Virological failure after 1 year of first-line ART is not associated with HIV minority drug resistance in rural Cameroon .

OBJECTIVES: The aim of this study was to describe clinical and virological outcomes in therapy-naive HIV-1-positive patients treated in a routine ART programme in rural Cameroon. METHODS: In a prospective cohort, 300 consecutive patients starting first-line ART were enrolled and followed for 12 months. Among 238 patients with available viral load data at Month 12, logistic regression was used to analyse risk factors for virological failure (≥1000 HIV RNA copies/mL) including clinical, immunological and virological parameters, as well as data on drug adherence. Population sequencing was performed to detect the presence of drug-resistance mutations in patients with virological failure at Month 12; minority drug-resistance mutations at baseline were analysed using next-generation sequencing in these patients and matched controls. RESULTS: At Month 12, 38/238 (16%) patients experienced virological failure (≥1000 HIV RNA copies/mL). Patients with virological failure were younger, had lower CD4 cell counts and were more often WHO stage 3 or 4 at baseline. Sixty-three percent of patients with virological failure developed at least one drug-resistance mutation. The M184V (n = 18) and K103N (n = 10) mutations were most common. At baseline, 6/30 patients (20%) experiencing virological failure and 6/35 (17%) matched controls had evidence of minority drug-resistance mutations using next-generation sequencing (P = 0.77). Lower CD4 count at baseline (OR per 100 cells/mm(3) lower 1.41, 95% CI 1.02-1.96, P = 0.04) and poorer adherence (OR per 1% lower 1.05, 95% CI 1.02-1.08, P < 0.001) were associated with a higher risk of virological failure. Unavailability of ART at the treatment centre was the single most common cause for incomplete adherence. CONCLUSIONS: Virological failure after 1 year of ART was not associated with minority drug resistance at baseline but with incomplete adherence. Strategies to assure adherence and uninterrupted drug supplies are pivotal factors for therapy success.

[Importation of rare but life-threatening and highly contagious diseases. Current situation and outlook]. / Import seltener, aber lebensbedrohlicher und hochansteckender Erreger : Heutige Situation und Ausblick.

Internists should expect to be the first contact for patients with rare, but highly contagious, life-threatening illnesses. Although certainly not encountered often, it is associated with significant consequences. Thus, physicians should be familiar with viral hemorrhagic fevers: filoviruses cause Ebola and Marburg fever, arenaviruses cause Lassa fever and South American hemorrhagic fevers, and the bunyaviruses cause among others Crimean-Congo hemorrhagic fever. Furthermore, physicians should be familiar with highly contagious respiratory infections, such as hantavirus pulmonary syndrome, pneumonic plague, and Middle East respiratory syndrome (MERS).

[Treatment of diseases acquired abroad]. / Behandlung von auf Fernreisen erworbenen Erkrankungen.

Most imported diseases can be well treated-provided the diagnosis is made in due time. For example, only the rapid and correctly performed treatment of falciparum malaria can impede severe complications and save the patient's life. Effective treatments for amebiasis, giardiasis, leishmaniasis and worm diseases are available. However, it has to be mentioned that evidence from clinical trials is often insufficient. Accordingly only few international guidelines for imported diseases exist.

[Malaria]. / Malaria.

Malaria is the most important infectious disease imported by travelers and migrants from tropical and subtropical areas. It is imported quite frequently. It is a life-threatening disease. Symptoms are nonspecific and cannot easily be distinguished from a wide range of other febrile conditions. Therefore, travel history must be taken in all patients with fever of unknown origin and malaria diagnostics must be performed immediately on suspicion of malaria. Uncomplicated falciparum malaria should be treated in the hospital with either atovaquone-proguanil or with an artemisinin-based combination preparation. If there is evidence of severe malaria, the patient must be moved to an intensive care unit. The antiparasitic agent of choice is then artesunate.

Necrotizing lymphadenitis: Kikuchi--Fujimoto disease alias lupus lymphadenitis?

Differentiation between lymphadenopathy in potentially life-threatening systemic lupus erythematosus (SLE) and self-limiting necrotizing lymphadenitis, also called Kikuchi- Fujimoto disease (KFD), is difficult. In the past, co-occurrence of SLE and KFD has been described repeatedly in case reports. Here, we report a case of necrotizing lymphadenitis, describe the clinical and histopathologic features in detail and discuss the current literature. KFD may in fact be a histopathologic characteristic of SLE supporting the hypothesis that KFD is a rare manifestation of SLE. To clarify whether KFD is the same entity as lupus lymphadenitis, more cases with SLE and lymphadenopathy should be examined in detail.

