Risk factors for surgical site infections in abdominal surgeries in Ghana: emphasis on the impact of operating rooms door openings.

Major surgery carried out in low- and middle-income countries is associated with a high risk of surgical site infections (SSI), but knowledge is limited regarding contributory factors to such infections. This study explores factors related to patients developing an SSI in a teaching hospital in Ghana. A prospective cohort study of patients undergoing abdominal surgical procedures was conducted at Korle Bu Teaching Hospital. Patient characteristics, procedures and environmental characteristics were recorded. A 30-day daily surveillance was used to diagnose SSI, and Poisson regression analysis was used to test for association of SSI and risk factors; survival was determined by proportional hazard regression methods. We included 358 patients of which 58 (16.2%; 95% CI 12.7-20.4%) developed an SSI. The median number of door openings during an operation was 79, with 81% being unnecessary. Door openings greater than 100 during an operation (P = 0.028) significantly increased a patient's risk of developing an SSI. Such patients tended to have an elevated mortality risk (hazard ratio 2.67; 95% CI 0.75-9.45, P = 0.128). We conclude that changing behaviour and practices in operating rooms is a key strategy to reduce SSI risk.

Nasal localization of a Pseudoterranova decipiens larva in a Danish patient with suspected allergic rhinitis.

Pseudoterranoviasis is a zoonotic disease caused by nematode larvae of species within the genus Pseudoterranova (seal worm, cod worm). Most infections are gastrointestinal, oesophageal or pharyngeal, but here we report a nasal infection. A 33-year-old patient suffering from rhinitis for 1.5 years recovered a worm larva from the nose. Diagnosis was performed by morphological and molecular characterization, showing the causative agent to be a third-stage larva of Pseudoterranova decipiens (sensu stricto). Various infection routes are discussed.

New filtration system for efficient recovery of waterborne Cryptosporidium oocysts and Giardia cysts.

AIMS: To develop a filtration unit for efficient recovery of waterborne Cryptosporidium oocysts and Giardia cysts ((oo-)cysts) in drinking water. METHODS AND RESULTS: This unit utilizes a metallic filter and an ultrasound transducer for eluting (oo-)cysts, with a fixed retentate backwash volume; approx. 400 µl. Changes in the viability was evaluated by seeding wild type (oo-)cysts (1 × 10(4)) followed by sonication for 5, 10, 20 or 40 s (five replicates for each period). Flow cytometry analysis showed negligible increase in the mortality of (oo-)cysts exposed to 5-10 s of sonication. Recovery rate was assessed by seeding ColorSeed(™) (10 replicates) into the filter unit followed by air backwash to a glass slide and counting of (oo-)cysts by epifluorescent microscopy. High recovery rates (mean ± SD) were found: 84·9% ± 4·8 for Giardia cysts and 70% ± 6·5 for Cryptosporidium oocysts. DNA of seeded wild type (oo-)cysts (1 × 10(2); 10 replicates) was successfully amplified using real-time PCR. CONCLUSIONS: The use of a metallic filter, sonication and 'air backwash' were key factors for creating a highly efficient system for recovery of apparently undamaged protozoa. SIGNIFICANCE AND IMPACT OF THE STUDY: This reagent-less system can be used for monitoring of parasite contamination in drinking water.

Progressive disseminated histoplasmosis in the HIV population in Europe in the HAART era. Case report and literature review.

INTRODUCTION: In highly endemic areas, up to 20 % of human immunodeficiency virus (HIV)-infected persons will develop progressive disseminated histoplasmosis (PDH). Europe is not endemic to histoplasmosis, and the disease is mainly found in immigrants often co-infected with HIV. METHODS: We present a case of a patient with HIV and PDH highlighting the possible diagnostic difficulties that may arise in a non-endemic area and review the literature of histoplasmosis in the context of HIV infection with special focus on Europe. DISCUSSION: When cellular immunity wanes (usually at CD4 T-lymphocyte counts <150 cells/µL) histoplasma infection, acquired earlier, can reactivate and disseminate. PDH is an acquired immune deficiency syndrome(AIDS)-defining disease and a life-threatening infection, with a clinical spectrum ranging from an acute, fatal course with lung infiltrates and respiratory failure, shock, coagulopathy and multi-organ failure, to a more subacute disease with focal organ involvement, pancytopenia and hepatosplenomegaly. Mortality rates remain high for untreated patients, but early diagnosis, proper antifungal treatment and early initiation of antiretroviral therapy have improved the prognosis. CONCLUSION: European infectious diseases physicians, microbiologists and pathologists must be aware of histoplasmosis, particularly when facing HIV-infected immigrants from endemic areas. This is increasingly important due to migration and travel activities from these areas.

