European Journal of Cardiovascular Medicine

Scrub typhus is the commonest occurring rickettsial infection in India. It is a leading cause of treatable non-malarial febrile illness in Southeast Asia. It is caused by a gram-negative, obligate intracellular bacillus Orientia tsutsugamushi. Scrub typhus is spread to people through bites of infected chiggers (larval mites)¹. The chigger mites of the family Trombiculidae of genus Leptotrombidium are responsible for the disease transmission².The greek meaning of the word“Typhus” is fever with stupor, which is related to the Sanskrit word for smoke,“dhupa” .This bacterium was first described by Hashimoto in 1810 and was first identified and named as Rickettsia tsutsuga-mushi by M.Oagta in 1931,but it has been reclassified as Orientia tsutsugamushi⁴. The first case Scrub typhus reported in China in Guangzhou, Guangdong province, in the 19th century, with the first scientific report published in 1885⁴.

Globally, scrub typhus was a cause for one-fourth (24.93%) of all febrile illness cases³.At present, one billion individuals residing in endemic areas are at a high risk of getting infected with scrub typhus¹.It is also estimated that more than 1 million cases occur worldwide annually⁵.Though scrub typhus has been in existence since more than a century, it still remains a highly neglected disease and has emerged as a significant public health problem in India in recent years. Originally, this re-emerging disease was found endemic in the tsutsugamushi triangle which includes countries like India, Pakistan, Sri Lanka, Japan, Thailand, Korea, extending from Afghanistan to Northern Australia. A recent evidence from in Arabian Peninsula, Chile,Kenya, everal regions of Micronesia and Maldives,suggests that it is rapidly re-emerging where it had previously been significantly neglected¹.

Currently, multiple epidemics and sudden outbreaks of scrub typhus have been documented across various parts of India⁵. In India,23 States out of 29 have reported the presence of scrub typhus.Where in the South,Tamil Nadu, Andhra Pradesh, Karnataka, and Kerala have reported high numbers of cases of this disease⁷. A rise in scrub typhus cases was observed during the rainy, post-monsoon and winter seasons, particularly in cooler months in India⁵. The disease is commonly seen in the rainy season due to increased exposure to trombiculid mites during harvesting and contact with newly growing vegetation. The combination of climate change and human expansion into previously uninhabited areas has increased the incidence and re-emergence of scrub typhus⁵.

The clinical presentation of scrub typhus ranges from subclinical disease to multiorgan failure and death⁷. The disease usually presents with fever, myalgia, rash, jaundice, diffuse lymphadenopathy, thrombocytopenia, capillary leak syndrome, hepatomegaly, and splenomegaly. The pathognomonic feature of scrub typhus is the necrotic eschar at the bite site². Clinically, this disease may range from asymptomatic to severe disease⁶. Globally, multi-organ failures occur in one-third of infections and the median case fatality rate (CFR) is 6% and can reach up to 70% if left untreated³.The disease has become a significant occupational hazard in rural workers, agricultural workers, people working in forests, soldiers in military camps, and in those living close to bushes and trees².

World Health Organization (WHO) states that scrub typhus is probably one of the most underdiagnosed and underreported febrile illnesses requiring hospitalization in the endemic. Though the awareness and availability of research data have been increased, the lack of data on the disease burden, prevalence, incidence and more specific diagnostic technique still exists¹. In view of low index of suspicion, nonspecific signs and symptoms, and absence of widely available sensitive and specific diagnostic test, these infections are very difficult to diagnose. In India, scrub typhus goes undiagnosed because its symptoms are similar to many other febrile illnesses, and there is a limited awareness among doctors. Failure of timely diagnosis leads to significant morbidity and mortality.

several environmental interventions like pesticide treatment and behavioural interventions, assessment of knowledge, attitudes and practices of occupational physicians towards mite borne diseases can be useful to improve the health and safety of high-risk outdoor workers. The disease can be prevented by the use of personal protective measures including repellents, people entering an exposed area must be advised to wear boots with socks, and long trousers. Exposed areas of skin and clothing should be treated with mite repellents. Repellents containing DEET, dusting sulphur, dimethyl phthalate or benzyl benzoate are suggested as suitable agents²⁰.

