Mosquito records from a hot and dry climatic area experiencing frequent outbreaks of Japanese encephalitis, Bellary district, Karnataka, India.

Mosquito species occurring in Bellary district, Karnataka, India were surveyed for Japanese encephalitis (JE) and West Nile virus (WNV) from 2001 to 2003. A total of 37 mosquito species in 6 genera were recovered from larval and adult habitats. Aedes, Anopheles and Culex were represented by 11 species each, Mansonia by 2 species, and Armigeres and Lutzia by a single species. A total of 68,506 mosquitoes belonging to 20 species were collected at dusk. Most (74.6%) were Cx. tritaeniorhynchus and occurred in 2 peaks of abundance in February (304 per man hour density [PMHD]) and October (465 PMHD). The mosquito fauna of Bellary district is not diverse, possibly because of the hot and dry climatic conditions in the area.

Ecological study on mosquito vectors of Japanese encephalitis virus in Bellary district, Karnataka.

BACKGROUND & OBJECTIVE: Japanese encephalitis virus (JEV) has been a serious public health problem in Bellary district since 1981. Though JE is a vector borne disease, no published record was available regarding prevalence of mosquito species in this region. A two years ecological study was therefore conducted to determine species composition, seasonal prevalence and relative abundance of culicid taxa, particularly JE vectors endemic to this area. METHODS: Three villages with recent JE out breaks, were selected for regular mosquito collections. During daytime, adult mosquitoes resting inside human and domestic animal habitations were collected using aspirators and flashlights at weekly intervals. Similarly, adult mosquitoes were collected from cattle sheds and pig enclosures at dusk hours. RESULTS: A total of 120113 mosquitoes collected at dusk belonged to 5 genera and 24 species, including 13 species those have already yielded JE virus in India with Cx. tritaeniorhynchus contributing to 70.3 per cent. General mosquito population showed bimodal pattern of peak occurrence during February and October in both the peaks, Cx. tritaeniorhynchus contributed maximum JE. Substantial densities of An. subpictus and An. peditaeniatus during JE season suggest the supportive role of these species. Other vector species viz., Cx. quinquefasciatus, Cx. pseudovishnui, Cx. vishnui, Cx. gelidus, Cx. fuscocephala, Cx. bitaeniorhynchus, Ma. annulifera, Ma. uniformis and An. barbirostris perhaps have a limited role in the transmission of JE virus due to their extremely poor density. INTERPRETATION & CONCLUSION: Cx. tritaenorhynchus appears to have a major role in the transmission of JE virus in Bellary district. Risk of transmission of JEV to humans can be reduced by house spraying with residual insecticides and intermittent paddy irrigation.

Venereal transmission of Chandipura virus by Phlebotomus papatasi (Scopoli).

Experiments were conducted in the laboratory on Phlebotomus papatasi to determine the possible role of males in maintaining or sustaining the Chandipura virus (CHPV) activity in nature. This study indicated that infected males are capable of passing on the virus to female sand flies while mating. The infection rate was found to be 12.5% in uninfected females when mated with infected males. The occurrence of venereal transmission of this virus may have epidemiologic importance in the natural cycle of CHPV.

Detection of chandipura virus from sand flies in the genus Sergentomyia (Diptera: Phlebotomidae) at Karimnagar District, Andhra Pradesh, India.

A total of 191 adult sand flies belonging to the genus Sergentomyia were collected from seven villages in Karimnagar and Warangal districts of Andhra Pradesh State, India, after an outbreak of encephalitis due to Chandipura virus (CHPV). Fifteen pools, each containing two specimens, were tested by reverse transcriptase-polymerase chain reaction and sequencing. One pool of Sergentomyia from Kolanur village in Karimnagar District was positive for CHPV.

New mosquito records of an area known for Japanese encephalitis hyperendemicity, Gorakhpur District, Uttar Pradesh, India.

During long-term ecological studies carried out between 1990 and 2000, a total of 67 mosquito species were collected from Gorakhpur District, Uttar Pradesh, India, of which 43 were documented for the 1st time. The genus Aedes was represented by 15 species, Anopheles by 15, Culex by 24, Mansonia by 3, and Mimomyia, Ochlerotatus, and Verrallina by 2 each. The genera Aedeomyia, Armigeres, Coquillettidia, and Uranotaenia were represented by single species. The impact of ecological changes on mosquito fauna in Gorakhpur District is discussed. The role of culicine mosquitoes in disease transmission in the area is highlighted.

First report on high-degree endophilism in Culex tritaeniorhynchus (Diptera: Culicidae) in an area endemic for Japanese encephalitis.

An unusually high occurrence of Culex tritaeniorhynchus Giles resting indoors during daytime was observed in a Japanese encephalitis (JE) endemic area, Bellary district, Karnataka, India. Cx. tritaeniorhynchus, the primary vector of JE in this area, was the dominant species collected, and its abundance showed two peaks corresponding to rice crops in the district. More specimens (n = 20,966) were found resting in indoor habitats than in outdoor vegetation (n = 383), despite the availability of outdoor resting sites. This resting behavior is opposite to the Cx. tritaeniorhynchus behavior reported in the majority of JE-affected areas, where this species was captured in small numbers from indoor resting sites. Increased endophilic resting behavior indicates that indoor residual insecticides may provide an effective control method in this area.