Implementation of minimally invasive and objective humane endpoints in the study of murine Plasmodium infections.

SUMMARY Defining appropriate and objective endpoints for animal research can be difficult. Previously we evaluated and implemented a body temperature (BT) of <32 °C as an endpoint for experimental cerebral malaria (ECM) and were interested in a similar endpoint for a model of severe malarial anaemia (SMA). Furthermore, we investigate the potential of a minimally invasive, non-contact infrared thermometer for repeated BT measurement. ECM was induced with Plasmodium berghei ANKA infection in C57Bl/6 mice. SMA was induced with Plasmodium chabaudi AS infection in A/J mice. Our previous published endpoint was applied in ECM and 30 °C was pre-determined as the lowest permitted limit for termination in SMA according to consultation with the Danish Animal Inspectorate. Infrared thermometer was compared with the rectal probe after cervical dislocation, ECM and SMA. Linear regression analysis of rectal versus infrared thermometry: cervical dislocation: Pearson R = 0·99, R 2 = 0·98, slope = 1·01, y-intercept = 0·55; ECM: 0·99, 0·98, 1·06, -2·4; and SMA: 0·98, 0·97, 1·14, -5·6. Implementation of the 30 °C endpoint captured all lethal infections. However, some animals with BT below 30 °C were not deemed clinically moribund. This study supports repeated measurement infrared thermometry. A humane endpoint of 30 °C was sensitive in capturing terminal animals but might overestimate lethality in this SMA model.

Simultaneous administration of vitamin A and DTP vaccine modulates the immune response in a murine cerebral malaria model.

The World Health Organisation recommends vitamin A supplementation (VAS) to children aged 6 months to 5 years in low-income countries, and for logistic reasons, this has been linked to routine childhood immunizations. Observational studies suggest that VAS given with diphtheria-tetanus-pertussis (DTP) vaccine may increase mortality from non-targeted diseases. We investigated the non-targeted effect of pretreatment with VAS and DTP vaccine in a murine model of experimental cerebral malaria. Our a priori hypothesis was that VAS/DTP would aggravate the infection. We found that the effect of VAS and DTP depended on pathogenesis; VAS/DTP tended to increase parasitaemia and significantly depressed cytokine responses in mice, which developed cerebral malaria, but this was not seen in mice dying of anaemia. The divergent effect according to pathogenesis may help elucidate why VAS has divergent effects on different diseases in humans. Our results support the hypothesis that immunological effects of VAS/DTP may have detrimental implications for disease outcomes.

Metronidazole-sensitive organisms in children with severe acute malnutrition: an evaluation of the indication for empiric metronidazole treatment.

