Leptospirosis: epidemiology,diagnosis and clinical aspects

Leptospires, world-wide distributed spirochetes, affect a great variety of mammalian hosts; several serovars belonging to the L. interrogans s.l. species can cause clinical manifestations in humans, becoming infected through the contact of skin cuts and mucous membranes with water and soil polluted by infected animals' urine; rodents serve as the main reservoirs but the epidemiological importance of pets and cattle, as leptospire shedder is increasing. While the infection remains endemic in tropical regions, there is a new epidemiological trend in developed countries where, with the typical seasonal pattern, sporadic cases and/or outbreaks occur related more to recreational activities and poor sanitation than to occupational activities. The sudden onset presents a "flu-like" syndrome; the course is usually characterised by two clearly defined stages. All of the variable clinical manifestations, often independent of the responsible serovar, arise from the effects of a general vasculitis. The prognostic factors associated with severe forms (renal failure, jaundice, haemorrhagies) are not defined. Within the first days of illness, the leptospires can be isolated from blood and cerebrospinal fluid; serological diagnosis relies on microagglutination, IFA and ELISA; PCR early in the course, before the appearance of specific antibodies, allows etiological diagnosis. Prompt treatment has an enormous impact on outcome.     

Complex pathological diagnosis of granulocytic sarcoma: apropos of a case

The diagnosis of granulocytic sarcoma can be very difficult when there is no demonstrable abnormality in the peripheral blood or bone marrow. We present the diagnostic algorithm of granulocytic sarcoma by reporting on a case mimicking large cell lymphoma without previous manifestation of acute myeloid leukemia or a myeloproliferative disorder. After standard histoprocessing, we used immunohistochemical and molecular biological methods to analyze our case. The lymph node showed diffuse infiltration of immature blast cells resembling large cell lymphoma. However, immunohistochemistry did not support this diagnosis. The tumor cells showed LCA, bcl-2, CD43, CD34 and myeloperoxidase positivity. We also detected bcl-2 gene rearrangement. In case of a lack of a specific histological picture, particularly in poorly differentiated tumors, only some minor histological signs in combination with immunohistochemistry and molecular diagnostic methods can help to render the correct diagnosis.     

Spontaneous stercoral fistula due to oxyurids: apropos of 1 case

A spontaneous stercoral fistula containing pinworms was observed in a patient, 35 years after an appendicectomy. The various surgical complications of oxyuriasis are reviewed, in particular, the possibilities for the parasite to traverse the intestinal wall. In the case reported here, it appears that infiltration occurred in the external wall of the caecum.     

Granulomatous peritonitis from ascariasis: apropos of 1 case in a Benin child

We report a case of granulomatous peritonitis in a child, due to Ascaris lumbrico?des eggs. A 6 year-old child was admitted to the emergency ward with acute abdomen pain. Upon performing a laparotomy, severe adhesive inflammation and adenopathies were found and abdominal tuberculosis was diagnosed. Specific treatment was administered. Later, the acurage diagnosis of Ascaris ova peritonitis was made by histopathological examination of tissue removed during the operation. The pathogenesis is briefly discussed.     

Pulmonary amebiasis and tuberculosis association. Two case reports in Libreville, Gabon

Amoebiasis and tuberculosis are common in Gabon. International travel, cultural exchanges, changing immigration and climate of tropical provide an ideal environment for these pathogenic organisms. However, the unexpected survival of these two pathologies in the same patient is exceptional.     

Non-Hodgkin lymphoma mimicking renal carcinoma: apropos of 1 case of follicular lymphoma

Primary renal non-Hodgkin's lymphoma (NHL) is unusual, in contrast to the frequent renal involvement in disseminated NHL. We report a case of follicular lymphoma presenting initially as a renal mass. In the literature, twenty-seven similar cases have been described since 1980. The median age at diagnosis is 64 years with a male predominance. Clinical and radiological findings generally evoke renal carcinoma. Histologically, tumors are usually large B-cell lymphomas. The existence of renal non-Hodgkin lymphoma mimicking renal carcinoma must be recognized. Such lymphomas can either be primitive or be nodal with a renal presentation. Nephrectomy followed by chemotherapy permits long disease free survival.     

Primary breast MALT lymphoma : apropos of one case

A 46-year-old patient was referred for a right mammary nodule associated with a chronic mastopathy. Cytological examination suggested an inflammatory process but frozen sections concluded to carcinoma with lymphoid stroma. Histological examination found characteristic features of MALT lymphoma: reactive lymphoid follicles, lymphoplasmocytoid lymphoid proliferation and lymphoepithelial lesions. Immunohistochemistry and in situ hybridation revealed a monotypic IgGk immunoglobulin. Molecular biology techniques found a rearrangement of IgH locus. Lymphocytic perigalactophoritis was found in the remaining breast tissue. After 33 months, no tumoral recurrence occurred. Primary MALT lymphoma of the breast is exceptional and its histogenesis is unclear. The role of pre-existent inflammatory lesions in the genesis of this tumour is not established. Our observation illustrates the diagnostic difficulty and the usefulness of complementary techniques in this diagnosis. The existence of inflammation close to tumour is interesting to emphasize.     

Leptospirosis with transient paraparesis and thrombocytopenia: a case report

Leptospirosis is the most widespread zoonosis in the world. We present an unusual case of leptospirosis in a 44-year-old man with severe thrombocytopenia and transient paraparesis. The diagnosis of leptospirosis was confirmed by blood nested polymerase chain reaction, seroconversion of Leptospira IgM and the microscopic agglutination test. Nerve conduction studies were suggestive of early polyneuropathy involving the right peroneal nerve and bilateral sural nerves. Peripheral nerve palsy is a potential clinical feature of leptospirosis.     

