Presence of an index case in households of newly registered leprosy patients: experience from a leprosy referral centre in South India.
In most of the world, man is the only reservoir of Mycobacterium leprae, and untreated leprosy patients are assumed to be the only source of infection. The main mode is through nasal droplets. (1,2) Multi-drug therapy (MDT) treats leprosy and reduces the number of cases in the community, but falls short of preventing transmission. (3,4) The risk of contracting leprosy is raised amongst contacts of a known leprosy-affected person. According to WHO (5) children represented 9-4% (12,043) of all new cases registered in India in 2013, indicating continued transmission of infection.
Previous studies by Jain et al. reported a history of contact in 38% of leprosy patients and 95% of them were intra-familial contacts. (6) Vijaykumaran et al. reported an incidence in contacts of 7-7 per 1000 PYR, (1) which was eight times more than that of the general population, while George et al. reported an incidence rate of 5-1/1000. (7) Many other studies also concluded that the presence of a household contact increased the risk of leprosy. (3,6,8-10)
This study reports the presence of index cases linked to newly diagnosed leprosy patients, in the absence of active contact surveillance.
The Blue Peter Health and Research centre (BPHRC) is a leprosy referral centre where leprosy affected attend for treatment of various leprosy-related complications. Services are offered by a Medical Officer, Physiotherapy Technician and Laboratory Technician. New patients report for diagnosis and management. The patients may be self-referred or are referred from either private or government health centres for management.
This is a record-based retrospective study of new leprosy patients registered at BPHRC over a period of 5 years (2009 to 2013). Any history of contact with a known leprosy patient is recorded for all newly diagnosed leprosy patients at our clinic. An index case is defined as a previously diagnosed leprosy patient living in the same house and sharing the same kitchen (intra-familial), or is within the social circle of the newly diagnosed leprosy patient.
BPHRC registered a total of 764 leprosy patients during the 5 year period (2009-2013). Among them, 257 were newly diagnosed (Table 1). Of these 179 (69-6%) were male and 26 (10-12%) were children. The age range was 4-75 years. A history of a known index case is observed in 71 (27-6%) patients: 57 within the household and 14 amongst social contacts. The duration of the exposure could not be ascertained in most cases. The classification of leprosy of the index cases was also difficult to determine, as most cases were already treated at other centres in the past and were only rarely registered at this clinic for complications such as Type II reactions and ulcers.
Among the 71 index cases 47 (66-2%) were male and 16 (22-5%) were children (age below 15 years). The majority of cases involved intra-familial contact. The presence of an index case was more likely among paucibacillary cases (38-3%). Parents and siblings contributed the majority of index cases (Table 2). A history of multiple index cases in the household was observed in seven (12-9%) patients.
Transmission of leprosy is still poorly understood. The long incubation period adds to the difficulty of understanding the mode of transmission. Previous studies done by Jain et al. (6) concluded that active leprosy patients are a potential source of infection.
The duration of association of the newly diagnosed patients with the index case could not be ascertained in this study. Also the patients who gave no history of previous exposure to the disease may have been unaware of a contact, or may have chosen not to disclose the details.
The high percentage (57/257 or 22-2%) of new cases having an index case in the household emphasises the continuing need to screen and follow up the asymptomatic contacts of newly diagnosed leprosy patients as suggested by Vijayakumaran et al., (1) Jain et al. (6) and Ranade et al. (9) The relatively high number of patients with MB type of leprosy suggests that knowledge of the signs of leprosy is lacking, but it is also important to remember that stigma may undermine any initial inclination to seek medical advice. These aspects need to be studied further for early diagnosis and treatment.
Even more significant is the fact that 16 of 26 cases amongst children (61-5%) had contact with an index case, showing that contact examination would have a large impact on early case detection in children, thus greatly reducing the risk of disability in children.
Though contact screening is part of the present National Leprosy Eradication Programme (NLEP) there is no follow-up of this activity. There has been tremendous change in socioeconomic status and lifestyle of people in India during the recent years. The question of how this influences transmission and susceptibility of the community to leprosy infection is yet to be explored.
The considerable number of new leprosy patients, and especially children, with a history of contact with a known leprosy patient suggests that examination and management of contacts is an important and cost-effective means of early case detection in leprosy. More operational research is warranted.
(1) Vijayakumaran P, Krishnamurthy P, Rao P, Declerq E. Chemoprophylaxis against leprosy: expectations and methodology of a trial. Lepr Rev, 2000; 71(Suppl): S37-40.
(2) Kumar Kar Hemanta, Kumar Bhushan. IAL Textbook of Leprosy 2010. Chapter 7: Bacteriological Aspects, New Delhi: Jaypee Brothers, pp. 74-86.
(3) Vijayakumaran P, Jesudasan K, Mozhi NM, Samuel JD. Does MDT arrest transmission of leprosy to household contacts? Int J Lepr Other Mycobact Dis, 1998; 66: 125-130.
(4) Sundar Rao PS, Jesudasan K, Mani K, Christian M. Impact of MDT on incidence rates of leprosy among household contacts. Part 1. Baseline data. Int J Lepr Other Mycobact Dis, 1989; 57: 647-651.
(5) Weekly Epidemiological Record No. 36, 2014; 89: 389-400.
(6) Jain S, Reddy RG, Osmani SN et al. Childhood leprosy in an urban clinic, Hyderabad, India: clinical presentation and the role of household contacts. Lepr Rev, 2002; 73: 248-253.
(7) George R, Rao PS, Mathai R, Jacob M. Intra-familial transmission of leprosy in Vellore Town, India. Int J Lepr Other Mycobact Dis, 1993; 61: 550-555.
(8) Swain JP, Mishra S, Jena S. Prevalence of leprosy among household contacts of leprosy cases in western Orissa. Indian J Lepr, 2004; 76: 19-29.
(9) Ranade MG, Joshi GY. Long-term follow-up of families in an endemic area. Indian J Lepr, 1995; 67: 411-425.
(10) Sharma P, Mukherjee R, Talwar GP et al. Immunoprophylactic effects of the anti-leprosy Mw vaccine in household contacts of leprosy patients: clinical field trials with a follow up of 8-10 years. Lepr Rev, 2005; 76: 127-143.
VASEEM ANJUM * & P. VIJAYAKUMARAN *
* Blue Peter Health and Research Center, Lepra Society, Hyderabad, Telangana, Indias
Accepted for publication 16 October 2015
Correspondence to: Vaseem Anjum, Lepra Society, Hyderabad, Telangana, India (e-mail: email@example.com)
Table 1. Type of leprosy in new patients and presence of index cases MB Cases % PB Cases % Total % With household index cases 42 74 15 26 57 100 With social index cases 11 79 3 21 14 100 No index case 157 84 29 16 186 100 Total 210 47 257 Table 2. Relationship of index case to the newly diagnosed leprosy patients Relationship of index case Number Percentage Father 18 25.4 Mother 14 19.7 Brother 12 16.9 Grand Parents 4 5.6 Sister 4 5.6 Son 4 5.6 Husband 1 1.4 Social 14 19.7 Total 71 100
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||SHORT REPORT|
|Author:||Anjum, Vaseem; Vijayakumaran, P.|
|Date:||Dec 1, 2015|
|Previous Article:||Effectiveness of Methotrexate in prednisolone and thalidomide resistant cases of Type 2 lepra reaction: report on three cases.|
|Next Article:||Bullous erythema nodosum leprosum masquerading as systemic onset juvenile idiopathic arthritis: a case report.|