Limited diagnostic facilities, underreporting, inadequate case management, and insufficient vector control exacerbate the situation. With a timely diagnosis, treatment becomes easy and successful with dramatic response to antimicrobials. In India, the management of scrub typhus lacks systematic case detection and appropriate measures for vector control. Since Primary care physicians are the medical officers working in the Primary health centres are the first referral units in case of patients with acute febrile illnesses their knowledge regarding the disease can help in increasing the index of suspicion. Hence the present study aims to assess the knowledge, perceptions, diagnostic and treatment practices on scrub typhus among Primary care physicians.

It was a Cross-sectional study conducted in Prakasam District of Andhra Pradesh among the medical officers working in the Primary Health Centres during June-July 2024. Pretested semi-structured questionnaire containing questions on knowledge, perceptions and practices of Scrub typhus disease were distributed among the medical officers on the day of monthly meeting to be filled by them. The levels of knowledge on scrub typhus, practices of diagnosing and treatment was categorized as Poor, Good based on responses given by the participants. A Knowledge Score was then calculated as the sum of correctly and incorrectly marked recommendations: when the participants answered correctly, +1 was added to a sum score, whereas a wrong indication or a missing/“don’t know” answer added 0 to the sum score. Knowledge Score was then dichotomized by median value in poor vs. good knowledge status; Scoring points of <8 was taken as having Poor knowledge and >8 points was taken as having Good knowledge. After obtaining Permission from the District Medical and Health Officer, a Semi-structured questionnaire containing questions on knowledge perceptions and practices of Scrub typhus disease was distributed among the medical officers on the day of monthly meeting and was filled up by them.

Ethical considerations: Before giving their consent to the survey, participants were briefed that all information would be gathered and handled confidentially. Participation was voluntary and written informed consent was taken. The questionnaire was collected only from subjects who had expressed consent for study participation.

Statistical analysis: The data thus collected from them was analyzed using MS Excel and SPSS 22.0 version. Categorical variables were reported as per cent values, and their distribution in respect of the outcome

A total of 105 Primary Health Centre physicians have participated in the study. Among them,45% (48) were female, 55% (57) were male and 79 (75%) of them were in the age group of 25-35 years and only one person is in age group of above 45 years. Most of them 89 (84%) were having a work experience of less than 5 years (Table 1).Majority (72, 69%) of them were working in Rural areas, 20 (19%) were working in tribal areas and 13 (12%) in Urban areas (Fig.1). Among all,70.5% of the doctors opined that India is endemic for scrub typhus whereas only 29 (28.5%) of them opined Prakasam district is endemic which shows that 75 (71.5%) of the physicians were not aware that Prakasam was a endemic district for scrub typhus.  Majority (93.3% & 92.3%) of them were aware that Scrub typhus is a vector -borne disease and caused by bacterial agent Orientia tsutsugamushi.

Fig 1: Distribution of Physicians based on type of PHC area

Around 84% of the participants were aware the mode of transmission of disease, is a Mite. Most (71%) of them opined the disease transmission by trans-placental route and Around 16 (15.3%) physicians of were in opinion that the disease was contagious and spread via close contact with infected individuals. Over half of the physicians (52.4%) reported scrub typhus incubation period as 10-12 days and 56% reported that scrub typhus spreads rapidly during the rainy season. Among all, 82.5% were aware of eschar as a pathognomic feature,50% opined eschar is found in all cases and 75.2% opined it is found in multiple sites. Around 78% and 76% were aware of Weil-felix as a confirmatory test and Rapid kit test. Around 25% were not aware of Doxycycline as Drug of choice. The present study shows that 92 (87.6%) were having fairly good knowledge regarding epidemiology, diagnosis and treatment of scrub typhus (Table 4).   

