Pratima L. Raghunathan

Investigation of bioterrorism-related anthrax, United States, 2001: epidemiologic findings.

In October 2001, the first inhalational anthrax case in the United States since 1976 was identified in a media company worker in Florida. A national investigation was initiated to identify additional cases and determine possible exposures to Bacillus anthracis. Surveillance was enhanced through health-care facilities, laboratories, and other means to identify cases, which were defined as clinically compatible illness with laboratory-confirmed B. anthracis infection. From October 4 to November 20, 2001, 22 cases of anthrax (11 inhalational, 11 cutaneous) were identified; 5 of the inhalational cases were fatal. Twenty (91%) case-patients were either mail handlers or were exposed to worksites where contaminated mail was processed or received. B. anthracis isolates from four powder-containing envelopes, 17 specimens from patients, and 106 environmental samples were indistinguishable by molecular subtyping. Illness and death occurred not only at targeted worksites, but also along the path of mail and in other settings. Continued vigilance for cases is needed among health-care providers and members of the public health and law enforcement communities.

Histopathologic features of Mycobacterium ulcerans infection.

Because of the emergence of Buruli ulcer disease, the World Health Organization launched a Global Buruli Ulcer Initiative in 1998. This indolent skin infection is caused by Mycobacterium ulcerans. During a study of risk factors for the disease in Ghana, adequate excisional skin-biopsy specimens were obtained from 124 clinically suspicious lesions. Buruli ulcer disease was diagnosed in 78 lesions since acid-fast bacilli (AFB) were found by histopathologic examination. Lesions with other diagnoses included filariasis (3 cases), zygomycosis (2 cases), ulcerative squamous cell carcinomas (2 cases), keratin cyst (1 case), and lymph node (1 case). Thirty-seven specimens that did not show AFB were considered suspected Buruli ulcer disease cases. Necrosis of subcutaneous tissues and dermal collagen were found more frequently in AFB-positive specimens compared with specimens from suspected case-patients (p<0.001). Defining histologic criteria for a diagnosis of Buruli ulcer disease is of clinical and public health importance since it would allow earlier treatment, leading to less deforming sequelae.

Risk factors for Buruli ulcer disease (Mycobacterium ulcerans infection) : Results from a case-control study in Ghana

BACKGROUND Morbidity due to Buruli ulcer disease (BUD), a cutaneous infection caused by Mycobacterium ulcerans, has been increasingly recognized in rural West Africa. The source and mode of transmission remain unknown. METHODS To identify BUD risk factors, we conducted a case-control study in 3 BUD-endemic districts in Ghana. We enrolled case patients with clinically diagnosed BUD and obtained skin biopsy specimens. M. ulcerans infection was confirmed by at least 1 of the following diagnostic methods: histopathologic analysis, culture, polymerase chain reaction, and Ziehl-Neelsen staining of a lesion smear. We compared characteristics of case patients with confirmed BUD with those of age- and community-matched control subjects using conditional logistic regression analysis. RESULTS Among 121 case patients with confirmed BUD, leg lesions (49%) or arm lesions (36%) were common. Male case patients were significantly more likely than female case patients to have lesions on the trunk (25% vs. 6%; P = .009). Multivariable modeling among 116 matched case-control pairs identified wading in a river as a risk factor for BUD (odds ratio [OR], 2.69; 95% confidence interval [CI], 1.27-5.68; P = .0096). Wearing a shirt while farming (OR, 0.27; 95% CI, 0.11-0.70; P = .0071), sharing indoor living space with livestock (OR, 0.36; 95% CI, 0.15-0.86; P = .022), and bathing with toilet soap (OR, 0.41; 95% CI, 0.19-0.90; P = .026) appeared to be protective. BUD was not significantly associated with penetrating injuries (P = .14), insect bites near water bodies (P = .84), bacille Calmette-Guerin vaccination (P = .33), or human immunodeficiency virus infection (P = .99). CONCLUSIONS BUD is an environmentally acquired infection strongly associated with exposure to river areas. Exposed skin may facilitate transmission. Until transmission is better defined, control strategies in BUD-endemic areas could include covering exposed skin.

