Evolutionary dynamics of the American African genotype of dengue type 1 virus in India (1962-2005).

Dengue is a major health problem in India with all four serotypes represented. Recently there has been an increase in the occurrence of dengue-1 outbreaks. It is possible that there have been changes in the genetics of dengue virus-1 (DENV-1), either by fresh introductions or by evolution in situ. The studies on DENV-1 evolution so far have no Indian sequences included. To gain insight into the dynamics of DENV-1 in India, the envelope (E) gene of thirteen virus isolates representative of the period 1962-2005 were sequenced and analyzed together with the available sequences of 40 globally representative isolates. All the Indian DENV-1 isolates were found to belong to the American African (AMAF) genotype. With the addition of 13 Indian isolates, the AMAF genotype can now be called Cosmopolitan. The Indian isolates were distributed into four lineages, India I, II, III and the Africa lineage, now called Afro-India. Of these, India III was the oldest and extinct lineage; the Afro-India was a transient lineage while India I, imported from Singapore and India II, evolving in situ, were the circulating lineages. Despite the extinction and introduction of lineages, no specific codon site was observed to be under selection pressure. The rate of nucleotide substitution estimated for DENV-1 was 6.5 × 10(-4) substitutions/site/year, and the time to the most recent common ancestor (tMRCA) was estimated to be 78-180 years (1825-1925), similar to previous estimates. The tMRCA for the AMAF/Cosmopolitan genotype was 56-98 years (1907-1949), a period that covers World War I and II. The two imports from Africa (1953-1968) and Singapore (1964-1975) and an export to the Americas (1955-1965) prove that there have been changes in the lineage of the DENV-1 viruses circulating in India which has contributed to the global dynamics of DENV-1 evolution and perhaps to the changing epidemiology of dengue in India.

Clinical profile of chikungunya fever in patients in a tertiary care centre in Maharashtra, India.

BACKGROUND & OBJECTIVE: In India a chikungunya fever outbreak started in December 2005 when the country experienced more than 13 lakhs of chikungunya infected cases. We undertook this study to study detailed clinical profile of chikungunya fever in both indoor and outdoor patients in a tertiary care hospital in Nagpur, Maharashtra in 2006. METHODS: Suspected cases of chikungunya fever (n=405) during the period of July to September 2006, having clinical triad of fever, arthralgia and/or rashes were included in the study. Clinical profile was studied in all the cases. Of the 405 samples collected, 166 were tested for serum CHIK IgM antibodies. RESULTS: Of the 166 samples tested for CHIKV IgM antibodies, 87 (52.4%) were positive (confirmed cases). Male: female ratio was 2.3:1. Fever and arthralgia were present in all cases. Rash was present in 27 (31%) confirmed and 38 (12%) suspected cases. Lymphadenopathy was present in 12 (13.8 %) confirmed and 4 of suspected cases. Chronic polyarthritis was seen in 22 (25.3%) confirmed and 75 (23.6%) suspected cases. Neurological manifestations were observed in 08 (9%) confirmed and 10 (3.14%) suspected cases. Mortality was 7 (2.2%) in 318 suspected cases and 3 (3.4%) in 87 confirmed cases. INTERPRETATION & CONCLUSION: Our findings showed that about half of the serum samples for CHIKV IgM antibody tested positive from cases suspected to have chikungunya fever. Fever, joint pain and headache were major symptoms. Certain rare manifestations like lymphodenopathy, oral ulcers and encephalitis were also seen. Mortality in confirmed cases was about 3.4 per cent.

Clinico-epidemiological profile of cases of fever with arthritis (Chikugunya) attending Urban Health Centre, Solapur.

This communication describes the findings of a hospital and community survey conducted in the UHC catchment area of solapur city to find out clinico-epidemiological profile of cases of chikungunya fever during mid 2006. A total of 208 cases who attended UHC and 962 community members were studied. 20-44 was the mostly affected age-group and Females outnumber male hospital attendees. Major presenting features were fever, joint pain, bodyache, headache, nausea. In majority of patients, joint pain lasted for two months and subsided by 6th month. Of 21 samples tested, 19 showed IgM positivity for chikungunya.

Establishment of a cell line from Indian bonnet monkey (Macaca radiata) kidney and its characterization.

A cell line (MRK-90) has been established from a kidney tissue of a macaque monkey (Macaca radiata) of India. The cells are in 150th passage and have been characterized for morphology, chromosome number, isoenzyme patterns (LDH and MDH) and virus susceptibility. These studies indicate that the cells are epithelial like, heteroploid (2n = 65) and grow easily on glass surface/plastic surface without any difficulty. The cells are susceptible to a broad spectrum of viruses.

