Vaccine-Preventable Disease Outbreaks among Healthcare Workers: A Scoping Review

BACKGROUND

Outbreaks of vaccine preventable diseases (VPDs) in health care workers (HCWs) can result in morbidity and mortality and cause significant disruptions to health care services, patients and visitors as well as an added burden on the health system. This scoping review is aimed to describe the epidemiology of VPD outbreaks in HCW, caused by diseases which are prevented by the ten vaccines recommended by World Health Organization (WHO) for HCWs.

METHODS

In April 2022 CINAHL, MEDLINE, Global Health and EMBASE were searched for all articles reporting on VPD outbreaks in HCWs since the year 2000. Articles were included regardless of language and study type. Clinical and epidemiological characteristics of VPD outbreaks were described.

RESULTS

Our search found 9363 articles, of which 216 met inclusion criteria. Studies describing six of the ten VPDs were found: influenza, measles, varicella, tuberculosis, pertussis and rubella. Most articles (93%) were from high- and upper middle-income countries. While most outbreaks occurred in hospitals, several influenza outbreaks were reported in long term care facilities. Based on available data, vaccination rates amongst HCWs were rarely reported.

CONCLUSION

We describe several VPD outbreaks in HCWs from 2000 to April 2022. The review emphasises the need to understand the factors influencing outbreaks in HCWs and highlight importance of vaccination amongst HCWs.

Disease-modifying interactions between chronic kidney disease and osteoarthritis: a new comorbid mouse model

OBJECTIVE

The prevalence of comorbid chronic kidney disease (CKD) and osteoarthritis (OA) is increasing globally. While sharing common risk factors, the mechanism and consequences of concurrent CKD-OA are unclear. The aims of the study were to develop a preclinical comorbid model, and to investigate the disease-modifying interactions.

METHODS

Seventy (70) male 8-10 week-old C57BL/6 mice were subjected to 5/6 nephrectomy (5/6Nx)±destabilisation of medial meniscus (DMM) or sham surgery. OA pathology and CKD were assessed 12 weeks postinduction by blinded histology scoring, micro-CT, immunohistochemistry for osteoclast and matrix metalloproteinase (MMP)-13 activity, and serum analysis of bone metabolic markers.

RESULTS

The 5/6Nx model recapitulated characteristic features of CKD, with renal fibrosis and deranged serum alkaline phosphatase, calcium and phosphate. There was no histological evidence of cartilage pathology induced by 5/6Nx alone, however, synovial MMP-13 expression and subchondral bone osteoclastic activity were increased (p<0.05), with accompanying reductions (p<0.05) in subchondral trabecular bone, bone volume and mineral density. DMM significantly (p<0.05) increased tibiofemoral cartilage damage, subchondral bone sclerosis, marginal osteophytes and synovitis, in association with increased cartilage and synovial MMP-13. DMM alone induced (p<0.05) renal fibrosis, proteinuria and increased (p<0.05) 5/6Nx-induced serum urea. However, DMM in 5/6Nx-mice resulted in significantly reduced (p<0.05) cartilage pathology and marginal osteophyte development, in association with reduced subchondral bone volume and density, and inhibition of 5/6Nx-induced subchondral bone osteoclast activation.

CONCLUSION

This study assessed a world-first preclinical comorbid CKD-OA model. Our findings demonstrate significant bidirectional disease-modifying interaction between CKD and OA.

Virtual hospital-level care—feasibility, acceptability, safety and impact of a pilot Hospital-In-The-Home model for COVID-19 infection

Background

Hospital-in-the-Home (HITH) delivers hospital level care to patients in the comfort of their own home. Traditionally HITH involves clinicians travelling to patients' homes. We designed and implemented a virtual model of care leveraging a combination of virtual health modalities for children with COVID-19 in response to rising patient numbers, infection risk and pressures on protective equipment. In contrast to other models for COVID-19 infection in Australia at the time, our HITH service catered only for children who were unwell enough to meet criteria for hospitalisation (ie bed-replacement).

Aims

To measure the feasibility, acceptability, safety and impact of a virtual model of care for managing children with COVID-19 infection requiring hospital-level care.

