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Hospital-acquired pneumonia (HAP) is often more severe and life-threatening than community-acquired pneumonia (CAP). The role of Streptococcus pneumoniae in CAP is well-understood, but its role in HAP is unclear. The objective of this study was to summarize the available literature on the prevalence of S. pneumoniae in HAP episodes. We searched MEDLINE for peer-reviewed articles on the microbiology of HAP in individuals aged ≥18 years, published between 2008 and 2018. We calculated pooled estimates of the prevalence of S. pneumoniae in episodes of HAP using a random-effects, inverse-variance-weighted meta-analysis. Forty-seven of 1908 articles met the inclusion criteria. Bacterial specimen isolation techniques for microbiologically defined HAP episodes included bronchoalveolar lavage, protective specimen brush, tracheobronchial aspirate and sputum, as well as blood culture. Culture was performed in all studies; five studies also used urine antigen detection (5/47; 10.6%). S. pneumoniae was identified in 5.1% (95% confidence interval (CI): 3.8-6.6%) of microbiologically defined HAP episodes (N = 20), with 5.4% (95% CI: 4.3-6.7%, N = 29) in ventilator-associated HAP and 6.0% (95% CI: 4.1-8.8%, N = 6) in non-ventilator-associated HAP. S. pneumoniae was identified in 5.3% (95% CI: 4.5-6.3%) of HAP occurring in the intensive care unit (ICU, N = 41) and in 5.6% (95% CI: 3.3-9.5%, N = 5) outside the ICU. A higher proportion of early-onset HAP (10.3%; 95% CI: 8.3-12.8%, N = 16) identified S. pneumoniae as compared with late-onset HAP (3.3%; 95% CI: 2.5-4.4%, N = 16). In conclusion, S. pneumoniae was identified by culture in 5.1% of microbiologically defined HAP episodes. The importance of HAP as part of the disease burden caused by S. pneumoniae merits further research.

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Surveillance systems for varicella in Europe are highly heterogeneous or completely absent. We estimated the varicella incidence based on seroprevalence data, as these data are largely available and not biased by under-reporting or underascertainment. We conducted a systematic literature search for varicella serological data in Europe prior to introduction of universal varicella immunization. Age-specific serological data were pooled by country and serological profiles estimated using the catalytic model with piecewise constant force of infection. From the estimated profiles, we derived the annual incidence of varicella infection (/100·000) for six age groups (<5, 5-9, 10-14, 15-19, 20-39 and 40-65 years). In total, 43 studies from 16 countries were identified. By the age of 15 years, over 90% of the population has been infected by varicella in all countries except for Greece (86·6%) and Italy (85·3%). Substantial variability across countries exists in the age-specific annual incidence of varicella primary infection among the <5 years old (from 7052 to 16 122 per 100 000) and 5-9 years old (from 3292 to 11 798 per 100 000). The apparent validity and robustness of our estimates highlight the importance of serological data for the characterization of varicella epidemiology, even in the absence of sampling or assay standardization.

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OBJECTIVES: To determine whether dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) can differentiate benign from malignant cartilage tumours compared to standard MRI. To investigate whether a cutoff value could be determined to differentiate enchondroma from low-grade chondrosarcoma (CS) more accurately. METHODS: One hundred six patients were included in this retrospective study: 75 with enchondromas (mean age = 41 years) and 31 with CS (mean age = 47 years). Within this population, a subgroup of patients was selected with the tumour arising in a long bone. At the time of diagnosis, the tumours were evaluated on MRI, including standard MRI, DCE-MRI, and region-of-interest (ROI) analysis to obtain information on tumour vascularisation and perfusion. RESULTS: The main cutoff value to differentiate enchondroma from CS contained a two-fold more relative enhancement compared with muscle, combined with a 4.5 (= 76°) slope value, with 100 % sensitivity and 63.3 % specificity. The prediction of CS diagnosis with DCE-MRI had 93.4 % accuracy. The accuracy of the standard MRI parameters was equal to the DCE-MRI parameters. CONCLUSIONS: Standard MRI and DCE-MRI both play an important and complementary role in differentiating enchondroma from low-grade CS. A combination of both imaging techniques leads to the highest diagnostic accuracy for differentiating cartilaginous tumours. KEY POINTS: • DCE-MRI plays an important role in differentiating benign from malignant cartilage tumours. • Retrospective study defined a threshold for 100 % detection of chondrosarcoma with DCE-MRI. • The threshold values were relative enhancement = 2 and slope = 4.5. • One hundred per cent chondrosarcoma detection corresponds with 36.7 % false-positive diagnosis of enchondroma. • Standard MRI is complementary to DCE-MRI in differentiating cartilaginous tumours.

