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Christoph Hatz

Publications and source records attributed to Christoph Hatz.

18 recordsLinked to original sources
PubMed2006

Risk factors for surgical site infection in a Tanzanian district hospital: a challenge for the traditional National Nosocomial Infections Surveillance system index.

The incidence of surgical site infections (SSIs) was 24% in a district hospital in Tanzania. Wound classification was not an independent risk factor for SSI, indicating that risk scores developed in industrialized countries may require adjustments for nonindustrialized countries. The National Nosocomial Infections Surveillance system score required adjustments to reliably predict SSI, probably to account for improper hygiene and the lack of adjustment for the duration of surgery (defined as the 75th percentile of the duration for each type of operative procedure) to reflect local circumstances. Multidrug-resistant pathogens, such as methicillin-resistant Staphylococcus aureus and gram-negative pathogens expressing broad-spectrum beta-lactamases, have already emerged.

Adult↗
PubMed2006

First case of ivermectin-induced severe hepatitis.

Loiasis, caused by the filarial parasite Loa loa, is endemic in West and Central Africa. Ivermectin has been shown to be an effective treatment of loiasis. We report the case of a 20-year-old woman originally from Cameroon who was infected by the L. loa parasite and developed severe hepatitis, identified 1 month after a single dose of ivermectin. Liver biopsy showed intralobular inflammatory infiltrates, confluent necrosis and apoptosis, compatible with drug-induced liver disease. To our knowledge, this is the first case of ivermectin-induced severe liver disease published in the literature.

Adult↗
PubMed2006

Moving up from 3 by 5.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed2005

Hepatitis A vaccines and the elderly.

Hepatitis A virus (HAV) exposure in unprotected adults may cause severe and serious symptoms, with risk of both morbidity and mortality increasing with age. As seroprevalence of HAV is low in industrialised countries, and an increasing number of people, with an increasing median age, travel from areas of low HAV endemicity to high endemicity, pre-travel vaccination is warranted. Vaccination of the elderly against HAV, however, may be associated with reduced seroprotection, since the immune response decreases with age. Studies with monovalent hepatitis A vaccine or combined hepatitis A and B vaccine show good efficacy in adults in general. Few studies have assessed the immune response in older adults. The only prospective study with monovalent hepatitis A vaccine in the elderly showed a reduced seroprotection of approximately 65% after a single primary dose in subjects over the age of 50 years, while seroprotection was 98% in this age group after receiving a booster dose. The only prospective study with combined hepatitis A and B vaccine in younger subjects or older than 40 years showed similar seroprotection (99-100%) against HAV compared to a monovalent vaccine after receiving three doses. As data on seroprotection for HAV in the elderly are limited, further studies are needed to elucidate how optimal protection in the elderly can be achieved. In the mean time, based on the available data, the suggestion is made to screen elderly travellers to areas endemic for HAV for the presence of naturally acquired immunity, and, if found susceptible, be immunised well in advance of their trip, to allow time for post-vaccination antibody testing and/or administration of a second dose of the vaccine.

Age Factors↗
PubMed2005

Mansonella perstans causing symptomatic hypereosinophilia in a missionary family.

Mansonella perstans is rarely pathogenic. The rare reports of symptomatic cases, however, include severe complications. Three cases of symptomatic hypereosinophilia with multi-organ involvement are described in a missionary family returning from tropical Africa. Pathogenicity may be related to the induction of hypereosinophilia rather than direct host-parasite interactions.

Adolescent↗
PubMed2005

Stonefish envenomation--a lucky outcome.

Stonefish are one of the most intriguing examples of a perilous marine inhabitant. Equipped with a sophisticated defence mechanism, 13 dorsal spines armed with one of the most toxic fish venoms, against its natural foes, it lays perfectly camouflaged under the sand in shallow waters. Unsuspicious bypassers can be in for a deadly surprise as several fatalities, even after minor injuries, have been reported. We present an unlucky patient who sustained a single puncture wound causing her tremendous pain immediately. Surprisingly she did not develop complications after a considerable delay in receiving medical care. A review of the literature gives a brief account of pathophysiolology, complications and treatment.

Animals↗
PubMed2005

Sushi delights and parasites: the risk of fishborne and foodborne parasitic zoonoses in Asia.