OBJECTIVES: Children with severe acute malnutrition (SAM) are treated with empiric amoxicillin or penicillin and gentamicin because of the high risk of severe infections. Experts have suggested, based on available evidence, adding metronidazole to cover anaerobic bacteraemia and diarrhoea caused by Giardia duodenalis or Clostridium difficile. The objective of this study was to assess the importance of these infections in children with SAM. METHODS: Children from 6 months to 15 years with SAM were enrolled and followed clinically. Aerobic and, when patient weight permitted, anaerobic blood cultures were done using Bactec® system, and isolates identified with matrix-assisted laser desorption ionization-time of flight mass spectrometry. Stool samples were tested for C. difficile, G. duodenalis and Entamoeba histolytica by PCR. RESULTS: A total of 334 children were enrolled and 174 out of 331 (53%) for which data on this was available had diarrhoea. Of 273 patients tested by blood culture, 11 had bacteraemia (4.0%, 95% CI 2.3-7.1%) but none with strict anaerobic bacteria (0/153, 95% CI 0-2.4%). There was no difference in the prevalence of C. difficile between children with (5/128, 4%) and without (7/87, 8%) diarrhoea (OR 0.47, 95% CI 0.14-1.53), and no difference in the prevalence of Giardia between these groups (78/138, 60% vs. 46/87, 53%; OR 1.34, 95% CI 0.77-2.32). Children with C. difficile had higher mortality than those without this infection (3/11, 27%, vs. 7/186, 4%; OR 43, 95% CI 3.9-483). CONCLUSION: Our results do not provide support for empiric metronidazole to cover for anaerobic bacteraemia. Trials evaluating the effect of empiric treatment and its effect on G. duodenalis and C. difficile are warranted.

Surveillance of surgical site infection in a teaching hospital in Ghana: a prospective cohort study.

BACKGROUND: Surveillance systems for surgical site infections (SSIs), as a measure of patient safety, help health institutions devise strategies to reduce or prevent them. No surveillance systems exist to monitor SSIs in Ghana. AIM: To establish a system for monitoring trends and detecting outbreaks in order to create awareness of and control SSIs. METHODS: An active 30-day surveillance was undertaken at the general surgical unit of the Korle Bu Teaching Hospital, from July 1st, 2017 to December 31st, 2018 to identify SSI. It involved a daily inpatient surveillance of patients who had had a surgical procedure, followed by post-discharge surveillance by means of a healthcare personnel-based survey and a patient-based telephone survey. We supplied quarterly feedback of results to surgeons. FINDINGS: Among the 3267 patients included, 331 were identified with an SSI, a 10% incidence risk. Patients who acquired an SSI experienced increased morbidity including nine extra days in hospital and an adjusted relative mortality risk of 2.3 (95% confidence interval: 1.3 - 4.1; P=0.006) compared to patients without SSI. Forty-nine per cent (161/331) of SSIs were diagnosed post discharge using the healthcare personnel-based survey. The patient-based telephone survey contributed 12 additional cases. SSI incidence risk decreased from 12.8% to 7.5% during the study period. CONCLUSION: Post-discharge surveillance is feasible using existing healthcare personnel, and the results highlight the high risk and burden of SSIs in Ghana. A surveillance system with feedback for monitoring SSIs may contribute to reducing SSIs; however, firm conclusions regarding the impact need longer observation time.

Genetic relationship between bacteria isolated from intraoperative air samples and surgical site infections at a major teaching hospital in Ghana.

BACKGROUND: In low- and middle-income countries (LMICs) the rate of surgical site infections (SSI) is high, leading to negative patient outcomes and excess healthcare costs. A causal relationship between airborne bacteria in the operating room and SSI has not been established, at a molecular or genetic level. We studied the relationship between intraoperative airborne bacteria and bacteria causing SSI in an LMIC. METHODS: Active air sampling using a portable impactor was performed during clean or clean-contaminated elective surgical procedures. Active patient follow-up consisting of phone calls and clinical examinations was performed 3, 14 and 30 days after surgery. Bacterial isolates recovered from SSI and air samples were compared by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) identification, ribotyping, whole genome sequencing (WGS), and metagenomic analysis. RESULTS: Of 128 included patients, 116 (91%) completed follow-up and 11 (9%) developed SSI. Known pathogenic bacteria were isolated from intraoperative air samples in all cases with SSI. A match between air and SSI isolates was found by MALDI-TOF in eight cases. Matching ribotypes were found in six cases and in one case both WGS and metagenomic analysis showed identity between air- and SSI-isolates. CONCLUSION: The study showed high levels of intraoperative airborne bacteria, an SSI-rate of 9% and a genetic link between intraoperative airborne bacteria and bacteria isolated from SSIs. This indicates the need for awareness of intraoperative air quality in LMICs.

In-depth validation of acridine orange staining for flow cytometric parasite and reticulocyte enumeration in an experimental model using Plasmodium berghei.