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HYPOTHESIS: The purpose of this study was to investigate the 3-dimensional (3-D) orientation of the glenoid and scapular planes. Different definitions of the glenoid plane were used and different planes measured, and we hypothesed that the 3-D plane with the least variation would be best to define the most reliable glenoid plane. METHODS: We studied 150 CT scans from nonpathological shoulders from patients between 18 and 80. The scapular plane and 5 different glenoid planes were determined: inferior, anterior, posterior, superior, and neutral. All plane versions and inclination angles were measured. Because all examinations were done in a standardized position to the coronal, sagittal, and transverse planes of the body, the scapular plane could be defined versus the coronal, sagittal, and transverse planes of the body. RESULTS: The version (mean, 3.76) of the inferior glenoid plane showed a significantly lower standard deviation than the version of the anterior (P < .001), posterior (P=.001), and superior (P=.001) glenoid plane (ANOVA). For inclination all planes have a similar variance. The scapular plane was different between gender (P=.022) and correlated with age. CONCLUSION: This study showed that the retroversion of the inferior glenoid is reasonably constant. The osseous anthropometry of the inferior glenoid can offer a reproducible point of reference to be used in prosthetic surgery of the shoulder.

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OBJECTIVE: Varicella vaccination was introduced at the end of 1999 into the Uruguayan immunisation schedule for children aged 12 months. Varilrix (Oka strain; GlaxoSmithKline Biologicals) has been the only vaccine used since then and coverage has been estimated to exceed 90% since the start of the universal varicella vaccination programme. We assessed the impact of the Uruguayan varicella vaccination programme during 2005, 6 years after its introduction. METHODS: Information on hospitalisations was collected from the main paediatric referral hospital and information on medical consultations for varicella was collected from two private health insurance systems in Montevideo. The proportion of hospitalisations due to varicella and the proportion of ambulatory visits for varicella since the introduction of the vaccine were compared between 1999 and 2005 and 1997 and 1999 in the following age groups: <1 year, 1-4 years, 5-9 years and 10-14 years. RESULTS: By 2005, the proportion of hospitalisations due to varicella among children, was reduced by 81% overall and by 63%, 94%, 73% and 62% in the <1, 1-4, 5-9 and 10-14 years age groups, respectively. The incidence of ambulatory visits for varicella among children was reduced by 87% overall and by 80%, 97%, 81% and 65% in the <1, 1-4, 5-9 and 10-14 years age groups, respectively. CONCLUSIONS: The burden of varicella has decreased substantially in Uruguayan children since the introduction of the varicella vaccination, including those groups outside the recommended vaccination age. It is expected to decrease further as more cohorts of children are vaccinated and herd immunity increases.

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Following allegations that Hepatitis B vaccination causes or triggers multiple sclerosis (MS), several epidemiological studies have been conducted to evaluate the association between MS and vaccination. In one study conducted in the US, a significant protective effect on the development of MS was observed for tetanus immunization. We reviewed the medical literature and found two additional recent studies, as well as several older studies, which also observed a significant protective effect of tetanus immunization on the development or progression of MS. Furthermore, decreased humoral and cellular immunity to tetanus toxoid has been observed among MS patients. We postulate that naturally acquired or vaccine-induced immunity to tetanus has a protective effect against the development and progression of MS. We also postulate that this link to tetanus is in part responsible for the gender, age, geographic and socio-economic distribution of MS, as well as its pattern among migrants. The biological basis for this protective effect could be an unspecific boost of bystander suppression of auto-immunity as shown for other infections. Our hypothesis can be tested in several ways. The simplest approach would be to compare tetanus exposure and MS occurrence on a population level. Stronger support would come from the re-analysis of previous studies that have information at the individual level on both tetanus exposure, whether induced or natural, and on the development of MS. Laboratory evidence could be sought by testing the effect of tetanus toxoid on experimental allergic encephalomyelitis, the experimental animal model of MS.