Regarding the diagnosis and treatment practices, when a patient presents with febrile illness, around 42%(44) responded that they always suspect scrub typhus in a patient with febrile illness, 19%(20) suspect sometimes, only 8.6% of them never suspect scrub typhus.57.1% (60) always inquire about insect bite in the past 2 weeks, 68.6% (72) always inquire about surroundings of the house, 57.1% (60) always inquire about travel history, Only 42% (44) always examine the patient’s body for ‘Eschar’(Table 2).35 (33.3%) physicians opined Weil-felix test to be prescribed for diagnosis and 31 (29.5%) opined Rapid kit test for diagnosis. More than 90% (92) had good knowledge on Scrub typhus whereas coming to practice of identifying and treating cases is (68) 65% only.       

Regarding the health education practices on scrub typhus responded that 44 (42%) never provided any educational material on scrub typhus to the patients, whereas 60 (57.1%) always discussed risk factors and 72 (68.6%) responded that they always discuss preventive measures of scrub typhus and 2 (1.9%) responded they never discuss (Table 3).

Majority (90.4%) of them opined non availability of RDT Kits as barrier in early identification of cases. Most (51.4%) of them were referring the patients to tertiary health care centres (GGH) for diagnosis. 46.6.% doctors responded that patients were always provided with educational material on scrub typhus in the health centres, 59% always ask about risk factors, 69.5% always discuss preventive measures.

Association of level of Knowledge with age, gender, type of PHC area and work experience have shown to be non-significant (Table-4). In the present study only 36 (34%) of the physicians were having good practice of identifying suspect cases, diagnosing and treating scrub typhus cases. Only 7% have diagnosed a case of scrub typhus in the past one year (Fig-2).

Fig 2: Diagnosed a case of scrub typhus in the past one year

Practices of suspecting and diagnosing cases is significantly associated with type of PHC area (Table-5). Whereas, no significant association was found with Age, gender and Work experience of the physicians. Comparatively tribal PHC physicians were more vigilant of these types of neglected tropical diseases.

Fig 3: Measures to be taken to prevent scrub typhus

In the present study, the Knowledge about preventive measures like removal of vegetations and clothes were around 78% and 11.4%. Half of the participants (50%) opined those anti rodent measures to be taken to prevent Scrub Typhus (Fig-3) and the steps to be taken for improved surveillance, most (77%) of them answered health education of public and increasing the testing (Fig-4). Preventive measures of scrub typhus, 66.7% of the doctors thought Lindane must be used on ground and only 8.1% said to wear benzyl benzoate impregnated clothing.

Fig 4: Opinion on steps to increase surveillance on scrub typhus

Creating public awareness on vector prevention measures is important in the control of scrub typhus as licensed vaccines are unavailable. This study provides new insights into level of knowledge on scrub typhus among primary health care physicians in endemic districts of Prakasam. Our study also promotes new practices for prevention and control of mite transmission. Up to our current knowledge, there were no similar studies done on knowledge, attitude and practices of primary health care physicians on Scrub typhus in Prakasam district.

Among our study participants majority (75%) of them were in 25-35 years of age and 48 (45%) were female, 57 (55%) were male, which were similar to a study by Matteo Riccò et al²¹, among Italian physicians. A similar study done by Miaohui Shao et al¹⁷ reported contrasting results as majority of their study participants were under 30 years old (34%) and Women accounted for 59.1%. Our study participants were educated upto undergraduate level which was similar with their study¹⁷.