Methods

Retrospective study of a new virtual model of care for all children admitted to the Royal Children's HITH service with COVID-19 infection between 7th October 2021 and 28th April 2022. The model consisted of at least daily video consultations, remote oximetry, symptom tracking, portal messaging and 24 h phone and video support. Patients were eligible if they met a certain level of severity (work of breathing, dehydration, lower oxygen saturations) without requiring intravenous fluids, oxygen support or intensive care. Online surveys were distributed to staff and consumers who experienced the model of care.

Results

331 patients were managed through the virtual HITH program with a mean length of stay of 3.5 days. Of these, 331 (100%) engaged in video consultations, 192 (58%) engaged in the patient portal and completed the symptom tracker a total of 634 times and communicated via a total of 783 messages. Consumer satisfaction (n = 31) was high (4.7/5) with the most useful aspect of the model rated as video consultation. Clinician satisfaction (n = 9) was also high with a net promoter score of 8.9. There were no adverse events at home. Eight children (2.4%) represented to hospital, 7 (2.1%) of whom were readmitted. The impact is represented by a total of 1,312 hospital bed-days saved in the seven-month period (2,249 bed-days per year). In addition, 1,480 home visits (travel time/ protective equipment/ infection risk) were avoided.

Conclusion

A virtual HITH program for COVID-19 in children is feasible, acceptable and safe and has a substantial impact on bed-days saved and nursing travel time. The implications for management of other acute respiratory viral illnesses that contribute to hospital bed pressure during winter months is immense. Virtual HITH is likely to be a key enabler of a sustainable healthcare system.

Modeling anabolic and antiresorptive therapies for fracture healing in a mouse model of osteogenesis imperfecta

Osteogenesis imperfecta (OI) is a genetic bone fragility disorder that features frequent fractures. Bone healing outcomes are contingent on a proper balance between bone formation and resorption, and drugs such as bone morphogenetic proteins (BMPs) and bisphosphonates (BPs) have shown to have utility in modulating fracture repair. While BPs are used for OI to increase BMD and reduce pain and fracture rates, there is little evidence for using BMPs as local agents for fracture healing (alone or with BPs). In this study, we examined wild-type and OI mice (Col1a2^+/G610C ) in a murine tibial open fracture model with (i) surgery only/no treatment, (ii) local BMP-2 (10 µg), or (iii) local BMP-2 and postoperative zoledronic acid (ZA; 0.1 mg/kg total dose). Microcomputed tomography reconstructions of healing fractures indicated BMP-2 was less effective in an OI setting, however, BMP-2 +ZA led to considerable increases in bone volume (+193% WT, p < 0.001; +154% OI, p < 0.001) and polar moment of inertia (+125% WT, p < 0.01; +248% OI, p < 0.05). Tissue histology revealed a thinning of the neocortex of the callus in BMP-2 treated OI bone, but considerable retention of woven bone in the healing callus with BMP + ZA specimens. These data suggest a cautious approach may be warranted with the sole application of BMP-2 in an OI surgical setting as a bone graft substitute. However, this may be overcome by off-label BP administration.

Murine models of orthopedic infection featuring Staphylococcus aureus biofilm

Introduction: Osteomyelitis remains a major clinical challenge. Many published rodent fracture infection models are costly compared with murine models for rapid screening and proof-of-concept studies. We aimed to develop a dependable and cost-effective murine bone infection model that mimics bacterial bone infections associated with biofilm and metal implants. Methods: Tibial drilled hole (TDH) and needle insertion surgery (NIS) infection models were compared in C57BL/6 mice (female, N = 150 ). Metal pins were inserted selectively into the medullary canal adjacent to the defect sites on the metaphysis. Free Staphylococcus aureus (ATCC 12600) or biofilm suspension (ATCC 25923) was locally inoculated. Animals were monitored for physiological or radiographic evidence of infection without prophylactic antibiotics for up to 14 d. At the end point, bone swabs, soft-tissue biopsies, and metal pins were taken for cultures. X-ray and micro-CT scans were performed along with histology analysis. Results: TDH and NIS both achieved a 100 % infection rate in tibiae when a metal implant was present with injection of free bacteria. In the absence of an implant, inoculation with a bacterial biofilm still induced a 40 %-50 % infection rate. In contrast, freely suspended bacteria and no implant consistently showed lower or negligible infection rates. Micro-CT analysis confirmed that biofilm infection caused local bone loss even without a metal implant as a nidus. Although a metal surface permissive for biofilm formation is impermeable to create progressive bone infections in animal models, the metal implant can be dismissed if a bacterial biofilm is used. Conclusion: These models have a high potential utility for modeling surgery-related osteomyelitis, with NIS being simpler to perform than TDH.

