Genotyping & diagnostic methods for hepatitis C virus: A need of low-resource countries

Hepatitis C virus (HCV) infection is a blood borne and transfusion-transmitted infection (TTI). It has emerged as one of the major health challenges worldwide. In India, around 12-18 million peoples are infected with HCV, but in terms of prevalence percentage, its looks moderate due to large population. The burden of the HCV infection increases due to lack of foolproof screening of blood and blood products before transfusion. The qualified screening and quantification of HCV play an important role in diagnosis and treatment of HCV-related diseases. If identified early, HCV infection can be managed and treated by recently available antiviral therapies with fewer side effects. However, its identification at chronic phase makes its treatment very challenging and sometimes ineffective. The drugs therapy for HCV infection treatment is also dependent on its genotype. Different genotypes of HCV differ from each other at genomic level. The RNA viruses (such as HCV) are evolving perpetually due to interaction and integration among people from different regions and countries which lead to varying therapeutic response in HCV-infected patients in different geographical regions. Therefore, proper diagnosis for infecting virus and then exact determination of genotype become important for targeted treatment. This review summarizes the general information on HCV, and methods used for its diagnosis and genotyping.

Emergencies in HIV--part 2.

In a short span of two and a half decades, HIV/AIDS has emerged as second largest killer disease that has affected mankind. The triple drug antiretroviral therapy (ART) has ensured a reasonably good quality of life to HIV infected individuals. Human immunodeficiency virus (HIV) infection is associated with several opportunistic infections/malignancies that may be life threatening and need quick intervention by health care workers. These emergencies could be related to opportunistic infections that are seen at presentation or that occur as the immune system gets weaker, or may bedue to HIV itself per se. The emergencies could also result from use of antiretroviral drugs like lactic acidosis, pancreatitis, bone marrow suppression and may include the immune reconstitution syndromes. The emergencies due to the opportunistic conditions and HIV per se had been dealt with in detail in the part 1, and this part describes various emergencies that could be encountered due to the administration of the anti retroviral treatment. Some patients may present due to emergencies as a result of co-administration of antiretroviral drugs with drugs used for treatment of some opportunistic infections like ATT etc.

Emergencies in HIV medicine--part I.

Human immunodeficiency virus (HIV) infection is now a chronic manageable disease due to which is it imperative for reviewing various medical emergencies which an individual case may encounter. Emergencies may occur at any stage of the disease. HIV infection is associated with several opportunistic infections/malignancies that may be life threatening and need quick intervention by health care workers. These emergencies could be related to opportunistic infections that are seen at presentation or that occur as the immune system gets weaker, or may be HIV induced diseases like enteropathy and wasting, diarrhea leading to dehydration and its sequel, neurological complication like PML etc. and from complications resulting from use of anti-HIV medication like lactic acidosis, pancreatitis, bone marrow suppression and may include the immune reconstitution syndromes.

Brainstem abscess: the nonsurgical management.

The brainstem is an unusual location for a pyogenic abscess. Stereotactic aspiration or microsurgical drainage may be required in antibiotic refractory cases. Prolonged antibiotic therapy, along with symptomatic treatment may provide successful outcome. We report a case of cerebellar and brainstem abscess, managed successfully with prolonged antibiotic administration.

Calvarial malignant fibrous histiocytoma.

Primary malignant fibrous histiocytoma (MFH) of the central nervous system (CNS) is uncommon. We report cases of two young patients of MFH arising from the cranial meninges and involving the adjacent skull and scalp. There was infiltration of the brain in one case. Both the lesions were excised and primary scalp repair was performed.

Raised intracranial pressure in hepatic encephalopathy.

Intracranial hypertension secondary to cerebral edema is the cause of death in 50%-80% of patients with fulminant hepatic failure (FHF). This is rarely seen in chronic hepatic failure. The genesis of cerebral edema in FHF is poorly understood. The grade of encephalopathy and coagulopathy are the most important predictors of outcome in FHF. However, it is important to emphasize that intracranial pressure (ICP) may not reflect clinical course. Decerebrate posturing may be seen with ICP recording of 16 mmHg, while a quarter of the patients may have brain damage without clinical signs of raised ICP. ICP monitoring is therefore vital. The gold standard for ICP monitoring is the intraventricular method. Non-invasive methods like computerized tomography scan and magnetic resonance imaging have poor correlation with ICP. Other methods like transcranial Doppler and jugular venous oximetry measurement of brain metabolites need evaluation. The main indications for ICP monitoring in FHF are (a) patients in grade III or IV encephalopathy and (b) patients undergoing liver transplantation. Generally, patients with an ICP >40 mmHg with cerebral perfusion pressure <50 mmHg for over 2 hours are poor subjects for liver transplant.

Recurrent intramedullary cervical ependymal cyst.

We report a rare case of high cervical intramedullary ependymal cyst in a young boy. This was associated with atlantoaxial dislocation. After partial removal and marsupialization, the cyst recurred and needed radical total resection.

Traumatic subarachnoid haemorrhage: a clinicoradiological and TCD correlation.

Twenty five consecutive patients with CT proven pure traumatic subarachnoid haemorrhage (tSAH) were studied, prospectively over a 6 month period. They constituted 2% of all head injuries. Most of the patients (88%) had a mild or moderate head injury at the time of admission, with a mean glasgow comma scale (GCS) of 10.68. The CT scan findings were divided into 3 grades. Grade 1 - blood in hemispheric region only (n=4), grade 2 - blood in basal region only (n=11), grade 3 - blood in both hemispheric as well as basal region (n=10). Transcranial doppler ultrasound (TCD) velocities were recorded in all patients by insonating the middle cerebral artery, internal carotid artery and anterior cerebral artery on both sides. All patients were also subjected to digital substraction angiography (DSA). All patients with mild head injury had normal TCD velocity (<100 cm/sec), while TCD velocities of more than 150 cm/sec were seen only in one patient with severe head injury. Patients with severe head injury were found to have grade 3 tSAH on CT. No statistically significant correlation was found between the CT grade and TCD velocities. Angiographic vasospasm was found in 2 patients with severe head injury only. 90.2% of patients had good outcome at discharge.