***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: the abiotrophies are assuming a less forbidding aspect than in the past . Considerable basic work will have to be done in medical ophthalmological units before any impression is made on the mass of systemic disease that underlies such afflictions as optic atrophy , diabetic retinopathy , uveitis , the hypertensive and vascular disorders , and possibly also the senile macular lesions . To face the problems of tomorrow ophthalmology must at the very least exp and beyond its surgical frontiers into the medical wards and the research laboratories.4 It is perhaps worth noting that during the period 1948 - 62 there has been an increase of about 25 % in the number of beds available for ophthalmic cases and there has been an expansion of some 50 % of patients treated over the same number of years , but the number of ophthalmic consultants has shown little change-from 295 to 310 . Little wonder that few ophthalmic consultants have the energy at the end of their day to contribute to the advance of their specialty Chemoprophylaxis was carried out on high risk group of extended contacts of new leprosy cases in Nyaungdon Township , Ayeyarwaddy Division , Myanmar and serological response was followed up for two years . In September 2003 , blood sample s were collected from 829 contacts after getting informed consent and sera were tested for immunoglobulin M antibodies using NTP-BSA ELISA test . These 300 seropositives were r and omized to treated and non-treated groups . In each group 102 each were enrolled in adults and 48 each in children . A single dose of ROM ( rifampicin , ofloxacin and minocycline ) and RMP ( rifampicin ) by body weight was administered to treated group of above 15 years and those below 15 years respectively . The vitamins were administered to non-treated group . The blood sample s of all contacts were collected again in September 2004 and September 2005 and ELISA was carried out on paired sample s on one plate . The mean optical density ( OD ) titers before vs after chemoprophylaxis were 0.24 vs 0.10 and 0.20 vs 0.09 in treated and non-treated group respectively in adults and 0.25 vs 0.11 and 0.22 vs 0.11 respectively in children after one year . These were 0.24 vs 0.17 and 0.20 vs 0.19 respectively in adults and 0.25 vs 0.19 and 0.22 vs 0.20 respectively in children after two years . The difference of mean antibody titers before and after chemoprophylaxis in treated group was significantly reduced compared to non-treated group in adults but was not significant in children . The findings show that there is a significant role of chemoprophylaxis on serological response in the form of decreasing antibody titer among the adult group of extended contacts Objective To determine the effectiveness of chemoprophylaxis using a single dose of rifampicin to prevent leprosy in close contacts . Design Single centre , double blind , cluster r and omised , placebo controlled trial . Setting Leprosy control programme in two districts of northwest Bangladesh with a population of more than four million . Participants 28 092 close contacts of 1037 patients with newly diagnosed leprosy . 21 711 contacts fulfilled the study requirements . Interventions A single dose of rifampicin or placebo given to close contacts in the second month of starting the index patient ’s treatment , with follow-up for four years . Main outcome measure Development of clinical leprosy . Results 18 869 of the 21 711 contacts ( 86.9 % ) were followed-up at four years . Ninety one of 9452 contacts in the placebo group and 59 of 9417 in the rifampicin group had developed leprosy . The overall reduction in incidence of leprosy using a single dose of rifampicin in the first two years was 57 % ( 95 % confidence interval 33 % to 72 % ) . The groups did not differ between two and four years . The overall number needed to treat ( NNT ) to prevent a single case of leprosy among contacts was 297 ( 95 % confidence interval 176 to 537 ) . Differences were found between subgroups at two years , both in reduction of incidence and in NNT . Conclusion A single dose of rifampicin given to contacts of patients with newly diagnosed leprosy is effective at preventing the development of clinical leprosy at two years . The effect was maintained , but no difference was seen between the placebo and rifampicin groups beyond two years . Trial registration Current Controlled Trials IS RCT N61223447 Because of the great efficacy of multidrug therapy ( MDT ) , it had been hoped that the widespread use of MDT would bring about a rapid decrease of the incidence of leprosy . To the present , a decrease of incidence has not been observed , possibly because of the long incubation period of the disease , and because general implementation of MDT is still recent . Other reasons , such as environmental sources of infection or the role of healthy carriers in transmitting Mycobacterium leprae , can not be excluded . Therefore , one must seek alternative or supplementary strategies , such as chemoprophylaxis . Household contacts of leprosy patients are at greater risk of developing leprosy than is the general population . Therefore , a r and omized , controlled trial of chemoprophylaxis , using a single 10 mg/kg dose of rifampicin , or a placebo , is planned in nine projects in India , among the household contacts of newly detected leprosy patients . Based upon assumptions of a protective efficacy of the chemoprophylaxis of 50 % , an annual incidence of 2 per 1000 contacts , a desired power of the study of 90 % , and a level of significance of 95 % , 15,000 household contacts will be allocated r and omly by household to each arm of the study , and followed for 5 years . Considered as household contacts will be all persons living in the same household as an index case and sharing the same kitchen . Pregnant women and infants will be excluded . To be certain that transmission of the organisms from the index case can not occur once the prophylaxis is administered , rifampicin will be administered 2 months after diagnosis of the index case . Diagnosis of leprosy will be clinical , and confirmed independently . Although household contacts usually constitute only a small proportion of the new patients detected in a control programme , their high-risk status makes them particularly appropriate for a study of the potential effect of chemoprophylaxis . Following the trial , one could evaluate the usefulness and feasibility of using the same strategy in other population -groups , based on the number of persons necessary to treat to prevent one case A r and omized controlled chemoprophylaxis trial was carried out in Madras city using 560 disease-free household child contacts of 264 multibacillary cases as study subjects . In the study , 13 cases were diagnosed among 280 contacts who received 3 injections of acedapsone at 10 weeks interval as against 30 cases among 280 contacts who had the same number of placebo injections  , during the follow-up period of 225 weeks . The difference in the incidences in the two groups was statistically significant . ( X2 6.45 ; P less than 0.02 ) . The protection due to the limited duration of  acedapsone  prophylaxis was 56.7 percent . There were no cases of multi-bacillary leprosy in either group . The efficacy of prophylaxis was significant in male children over 9 years of age and female children in the age-group 1 - 8 years . The other prognostic factors like the infectivity status of the index cases in the household and the duration of exposure to them could have possibly influenced the effectiveness of prophylaxis in preventing progression from infection to clinical disease among the subjects studied . Their effects could not be assessed in this study 
    Output:
    
CONCLUSION Chemoprophylaxis is effective in lowering the incidence of leprosy in contacts of patients diagnosed with the disease