What's New in Cryptococcus gattii: From Bench to Bedside and Beyond

Cryptococcus species are a major cause of life-threatening infections in immunocompromised and immunocompetent hosts. While most disease is caused by Cryptococcus neoformans, Cryptococcus gattii, a genotypically and phenotypically distinct species, is responsible for 11-33% of global cases of cryptococcosis. Despite best treatment, C. gattii infections are associated with early mortality rates of 10-25%. The World Health Organization's recently released Fungal Priority Pathogen List classified C. gattii as a medium-priority pathogen due to the lack of effective therapies and robust clinical and epidemiological data. This narrative review summarizes the latest research on the taxonomy, epidemiology, pathogenesis, laboratory testing, and management of C. gattii infections.

The application of ceragenins to orthopedic surgery and medicine

Osteomyelitis and infections associated with orthopedic implants represent a significant burden of disease worldwide. Ceragenins (CSAs) are a relatively new class of small-molecule antimicrobials that target a broad range of Gram-positive and Gram-negative bacteria as well as fungi, viruses, and parasites. This review sets the context of the need for new antimicrobial strategies by cataloging the common pathogens associated with orthopedic infection and highlighting the increasing challenges of managing antibiotic-resistant bacterial strains. It then comparatively describes the antimicrobial properties of CSAs with a focus on the CSA-13 family. More recently developed members of this family such as CSA-90 and CSA-131 may have a particular advantage in an orthopedic setting as they possess secondary pro-osteogenic properties. In this context, we consider several new preclinical studies that demonstrate the utility of CSAs in orthopedic models. Emerging evidence suggests that CSAs are effective against antibiotic-resistant Staphylococcus aureus strains and can prevent the formation of biofilms. There remains considerable scope for developing CSA-based treatments, either as coatings for orthopedic implants or as local or systemic antibiotics to prevent bone infection.

Lung adenocarcinoma with thyroid metastasis: a case report

BACKGROUND

The metastases of a primary lung cancer over the thyroid gland are extremely rare. We report on an unusual presentation of thyroid metastasis of lung cancer in order to improve the management of similar cases.

CASE PRESENTATION

Three years ago, a Moroccan male 59-year-old was admitted for dyspnea, dry cough, and chest pain. He had smoked about 30 cigarette packs a year. Clinical examination revealed a right thyroid nodule. Chest and neck computed tomography (CT) scan showed a proximal left tumor in contact with the pulmonary artery and revealed a suspected nodule in the right lobe of the thyroid with homolateral neck node. Transbronchial biopsy was performed and pathological examination revealed adenocarcinoma of the lung and positive for thyroid transcription factor. Other explorations carried out, such as brain CT, bone scan and abdominal ultrasound were normal. After a repeated negative fine needle aspiration biopsy of the suspected nodule of the right lobe of the thyroid, we performed total thyroidectomy with neck dissection. An anatomopathologic exam revealed a tubulopapillary adenocarcinoma poorly differentiated. An Immunohistochemistry showed positive tumor cells with TTF1 and cytokeratin (CK) 7 but negative cells with thyroglobulin and CK20. Thus, the pulmonary tumor was classified stage IV. Chemotherapy based on the combination of cisplatin and etoposide was conducted along with supportive care. The tumor grew up with brain metastases after three cycles of chemotherapy. Unfortunately, the patient died 2 months after despite brain radiotherapy.

CONCLUSION

We presented a medical case of a patient with thyroid metastasis resulting from a pulmonary adenocarcinoma which has rapidly evolved to brain metastases. The prognosis was pejorative in our clinical case (5 months after admission).