Of guinea pigs and men--an unusual case of jaundice.

A 21-year-old male presented at the emergency room with jaundice, itching, dry cough, malaise and weight loss of 10 kg during the preceding four weeks. Eighteen months earlier, the patient had suffered an automobile accident leading to polytrauma. Serological markers for viral or other causes of hepatitis were absent. For suspected secondary sclerosing cholangitis, ultrasound and ERCP were performed but failed to reveal pathological findings. A liver biopsy showed cholestatic liver disease without signs of portal field-associated hepatitis. Hepato-biliary scintigraphy demonstrated hepatocellular dysfunction. The patient finally mentioned his guinea pig farm with around 50 animals, 20 of which had recently died for unknown reasons. The patient and three of his guinea pigs were subsequently tested for serological evidence of leptospirosis. IgG and IgM antibodies reacting with Leptospira interrogans were detected in the patient's serum, and all 3 guinea pigs were serologically positive for serovar Bratislava. Bacterial culture was not successful, and also PCR tests remained negative. The clinical symptoms quickly resolved after the initiation of antibiotic therapy with amoxicillin.

Prophylactic immunisation against traveller's diarrhoea caused by enterotoxin-forming strains of Escherichia coli and against cholera: does it make sense and for whom?

Traveller's diarrhoea (TD) constitutes the most common disease relevant to travel medicine with ETEC as the leading causative pathogen. Cholera is the most serious, but very rare form of TD. ETEC and cholera share pathogenic mechanisms by producing a toxin that has an 80% amino acid homology. A consensus of German-speaking experts sees the indication to use the whole cell/B subunit oral cholera vaccine (WC--BS) if cholera is a risk for aid workers or travellers with an anticipated threat of cholera who stay under poor hygienic conditions. The use of the vaccine should be considered in the indication to avoid ETEC TD for travellers with predisposing illness or medication or for travellers at risk to develop a serious course.

Variability of the CD36 gene in West Africa.

Studying 12 selected individuals from a malaria-endemic area in West Africa, 24 variants of the CD36 gene were found, 21 of them novel ones. These included three single-nucleotide substitutions causing non-conservative amino acid exchanges E123K, T174A, and I271T as well as a three base pair (bp) insertion resulting in the addition of an asparagine residue (N232-233ins). The E123K variant was located within the putative ligand-binding domain for oxidized low density lipoprotein, while the other substitutions resided outside any of the binding sites for reaction partners mapped on CD36 so far. Twelve single-nucleotide polymorphisms (SNPs) were identified in untranslated parts of the exons and in introns. Five additional SNPs were located in the promoter region whereby -144G-->T, -53G-->T, and -2A-->G alter putative binding sites for the transcription factors purine factor (PuF), phorbol ester-responsive element AP-2, and CCAAT/enhancer-binding protein. A G-->T exchange at position -50 appears to introduce a new recognition site for PuF. Calculations of nucleotide diversity revealed extraordinarily high numbers for all parts of the gene, which may, however, to some extent be due to the selection of individuals studied.

Serum-independent and serum-dependent cytoadherence in the interaction of Entamoeba histolytica with mammalian target cells.

Entamoeba histolytica kills target cells only on direct contact, suggesting that trophozoite-mediated cytolysis is initiated by the contact between trophozoites and target cells. We have shown that adherence between E. histolytica and target cells (polymorphonuclear granulocytes, erythrocytes, Chinese hamster ovary cells, human colon carcinoma cells) was inhibited by specific carbohydrates, and adherence between E. histolytica and polymorphonuclear granulocytes (PMN) was enhanced by preincubation of the trophozoites with serum. Inhibition of adherence clearly paralleled inhibition of cytolysis and phagocytosis of target cells. Cytolysis of PMN, however, was not increased by preincubation of the trophozoites with serum. These results suggest that the effector functions of trophozoites are only dependent on carbohydrate-specific adherence mechanisms mediated by the amoebic Gal/GalNAc-binding lectin. E. histolytica trophozoites themselves can be killed by PMN, depending on the virulence of the trophozoites. PMN could not kill E. histolytica trophozoites more effectively when the adherence was enhanced by preincubation of the trophozoites with serum or when adherence was only mediated by serum-dependent mechanisms.