Malaria in Gabon. I. Study of 500 children with fever in Libreville

Among 500 febrile children who came for medical examination in the Pediatric Department at the H?pital Général de Libreville, 29.2% were infected by malaria. P. falciparum was the most common (96.7%), P. malariae and P. ovale were sparsely present. Rarely detected in people consulting for fever, shivering and headache were the two symptoms directly related to paludism. There is a direct correlation between the size of the spleen and the rate of infestation. Screening among babies from 3 to 6 months' old, shows 13% already infected. The top of malaria incidence lies between 2 and 3 years of age (42% were infected).     

A-leukemic caecal myeloid sarcoma: a difficult diagnosis

Myeloid sarcoma is a malignant neoplasia composed of abnormal myeloid or monocytic cells, often localized in bones, but also rarely in extra-medullary sites such as lymph nodes, skin and soft tissue. We report a case of caecal myeloid sarcoma, diagnosed in a 60 year old woman who complained from abdominal pain and weight loss, in absence of any medullary disorder. Initially misdiagnosed as a B lymphoma because of a weak positivity for CD79a, the diagnosis of primitive caecal myeloid sarcoma was eventually established after further investigations showing a positivity for lysozyme and myeloperoxidase. This report of such a rare clinical and pathological presentation of a myeloid sarcoma underlines a difficult differential diagnosis for which adequate immunohistochemistry, including lysozyme and myeloperoxydase is mandatory.     

Contribution of heparin therapy in the medical treatment of Buruli ulcer apropos of 1 case

Medical treatment of Buruli ulcer is mostly disappointing even if Mycobacterium ulcerans is susceptible to many antibacterial drugs. The inefficiency in vivo of the drugs may be due to the tissue vascularisation disorders caused by the toxin that Mycobacterium ulcerans produces. This toxin causes an endarteritis followed by a thrombosis of the dermal vessels responsible for an ischemia which prevents the antibacterial drugs from reaching the infected area. Removal or prevention of that thrombosis should allow the drugs to be more effective. To verify this assumption, we used a combined therapy with two gold standard medicines in an oedematous form of Buruli ulcer on the face which could not be surgically treated: heparin for its activity on thrombosis and rifampin for its bactericidal activity on Mycobacterium ulcerans. Rifampin was administered at 300 mg dose per day. Based on the management of envenomisation cases due to viper bites, we used standard heparin at 500 Ul dose per kg repeatedly administered by an electrical syringe releasing 1 cc per hour in the tubulure of isotonic glucose infusion. The results were encouraging. The dreadful oedema of the face started to reduce on the 15th day and disappeared on the 30th day. A small area at the temple dried. But we were obliged to stop the use of standard heparin due to an occurrence of Klebsiella oxytoca septicaemia from permanent vein route. Rifampin was still administered at the same dose. The face oedema reappeared quickly, followed by a full closure of the eyelids and an ulceration at the right temple level. The standard heparin was therefore substituted by low weight molecular heparin, enoxaparin, administered at 40 mg twice per day by subcutaneous route. 45 days later the oedema reduced and ulceration did not develop. After 90 days of treatment, usual signs of mycobacterial infection progression disappeared. We stopped therefore the use of enoxaparin but continued with rifampin until healing of the ulceration which occurred after 12 months of treatment. We observed no recurrence over a period of 16 months after complete healing. We can conclude that heparin combined with antimycobacterial drugs--which are active in vitro on Mycobacterium ulcerans--could provide an effective medical treatment for Buruli ulcer.     

Leptospirosis vaccines: past, present, and future

It is well known that Leptospira vaccine prevents the disease. However specificity for serovars limits the efficacy of killed whole cell vaccines. Leptospiral antigens that induce cross-protective immunity to the various serovars are sought as new vaccine candidates. In this paper, we have summarized both past and current findings about leptospiral antigens that are conserved among pathogenic leptospires and that induce protective immunity in animal models. The full-length genome sequences of two Leptospira strains have been published and reverse vaccinology has been used to identify leptospiral vaccine candidates. Although humoral immunity is thought to be dominant in protection from leptospiral infection, a role for cell-mediated immunity is now being explored.     

Drug-induced hepatitis: histologic clues to a difficult diagnosis

Drug-induced liver injury (DILI) results from two chief mechanisms of action: idiosyncratic hepatotoxicity, which typically manifests with prominent inflammation, and intrinsic hepatotoxicity, which demonstrates necrosis with negligible inflammation. Clinically, DILI is classified into hepatitic, cholestatic, or mixed presentations based on the pattern of liver enzyme elevation. As many etiologic factors can result in abnormal liver enzymes, the clinical clue to diagnosing DILI is symptomatic and biochemical improvement upon withdrawal of the offending agent. Histologically, DILI manifests in four main patterns of injury: i) inflammation-predominant acute hepatitis, ii) necrosis-predominant acute hepatitis, iii) resolving hepatitis, and iv) syncytial giant cell hepatitis. In contrast to the characteristic features of both acute hepatitis and syncytial giant cell hepatitis, resolving drug-induced hepatitis lacks specific histologic features and may mimic other mild forms of chronic hepatitis. Ultimately, the presence of sinusoidal PASD + Kupffer cell aggregates – in the absence of significant hepatocellular inflammation or injury – is the histologic hallmark of resolving drug-induced hepatitis.