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The Vaccine Adverse Event Reporting System (VAERS) is the passive reporting system for postmarketing surveillance of vaccine safety in the United States. The proportion of cases of an adverse event after vaccination that are reported to VAERS (i.e., VAERS reporting completeness) is mostly unknown. Therefore, the risk of such an event cannot be derived from VAERS only. To study whether its reporting sensitivity and risks could be estimated, VAERS was linked to data from a case-control and a retrospective cohort study in a capture-recapture analysis of intussusception after rotavirus vaccination (RV). Cases of intussusception after RV were selected from the common time frame (December 1998 through June 1999) and the common geographic area (19 states) of the three sources. Matching occurred on birth date, gender, state, date of vaccination, and date of diagnosis. Thirty-five matches were identified among a total of 84 cases. The estimated VAERS reporting completeness was 47%. The relative risks of intussusception in the periods 3-7 and 8-14 days after RV (relative risk = 22.7 and 4.4, respectively) were comparable with those reported in the two studies. Linkage of VAERS to complimentary data sources may permit more timely postmarketing assessment of vaccine safety.

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Whether the aim is to diagnose individuals or estimate prevalence, many epidemiological studies have demonstrated the successful use of tests on pooled sera. These tests detect whether at least one sample in the pool is positive. Although originally designed to reduce diagnostic costs, testing pools also lowers false positive and negative rates in low prevalence settings and yields more precise prevalence estimates. Current methods are aimed at estimating the average population risk from diagnostic tests on pools. In this article, we extend the original class of risk estimators to adjust for covariates recorded on individual pool members. Maximum likelihood theory provides a flexible estimation method that handles different covariate values in the pool, different pool sizes, and errors in test results. In special cases, software for generalized linear models can be used. Pool design has a strong impact on precision and cost efficiency, with covariate-homogeneous pools carrying the largest amount of information. We perform joint pool and sample size calculations using information from individual contributors to the pool and show that a good design can severely reduce cost and yet increase precision. The methods are illustrated using data from a Kenyan surveillance study of HIV. Compared to individual testing, age-homogeneous, optimal-sized pools of average size seven reduce cost to 44% of the original price with virtually no loss in precision.

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Two HIV infected patients with visceral leishmaniasis and unusual cutaneous lesions are described. The first patient developed linear brown macules containing Leishmania parasites on the fingers and palms of the hands. This patient never received highly active antiretroviral treatment and the visceral leishmaniasis could not be cured even with liposomal amphotericin. In the second patient, Leishmania parasites were present in a skin biopsy of a fibrous histiocytoma. After completing visceral leishmaniasis treatment, a discrete elevation of one of his tattoos was seen. A biopsy specimen of this tattoo revealed Leishmania amastigotes. In this patient the visceral leishmaniasis was finally cured with meglumine antimoniate, followed by pentacarinat isothianate as maintenance therapy in conjunction with highly active antiretroviral treatment.

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Seroprevalence studies are crucial in HIV control programs but too expensive at district level. We evaluated the applicability of pooling sera and how it can reduce cost and affect accuracy at district level. 740 samples collected from antenatal clinic attendants for a sentinel survey in a rural Kenyan district were screened individually and in pools of 10. The seroprevalence when measured individually was 7.30%, while the calculated seroprevalence from pooled testing was 7.49%. Pooling was practicable and reduced costs by 62% for a marginal loss of accuracy. It is a useful tool in increasing the affordability of surveillance at district level. A pool size of 8 would have resulted in optimal cost reduction at minimal loss of accuracy.

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Five cases of blackwater fever (BWF) are described, all of whom had a history of recent quinine therapy. In two cases a second haemolytic crisis was induced by halofantrine, in one case also a third. Increasing frequency of this syndrome with its dramatic clinical presentation is to be expected as imported P. falciparum infection, parasite resistance to chloroquine and the use of quinine and other related antimalarials become more frequent.