MLST-Based Population Genetic Analysis in a Global Context Reveals Clonality amongst Cryptococcus neoformans var. grubii VNI Isolates from HIV Patients in Southeastern Brazil

Cryptococcosis is an important fungal infection in immunocompromised individuals, especially those infected with HIV. In Brazil, despite the free availability of antiretroviral therapy (ART) in the public health system, the mortality rate due to Cryptococcus neoformans meningitis is still high. To obtain a more detailed picture of the population genetic structure of this species in southeast Brazil, we studied 108 clinical isolates from 101 patients and 35 environmental isolates. Among the patients, 59% had a fatal outcome mainly in HIV-positive male patients. All the isolates were found to be C. neoformans var. grubii major molecular type VNI and mating type locus alpha. Twelve were identified as diploid by flow cytometry, being homozygous (AαAα) for the mating type and by PCR screening of the STE20, GPA1, and PAK1 genes. Using the ISHAM consensus multilocus sequence typing (MLST) scheme, 13 sequence types (ST) were identified, with one being newly described. ST93 was identified from 81 (75%) of the clinical isolates, while ST77 and ST93 were identified from 19 (54%) and 10 (29%) environmental isolates, respectively. The southeastern Brazilian isolates had an overwhelming clonal population structure. When compared with populations from different continents based on data extracted from the ISHAM-MLST database (mlst.mycologylab.org) they showed less genetic variability. Two main clusters within C. neoformans var. grubii VNI were identified that diverged from VNB around 0.58 to 4.8 million years ago.

The members of the Cryptococcus neoformans / Cryptococcus gattii species complex are the cause of cryptococcosis, a life-threatening human disease responsible for 624,000 deaths annually. Infection is acquired through inhalation of dehydrated yeast cells from environmental sources. After reaching the lungs, the fungus disseminates to the central nervous system causing meningoencephalitis. The majority of meningitis cases in HIV-infected patients are caused by C. neoformans, a species well studied in regions with a high prevalence of HIV infection, such as Asia and Africa. A similar high prevalence has been reported from Brazil however the epidemiology of these infections is less well understood. We studied clinical and environmental isolates from the southeast region of Brazil using MLST. The results that we obtained showed a clonal population structure of C. neoformans var. grubii VNI, with low variability when compared against populations from different continents. This lower variability is probably the result of multiple recent dispersal events from Africa to the Americas. The majority of clinical isolates were of one sequence type (ST93), which was also found in environmental samples. By expanding the analysis to isolates from around the globe, it was possible to identify two major groups among C. neoformans var. grubii VNI.

Seasonal variation in spatial distributions of Anopheles gambiae in a Sahelian village: evidence for aestivation

Changes in spatial distribution of mosquitoes over time in a Sahelian village were studied to understand the sources of the mosquitoes during the dry season when no larval sites are found. At that time, the sources of Anopheles gambiae Giles may be local shelters used by aestivating mosquitoes or migrants from distant populations. The mosquito distribution was more aggregated during the dry season, when few houses had densities 7- to 24-fold higher than expected. The high-density houses during the dry season differed from those of the wet season. Most high-density houses during the dry season changed between years, yet their vicinity was rather stable. Scan statistics confirmed the presence of one or two adjacent hotspots in the dry season, usually found on one edge of the village. These hotspots shifted between the early and late dry season. During the wet season, the hotspots were relatively stable near the main larval site. The locations of the hotspots in the wet season and early and late dry season were similar between years. Season-specific, stable, and focal hotspots are inconsistent with the predictions based on the arrival of migrants from distant localities during the dry season, but are consistent with the predictions based on local shelters used by aestivating mosquitoes. Targeting hotspots in Sahelian villages for vector control may not be effective because the degree of aggregation is moderate, the hotspots are not easily predicted, and they are not the sources of the population. However, targeting the dry-season shelters may be highly cost-effective, once they can be identified and predicted.

Reproductive output of female Anopheles gambiae (Diptera: Culicidae): comparison of molecular forms

Knowledge of ecological differences between the molecular forms of Anopheles gambiae Giles (Diptera: Culicidae) might lead to understanding of their unique contribution to disease transmission, to better vector control, and to identification of the forces that have separated them. We compared female fecundity measured as egg batch size in relation to body size between the molecular forms in Mali and contrasted them with their sibling species, Anopheles arabiensis Patton. To determine whether eggs of different egg batches are of similar "quality," we compared the total protein content of first-stage larvae (L1s), collected < 2 h after hatching in deionized water. Egg batch size significantly varied between An. gambiae and An. arabiensis and between the molecular forms of An. gambiae (mean batch size was 186.3, 182.5, and 162.0 eggs in An. arabiensis and the M and the S molecular form of An. gambiae, respectively). After accommodating female body size, however, the difference in batch size was not significant. In the S molecular form, egg protein content was not correlated with egg batch size (r = -0.08, P > 0.7) nor with female body size (r = -0.18, P > 0.4), suggesting that females with more resources invest in more eggs rather than in higher quality eggs. The mean total protein in eggs of the M form (0.407 microg per L1) was 6% higher than that of the S form (0.384 microg per L1), indicating that the M form invests a greater portion of her resources into current (rather than future) reproduction. A greater investment per offspring coupled with larger egg batch size may reflect an adaptation of the M form to low productivity larval sites as independent evidence suggests.

