Tropical fevers: Management guidelines

Tropical fevers were defined as infections that are prevalent in, or are unique to tropical and subtropical regions. Some of these occur throughout the year and some especially in rainy and post-rainy season. Concerned about high prevalence and morbidity and mortality caused by these infections, and overlapping clinical presentations, difficulties in arriving at specific diagnoses and need for early empiric treatment, Indian Society of Critical Care Medicine (ISCCM) constituted an expert committee to develop a consensus statement and guidelines for management of these diseases in the emergency and critical care. The committee decided to focus on most common infections on the basis of available epidemiologic data from India and overall experience of the group. These included dengue hemorrhagic fever, rickettsial infections/scrub typhus, malaria (usually falciparum), typhoid, and leptospira bacterial sepsis and common viral infections like influenza. The committee recommends a ‘syndromic approach’ to diagnosis and treatment of critical tropical infections and has identified five major clinical syndromes: undifferentiated fever, fever with rash / thrombocytopenia, fever with acute respiratory distress syndrome (ARDS), fever with encephalopathy and fever with multi organ dysfunction syndrome. Evidence based algorithms are presented to guide critical care specialists to choose reliable rapid diagnostic modalities and early empiric therapy based on clinical syndromes.     

Genetically determined recurrent fevers.

The usefulness of molecular diagnosis is now well established for genetically determined recurrent fevers. In familial Mediterranean fever, the severity of the disease and the risk of renal amyloidosis are correlated with mutations in MEFV, and the serum amyloid-associated protein (SAA)1 alpha/alpha allele is a modifying factor for amyloidosis. Study of the genes in various species shows that the human mutations represent a reappearance of the ancestral amino acid state and the B30-2 domain, where most human mutations are localized, is absent in the rat and mouse proteins. Since the discovery of the responsible gene, TNF-receptor-associated periodic syndrome seems to be more frequent than previously considered. Among the new mutations described, some are associated with an incomplete penetrance.     

Clinico-epidemiologic and laboratory research on hemorrhagic fevers in Guinea

In 1982-1983, were reported the cases of haemorrhagic fevers among populations living in the Madina-Ula district of Guinea. Clinico-epidemiological and serological studies (experimental studies) reveal into presumption of Ebola and Lassa fever viruses significance in the etiology of the disease outbreaks. Antibodies to Ebola virus were recognized in 19% from total number of sweating reconvalescent patients with the same clinical features, in order to 8% in healthy local populations. Antibodies to Lassa virus were detected in 3 cases, in 4 cases was revealed Lassa virus antigen in small rodents.     

Periodic fevers with aphthous stomatitis,pharyngitis, and adenitis (PFAPA)

PFAPA syndrome (acronym of periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis) is the most common cause of periodic fever in childhood. Nowadays, it is considered part of the wide family of the autoinflammatory diseases, but a genetic or molecular marker hasn't been identified yet, therefore, its etiology is still unknown. Diagnosis is essentially based on clinical criteria but, especially in younger children, it is sometimes difficult to differentiate it from other hereditary periodic fever syndromes. Fever attacks in PFAPA have a spontaneous resolution and in a high rate of patients the syndrome ends spontaneously over time. Treatment is still a matter of debate. Usually a single administration of oral corticosteroids aborts attacks. Tonsillectomy may be an alternative option but its role remains to be clarified.     

Serological studies on sandfly fevers in the Republic of Bangladesh

Blood samples from 160 inhabitants of the Republic of Bangladesh were studied by haemagglutination inhibition (HI), indirect HI, and radial haemolysis in gel tests. The sera were found to contain antibodies to the arborviruses of Sicilian (6.25%) and Naples (1.25%) sandfly fevers and to the Karimabad virus (11.25%) which are transmitted by Phlebotomus papatasi. Antibodies to the Karimabad virus were found among the Bangladesh population for the first time.