Outbreak Indian Tick Typhus amongst residents of Deol village , District , Kangra , Himachal Pradesh ( INDIA ) * *

an epidemiological and entomological investigation of tick typhus outbreak in village, Deol District Kangra (Himachal Pradesh) was undertaken with the aim to determine the occurrence of outbreak in the area and to reinforce control measures for the continent of diseases. During the outbreak a total of 357 cases of acute febrile illness among the total 1223 population was reported. the methodology used was to review of the records of health facilities, rapid fever survey in affected and non affected village, entomological survey for collection of ticks from domestic animals/rodents serological investigation and study of eco-epidemiological feature of the study area. Based on the working case definition, clinical features, symptomatology, serological evidence in the form of IgM antibodies in patient serum, presence of vector species in good number it was concluded that an episode of Indian Typhus has occurred in the village Deol, District Kangra (H.P.) during July 2007. Details of the finding are discussed in the communication. action taken by local health authorities and recommendations for containment of outbreak has been discussed.


INTrODucTION
Rickettsiosis is known as oldest and most recently recognized disease in India.In India an outbreak during spring near Bunji in Gilgit is the earliest report of epidemic typhus mentioned in Medical Administrative reports of Jammu and Kashmir State (1804).The origin of tick typhus in India can be traced directly to Col. Megaw, who narrated his own experience of tick bite and his subsequent illness.The isolation of Rickettsiae has been done successfully from Ixodid pools; Haemaphysalis leachi variety indica from Imphal, Ixodes ricinus from Almora and Rhipicephalus sanguineus from Srinagar. 1,2dian tick typhus infection is widely prevelant in the hilly forest tract in different parts of India and seroepidemiologically the infection has been reported from various parts of the country like Nagpur, Jabalpur, Jammu and Kashmir, Kanpur, Sagar, Pune, Lucknow and Banglore. 1 During July 2007 amongst 1223 residents of Deol village, Kangra district, Himachal Pradesh, 357 cases of acute febrile illness, was reported.This localized fever episode was investigated by a team of an epidemiological and entomological from the than NCDC (Formerly NICD) with the objective: To determine if an outbreak has occurred in the area: To determine the occurrence of outbreak and to review and reinforce control measures based on the findings: The results of the investigation are presented in the manuscript.

Study area
Kangra is one of the twelve districts of Himachal Pradesh situated in the eastern part of Himachal Pradesh.The district has an area of 5739 Sq. km. and a population of more than 1.3 million.It is situated about 526-km north-west of New Delhi.Dharamshala is the headquarters of the Kangra.
The affected village Deol is situated at a distance of about 60 kms from district headquarter and 8 kms from Baijnath the nearest town.The village is connected by a motorable road in hilly terrain.Sanitation and hygiene in general was poor.The population of the village was 1223 as per 2001 census.An Ayurvedic dispensary with one medical officer survey covering all the households in the affected Deol village and a nearby unaffected village Sirajra was carried out for the rapid health assessment.The team also carried out eco-entomological survey of the affected area and collected ticks from domestic animals by hand pick method.Rodent trapping was done in the village covering domestic and per-domestic situations to collect ectoparasites (Tick, mites, flea and lice) as per the standard procedure. 3

resulTs AND DIscussION
Analysis of month wise number of fever cases reported to the local Ayurvedic dispensary situated in the Deol village from 2004 onwards indicate that during 2007, the number of fever cases started increasing from the month of May onwards and reached its peak in July 2007 (figure 1).
During July 2007, a total of 357 cases of fever were reported in the Ayurvedic dispensary of Deol village as compare to 40 cases during July 2006.During 1 st to 3 rd August 2007 (teams visiting period), 24 fever cases were reported to the dispensary.Period distribution of 381 cases reported during 1 July to 3 August 2007 shows that maximum cases were reported during the period 15 July to 28 July 2007, after this the cases started declining.Week-wise distribution of cases is shown in figure 2.

Community Survey
After interaction with the persons who were still ill/ recovered and clinical examination of patients based on is located in the village.The following were the ecological and other observation in the village: • The source of water supply was predominantly tap water.
• Defecation in open field is the general practice.
• Cases were reported to the outpatient of Ayurvedic dispensary located in the village.• The houses in the village are of made-up of brick walls and roof with tin shade.• The main occupation of the villagers is sheep rearing by Gadaria tribes and as laborer in agricultural activities.The sheep's along with man folk goes to higher altitudes during April months and returned with the onset of winter during October/November.The sheep's went this year in April to higher altitudes has not returned back till the visit of survey team.

MATerIAl AND MeTHODs
Studies were undertaken by visiting the affected village and carried out clinical examination of cases.Local medical officers, health workers and community leaders were interacted to get the back ground information and assess the magnitude of the problem.
The persons who were ill and reporting to the local health facility or recovered were clinically examined and clinical specimens were collected as per the standard procedure.1).