Complete recovery from Cryptosporidium parvum infection with gastroenteritis and sclerosing cholangitis after successful bone marrow transplantation in two brothers with X-linked hyper-IgM syndrome

We describe two brothers who suffered from hyper-IgM syndrome (HIGM1) with similar clinical features: recurrent infections, especially cryptosporidium gastroenteritis with cholangitis. Their activated T cells did not express CD40L. Nucleotide sequencing revealed a mutation in both boys with respect to intron 4 and exon 5 boundaries of the CD40L gene in Xq26. They underwent successful bone marrow transplantation (BMT) from HLA-geno-identical siblings. The Cryptosporidium infection and cholangitis resolved thereafter. At 6 months after BMT, expression of CD40L on activated T lymphocytes was normal. After 1 year, both boys are well, and immune reconstitution has improved. Based on these two successful experiences, BMT with a genoidentical sibling seems a reasonable therapeutic approach for HIGM1, if Cryptosporidium infection occurs.

Unspecific reactivity of IgM directed against the low-molecular-weight antigen of Toxoplasma gondii

During routine serological survey, eight patients (5 pregnant women, 3 grafted patients) were positive for Toxoplasma gondii-specific IgM by enzyme-linked immunoassay but negative by a simultaneously performed immunosorbent agglutination assay. No clinical or biological symptoms of toxoplasmosis were observed later, despite the absence of treatment. Only one IgM-reactive band, which corresponded to the low-molecular-weight antigen of Toxoplasma gondii, was observed by Western blotting of these patients' sera. Dot blotting of lipid extracts of Toxoplasma gondii demonstrated that this reactivity was directed against sphingolipids or ceramides. This IgM positivity, which is unrelated to acute toxoplasmosis, raises strong concerns about the possibility of misleading results of this test in the diagnosis of toxoplasmosis in humans.

Behavioural determinants of gene flow in malaria vector populations: Anopheles gambiae males select large females as mates

BACKGROUND

Plasmodium-refractory mosquitoes are being rapidly developed for malaria control but will only succeed if they can successfully compete for mates when released into the wild. Pre-copulatory behavioural traits maintain genetic population structure in wild mosquito populations and mating barriers have foiled previous attempts to control malaria vectors through sterile male release.

METHODS

Varying numbers of virgin male and female Anopheles gambiae Giles, from two strains of different innate sizes, were allowed to mate under standardized conditions in laboratory cages, following which, the insemination status, oviposition success and egg batch size of each female was assessed. The influence of male and female numbers, strain combination and female size were determined using logistic regression, correlation analysis and a simple mechanistic model of male competition for females.

RESULTS

Male An. gambiae select females on the basis of size because of much greater fecundity among large females. Even under conditions where large numbers of males must compete for a smaller number of females, the largest females are more likely to become inseminated, to successfully oviposit and to produce large egg batches.

CONCLUSIONS

Sexual selection, on the basis of size, could either promote or limit the spread of malaria-refractory genes into wild populations and needs to be considered in the continued development and eventual release of transgenic vectors. Fundamental studies of behavioural ecology in malaria vectors such as An. gambiae can have important implications for malaria control and should be prioritised for more extensive investigation in the future.

[Multiple exostoses. Review of the literature. Apropos of a case disclosed during an injury]

The authors report a case of bilateral fracture of the thigh bone that occurred in a 22 year old man with multiple exostosis. Clinical deformities, radiology and histology confirmed the diagnosis. Traumatic fractures were caused by a road accident. The treatment, because of deformities, consisted of an open fire synthesis of the both thigh bones with Küntscher's nails. The post-operative evolution was marked by rapid healing of fractures. The scarcity of this genetic affection and the symmetrical lesions have lead the authors to conduct a literature review.