Identification of Haemophilus influenzae Serotypes by Standard Slide Agglutination Serotyping and PCR-Based Capsule Typing

ABSTRACT To resolve discrepancies in slide agglutination serotyping (SAST) results from state health departments and the Centers for Disease Control and Prevention (CDC), we characterized 141 of 751 invasive Haemophilus influenzae isolates that were identified in the United States from January 1998 to December 1999 through an active, laboratory-based, surveillance program coordinated by the CDC. We found discrepancies between the results of SAST performed at state health departments and those of PCR capsule typing performed at the CDC for 56 (40%) of the isolates characterized: 54 isolates that were identified as a particular serotype by SAST were shown to be unencapsulated by PCR, and two isolates that were reported as serotypes b and f were found to be serotypes f and e, respectively, by PCR. The laboratory error most likely to affect the perceived efficacy of the conjugate H. influenzae type b (Hib) vaccine was the misidentification of isolates as serotype b: of 40 isolates identified as serotype b by SAST, 27 (68%) did not contain the correlating capsule type genes. The frequency of errors fell substantially when standardized reagents and routine quality control of SAST were used during a study involving three laboratories. An overall 94% agreement between SAST and PCR results showed that slide agglutination could be a valid and reliable method for serotyping H. influenzae if the test was performed correctly, in accordance with standardized and recommended procedures. An ongoing prospective analysis of all H. influenzae surveillance isolates associated with invasive disease in children less than 5 years old will provide more accurate national figures for the burden of invasive disease caused by Hib and other H. influenzae serotypes.

First Case of Bioterrorism-Related Inhalational Anthrax in the United States, Palm Beach County, Florida, 2001

On October 4, 2001, we confirmed the first bioterrorism-related anthrax case identified in the United States in a resident of Palm Beach County, Florida. Epidemiologic investigation indicated that exposure occurred at the workplace through intentionally contaminated mail. One additional case of inhalational anthrax was identified from the index patient’s workplace. Among 1,076 nasal cultures performed to assess exposure, Bacillus anthracis was isolated from a co-worker later confirmed as being infected, as well as from an asymptomatic mail-handler in the same workplace. Environmental cultures for B. anthracis showed contamination at the workplace and six county postal facilities. Environmental and nasal swab cultures were useful epidemiologic tools that helped direct the investigation towards the infection source and transmission vehicle. We identified 1,114 persons at risk and offered antimicrobial prophylaxis.

Susceptibility to Buruli ulcer is associated with the SLC11A1 (NRAMP1) D543N polymorphism

Similar to other mycobacterial diseases, susceptibility to Buruli ulcer (Mycobacterium ulcerans infection) may be determined by host genetic factors. We investigated the role of SLC11A1 (NRAMP1) in Buruli ulcer because of its associations with both tuberculosis and leprosy. We enrolled 182 Buruli ulcer patients (102 with positive laboratory confirmation) and 191 healthy neighbourhood-matched controls in Ghana, and studied three polymorphisms in the SLC11A1 gene: 3′ UTR TGTG ins/del, D543N G/A, and INT4 G/C. Finger prick blood samples from study subjects were dried on filter papers (FTA) and processed. D543N was significantly associated with Buruli ulcer: the odds ratio (adjusted for gender, age, and region of the participant) of the GA genotype versus the GG genotype was 2.89 (95% confidence intervals (CI): 1.41–5.91). We conclude that a genetic polymorphism in the SLC11A1 gene plays a role in susceptibility to develop Buruli ulcer, with an estimated 13% population attributable risk.

Analysis of an IS2404-based nested PCR for diagnosis of Buruli ulcer disease in regions of Ghana where the disease is endemic.

ABSTRACT Mycobacterium ulcerans causes Buruli ulcer disease (BUD), an ulcerative skin disease emerging mainly in West Africa. Laboratory confirmation of BUD is complicated as no “gold standard” for diagnosis exists. A nested primer PCR based on IS2404 has shown promise as a diagnostic assay. We evaluated the IS2404-based PCR to detect M. ulcerans DNA in tissue specimens from 143 BUD patients diagnosed according to the World Health Organization BUD clinical case definition in Ghana. Comparisons were made with culture and histopathology results. Variables influencing detection rate tested in this PCR protocol included the amount of tissue used and the stage of disease. The nested PCR was repeated on DNA extracted from a different part of the same biopsy specimen of 21 culture-positive samples. Of all 143 specimens, 107 (74.8%; 95% confidence interval, 68 to 82%) showed the presence of M. ulcerans DNA by PCR. Of the 78 histology-confirmed BUD patient samples, 64 (83%) were PCR positive. Detection rates were influenced neither by the amount of tissue processed for PCR nor by the stage of disease (preulcerative or ulcerative). Taken together, the two nested PCR tests on the subset of 21 culture-positive samples were able to detect M. ulcerans DNA in all 21 culture-confirmed patients. For future studies, small tissue samples, e.g., punch biopsy samples, might be sufficient for case confirmation.

