Entomological investigation of Japanese encephalitis outbreak in Malkangiri district of Odisha state, India

BACKGROUND A severe outbreak of Japanese encephalitis (JE) and acute encephalitis syndrome (AES) with high case fatality was reported from Malkangiri district of Odisha state, India during September to November 2016 affecting 336 children with 103 deaths. OBJECTIVES The purpose of this study was to investigate the outbreak in the light of entomological determinants. METHODS Entomological investigation was carried out in 48 villages from four mostly affected Community Health Centres (CHCs) of Malkangiri district. Dusk collections of resting adults was done in villages from indoor and outdoor sites to record the density of mosquito species, including the known JE vectors, feeding behaviour, parity, dusk index and infection status with JE virus (JEV). FINDINGS The per man hour density and dusk index of JE vector species varied from 2.5 to 24.0 and 0.81 to 7.62, respectively in study villages. A total of 1136 mosquitoes belonging to six vector species were subjected to PCR and one pool of Culex vishnui was found to be positive for JEV. CONCLUSION The JE transmission in Malkangiri district was confirmed. Thorough screening of human blood samples of JE/AES suspected cases and JE vector mosquitoes for the presence of JEV during rainy season every year is recommended.

Situation Analysis of Malaria in Godda District of Jharkhand During Malaria Epidemic.

The epidemiological and entomological investigations were carried out in 18 tribal villages of Godda district of Jharkhand state revealed average slide positivity rate (SPR) 9.9% and slide positivity rate for Plasmodium falciparum (SfR) 5.0%, respectively. P. falciparum was the dominant parasite accounting 51.2 per cent of the total infections. All the villages are situated in the deep forest and forest fringes. A total of 416 blood slides were collected and examined. Out of which 41 slides were found positive for malaria parasite (21 positive for P. falciparum and 20 positive for P. vivax). All the positive cases were treated with Blister Packs of anti-malarial of chloroquine and primaquine as per NBVDCP schedule to prevent further transmission of malaria, which were available. Rapid diagnostic Kits were used selectively only on the recommendation of the Physician/Medical Officer. Results of house to house fever survey indicated the presence of high percentage of symptomatic carriers of malaria parasites in the local population and in our study Pf % is more than reported data by District Malaria Office, Godda district, Jharkhand. In entomological studies, for mosquito fauna with reference to both Anopheline, 11 species belonging to one genus Anopheles were collected and identified during the survey; among them some species were most prevalent. A total of 599 mosquitoes were recorded and average density of mosquitoes recorded was 13.19 in human dwellings and 86.11 in cattle sheds.

Entomological study of chikungunya infections in the State of Kelantan, Malaysia.

Background & objectives: Chikungunya infection has become a public health threat in Malaysia since the 2008 nationwide outbreaks. Aedes albopictus Skuse has been identified as the chikungunya vector in Johor State during the outbreaks. In 2009, several outbreaks had been reported in the State of Kelantan. Entomological studies were conducted in Kelantan in four districts, namely Jeli, Tumpat, Pasir Mas and Tanah Merah to identify the vector responsible for the virus transmission. Methods: CHIKV cases records were obtained from State Health Department, Kelantan and localities involved were identified. Larva survey was conducted to collect the immature mosquito stages. Modified aspirators were used to collect the adult mosquitoes. All samples on dry ice were transferred to laboratory and the presence of the virus was detected using reverse transcriptase PCR. Results: A total of 1,245 mosquito larvae were collected during larval survey and 2,019 adult mosquitoes were collected using aspirator. From these collections, 640 mosquito pools were tested for the presence of CHIKV by RT-PCR but none found positive. Ae. albopictus was the most abundant mosquito collected, followed by Culex sp., Armigeres sp. and Anopheles sp. A total of 2, 814 artificial containers were inspected during the study. Interpretation & conclusions: Since none of the mosquito samples was found to be positive for chikungunya virus, the vector(s) of chikungunya virus in these localities could not be identified.

Clinico-Epidemiological Profile of an Outbreak of Dengue Fever in Rural Area of Ambajogai Mandai, District Beed.

A c1inico-epidemiological study of fever cases was carried out in three villages of Ambajogai Mandal, Beed, Maharashtra. Out of 123 fever cases studied, most common affected age group was 21-45 years with more number of females i.e.55.28%. The patients mainly presented with fever and joint pain with no any evidence of haemorrhagic manifestation. Of the 36 blood samples tested 03 samples were found positive for IgM antibodies to dengue virus. Larval survey showed highest breeding preference in domestic water container like earthen pots. Entomological indices were found out to be higher as house index 19.76%; container index 19.02%; Breteau index 22.31%. Clinico-epidemiological, laboratory and entomological investigations indicate present episode of fever outbreak was due to dengue fever. It demands for strengthening the surveillance activity and alert reporting of peripheral health staff along with IEC activities for community participation and involvement of other departments.