[Evaluation of the Immulite 2000 Toxoplasma quantitative IgG et Toxoplasma IgM for the diagnosis of human toxoplasmosis]

Four hundred and ninety five human sera with clinical and biological data were tested for the evaluation of Immulite 2000 Toxoplasma Quantitative IgG and Immulite 2000 Toxoplasma IgM produced by Diagnostic Products Corporation (Los Angeles, USA) for the diagnosis of human toxoplasmosis. The results of these kits were compared to those of the University Hospital of Nancy where the reference assays were Enzygnost Toxoplasmosis IgG and Enzygnost Toxoplasmosis IgM (Berhing-Dade, Germany), Toxoscreen (bioMérieux, France), ISAgA Plus (IgM et IgA) (bioMérieux, France). The sensitivity and the specificity of IgG detection by Immulite 2000 Toxoplasma Quantitative IgG were 98% and 100%, respectively. The high sensitivity of IgM detection by Immulite 2000 Toxoplasma IgM was adapted to the early diagnosis of toxoplasmic primo-infection and to the pediatric diagnosis or follow-up of congenital toxoplasmosis but could reveal IgM a long time after primary infection.

Successful reinfection of chronically infected mice by a different Toxoplasma gondii genotype

It is generally assumed that primary infection by Toxoplasma gondii protects from reinfection. A recent study using a murine model has questioned this dogma using indirect procedures to detect the reinfecting strain. We have reinvestigated this issue using a transfected strain of T. gondii (Prugniaud beta galactosidase: Pru beta gal) which expresses Escherichia coli beta-galactosidase. Detection of enzyme activity on fixed parasites allows a direct distinction between transfected and untransfected strains. We have found that in OF1 mice primary infection with the 76 K strain of T. gondii fully protects mice against tissue cyst production upon reinfection with the Pru beta gal T. gondii strain whereas primary infection with the Pru beta gal T. gondii strain does not impair tissue cyst formation upon reinfection with the Ned strain of T. gondii, which belongs to another T. gondii genotype. These results suggest that the immune protection conferred by one strain of T. gondii can be breached by reinfection with a strain belonging to another genotype; which can have significant consequences in human or veterinary medicine.

Laboratory diagnosis of cystic hydatic disease

The main purpose of this article is to answer the questions about which test to perform for hydatic diagnosis and when. Several techniques for biologic diagnosis and follow-up of human cystic hydatidosis are reviewed. The specificity and sensitivity of immunologic reactions are reported. The differential diagnosis between Echinococcus granulosus and E. multilocularis is examined. The characteristics of the immunologic diagnosis according to the stage and the treatment of hydatidosis disease is discussed. Laboratory diagnosis of cystic hydatic disease is complementary to the clinical data. A judicious association of the usual techniques (indirect immunofluorescence assay, indirect hemagglutination assay, immunoelectrophoresis, co-electrophoresis with antigen 5 identification) confirms the diagnosis in 80% to 94% of hepatic hydatidosis cases and in 65% of pulmonary hydatidosis cases. Special techniques (enzyme-linked immunosorbent assay, Western blot, polymerase chain reaction) must be used for other localizations or when cysts are calcified. A serologic survey is necessary for the follow-up of operated medically treated patients. Despite poor standardization, purified antigens can distinguish between E. granulosus and E. multilocularis infections, although false-positive results are observed during other helminthiases, such as cysticerocosis.

Osteonecrosis of the hip in sickle-cell disease associated with tuberculous arthritis. A review of 15 cases

We report a study of 15 cases of tuberculous hips with sickle-cell disease who presented during 1991-1993. Although the osteonecrosis was long-standing, biopsy was nearly always required to reveal the more recent tuberculous infection. Management consisted of 6 months of anti-tuberculous chemotherapy with appropriate palliative surgery 5-8 weeks after the start of drug treatment. The operative techniques which we used are described. The results were good both post-operatively, and in 12 patients followed-up at an average of 3 years. We recommend this combined management for the treatment of secondary tuberculous infections of hips previously damaged by sickle-cell disease.