Predictors of Immunity after a Major Serogroup W-135 Meningococcal Disease Epidemic, Burkina Faso, 2002

BACKGROUND The African meningitis belt undergoes recurrent epidemics caused by Neisseria meningitidis serogroup A. During 2002, Burkina Faso documented the first large serogroup W-135 (NmW-135) meningococcal disease epidemic. To understand the emergence of NmW-135, we investigated meningococcal carriage and immunity. METHODS Immediately after Burkina Fasos epidemic, we conducted a cross-sectional survey of meningococcal carriage and seroprevalence in an epidemic and a nonepidemic district. We identified predictors of elevated NmW-135 serum bactericidal activity (SBA), a functional correlate of protection, using multivariate logistic regression. RESULTS The NmW-135 carriage rate was 25.2% in the epidemic district and 3.4% in the nonepidemic district (P<.0001). Compared with residents of the nonepidemic district, those of the epidemic district had higher geometric mean titers of NmW-135 SBA (P<.0001). NmW-135 SBA titers>or=1:8, an estimated protective threshold, were observed in 60.4% and 34.0% of residents of the epidemic and nonepidemic district, respectively (P=.0002). In a multivariate model, current NmW-135 carriage, age, and residence in the epidemic district were independent predictors of having an NmW-135 SBA titer>or=1:8. CONCLUSIONS Extensive NmW-135 carriage and transmission in the epidemic area caused residents to acquire natural immunity. Serial carriage and seroprevalence surveys could establish the duration of immunity in the population. The persistent circulation of NmW-135 underscores the potential for periodic NmW-135 epidemics in Africa.

Cell phone-based and internet-based monitoring and evaluation of the National Antiretroviral Treatment Program during rapid scale-up in Rwanda: TRACnet 2004-2010.

Background:Monitoring and evaluation of antiretroviral treatment (ART) scale-up has been challenging in resource-limited settings. We describe an innovative cell-phone-based and internet-based reporting system (TRACnet) utilized in Rwanda. Methods:From January 2004 to June 30, 2010, all health facilities with ART services submitted standardized monthly aggregate reports of key indicators. National cohort data were analyzed to examine trends in characteristics of patients initiating ART and cumulative cohort outcomes. Estimates of HIV-infected patients eligible for ART were obtained from Joint United Nations Program on HIV/AIDS (Estimation and Projection Package-Spectrum, 2010). Results:By June 30, 2010, 295 (65%) of 451 health centers, District and referral hospitals provided ART services; of these, 255 (86%) were located outside Kigali, the capital. Cell phone–based and internet-based reporting was used by 253 (86%) and 42 (14%), respectively. As of June 30, 2010, 83,041 patients were alive on ART, 6171 (6%) had died, and 9621 (10%) were lost-to-follow-up. Of those alive on ART, 7111 (8.6%) were children, 50,971 (61.4%) were female, and 1823 (2.2%) were on a second-line regimen. The proportion of all patients initiating ART at World Health Organization clinical stages 3 and 4 declined from 65% in 2005 to 27% in 2010. National ART coverage of eligible patients increased from 13% in 2005 to 79% in 2010. Conclusions:Rwanda has successfully expanded ART access and achieved high national ART coverage among eligible patients. TRACnet captured essential data about the ART program during rapid scale-up. Cell phone-based and internet-based reporting may be useful for monitoring and evaluation of similar public health initiatives in other resource-limited settings.

Immunoglobulin M Antibody Responses to Mycobacterium ulcerans Allow Discrimination between Cases of Active Buruli Ulcer Disease and Matched Family Controls in Areas Where the Disease Is Endemic

ABSTRACT Buruli ulcer disease (BUD) is an emerging disease caused by Mycobacterium ulcerans. In the present study we have characterized the serological reactivities of sera from volunteer case patients with laboratory-confirmed BUD and controls living in three different regions of Ghana where the disease is endemic to determine if serology may be useful for disease confirmation. Our results showed highly reactive immunoglobulin G (IgG) responses among patients with laboratory-confirmed disease, healthy control family members of the case patients, and sera from patients with tuberculosis from areas where BUD is not endemic. These responses were represented by reactivities to multiple protein bands found in the M. ulcerans culture filtrate (CF). In contrast, patient IgM antibody responses to the M. ulcerans CF (MUCF) proteins were more distinct than those of healthy family members living in the same village. A total of 84.8% (56 of 66) of the BUD patients exhibited strong IgM antibody responses against MUCF proteins (30, 43 and 70 to 80 kDa), whereas only 4.5% (3 of 66) of the family controls exhibited such responses. The sensitivity of the total IgM response for the patients was 84.8% (95% confidence interval [CI], 74.3 to 91.6%), and the specificity determined with sera from family controls was 95.5% (95% CI, 87.5 to 98.4%). These studies suggest that the IgM responses of patients with BUD will be helpful in the identification and production of the M. ulcerans recombinant antigens required for the development of a sensitive and specific serological assay for the confirmation of active BUD.