A long-term study on vector abundance & seasonal prevalence in relation to the occurrence of Japanese encephalitis in Gorakhpur district, Uttar Pradesh.

BACKGROUND & OBJECTIVES: Japanese encephalitis (JE) virus is an important cause of viral encephalitis in Gorakhpur district, UP. The area has been experiencing outbreaks of JE since 1978. No in-depth longitudinal studies have been carried out on the mosquito species, particularly JE vectors prevailing in the area. Entomological studies were carried out in the district in order to determine the species composition, relative abundance and seasonal prevalence of mosquitoes in relation to the incidence of JE. METHODS: Three JE affected villages were selected as study sites. Weekly visits were made to each village and mosquito collections were made in and around the pig enclosures and cattle sheds with the help of mouth aspirators, aided by flash lights at dusk. RESULTS: The overall mosquito population showed a bimodal pattern with short and tall peaks during March and September respectively. Based on the elevated density and infection with JE virus, Culex tritaeniorhynchus has been considered responsible for causing epidemics in the area. Cx. pseudovishnui, Cx. whitmorei, Cx. gelidus, Cx. epidesmus, Anopheles subpictus, An. peditaeniatus and Mansonia uniformis are suspected to have played some role in the epidemiology of JE in the region. JE cases were reported between August and November with the peak in October when the vectors population, particularly Cx. tritaeniorhynchus was on the decline. INTERPRETATION & CONCLUSION: The results of the study indicate that Cx. tritaeniorhynchus, the most likely vector of JE together with other known vector species remained more active during the period of paddy cultivation. Integrated antilarval measures before the beginning of paddy irrigation may check the breeding of JE vectors in the paddy fields. It may prove beneficial in reducing the vector population during the JE transmission season.

Bionomics of Culex epidesmus associated with Japanese encephalitis virus in India.

Various biological characteristics, including seasonal abundance, diurnal resting habits, feeding behavior, larval habitats, and oviposition, of Culex epidesmus were studied in Gorakhpur District, Uttar Pradesh, India, from 1990 to 1999. Prevalence of adults was recorded between June and October, with a peak in August. The bushy undergrowth of mango and teakwood plantations served as diurnal resting habitat. Blood-meal analysis of wild-caught females showed that the most of them had fed on bovines. Temporary pools of rainwater and paddy fields containing freshwater and filamentous green algae were found to be suitable larval habitats. Gravid females laid eggs and immature stages grew well in the presence of green algae. Freshly laid egg rafts were found to be boat shaped and individual eggs were a white-cream color. The number of eggs per raft deposited by individual Cx. epidesmus varied from 118 to 288, with an average of 199 eggs per specimen.

Finasteride increases anagen hair in men with androgenetic alopecia.

BACKGROUND: The growth of scalp hair is a cyclical process of successive phases of growth (anagen) and rest (telogen). In previous clinical trials in men with androgenetic alopecia, treatment with finasteride increased scalp hair counts in a defined area (i.e. increased hair density). OBJECTIVES: The current study used a phototrichogram methodology to assess the effect of finasteride on the phases of the hair growth cycle. PATIENTS/METHODS: Two hundred and twelve men, age 18-40 years, with androgenetic alopecia were randomized to receive finasteride 1 mg daily or placebo for 48 weeks. At baseline and at 24 and 48 weeks, macrophotographs were taken to measure total and anagen hair count in a 1-cm(2) target area of the scalp. RESULTS: At baseline, mean total and anagen hair counts in the finasteride group were 200 and 124 hairs, respectively (% anagen = 62%) and the anagen to telogen ratio was 1.74 (geometric mean). In the placebo group, the respective values were 196 and 119 hairs (% anagen = 60%) and 1.57. At week 48, the finasteride group had a net improvement (mean +/- SE) compared with placebo in total and anagen hair counts of 17.3 +/- 2.5 hairs (8.3% +/- 1.4%) and 27.0 +/- 2.9 hairs (26% +/- 3.1%), respectively (P < 0.001). Furthermore, treatment with finasteride resulted in a net improvement in the anagen to telogen ratio of 47% (P < 0.001). In this study, treatment with finasteride 1 mg day(-1) for 48 weeks increased both total and anagen hair counts, and improved the anagen to telogen ratio. CONCLUSIONS: These data provide direct evidence that finasteride 1 mg daily promotes the conversion of hairs into the anagen phase. These data support that finasteride treatment results in favourable effects on hair quality that contribute to the visible improvements in hair growth observed in treated patients.

First isolation of Japanese encephalitis virus from the mosquito, Culex tritaeniorhynchus Giles, 1901 (Diptera: Culicidae) in Gorakhpur district, Uttar Pradesh.

A strain of Japanese encephalitis (JE) virus has been isolated from a pool of female mosquitoes of C. tritaeniorhynchus, using C. bitaeniorhynchus cell line. This is the first report of JE virus isolation from mosquitoes in Gorakhpur district of Uttar Pradesh, north India.