Development of monoclonal antibodies specifically recognizing the cyst stage of Entamoeba histolytica.

Protozoan cysts were isolated according to a two-step sucrose gradient procedure. Pure cysts of Entamoeba histolytica, in fixed and native states, were injected into BALB/c mice intraperitoneally for immunization. The spleens of these animals were used for fusion with AG8 mouse myeloma cells. Hybridomas were obtained and tested for the recognition of E. histolytica, E. dispar, E. coli, E. hartmanni, Endolimax nana, Jodamoeba biitschlii, and Giardia lamblia. Three monoclonal antibodies were identified that reacted only with cysts and trophozoites of E. histolytica. These can be used for differentiation and identification of E. histolytica in feces.

Analysis of renal function in onchocerciasis patients before and after therapy.

The occurrence of renal abnormalities was investigated in patients with onchocerciasis in comparison to individuals without onchocerciasis in Guinea. Serum creatinine levels, excretion of urinary marker proteins, and kidney size by ultrasound were determined. A high prevalence of glomerular as well as tubular dysfunctions was observed; however, no association with onchocerciasis could be detected. We also hypothesized that patients with hyperreactive onchocerciasis might be prone to develop immune-mediated glomerular disorders; however, this could not be verified. Following treatment with ivermectin, a slight but significant increase in the excretion of urinary albumin and alpha1-microglobulin was seen five days after treatment in all treated patients, whereas levels of proteinuria were significantly higher five days after treatment only in patients with high microfilarial densities. Our results indicate that ivermectin can cause glomerular and tubular disturbances in patients with onchocerciasis; however, these are minor and do not seem to be clinically relevant.

Increased erythropoietin production in children with severe malarial anemia.

Plasma immunoreactive erythropoietin concentrations were determined in 84 children with Plasmodium falciparum malaria in Gabon. There was an inverse log/linear relationship between hemoglobin or hematocrit and plasma erythropoietin, indicating that erythropoietin levels increased exponentially as circulating hemoglobin decreased. These result show that P. falciparum malaria does not lead to decreased erythropoietin production, and in turn reduced erythropoietin production does not contribute to the pathogenesis of malarial anemia. There is an adequate response of erythropoietin to anemia in children with P. falciparum malaria.

Failure of high dose mebendazole as a microfilaricide in patients with loiasis.

The effectiveness of mebendazole as a microfilaricide in patients with loiasis was studied. The drug regimen was 1 g twice daily for 21 days in adults. During and after treatment, the microfilarial density was unchanged. Therefore, mebendazole has no direct effect on the microfilarial density of Loa loa.

Similar blackfly attraction by onchocerciasis patients and individuals putatively immune to Onchocerca volvulus.

In areas endemic for onchocerciasis, a small number of individuals show no detectable infection with Onchocerca volvulus despite an apparently similar exposure to the transmitting blackflies. Such individuals have been termed putatively immune. Since several studies have indicated marked host differences in attractiveness for blood-seeking insects, putative immunity in O. volvulus infection may result, at least in part, from low vector attractiveness of the respective individuals. In an area hyperendemic for onchocerciasis (Guinea), where Simulium yahense is the predominant vector, we organized fly catches by putatively immune individuals and individuals with moderate-to-high worm counts. No differences were found between the 2 groups with respect to (i) the attraction of blackflies, (ii) the attraction of blackflies infected with O. volvulus, or (iii) the numbers of O. volvulus larvae carried by the attracted blackflies.

Delayed-type hypersensitivity reactions to Onchocerca volvulus antigens in exposed and non-exposed African individuals.

Although considered of critical importance, the mode of helper T-lymphocyte function in Onchocerca volvulus infection is still unclear including the role of the Th1/Th2 dichotomy. We studied the delayed-type hypersensitivity (DTH) reaction, which is the classical Th1 response, to O. volvulus antigens in Africans exposed and not exposed to the infection. DTH reactions were found in a small percentage of patients with generalized onchocerciasis, but in a high percentage of patients with localized onchocerciasis, in putatively immune subjects, and also in non-exposed individuals, which may be due to cross-reactivity with other nematodes. These findings support the notions of (i) prenatal influence of maternal O. volvulus infection preventing development of Th1 responses and/or (ii) suppression of Th1 responses by the infection itself.