Flow cytometry is potentially an effective method for counting malaria parasites, but inconsistent results have hampered its routine use in rodent models. A published two-channel method using acridine orange offers clear discrimination between the infected and uninfected erythrocytes. However, preliminary studies showed concerns when dealing with Plasmodium berghei-infected blood samples with high numbers of reticulocytes. In hyperparasitemic or chronic P. berghei infection, enhanced erythropoietic activity results in high numbers of circulating immature reticulocytes. We show that even though the protocol offered good discrimination in newly infected animals, discrimination between infected erythrocytes and uninfected reticulocytes became difficult in animals with hyperparasitemia or chronic infections maintained with subcurative treatment. Discrimination was especially hampered by increased nucleic acid content in immature uninfected reticulocytes. Our data confirms that though flow cytometry is a promising analytical tool in malaria research, care should still be taken when analysing samples from anemic or chronically infected animals.

Traffic flow and microbial air contamination in operating rooms at a major teaching hospital in Ghana.

BACKGROUND: Current literature examining the relationship between door-opening rate, number of people present, and microbial air contamination in the operating room is limited. Studies are especially needed from low- and middle-income countries, where the risk of surgical site infections is high. AIM: To assess microbial air contamination in operating rooms at a Ghanaian teaching hospital and the association with door-openings and number of people present. Moreover, we aimed to document reasons for door-opening. METHODS: We conducted active air-sampling using an MAS 100® portable impactor during 124 clean or clean-contaminated elective surgical procedures. The number of people present, door-opening rate and the reasons for each door-opening were recorded by direct observation using pretested structured observation forms. FINDINGS: During surgery, the mean number of colony-forming units (cfu) was 328 cfu/m3 air, and 429 (84%) of 510 samples exceeded a recommended level of 180 cfu/m3. Of 6717 door-openings recorded, 77% were considered unnecessary. Levels of cfu/m3 were strongly correlated with the number of people present (P = 0.001) and with the number of door-openings/h (P = 0.02). In empty operating rooms, the mean cfu count was 39 cfu/m3 after 1 h of uninterrupted ventilation and 52 (51%) of 102 samples exceeded a recommended level of 35 cfu/m3. CONCLUSION: The study revealed high values of intraoperative airborne cfu exceeding recommended levels. Minimizing the number of door-openings and people present during surgery could be an effective strategy to reduce microbial air contamination in low- and middle-income settings.

Measurement of antigen-dependent interleukin-4 production by human peripheral blood mononuclear cells. Introduction of an amplification step using ionomycin and phorbol myristate acetate.

The study of T cell responses in parasitic disease and allergy in humans has been limited by difficulties in the measurement of interleukin-4 (IL-4) in supernatants from antigen-stimulated peripheral blood mononuclear cells (PBMC). To obtain measurable amounts of IL-4 in vitro, we have added an amplification step to the antigen-specific response. Human PBMC were stimulated by tetanus toxoid (TT) or tuberculin (PPD) for 6 days and then pulsed with ionomycin and phorbol myristate acetate (PMA) for 24 h. TT-stimulated cells from nine revaccinated donors but not from seven unvaccinated donors and four that had only received childhood vaccinations against tetanus produced high levels of IL-4 (median (range) 1500 (300-3800), 316 (0-1600), and 270 (100-410) pg/ml, respectively, as measured by an enzyme linked immunosorbent assay, P = 0.005). PPD did not increase IL-4 production above the background level, although the majority of PPD-stimulated PBMC proliferated and produced interferon-gamma (IFN-gamma) in cultures without ionomycin and PMA. TT-induced IL-4 production correlated positively with proliferation. Culture supernatants did not interfere with IL-4 immunoreactivity and failed to affect ionomycin and PMA induced IL-4 production. The findings suggest that proliferating antigen-specific T cells were the source of IL-4 in these experiments. The method should prove useful for comparing the IL-4 producing ability of antigen-specific T cells from different individuals.

Production of interferon-gamma and interleukin-4 by human T cells recognizing Leishmania lipophosphoglycan-associated protein.