Because of the worldwide popularization of Japanese cuisine, the traditional Japanese fish dishes sushi and sashimi that are served in Japanese restaurants and sushi bars have been suspected of causing fishborne parasitic zoonoses, especially anisakiasis. In addition, an array of freshwater and brackish-water fish and wild animal meats, which are important sources of infection with zoonotic parasites, are served as sushi and sashimi in rural areas of Japan. Such fishborne and foodborne parasitic zoonoses are also endemic in many Asian countries that have related traditional cooking styles. Despite the recent increase in the number of travelers to areas where these zoonoses are endemic, travelers and even infectious disease specialists are unaware of the risk of infection associated with eating exotic ethnic dishes. The aim of this review is to provide practical background information regarding representative fishborne and foodborne parasitic zoonoses endemic in Asian countries.

Animals↗
PubMed2005

Meta-analysis: accuracy of rapid tests for malaria in travelers returning from endemic areas.

BACKGROUND: Microscopic diagnosis of malaria is unreliable outside specialized centers. Rapid tests have become available in recent years, but their accuracy has not been assessed systematically. PURPOSE: To determine the accuracy of rapid diagnostic tests for ruling out malaria in nonimmune travelers returning from malaria-endemic areas. DATA SOURCES: The authors searched MEDLINE, EMBASE, CAB Health, and CINAHL (1988 to September 2004); hand-searched conference proceedings; checked reference lists; and contacted experts and manufacturers. STUDY SELECTION: Diagnostic accuracy studies in nonimmune individuals with suspected malaria were included if they compared rapid tests with expert microscopic examination or polymerase chain reaction tests. DATA EXTRACTION: Data on study and patient characteristics and results were extracted in duplicate. The main outcome was the likelihood ratio for a negative test result (negative likelihood ratio) for Plasmodium falciparum malaria. Likelihood ratios were combined by using random-effects meta-analysis, stratified by the antigen targeted (histidine-rich protein-2 [HRP-2] or parasite lactate dehydrogenase [LDH]) and by test generation. Nomograms of post-test probabilities were constructed. DATA SYNTHESIS: The authors included 21 studies and 5747 individuals. For P. falciparum, HRP-2-based tests were more accurate than parasite LDH-based tests: Negative likelihood ratios were 0.08 and 0.13, respectively (P = 0.019 for difference). Three-band HRP-2 tests had similar negative likelihood ratios but higher positive likelihood ratios compared with 2-band tests (34.7 vs. 98.5; P = 0.003). For P. vivax, negative likelihood ratios tended to be closer to 1.0 for HRP-2-based tests than for parasite LDH-based tests (0.24 vs. 0.13; P = 0.22), but analyses were based on a few heterogeneous studies. Negative likelihood ratios for the diagnosis of P. malariae or P. ovale were close to 1.0 for both types of tests. In febrile travelers returning from sub-Saharan Africa, the typical probability of P. falciparum malaria is estimated at 1.1% (95% CI, 0.6% to 1.9%) after a negative 3-band HRP-2 test result and 97% (CI, 92% to 99%) after a positive test result. LIMITATIONS: Few studies evaluated 3-band HRP-2 tests. The evidence is also limited for species other than P. falciparum because of the few available studies and their more heterogeneous results. Further studies are needed to determine whether the use of rapid diagnostic tests improves outcomes in returning travelers with suspected malaria. CONCLUSIONS: Rapid malaria tests may be a useful diagnostic adjunct to microscopy in centers without major expertise in tropical medicine. Initial decisions on treatment initiation and choice of antimalarial drugs can be based on travel history and post-test probabilities after rapid testing. Expert microscopy is still required for species identification and confirmation.

Aldehyde-Lyases↗
PubMed2004

Screening for mutations related to atovaquone/proguanil resistance in treatment failures and other imported isolates of Plasmodium falciparum in Europe.

