Measuring impact on filarial infection status in a community study: role of coverage of mass drug administration (MDA).

Lymphatic filariasis is still endemic in many parts of India. The main strategy to implement mass drug administration with DEC and albendazole was added in 2006 to ensure increased impact on the microfilaria (mf) rate in the community. However, the effective coverage remained low in the community leading to lower than desired impact on the parasite population in human. This paper presents the dynamics of participation in annual repeated rounds of mass drug administration in some villages of Kanpur Nagar district in Uttar Pradesh and its impact over the infection rate. It is revealed that after 6 annual rounds of MDA, mf rate could only be reduced by 17.3% in population subgroups who participated only once in comparison to 88% in those who participated in 6 or all annual rounds.

A study to compare the effect of adding 12 days DEC regimen to 6 years annual mass drug administration to eliminate microfilaraemia infection in the community in rural Kanpur, Uttar Pradesh, India.

Lymphatic filariasis is a major public health problem of tropical countries. Although its elimination is planned as global effort using mass drug administration in affected communities but its impact has been influenced by MDA coverage across countries. The drug coverage is affected by fever as side effect and its continuation for over 6 years which affect the population participation. Therefore alternative approaches are needed which can show impact faster than standard MDA. Present research using additional 12 days dose of DEC to mf carriers, show that if drug coverage could be regular, sustainable impact could be created in 4 years.

Detection of viable Mycobacterium leprae in soil samples: insights into possible sources of transmission of leprosy.

Leprosy has ceased to be a public health problem world wide, after the successful implementation of effective chemotherapy (MDT) and use of control measures. However, new cases of leprosy continue to occur. Mycobacterium leprae cannot be grown in any acceptable culture medium and besides the wild armadillos, there is no known animal reservoir for leprosy. The transmission of leprosy is believed to be due to a large extent by droplet discharge of bacilli through nose and mouth and to a lesser extent by direct contact of susceptible host with a patient for long duration. The exact role of the environment in the transmission dynamics is still speculative. In the present study, we have tried to detect viable M. leprae from soil samples in endemic areas by using molecular methods. Eighty soil samples were collected from villages of this area, DNA and RNA of M. leprae extracted and identified using specific M. leprae primers. PCR amplification was done and real-time RT-PCR was used to detect viable M. leprae. DNA targeting the 16S region of M. leprae was detected in 37.5%, whereas M. leprae RNA targeting the same region was detected in 35% of these samples. Of the total 80 samples, 40 were collected from residential areas of leprosy patients whereas 40 samples were from no-patient areas. Fifty-five percent positivity for 16S rRNA of M. leprae was observed from the "patient" area in comparison to 15% positivity from the "no-patient" area (p < 0.001). This study thus provides valuable information of presence of viable M. leprae in soil specimens, which would be of use in investigating the transmission dynamics in leprosy.

Predominance of three copies of tandem repeats in rpoT gene of Mycobacterium leprae from Northern India.

This study has been carried out to get understanding of the origin among the strains of Mycobacterium leprae in patients from Northern India by using number of tandem repeats in rpoT gene as marker. Biopsies were collected from hundred leprosy cases (paucibacillary (PB) as well as multibacillary (MB)) across the spectrum from patients attending clinic at JALMA or diagnosed in Field Unit at Ghatampur (Kanpur). These biopsies were homogenized and DNA was extracted by a physiochemical procedure. rpoT region was amplified by using the primers and conditions earlier published. Among 100 strains from Northern Indian patients, 89% exhibited the presence of three copies of the 6bp tandem repeat in the rpoT gene, while 11% contained four copies. These profiles along with other genotyping data may help in studying the historical spread of leprosy by strains of M. leprae disseminated by various human races that migrated to Northern India from other places of Asian continent.

Detection of Mycobacterium leprae DNA from soil samples by PCR targeting RLEP sequences.

Despite near elimination of leprosy as a public health problem, several problems in leprosy still remain. These include early detection, determining efficacy of the treatment and differentiating relapses from re-infection. These aspects have important impact on the patients undergoing treatment and also have a bearing on understanding transmission dynamics in the community. While early diagnosis and management do not need major technological inputs, various reports have suggested that M. leprae is found in the environment and may have a role in continued transmission of disease. In earlier studies from other parts of world the presence of M. leprae DNA in the environment has been investigated both by microbiological and molecular studies. In the present study, an attempt was made to extract M. leprae DNA from soil samples, which were collected from eighteen different locations including 3 from our Institute area and 15 from different villages of Ghatampur area. We optimized a protocol for the extraction of DNA and amplified a fragment of M. leprae using specific primers targeting RLEP sequences. It was found that 33.3% of these soil samples collected from areas inhabited by leprosy cases gave positive result for M. leprae specific DNA. The utility of this method needs to be explored on a larger scale to establish the presence of M.leprae in the environment, and its role in the spread of the disease.

Filariasis in Ghatampur Tahsil of Kanpur Nagar District: indications of high endemicity locus.

A study in the 26 villages surveyed, the mf rate was observed to vary from 6.4% to 17.8%, the disease rate ranged from 1.9% to 10% and total infection rate from 8.2% to 26.4%. The median microfilaraemia density among positives was 10 and 90% of persons had density below 60 and in 10% above this level. The mf rate among those who never used bednets while sleeping was found to be 11.8%, 15.7% higher than 10.2% among those who ever used bednets (8.7% in regular users and 10.7% among irregular users) to protect from mosquitoes bites (p < 0.05). The lymphatic disease was found to be 3.8%; 3.7% in males and 4.1% in females. Of the males, 16.3% had acute disease, 51.8%) hydroceles of varying grades and 32% edema of different grades including elephantiasis. Of the females with lymphatic disease, 25.6% acute disease, 62.8% edema including elephantiasis and 11.6% had mastitis. The study indicates that area is endemic for filariasis and needs control programmes.