The Leishmania protein LPGAP which is co-isolated with lipophosphoglycan is a specific activator of T cells from individuals who have recovered from American leishmaniasis. We have tested the effect of LPGAP on peripheral blood mononuclear cells (PBMC) from Kenyan donors cured from L. donovani infections. LPGAP induced vigorous proliferation and production of interferon-gamma (IFN-gamma) by the cells. In addition PBMC incubated with LPGAP released interleukin-4 (IL-4) after pulsing with ionomycin and phorbol myristate acetate. Single cells were isolated from LPGAP-stimulated cell lines and expanded as T-cell clones. LPGAP-reactive T-cell clones were activated by crude preparations of both promastigotes and axenic grown amastigote-like parasites. Among 9 CD4+ T-cell clones recognizing LPGAP, cells secreting predominantly IFN-gamma as well as cells secreting predominantly IL-4 were identified. The results show that both IFN-gamma producing (Th1-like) and IL-4 producing (Th2-like) T cells recognizing LPGAP are expanded after infection with L. donovani in humans.

T-cell response in human leishmaniasis.

In the present communication we provide evidence for the existence of a Th1/Th2 dichotomy in the T-cell response to Leishmania antigens in human leishmaniasis. Our data suggest that the pattern of IL-4 and IFN-gamma response is polarised in these patients. Lymphocytes from individuals recovered from cutaneous leishmaniasis (CL) responded by IFN-gamma production following stimulation with Leishmania antigens whereas cells from patients recovered from visceral leishmaniasis (VL) showed a mixed pattern of IFN-gamma and IL-4 responses. The cells producing these cytokines were predominantly CD4+. Furthermore, IL-10 plays an important role in the development of post kala azar dermal leishmaniasis (PKDL) from VL. The balance between the parasitic-specific T-cell response plays an important regulatory role in determining the outcome of Leishmania infections in humans.

Dichotomy in the human CD4+ T-cell response to Leishmania parasites.

Leishmania parasites cause human diseases ranging from self-healing cutaneous ulcers to fatal systemic infections. In addition, many individuals become infected without developing disease. In mice the two subsets of CD4+ T cells, Th1 and Th2, have different effects on the outcome of experimental Leishmania infections. Th1 cells producing interferon-gamma (IFN-gamma) mediate resistance, whereas Th2 cells producing interleukin-4 (IL-4) and IL-10 are associated with susceptibility and exacerbation. Evidence is accumulating that a Th1/Th2 dichotomy in the T-cell response to Leishmania exists also in humans, and that the balance between subsets of parasite-specific T cells may play an important regulatory role in determining the outcome of the infections.

Immunity against diphtheria and tetanus in human immunodeficiency virus-infected Danish men born 1950-59.

To evaluate the possible need for vaccination against diphtheria and tetanus of patients infected with the human immunodeficiency virus (HIV), antibodies were measured in blood samples from 78 Danish HIV-infected men, born 1950-59, who could be expected to have received primary vaccination before they contracted the HIV infection. No patients (95% confidence interval: 0-4) had tetanus antibodies below the protective level, whereas 24 of the 78 patients (16-33) were unprotected against diphtheria. In the background population of the same age group and sex, 5% and 10% have been found unprotected against tetanus and diphtheria, respectively. No relationship between disease stages and antibody levels could be found. Neither was there any difference between patients with normal and reduced numbers of CD4+ lymphocytes. From 25 patients two blood samples were taken at an interval of at least one year. Anti-tetanus titres showed a decrease comparable to that found in the background population, whereas the change in anti-diphtheria titres was more variable with rising antibody concentrations in nine patients. The fall off in antibodies did not increase with progression of the disease. It is concluded that HIV-positive younger men who have followed the vaccination program against tetanus prior to the HIV infection can be expected to be protected, whereas revaccination against diphtheria must be considered.

Effect of trans(E)-clopenthixol on Plasmodium berghei in vivo.