BACKGROUND: Two single-point mutations of the Plasmodium falciparum cytochrome b gene (Tyr268Asn and Tyr268Ser) were recently reported in cases of atovaquone/proguanil (Malarone) treatment failure. However, little is known about the prevalence of codon-268 mutations and their quantitative association with treatment failure. METHODS: We set out to assess the prevalence of codon-268 mutations in P. falciparum isolates imported into Europe and to quantify their association with atovaquone/proguanil treatment failure. Isolates of P. falciparum collected by the European Network on Imported Infectious Disease Surveillance between April 2000 and August 2003 were analyzed for codon-268 mutations, by use of polymerase chain reaction-restriction fragment-length polymorphism. RESULTS: We successfully screened 504 samples for the presence of either Tyr268Ser or Tyr268Asn. One case of Ser268 and no cases of Asn268 were detected. Therefore, we can be 95% confident that the prevalence of Ser268 in the European patient pool does not exceed 0.96% and that Asn268 is less frequent than 0.77%. In 58 patients treated with atovaquone/proguanil, Tyr268Ser was present in 1 of 5 patients with treatment failure but in 0 of 53 successfully treated patients. CONCLUSIONS: Tyr268Ser seems to be a sufficient, but not a necessary, cause for atovaquone/proguanil treatment failure. The prevalence of both codon-268 mutations is currently unlikely to be >1% in the European patient pool.

Adolescent↗
PubMed2003

Successful booster antibody response up to 54 months after single primary vaccination with virosome-formulated, aluminum-free hepatitis A vaccine.

This study demonstrates that a booster dose of the virosome-formulated, aluminum-free hepatitis A vaccine Epaxal (Berna Biotech) is highly immunogenic in subjects who received a single primary dose of this vaccine 18-54 months earlier. There were no significant differences in geometric mean antibody titers (GMTs) among subjects who received the booster dose 18-29 months (GMT, 2330 mIU/mL), 30-41 months (GMT, 2395 mIU/mL), or 42-54 months (GMT, 2432 mIU/mL) after primary vaccination, indicating that delays in the administration of booster vaccination do not lead to a loss of immunogenicity.

Adult↗
PubMed2003

Ultrasound in tropical and parasitic diseases.

CONTEXT: Migration and worldwide travel mean that western clinicians and radiologists more and more face imported tropical diseases. Diseases with unclear signs and symptoms are likely to be investigated with ultrasound. Many tropical diseases have particular ultrasonographic features that are not familiar to the examiner and which may lead to further unnecessary or even harmful diagnostic investigations. In developing countries, ultrasound machines are becoming more widely distributed and are fairly cheap. Portable devices allow field use of ultrasound for population studies and individual diagnosis of tropical diseases. STARTING POINT: Recently, WHO introduced a standardised classification of ultrasonographic images of cystic echinococcosis (Acta Trop 2003; 85: 253-61), to obtain comparable results in patients worldwide and to link disease status with each morphological type of echinococcosis cyst. WHO also defined guidelines for the puncture, aspiration, injection of ethanol, and re-aspiration of such cysts. Ultrasound allows diagnosis of schistosomiasis-induced periportal fibrosis and bladder abnormalities. Liver abscesses can be differentiated from other focal lesions such as cysts or neoplasms. For amoebic abscesses, invasive procedures are usually not required. In doubtful cases ultrasound-guided puncture can give adequate material for microscopy and culture. Helminths (eg, ascaris), flukes, and filariae can be seen directly with ultrasound. Filaria-induced damage also includes hypoechogenic splenic foci and ultrasonographic abnormalities due to tropical hypereosinophilia. WHERE NEXT? Classification of cysts and procedures that are less invasive than conventional surgery are being developed further for cystic echinococcosis. Novel methods are needed for the assessment of polycystic and alveolar echinococcosis. Ultrasound protocols for schistosomiasis are being evaluated for interobserver reliability, relation to clinical disease status, and power to predict complications. A WHO expert-group is also developing a standardised protocol for Asian schistosomiasis. International consensus on an algorithm for managing amoebic liver abscesses is needed.

Echinococcosis↗
PubMed2003

Molecular surveillance of the antifolate-resistant mutation I164L in imported African isolates of Plasmodium falciparum in Europe: sentinel data from TropNetEurop.

BACKGROUND: Malaria parasites that carry the DHFR-mutation I164L are not only highly resistant to sulfadoxine-pyrimethamine but also to the new antimalarial drug chlorproguanil-dapsone. The spread of this mutation in Africa would result in a public health disaster since there is a lack of effective alternatives that are both affordable and safe. Up to now, this mutation has only been described in Asian and Latin-American countries. The objective of this study was to assess the prevalence of this mutation in African isolates of Plasmodium falciparum that have been imported into Europe through travellers. METHODS: TropNetEurop is a network for the surveillance of travel-associated diseases and seems to cover approximately 12% of all malaria cases imported into Europe. Within this network we screened 277 imported African isolates of P. falciparum with the help of PCR- and enzyme-digestion-methods for the antifolate-resistant mutation I164L. RESULTS: The I164L mutation was not detected in any of the isolates tested. DISCUSSION: Continuous molecular surveillance of mutations in P. falciparum, as it is practised within TropNetEurop, is an essential tool for the understanding and early detection of the spread of antimalarial drug resistance in Africa.