In our study, a very high levels of awareness on epidemiology of scrub typhus was found among the physicians. A study done by Gautam et al⁷ revealed that 75.7% of the respondents had knowledge on causative agent of scrub typhus, whereas Ashani Liyanage et al¹⁸ reported that vector-borne aspect was known to be 53.5% which shows low levels of knowledge in comparision to our study. The awareness rate of scrub typhus was 75.1% in a study done by Kwan lee et al¹⁹ which was less than our study (93.3%). A study done by Miaohui Shao et al¹⁷ reported the average score rate of 55.8% for knowledge dimension, among their study participants which was less than our study results.

As per Miaohui Shao et al¹⁷regarding disease seasonal variations, the majority of doctors were aware that the peak of scrub typhus cases can be seen after rainfall which were consistent with the results reported by a study on scrub typhus among Physicians¹⁶ which reported a significant association of rainfall with the peak of scrub typhus cases. Whereas Neelima varania reported low levels of knowledge on seasonal variations. A study done by Gautam et al⁷ revealed that over half of respondents had knowledge on mode of transmission of scrub typhus which was less than our study participants. Levels of awareness on routes of transmission among the study participants done by Kwan lee et al¹⁹, shows low levels of knowledge as compared to our study.

Awareness on the main disease symptoms including fever, headache, lymphadenopathy, and eschar as a pathognomic feature were significantly higher. This agrees with the findings of a study conducted on scrub typhus awareness in South Korea¹⁹.Ashani Liyanage et al¹⁸ reported half of the population (57.3%) were aware of key symptoms which were less than our study. Knowledge on disease symptomatology would promote early identification of cases based on clinical features and thereby reducing morbidity and mortality.

The significant finding of this study was low practices of suspecting a scrub typhus case and giving appropriate treatment among physicians working in rural and tribal areas. Case detection can be improved by undertaking repeated training sessions to physicians by the district heath authorities. In our study, case finding practices were not significantly associated with age, gender and work experience of physicians which was in contrast to a study by Miaohui Shao et al¹⁷ which reported a significant influence of age, education level, working years, position, and training on practices of diagnosing and treatment of scrub typhus. The type of PHC area is significantly associated with practices of suspecting and diagnosing the cases.

Scrub typhus is preventable if appropriate vector protective measures are adopted such as usage of insect repellents, protective clothing (long sleeves, long trousers and covered footwear) and showering after exposure to vector infested areas. In the present study, knowledge about preventive measures like using clothes, insecticide repellents usage like lindane, benzyl benzoate, anti-rodent measures which were higher than a study reported by Kalpana Sharma et al²².In the absence of effective vector control measures, community sensitization on scrub typhus fevers is a priority so that people know how to protect themselves and their community by adopting protective behaviours.

The present study was done among physicians working in primary health care centres (Health & wellness clinics) as they act as first referral units for disease diagnosis and treatment. The present study shows that though the physicians were having 1-5 years of work experience in rural and tribal areas but almost half of the physicians were not aware that Prakasam was an endemic district for scrub typhus. It can be observed that though half of the them were having good knowledge on disease epidemiology, practices of suspecting, treating and providing health education to the patients were lacking among physicians working in urban and rural areas in comparision to tribal areas. The lack of diagnosing& treating practices can be attributed to low levels of knowledge on changing epidemiology, poor availability of RDT kits,diagnostic methods and supply of antibiotic drugs at Primary health care level for initiating treatment, non-availability of educational materials on scrub typhus, lack of regular trainings to the physicians, lack of funding and limited research work in Prakasam district. Hence there is an urgent need for regular trainings on rickettsial diseases to the physicians working at all levels of health care, accompanied by increase funding for research in endemic areas which can help in early diagnosis and treatment of neglected tropical diseases like Scrub Typhus in Prakasam district and in India. Community awareness campaigns on preventive measures of scrub typhus and other rickettsial diseases.

Limitations of the study:

The results cannot be generalized as the study was done among physicians working in government health care centres. Due to constraints of time and resources physicians from private sector were not included.

Financial support and sponsorship: Nil

Conflicts of interest: There are no conflicts of interest

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