Previous in vitro studies have shown suppression of the growth of Plasmodium falciparum by the neuroleptic agents chlorpromazine and zuclopenthixol (formerly known as cis(Z)-clopenthixol) as well as by the neuroleptic inactive steroisomer trans(E)-clopenthixol. These compounds are chemically related to riboflavin and may act as inhibitors of riboflavin metabolism. As trans(E)-clopenthixol has been found active against chloroquine-resistant strains of P. falciparum in vitro and has been approved for human use, though inactive as a neuroleptic, this drug was selected for the present in vivo study. The dosage of trans(E)-clopenthixol was optimized through a pharmacokinetic study, and the suppression of the growth of Plasmodium berghei in vivo was tested in mice, with chloroquine acting as the positive and saline as the negative control. Trans(E)-clopenthixol did not inhibit the growth of P. berghei, whereas chloroquine almost eradicated the infection. The use of in vitro screening for anti-malarial activity in drugs approved for human use for other indications is discussed in the light of the results. It is concluded that the selection of drugs for further studies in vivo cannot solely be based on positive results in vitro.

Measurement of serum antibodies against native Leishmania gp63 distinguishes between ongoing and previous L. donovani infection.

An enzyme-linked immunosorbent assay (ELISA) using native gp63 for detection of serum antibodies to Leishmania was evaluated. The test identified antibodies in sera from 16 of 16 visceral leishmaniasis (VL) patients and 9 of 12 sera from patients with Trypanosoma brucei infection. In comparison, sera from 80 Danish controls and 40 control donors from a malaria endemic area of Ghana without known exposure to Leishmania were negative, as were sera from 12 Kenyan malaria patients and 9 schistosomiasis patients. After cure of VL, sera rapidly became negative. Only 1 of 7, 1 of 21, and 1 of 27 sera from cured VL patients 6-12 months, 1-2 years and > 2 years after cure were positive. Thus, in contrast to other serological tests for VL, the gp63 ELISA seems to distinguish an ongoing from a past infection. This might prove useful both for diagnostic and epidemiological purposes.

Interferon-gamma and interleukin-4 production by human T cells recognizing Leishmania donovani antigens separated by SDS-PAGE.

Crude preparations of Leishmania donovani proteins were separated by preparative SDS-polyacrylamide gel electrophoresis. Fractions of separated proteins were recovered by electroelution directly from the gel into separate chambers. The isolated protein fractions were tested for induction of proliferation and interferon-gamma (IFN-gamma) production in cultures of peripheral blood mononuclear cells (PBMC) from individuals who had recovered from visceral leishmaniasis caused by L. donovani. The release of interleukin-4 (IL-4) by PBMC stimulated with the isolated L. donovani antigen fractions was measured after treatment with phorbol-myristate-acetate and ionomycin. The cells proliferated in response to all protein fractions with molecular weights in the range < 12 kDa to 85 kDa. In general, IFN-gamma was secreted in response to stimulation with all the protein fractions, whereas IL-4 production was infrequently observed. The results show that T cells from individuals who have been cured of visceral leishmaniasis recognize and respond to a wide range of leishmanial antigens. There was no evidence of particular fractions constantly giving either IFN-gamma or IL-4-producing responses.

Immunity to tetanus and diphtheria in rural Africa.

To assess the effect of the Expanded Program on Immunization (EPI) in rural Africa, blood samples were collected in two Kenyan sublocations. Serum antibodies against tetanus toxoid were measured in 155 individuals 1-70 years of age. Titers greater than the protective level of 0.01 IU/ml were found in 47% of the population. Protection was significantly higher in children born after the launching of the EPI (68%) and in women who had been at childbearing age since then (69%). Significantly lower protection was demonstrated in other age and sex-groups. The level of protection in children was equal in the two populations, whereas protection in fertile women was significantly lower in the population living a long distance from a health center. Diphtheria anti-toxin was measured in the samples from one sublocation, and 70 of 84 individuals (83%) had antibody levels greater than the protective level. No age or sex difference could be found, and there was no correlation between response levels to diphtheria and tetanus. This implicates natural infections as an important source of diphtheria antibodies. Our findings demonstrate a need for better coverage of the adult population against tetanus. Furthermore, diphtheria transmission still appears to take place, underscoring the importance of diphtheria vaccination of travelers to rural Africa.