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The sensitivity and specificity of two rapid, low cost latex agglutination HBsAg detection tests were compared to a EIA HBsAg detection test using serum samples from 371 pregnant women in Kajiado, a rural Kenyan district. The sensitivity of the latex agglutination tests when compared to the EIA was 70.6% and 61.8%, while specificity was 92.0% and 85.2% respectively for the same tests. In view of their low sensitivity these rapid tests are not suitable for screening blood in district hospitals.

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PURPOSE: To define one possible etiology for the rise in intraocular pressure (IOP) after neodymium: YAG (Nd:YAG) laser capsulotomy and provide information for the continued investigation of this process. SETTING: Laser Center, Eye and Ear Institute, Pittsburgh, Pennsylvania. METHODS: Samples of 1% sodium hyaluronate or balanced salt solution (BSS) (control) were placed in a closed system and exposed to varying amounts of Nd:YAG energy delivered by a Coherent YAG laser. This system was hydrostatically coupled to a pressure monitor, and changes in pressure were recorded as a function of time. RESULTS: Average pressure increase was 0.140 mm Hg/mJ of YAG energy in the sodium hyaluronate samples and 0.017 mm Hg/mJ in BSS (P < .01). The relationship between total energy delivered and maximum pressure recorded for both substances was nearly linear. Further analysis of treated sodium hyaluronate samples showed that Nd:YAG energy can produce structural alterations. CONCLUSIONS: Neodymium:YAG laser energy has a pronounced effect on sodium hyaluronate that exceeds the thermal effect seen with BSS when the pressure is monitored in a closed system. These structural changes might contribute to the IOP rise seen clinically.

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BACKGROUND: Acute posterior multifocal placoid pigment epitheliopathy (APMPPE) is a chorioretinal disease that causes acute visual symptoms with characteristic fundus findings. Although this entity has been associated with a variety of neurological complications, it has received little attention in the neurological literature. We wanted to emphasize the spectrum of neurological involvement, in particular the occurrence and management of strokes in patients with APMPPE. CASE DESCRIPTIONS: We report three patients with APMPPE and neurological disease. All three presented with marked visual disturbances and headaches. One patient developed recurrent strokes involving different vascular territories of the brain and required immunosuppressive treatment for presumed cerebral vasculitis. The other two patients had cerebrospinal fluid pleocytosis and persistent headaches but recovered spontaneously. The review of the literature demonstrates a particular pattern of neurological complications in a subgroup of patients with APMPPE. CONCLUSIONS: APMPPE should be considered among the causes of stroke and aseptic meningitis in young adults. The diagnosis is critically dependent on a thorough ophthalmologic examination. Severe neurological complications are difficult to predict at the onset of the ophthalmologic disease. The patients should be monitored closely. If investigations suggest cerebral vasculitis, immunosuppressive treatment may be helpful to prevent recurrences.

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Three cases of AIDS complicated by Rhodococcus equi infection are reported. At least one of the patients acquired his Rhodococcus infection in Africa. Despite the fact that the R. equi strains were susceptible to tetracycline, erythromycin, amikacin, co-trimoxazole, rifampicin and vancomycin, these antibiotics were clinically not successful. A clinical improvement was observed in only one patient during teicoplanin and imipenem-cilastatin treatment. Multicentre clinical trials are needed to determine the optimal treatment of R. equi infections in AIDS patients.

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Acute schistosomiasis or "Katayama syndrome" occurs in previously uninfected persons 3-6 weeks after exposure to cercaria-infested water.1,2 Many outbreaks among tourists have been reported.3-11 Such outbreaks occur because tourists are bathing or swimming in waters thought by tourist organizations to be bilharzial free. Imported schistosomiasis acquired in the Dogon country in Mali, West Africa, was first demonstrated in 1989 in three Spanish travelers;3 in 1991, an outbreak was described among Dutch travelers.7 In 1993, we investigated a similar outbreak among European and American travelers returning from the same area.

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