Amino Acid Substitution↗
PubMed2002

Molecular surveillance of drug resistance through imported isolates of Plasmodium falciparum in Europe.

BACKGROUND: Results from numerous studies point convincingly to correlations between mutations at selected genes and phenotypic resistance to antimalarials in Plasmodium falciparum isolates. In order to move molecular assays for point mutations on resistance-related genes into the realm of applied tools for surveillance, we investigated a selection of P. falciparum isolates that were imported during the year 2001 into Europe to study the prevalence of resistance-associated point mutations at relevant codons. In particular, we tested for parasites which were developing resistance to antifolates and chloroquine. The screening results were used to map the prevalence of mutations and, thus, levels of potential drug resistance in endemic areas world-wide. RESULTS: 337 isolates have been tested so far. Prevalence of mutations that are associated with resistance to chloroquine on the pfcrt and pfmdr genes of P. falciparum was demonstrated at high levels. However, the prevalence of mutations associated with resistance to antifolates at the DHFR and DHPS genes was unexpectedly low, rarely exceeding 60% in endemic areas. CONCLUSIONS: Constant screening of imported isolates will enable TropNetEurop to establish a screening tool for emerging resistance in endemic areas.

ATP-Binding Cassette Transporters↗
PubMedDate not supplied

Antigenic cross-reactivity between different alleles of the Plasmodium falciparum merozoite surface protein 2.

The polymorphic domain of the gene encoding Plasmodium falciparum merozoite surface protein 2 (MSP2) was PCR amplified from blood of malaria patients, genotyped, and 19 distinct fragments were cloned and expressed in E. coli. The reactivity of naturally occurring antibodies against this panel of recombinant MSP2 antigens was tested using 67 homologous or heterologous sera from a serum bank of travel clinic patients. Sera from semi-immune individuals strongly recognized almost all recombinant antigens. Sera from primary infected patients either did not react at all (9 sera), or reacted weakly against varying numbers of antigens (39 sera). The antigens that showed reactions were mostly of the allelic family corresponding to the infecting clone, but in very few cases also of the alternative allelic family. Single clone infections and repeated samples from the same individual were analysed in greater detail. Thus, we were able to quantify cross-reactivity induced by a single P. falciparum infection. Within the two allelic families of MSP2, cross-reactivity was observed between some but not all alleles of the same family, whereas antibodies cross-reactive between variants belonging to different allelic families were detected in only a few cases.

Adult↗
PubMedDate not supplied

Impact of organized violence on illness experience of Turkish/Kurdish and Bosnian migrant patients in primary care.

BACKGROUND: Migration, particularly when associated with exposure to organized violence, can seriously affect mental and physical health in ways that are not obvious. This study considers the clinical impact of organized violence on emotional and somatic problems encountered in the course of primary health care. METHODS: Migrant patients from Bosnia (n=36) and Turkey (n=62) in primary care were recruited into the study and divided into two groups: male and female migrants of both countries who reported experience of organized violence and those who did not. Symptom profiles and patterns of distress were compared between those with and without experience of organized violence. RESULTS: Somatic and emotional problems, such as diffuse pain, numbness in arms and legs, stress, flashbacks, disturbed sleep and nightmares were reported significantly more often by violence survivors than by the control group. Also associated with experience of organized violence were higher frequencies of reported emotional problems, such as feeling out of balance in the previous months, extreme sadness and difficulties settling in Switzerland. Among the men, more than 62% of the violence survivors reported thoughts of self-harm compared with 11% of the control group whereas thoughts of self-harm among the women were more associated with the uncertain legal status in Switzerland than with violence experience. CONCLUSION: Exposure to organized violence contributed to increased health problems of these migrant patients who were presenting in primary care. A useful feature of this research should also be incorporated into clinical practice. Consideration of relevant aspects of patients' social experience, including victimization by violence, requires attention not only to spontaneous accounts in the course of history taking but also focused queries to clarify such questions.

Adolescent↗