Simple and fast lateral flow test for classification of leprosy patients and identification of contacts with high risk of developing leprosy

The interruption of leprosy transmission is one of the main challenges for leprosy control programs since no consistent evidence exists that transmission has been reduced after the introduction of multidrug therapy. Sources of infection are primarily people with high loads of bacteria with or without clinical signs of leprosy. The availability of a simple test system for the detection of antibodies to phenolic glycolipid-I (PGL-I) of Mycobacterium leprae to identify these individuals may be important in the prevention of transmission. We have developed a lateral flow assay, the ML Flow test, for the detection of antibodies to PGL-I which takes only 10 min to perform. An agreement of 91% was observed between enzyme-linked immunosorbent assay and our test; the agreement beyond chance (kappa value) was 0.77. We evaluated the use of whole blood by comparing 539 blood and serum samples from an area of high endemicity. The observed agreement was 85.9% (kappa = 0.70). Storage of the lateral flow test and the running buffer at 28 degrees C for up to 1 year did not influence the results of the assay. The sensitivity of the ML Flow test in correctly classifying MB patients was 97.4%. The specificity of the ML Flow test, based on the results of the control group, was 90.2%. The ML Flow test is a fast and easy-to-perform method for the detection of immunoglobulin M antibodies to PGL-I of M. leprae. It does not require any special equipment, and the highly stable reagents make the test robust and suitable for use in tropical countries.

Increase of leptospirosis in dengue-negative patients after a hurricane in Puerto Rico in 1996 [correction of 1966].

Leptospirosis has rarely been reported in Puerto Rico, although in the period from 1948 to 1952, 208 cases of leptospirosis and an island-wide seroprevalence of antibody to Leptospira of 14% were documented. In Puerto Rico in October 1996, following rainfall and a period of flooding generated by Hurricane Hortense, serum specimens of 4 patients with suspected dengue fever that were negative for dengue tested positive for Leptospira-specific IgM antibodies in a dipstick assay. Subsequently, we used an island-wide dengue laboratory-based surveillance system to determine the increase in leptospirosis after hurricane-generated floods. All anti-dengue IgM-negative patients (n = 142) with disease onset from August 8 to October 6, 1996 from prehurricane and posthurricane groups were investigated for leptospirosis. Laboratory-confirmed leptospirosis cases were defined as microscopic agglutination test titers > or = 1 :400 to 1 or more serovars, or positive immunohistochemistry in autopsy tissues. Four (6%) of 72 prehurricane and 17 (24%) of 70 posthurricane patients had laboratory-confirmed cases of leptospirosis (relative risk [RR] = 4.4, 95% confidence interval [CI] = 1.6-12.4). The mean age of case-patients was 34 years (range = 13-64). Eighteen (86%) of 21 confirmed case-patients were males, including one patient who died (31 years old). Patients were located in 18 (38%) of 48 municipalities that submitted serum samples. Clinical features significantly associated with leptospirosis were eye pain (RR = 1.5, 95% CI = 1.3-1.9), joint pain (RR = 1.4, 95% CI = 1.1-1.6), diarrhea (RR = 1.7, 95% CI = 1.2-2.5), and jaundice (RR = 3.3, 95% CI = 1.5-7.2). This study demonstrates the utility of a dengue laboratory-based surveillance system for the detection of an increase of leptospirosis, which most likely would have gone unrecognized. Leptospirosis is treatable with antibacterial agents; knowledge of this diagnosis may significantly reduce morbidity and mortality.

Identification of a unique group of human papillomavirus type 16 sequence variants among clinical isolates from Barbados.

The naturally occurring sequence variation of human papillomavirus type 16 (HPV-16) was analysed by direct sequence analysis of the PCR products of the long control region (LCR), the E5 and E7 open reading frames (ORFs), a segment of the L2 ORF overlapping the early viral poly(A) signal and a small segment of the L1 ORF or clinical isolates from Barbados and The Netherlands. Despite the widely different geographical and ethnic origin of the two groups of specimens, sequence analysis revealed relatively few mutational differences. Analysis of the LCR and the E5 ORF appeared to be the minimum requirement for the correct positioning of these variants in the HPV-16 phylogenetic tree. Most of the Barbadian variants appeared to be located at a unique position in the HPV-16 phylogenetic tree, at the internal branch close to the point where the European and Asian branches diverge. In contrast, most of the Dutch samples were located on the European branch.

Detection of oncogenic HPV DNA by a consensus polymerase chain reaction method in genital carcinomas in twenty women in Barbados.

Paraffinized tissue from Barbadian women with histologically proven genital carcinoma was subjected to a consensus polymerase chain reaction method. Nineteen patients had cervical and one, vaginal carcinoma. The histological types were 17 squamous cell carcinoma, 2 adenocarcinoma and 1 adenosquamous carcinoma. HPV DNA was detected in 18/20 (90%). HPV DNA type 16 in 13 (65%), type 33 and type 45 in 1 (5%) each and 3 (15%) could not be typed. HPV DNA, type 16, was detected in one (50%) of the two cases of adenocarcinoma and 12/17 (71%) cases of squamous cell carcinoma. DNA HPV, type 33, and type 45 were each detected in 1/17 (6%) cases of squamous cell carcinoma. No HPV DNA, type 18, was detected.

Detection of oncogenic HPV DNA by a consensus polymerase chain reaction method in genital carcinomas in twenty women in Barbados

Paraffinized tissue from Barbadian women with histologically proven gential carcinoma was subjected to a censensus polymerase chain reaction method. Nineteen patients had cervical and one, vaginal carcinoma. The histological types were 17 squamous cell carcinoma, 2 adenocarcinoma and 1 adenosquamous carcinoma. HPVDNA was detected in 18/20 (90 per cent ). HPVDNA type 16 in 13 (65 per cent ), type 33 and type 45 in 1 (5 per cent ) each and 3 (15 per cent ) could not be typed. HPVDNA, type 16, was detected in one (50 per cent ) of the two cases of adenocarcinoma and 12/17 (71 per cent ) cases of squamous cell carcinoma. DNAHPV, type 33, and type 45 were each detected in 1/17 (6 per cent ) cases of squamous cell carcinoma. No HPVDNA, type 18, was detected.