Circulating interferon-alpha in patients with Kyasanur forest disease.

Endogenous interferon (IFN) levels were monitored in acute (51) and convalescent phase (19) sera collected from patients suffering from Kyasanur forest disease (KFD). Levels of circulating IFN in the acute samples (GM 216.3 +/- 8.7) collected between 4 to 7 post onset day (POD) were significantly higher (P less than 0.001) than the convalescent samples (GM 13.19 +/- 1.6) collected between 30th to 90th POD. Interferonemia was concomitant with the viraemic phase. Neutralization studies indicated that the endogenous (circulating) IFN was antigenically similar to acid stable form of IFN-alpha.

Protective effect of 6-MFA, a fungal interferon inducer against Japanese encephalitis virus in bonnet macaques.

6-MFA, an extract from the fungus Aspergillus ochraceus was administered to 8 bonnet macaques. An equal number of monkeys matched for age, sex and weight received placebo and served as controls. Twenty hours after the administration of the 6-MFA/placebo the monkeys were challenged with an Indian strain of Japanese encephalitis virus by the intranasal route. Signs and symptoms of the disease such as fever, tremors, loss of appetite, dehydration, flaccid paraplegia or quadriplegia were pronounced in all the control monkeys, while in the 6-MFA treated group only two developed symptoms. Virus could be isolated from only one of the 6-MFA treated monkeys on day 6, and from four control monkeys; one each from CSF, spinal cord, blood and from both nasal swab and blood of the fourth monkey. The appearance of HI and N antibodies in 6-MFA treated group was either delayed or completely suppressed. The results indicate that 6-MFA is a potential antiviral agent which can be used to reduce the morbidity and mortality in bonnet macaques (Macaca radiata) experimentally infected with Japanese encephalitis virus.

Epitope analysis of strains of Japanese encephalitis virus by monoclonal antibodies.

Twenty one strains of Japanese encephalitis (JE) virus, including 16 from India, were compared antigenically on the basis of their reactivity in immunofluorescence (IF), haemagglutination inhibition (HI), ELISA with captured antigen (ECA), and neutralization (N) tests with JE monoclonal antibodies (MAbs). These MAbs represented three domains of distinct epitopes on the envelope protein, designated as Hs-1 to 4 (JE specific in HI), Hx-1 to 5 (flavivirus cross reactive in HI) and NHs-1 to 2 (non-HI JE virus specific). Fifteen of the 21 strains studied were placed in group I. These reacted with MAbs representing the three domains in all the tests indicating presence of the three types of epitopes with full functional activity. The remaining six strains were placed in group II and showed loss in HI reactivity with Hs MAbs but not with Hx MAbs. All the group II strains also reacted in IF and ECA with NHs-1. Hs epitopes in three strains, G9473 (Tamil Nadu), 641686 (Tamil Nadu) and 822199 (Karnataka), appeared to have mutated partially, indicating loss in HI reactivity with Hs MAbs only, while there was retention of other reactivities, viz., IF, ECA and to some extent N test with G9473 and 641686. The remaining three strains, 691004 (Sri Lankan), 755468 (West Bengal) and Yoken (Japan) of group II showed almost complete loss of Hs-1 and Hs-2 epitopes as there was absence of reactivity in IF, ECA and N test in addition to HI. However, Hs-3 MAb showed reactivity in IF with these strains.(ABSTRACT TRUNCATED AT 250 WORDS)

Interferon producing capacity (IPCA) of peripheral mononuclear cell in oral cancer patients.

Interferon producing capacity (IPCA) of peripheral blood mononuclear cells is ability of these cells to produce IFN with suitable IFN inducer. In Vitro IPCA of cryopreserved mononuclear cells (MNC) from peripheral blood of 46 oral cancer patients was studied and was compared to that of healthy, age matched donors. New castle disease virus (NDV) and staphylococcal enterotoxin A (SEA) were used as inducers for evaluating Type alpha IPCA (AIPCA) and Type gamma IPCA (GIPCA) respectively. Age of healthy donors did not influence the AIPCA or GIPCA. Oral cancer patients demonstrated significant low AIPCA (P less than 0.05) (Range Healthy donors 3.5 to 4.6 log 10Iu/ml Oral Cancer 2.0 to 4.6 log 10Iu/ml GIPCA was found to be further depressed (P less than 0.005) (Range Healthy donors 2.87 to 3.6 Log 10 U/ml, Oral cancer 1.7 to 3.6 log 10 U/ml. The depression in IPCA was found to be more pronounced in advanced stage of disease.