doctor. The aim of this study was to investigate demographic parameters that may affect antibiotic consumption.
We carried out a retrospective longitudinal study from 2001 to 2005 on the basis of antibiotic consumption data provided by the information system of the drugstore “Concylia”. The consumption indicator used is the number of defined daily doses per 1000 inhabitants per day (DID). The area studied was the region of Castile and Leon, with nine provinces and eleven health districts.
Global consumption per health district under study was as follows: Avila (22.37 DID), Zamora (21.83 DID), Salamanca (21.0 DID), Soria (20.67 DID), Palencia (18.97 DID), Leon (17.56 DID), Burgos (16.59 DID), Segovia (16.50 DID), East Valladolid (16.36 DID), The Bierzo (16 DID) and the lowest consumer, West Valladolid (13.46 DID). Different patterns of consumption were found in the study period, according to the variability of infectious diseases and demographic factors such as population age and population density.
Significant area-dependent global consumption differences were observed in relation to acute respiratory infections and population-dependent factors. The differences were more marked when studying the geographical distribution of the consumption of the principal active ingredients.
Case report
Use of direct renin inhibitor in an HIV positive subject
Ucciferri Claudio,
Brescini Lucia,
Staffolania Silvia,
Falasca Katia,
Cirioni Oscar,
Giacometti Andrea,
Vecchiet Jacopo
Objectives: Drugs acting on the renin angiotensin system (RAS), such as angiotensin converting enzyme (ACE) inhibitors and sartans, have been used for hypertension treatment in the HIV-negative population. These drugs reduce hypertension related cardiovascular diseases such as renal impairment in the general population. Limited data show similar findings also in the HIV-positive population. A new drug called aliskiren has recently become available on the market: it is able to block the RAS by a different mechanism acting as direct renin inhibitor. No data are available about the use of aliskiren in HIV-positive patients.
Case report: A 61-year-old HIV-infected Caucasian male (CDC C3) patient with hypertension for ten years and cardiovascular complications took carvedilol 25 mg twice a day, plus daily administration of irbesartan 300 mg, hydroclorotiazide 25 mg, doxazosin 4 mg, lacidipine 6 mg, and simvastatin 40 mg. He took AZT+ 3TC + RAL with a good profile on HIV replication and immunological parameters. We found a non-optimal blood pressure value and decided to start aliskiren 150 mg a day to improve blood pressure control. After one month blood pressure control and proteinuria improved.
In our case the use of low doses of aliskiren appeared to improve the level of blood pressure, although five antihypertensive agents had already been used on the patient. Finally, although aliskiren would appear to have no direct effect on viro-immunological parameters and does not seem to interfere with cART, further studies are warranted in this context.
The Infections in the History of Medicine
Hepatitis: a longstanding companion in human history
Craxì Lucia
Hepatitis has gone along with human history since its origins, due to its prompt identifiability linked to jaundice as a symptom. Written evidence of outbreaks of epidemic jaundice can be tracked back a few millenniums before Christ.
Unavoidable confusion arises due to the overlap of different sources possibly linked to different aetiologies, identified over time as “epidemic jaundice” (HAV or HEV hepatitis?) and “serum hepatitis” (HBV or HCV hepatitis?). The journey that brought to recognize viruses as the main cause of jaundice was long and started midway during the last century, when the infectious hypothesis, which had taken place step by step, was finally confirmed by epidemiological investigations of an outbreak occurring in the US army in 1942, after a yellow fever immunization campaign. Further research identified two clinically different types of hepatitis, called for the first time hepatitis A and hepatitis B.
From miasmas to germs: a historical approach to theories of infectious disease transmission
Karamanou Marianna,
Panayiotakopoulos George,
Tsoucalas Gregory,
Kousoulis Antonis A.,
Androutsos George
From miasma to germ theory we trace the evolution of conceptions in infectious disease transmission. Starting from the unproved theories of contagiousness we move on to miasma theory, contagion theory and spontaneous generation theory up to the revolutionary germ theory of disease transmission.
