Chronic bacterial and parasitic infections and cancer: a review.

BACKGROUND: A relatively underestimated facet of infectious diseases is the association of chronic bacterial and parasitic infections with cancer development. Therefore, we sought to evaluate the evidence regarding the association of such infections with the development of malignancy, excluding the overwhelming evidence of the association of Helicobacter pylori and cancer. METHODOLOGY: We searched Pubmed, Cochrane, and Scopus without time limits for relevant articles. RESULTS: There is evidence that some bacterial and parasitic infections are associated with cancer development. The level of evidence of this association varies from high to low; in any case, a long time interval is mandatory for the development of cancer. A high level of evidence exists for the association of Salmonella Typhi with gallbladder and hepatobiliary carcinoma; Opisthorchis viverrini and Clonorchis sinensis with cholangiocarcinoma; Schistosoma hematobium with bladder cancer; chronic osteomyelitis with squamous cell carcinoma of the skin; and hidradenitis suppurativa with squamous cell carcinoma of the skin. In contrast, the level of evidence regarding the association of Chlamydia spp. with cancer is low. Mycobacterium tuberculosis is associated with lung cancer, albeit probably not etiopathogenetically. CONCLUSIONS: A considerable number of bacterial infections and parasitic infections are associated with the development of cancer. Further research into recognizing additional associations of bacterial and parasitic infections with cancer is mandatory.

Resiniferatoxin in the treatment of interstitial cystitis: a systematic review.

Resiniferatoxin, a treatment based on a physiopathological concept (the involvement of C fibers and transient receptor potential vanilloid 1 in the transmission of pain) is undergoing evaluation for interstitial cystitis. We evaluated the current evidence from relevant studies identified in PubMed and Scopus databases. Six studies provided contradictory results regarding the effectiveness of resiniferatoxin treatment. The largest study showed no improvement of overall symptoms following a single administration of resiniferatoxin. Three other articles that studied the effectiveness of a single dose of resiniferatoxin gave contradictory results. However, the other two studies, those that examined the effect of multiple or prolonged administration schemes, gave more encouraging results. The use of the regimen is generally well tolerated although mild adverse events such as increase of bladder pain during instillation were sometimes reported by patients and serious adverse events rarely occur. In conclusion, the effectiveness of resiniferatoxin in the treatment of interstitial cystitis remains unknown.

Matching criteria in case-control studies in the field of antimicrobial resistance.

OBJECTIVE: We evaluated the available evidence from case-control studies in the field of antimicrobial resistance to identify the degree that matching was performed and the criteria used to do so. METHODS: We performed a systematic search of the PubMed database (articles archived by 08/2006) to identify relevant studies. Studies that used the individual matching technique were further analyzed. RESULTS: 115 case-control studies with a focus on antimicrobial resistance were identified: 28 regarding Acinetobacter baumannii, 25 regarding Pseudomonas aeruginosa, and 62 for other bacteria. Individual matching was performed in 32 (27.8%) out of the 115 studies. Age was the most frequently used matching criterion in 22 of 32 (69%) evaluated matched case-control studies, while sex was used in 11 (34%), presence of underlying illness in 8 (25%), site of infection in 5 (16%), and area of residence in 4 studies (12.5%). Other criteria were used in less than 10% of the studies. Analysis of data for matched pairs was performed in 18 of 32 (56.3%) studies that used a matched case-control design. DISCUSSION: The available evidence from the analyzed data from case-control studies in the field of antimicrobial resistance shows that individual matching is employed only in a proportion of such studies and only for a few characteristics, when it was used. Also, analysis for matched pairs was not used by almost a half of the relevant studies.

Severe cytomegalovirus infection in apparently immunocompetent patients: a systematic review.

BACKGROUND: The morbidity and mortality associated with cytomegalovirus (CMV) infection in immunocompromised patients (especially in HIV-infected patients and transplant recipients), as well as with congenital CMV infection are well known. In contrast, relatively little attention has been paid to the morbidity and mortality that CMV infection may cause in immunocompetent patients. METHODS: We reviewed the evidence associated with severe manifestations of CMV infection in apparently immunocompetent patients and the potential role of antiviral treatment for these infections. We searched in PubMed, Scopus, and the Cochrane Library for the period of 1950-2007 to identify relevant articles. RESULTS: We retrieved 89 articles reporting on severe CMV infection in 290 immunocompetent adults. Among these reports, the gastrointestinal tract (colitis) and the central nervous system (meningitis, encephalitis, transverse myelitis) were the most frequent sites of severe CMV infection. Manifestations from other organ-systems included haematological disorders (haemolytic anaemia, thrombocytopenia), thrombosis of the venous or arterial vascular system, ocular involvement (uveitis), and lung disease (pneumonitis). The clinical practice reported in the literature has been to prescribe antiviral treatment for the most severe manifestations of monophasic meningoencephalitis (seizures and coma), ocular involvement, and lung involvement due to CMV. CONCLUSION: Severe life-threatening complications of CMV infection in immunocompetent patients may not be as rare as previously thought.

Aspects of the association between leishmaniasis and malignant disorders.

Given the prevalence of leishmaniasis and cancer, the co-existence of these two diseases may be merely coincidental. However, a number of epidemiological, experimental and laboratory studies suggest that an association between these two entities does exist. The aim of this review is to summarise the occurrence of leishmaniasis as an opportunistic infection associated with malignant disorders and to present the available literature potentially linking this infection with the development of cancerous lesions. We searched electronic databases and evaluated 37 studies involving 44 patients. Four different types of association between leishmaniasis and cancer were established: leishmaniasis mimicking a malignant disorder, such as lymphoma; leishmaniasis arising as a difficult to diagnose and treat infection among patients receiving chemotherapy for various malignant disorders; simultaneous diagnosis of leishmaniasis and a neoplastic disorder in the same tissue samples of immunocompromised patients; and direct involvement of Leishmania spp. in the pathogenesis/occurrence of malignant lesions, especially of the skin and mucous membranes. The main conclusion of this review is that leishmaniasis can directly or indirectly affect the presentation, diagnosis and course of various malignant disorders and it should be considered in the differential diagnosis of malignancies in geographic areas where it is endemic and/or in patients with travel history to these areas.

Sex differences in the incidence and severity of respiratory tract infections.

Sex is a significant epidemiological factor for several diseases. However, the role of sex in the development and outcome of various infections has not been extensively studied with the notable exception of urinary tract infections. We searched in the PubMed database to identify articles that could provide relevant data regarding sex differences in the incidence and severity of respiratory tract infections (RTIs). We extracted data from 84 relevant studies that provided information regarding sex differences in the incidence and severity of RTIs. Females are more commonly affected with infections of the upper respiratory tract, specifically sinusitis, tonsillitis, and otitis externa. On the other hand, males are more commonly affected with otitis media, croup, and most important, lower RTIs. It is also evident from the reviewed evidence that the course of most RTIs is more severe in males than in females, leading to higher mortality in males, especially in community-acquired pneumonia. In conclusion, the available data suggest that males are more susceptible than females to most types of RTIs in all age groups (adults and children). Overall, it seems that males develop RTIs more frequently than females, except for sinusitis, otitis externa, and probably tonsillitis. Anatomic, lifestyle, behavioural, and socioeconomic differences between males and females may explain the observed findings. The role of sex hormones in the regulation of the immune system may also contribute to the reported sex differences in the incidence and severity of the various types of RTIs, especially in adolescents and adults.