Distribution of cases by place
A total of 209 households covering all parts of the village were surveyed and 60.3% households reported one or more fever cases in the last one month.About half (46.8%) of these households had reported multiple case i.e. more than one case of fever in their family.

Clinical features
The disease had an abrupt onset.The main presenting features were fever with chills, headache, and cough (Table 2).
No history of rash and haemorrhagic manifestations was found in any case.There was no history of loose motion or vomiting.
the history and clinical presentation a working case definition given below was developed to gather further information about the cases.

'Any person residing in the village Deol who had or develop fever with one of the following chills, headache and cough during the month of July 2007'.
A total of 245 households in two villages (209 households in affected village -Deol and 36 households in a nearby unaffected village -Sarajra) were surveyed using this case definition.The survey covered a total of 945 population in affected village and 153 in the unaffected village.The information on the epidemiological and clinical aspects was recorded on a pre-designed proforma.

Age and sex distribution of cases
It was found that cases were in all age groups affecting both male and females.Over all 25.5% persons of this  and Haemaphysalis bispinosa.Rhipicephalus sanguenius is the proven vector of Indian Tick typhus in the hilly forest tract of the country.Ixodes ricinus was collected from Suncus murinus (Rodent) caught during the rodent tapping in the village.Village wise and animal wise details of the ticks collected is given in the table 3.
Rodent trapping were done in Deol village.A total of 138 traps (18 wire cage trap and 120 break back traps) were laid to catch the rodents.8 traps were found positive giving an over all trap positivity rate of 5.07 percent.From the traps a total of 8 rodents comprising of Rattus rattus (5)  and Suncus murinus (3) were retrieved.Only one Suncus murinus was found positive for the presence of Trombiculid mite (Vector of Scrub Typhus) and one for ticks (Ixodes ricinus), no flea and lice was found on the rodents.

Laboratory Investigations
Results of the sixteen sera samples drawn from patients by state health authorities showed ten samples positive for IgM antibodies against Rickettsia conorii indicating recent infection of Indian tick typhus.
A total of another five serum samples were collected by the team during investigation (4 sera and 1 one blood sample in glucose broth).Of the 4 sera samples collected, two were from convalescing patients (second samples from patients found IgM antibodies positive for R. conorii earlier) and rest two from new cases of the fever.
Both the second serum samples from convalescent patients tested positive for R. conorii where as the serum samples from new patients were negative.
The fever did not respond to Ofloxacin or Cefixime prescribed by the local medical officer.However, all the fever cases responded to Doxycycline and supportive treatment.There was no residual motor/neurological deficit.No death due to this acute febrile illness was reported from this village.
No significant history of previous such episode, movement of population, festival/fair, vaccination in recent past as well as consumption of drugs could be elicited from study of case studies records, interview of relatives of the cases and district health officials.

Situation in the unaffected village -Sirajara:
During the community survey covering 153 population in 36 households in village Sarajra , no such fever cases was found.The fever rate in this village was found to be 2.6% in the month of July, 2007.

Figure 2 :
Figure 2: Week wise distribution of 381 cases of acute febrile illness reporting to the outpatient health facility, Deol village, Kangra district, 1 July -3 August, 2007

No. of fever cases reporting at dispensary
July to 3 August 2007.The attack rate of fever was more among persons 1-14 years of age.The attack rate of fever in this age group was 41% as compared to 21.1% in other age groups (Table The record of the local health facility was reviewed of the fever cases reported during the last 3 years.A rapid fever Figure 1: Month wise distribution of fever cases, Deol Village, Kangra district, Himachal Pradesh, 2004 to 2007 village suffered with acute febrile illness during 1

Table 2 : Symptomatology of cases of acute febrile illness, Deol Village, Kangra district, Himachal Pradesh, July-August, 2007 (n = 241)
Fever cases suggesting Typhus group of fever in the villagers of all society and age group are distributed far and wide in the village.Ecologically terrain features of the village are congenial and supportive for the propagation and development of tick vector of Typhus fever.Deol, Village having hilly forest tract , supporting propagation and multiplication of vector ticks population, clinically, epidemiologically and entomologically is supportive of moderate and less severe out break of Rekettsiosis.Laboratory findings of IgM antibodies in the patients serum further suggest that the present episode of fever outbreak was of Indian tick typhus .Presence of tick vector Rhipcephalus sanguenieus in good number and presence of Ixodes ricinus on rodent also is supportive for the existence of tick typhus in the area.However, further studies are needed for the isolation of rickettsia from vector ticks to determine the exact origin and phylogeny of the ricekttsia strain prevalent in this part of India.