Eosinophils, eosinophil cationic protein and eosinophil-derived neurotoxin in serum and urine of patients with onchocerciasis coinfected with intestinal nematodes and in urinary schistosomiasis.

Eosinophils, eosinophil cationic protein (ECP), eosinophil-derived neurotoxin (EDN/EPX), myeloperoxidase (MPO) and IgE were measured in blood, serum and/or urine in Schistosoma haematobium- and Onchocerca volvulus-infected Guineans and O. volvulus- and S. haematobium-negative Guineans coinfected or infected with intestinal nematodes. The number of eosinophils and levels of eosinophil granule proteins but not of MPO were found to be strongly elevated in all Africans as compared to European controls. The highest serum ECP and serum and urinary EDN/EPX levels were observed in the hyperreactive form of onchocerciasis (sowda). Onchocerciasis patients and O. volvulus-negative Africans coinfected or infected with intestinal nematodes (hookworm and/or Ascaris lumbricoides) revealed higher serum granule protein concentrations and/or absolute eosinophil counts and urinary ECP than those without nematode infections. Statistical differences between both sections were found for the absolute eosinophil counts and for serum EDN/EPX and IgE in generalized onchocerciasis, and for urinary ECP in sowda, indicating stimulation of the eosinophil potential of O. volvulus-positive patients by coexistent hookworm infection. This worm species, in contrast to A. lumbricoides, causes especially high eosinophil counts and EDN/EPX and IgE levels. From these results it is concluded that in nematode diseases, ECP and EDN/EPX levels reflect the degree of antigenic stimulation, eosinophil activation and eosinophil turnover rates. Serum ECP and serum and urinary EDN/EPX may, therefore, serve as parameters to monitor helminth infection. Urinary ECP may be a marker of eosinophiluria secondary to urogenital manifestation of S. haematobium. It is elevated in hyperreactive onchocerciasis activated by intestinal nematodes.

Spleen size determined by ultrasound in patients with sickle cell trait, HbAC trait and glucose-6-phosphate-dehydrogenase deficiency in a malaria hyperendemic area (Ashanti Region, Ghana).

The occurrence of enlarged spleens and its age distribution has long been used as a crude measure to estimate malaria endemicity in cross-sectional surveys. Spleen size, however, is influenced by several variables that should be considered if they are observed in a population under study. We hypothesized that spleen indices are dependent on distinct red blood cell polymorphisms. Accordingly, we expected a lower prevalence of splenomegaly among patients with the sickle-cell trait (HbAS), HbAC trait and G6PD deficiency than in patients without red cell disorders, possibly due to the lower incidence of malaria attacks in these individuals. In our survey, however, spleen rates and sizes did not differ significantly between HbAA-, HbAS- and HbAC-positive individuals. Furthermore, enlargement of spleens was found at similar frequencies in persons with and without glucose-6-phosphate-dehydrogenase (G6PD)-deficiency (G6PD-A(-)).

Interaction of various Entamoeba histolytica strains with human intestinal cell lines.

The interaction of four pathogenic and three nonpathogenic E. histolytica strains with two human intestinal cell lines (Caco-2 and HT-29) was examined. The adherence of pathogenic and nonpathogenic E. histolytica to these cells was similar, indicating that defective adherence to intestinal cells is not a common feature of nonpathogenic strains. The addition of different carbohydrates confirmed the importance of the galactose-binding lectin of E. histolytica in binding to these intestinal cells. On the other hand, only virulent E. histolytica strains damaged monolayers of intestinal cells. The results indicate that Caco-2 cells and differentiated HT-29 cells are useful models for research of intestinal amebiasis.

Study on the micromorphology of Mycobacterium leprae.

The micromorphology of Mycobacterium leprae is described. After fixation with osmium tetroxide supplemented with calcium ions, the cell wall was seen to be composed of three layers; the cytoplasmic membrane exhibited the architecture of an elementary membrane. The mesosomes were best visualized after fixation with glutaraldehyde; they were sometimes in contact with the nuclear equivalent. Only one sort of phosphate body was found. The nucleoid was best visualized after fixation with osmium tetroxide.

Travel medicine--the next 10 years.

In summary, the development of travel medicine in the next years will be characterized by new risks, and on the other hand by new methods of therapy and prophylaxis. Formally, travel medicine will be established as an interdisciplinary special discipline, while the know-how in travel medicine will be consolidated by certificates.