Mark-release-recapture experiments with Anopheles gambiae s.l. in Banambani Village, Mali, to determine population size and structure

Mark-release-recapture experiments with Anopheles gambiae s.l. were performed during the wet seasons of 1993 and 1994 in Banambani, Mali. All recaptured mosquitoes were identified to species by PCR analysis and, when possible, by chromosomal analysis to chromosomal form. Two species of the An. gambiae complex were present: An. gambiae s.s. and An. arabiensis; their ratio differed greatly from one year to the next. Three chromosomal forms of An. gambiae s.s. were found--Bamako, Savanna and Mopti. The drier 1993 was characterized by a high frequency of An. arabiensis and of the Mopti chromosomal forms of An. gambiae s.s. These trends were consistent with large-scale geographical patterns of abundance along a precipitation gradient. We observed no difference in dispersal between the two species, nor among the chromosomal forms of An. gambiae s.s. Therefore, in this situation at least, it is reasonable to group such data on the An. gambiae complex as a whole for analysis. Population size of An. gambiae s.l. females in the village was estimated to be 9000-11,000 in 1993 and 28,000 in 1994. The corresponding numbers were somewhat higher when independently-derived values of daily survival were used. These were consistent with estimates of effective population size obtained from patterns of gene frequency change.

[Application from chemiluminescence to serological diagnosis of human toxoplasmosis]

Diagnostic Products Corporation has chosen chemiluminescent for the new kit of quantitative measurement of IgG and qualitative detection of IgM antibodies to Toxoplasma gondii, 878 human sera of principal diagnosis situations were tested, and the results obtained with the IMMULITE Toxoplasmosis kit were compared with those of the Parasitology and Mycology Laboratory of the University of Lille. Chemiluminescent allows a sensitive and specific determination of immunity. In the same ways, this method is able to detect earlier specific IgM and IgG during seroconversion. The kit of quantitative measurement of IgG and qualitative detection of IgM is reproducible and sensitive; this confirms the interest for the pediatric diagnosis of congenital toxoplasmosis.

[Study of developing clinical outbreak and serological rebounds in children with congenital toxoplasmosis and follow-up during the first 2 years of life]

BACKGROUND

The survival of T gondii bradyzoites in cysts explains clinical recurrences and serological rebounds after birth in children with congenital toxoplasmosis. At the present time, management of such manifestations is not well defined.

PATIENTS AND METHODS

Sixty-three infants with congenital toxoplasmosis were followed-up at the University Hospital of Lille (France) during the first two years of life. For each child, the treatment before and after birth was well defined. Clinical, ophthalmological, radiological and serological data were collected every third month. Serological assays specially adapted to this age bracket were used for the quantification of specific IgG, or for the detection of T gondii specific IgM and IgA.

RESULTS

Seventy-six serological rebounds were reported in 55 of the 63 children (87%). They concerned essentially IgG (96%) and less frequently IgM (47%) or IgA (60%). At the same time, only five clinical recurrences were observed, four of them being preceded by a serological rebound.

DISCUSSION

Treatment of fetuses or children with pyrimethamine and sulfonamides versus spiramycin alone was associated with a decrease in the frequency of serological rebounds during the first year of life (P < 0.001). Such a therapeutic regimen during the second year of life decreases the appearance of serological rebounds in children without rebound antecedent (P < 0.001).

CONCLUSION

The increase in number of rebounds after the end of a course of pyrimethamine and sulfonamides necessitates the evaluation of such a long term treatment without interruption.

Proliferative pancreatic cysts: pathogenesis and treatment options

Proliferative pancreatic cysts are subdivided into microcystic and mucinous cystadenomas. These rare, slow-growing, multilocular lesions usually remain localized for long periods of time, therefore frequently becoming rather sizeable before becoming symptomatic. Patients present with intermittent abdominal or back pain, nausea and vomiting, early satiety, and a palpable mass without a history of trauma or alcoholism. Computed tomographic scanning is the most useful laboratory test. The lesions are more often found in women, with the microcystic adenomas usually located in the head of the pancreas and the mucinous lesions in the pancreatic body or tail. At surgery, if it is at all possible, the lesions should be completely removed, even if it means performance of a Whipple procedure. This is particularly important for mucinous cysts because of their potential for malignant degeneration. Internal drainage or marsupialization procedures should not be done in these patients. The long-term results are excellent if the entire lesion is removed.

Cutaneous metastatic adenocarcinoma of gallbladder origin

Cutaneous metastases developed in a 74-year-old woman from an adenocarcinoma of the gallbladder. A biopsy specimen of a cutaneous nodule showed the presence of systemic cancer. Results of a histopathologic examination, along with the autopsy findings, established that the cutaneous metastasis was of gallbladder origin. This article reports the extreme rarity of metastases from a cancer of the gallbladder to the skin.