Doxycycline Prophylaxis for Skin and Soft Tissue Infections in Naval Special Warfare Trainees, United States1.

In 2015, several severe cases of skin and soft tissue infection (SSTI) among US Naval Special Warfare trainees prompted the introduction of doxycycline prophylaxis during the highest-risk portion of training, Hell Week. We performed a retrospective analysis of the effect of this intervention on SSTI incidence and resulting hospital admissions during 2013-2020. In total, 3,371 trainees underwent Hell Week training during the study period; 284 SSTIs were diagnosed overall, 29 of which led to hospitalization. After doxycycline prophylaxis was introduced, admission rates for SSTI decreased from 1.37 to 0.64 admissions/100 trainees (p = 0.036). Overall SSTI rates remained stable at 7.42 to 8.86 SSTIs/100 trainees (p = 0.185). Hospitalization rates per diagnosed SSTI decreased from 18.4% to 7.2% (p = 0.009). Average length of hospitalization decreased from 9.01 days to 4.33 days (p = 0.034). Doxycycline prophylaxis was associated with decreased frequency and severity of hospitalization for SSTIs among this population.

Impact of international travel and diarrhea on gut microbiome and resistome dynamics.

International travel contributes to the global spread of antimicrobial resistance. Travelers' diarrhea exacerbates the risk of acquiring multidrug-resistant organisms and can lead to persistent gastrointestinal disturbance post-travel. However, little is known about the impact of diarrhea on travelers' gut microbiomes, and the dynamics of these changes throughout travel. Here, we assembled a cohort of 159 international students visiting the Andean city of Cusco, Peru and applied next-generation sequencing techniques to 718 longitudinally-collected stool samples. We find that gut microbiome composition changed significantly throughout travel, but taxonomic diversity remained stable. However, diarrhea disrupted this stability and resulted in an increased abundance of antimicrobial resistance genes that can remain high for weeks. We also identified taxa differentially abundant between diarrheal and non-diarrheal samples, which were used to develop a classification model that distinguishes between these disease states. Additionally, we sequenced the genomes of 212 diarrheagenic Escherichia coli isolates and found those from travelers who experienced diarrhea encoded more antimicrobial resistance genes than those who did not. In this work, we find the gut microbiomes of international travelers' are resilient to dysbiosis; however, they are also susceptible to colonization by multidrug-resistant bacteria, a risk that is more pronounced in travelers with diarrhea.

TaqMan Array Card testing of participant-collected stool smears to determine the pathogen-specific epidemiology of travellers' diarrhoea†.

BACKGROUND: We assessed the compliance with self-collection of stool smears on Whatman® FTA® Elute Card (FTA Card) and detection of travellers' diarrhoea (TD)-associated pathogens by using a quantitative Polymerase Chain Reaction (PCR) assay [customized TaqMan® array card (TAC)] in a prospective, observational cohort of travellers. METHODS: Enrolled travellers documented symptoms on a travel diary and collected an FTA Card during a diarrhoeal episode, or at the end of travel if they remained asymptomatic. TAC testing was performed on FTA Cards from TD cases and 1:1 matched asymptomatic controls and 1:1 matched loose stool cases that did not meet TD criteria. Odds ratios were used to determine the association between detected pathogens and TD. RESULTS: Of 2456 travellers, 484 (19.7%) completed an illness diary and met TD criteria, and 257 (53.1%) collected an FTA Card during the TD episode. FTA Cards were stored for a median of 2 years at room temperature (IQR: 1-4 years) before extraction and testing. The overall TAC detection rate in TD cases was 58.8% (95% CI: 52.5-64.8). Enterotoxigenic Escherichia coli was the most common pathogen in TD cases (26.8%), and 3.5% of samples were positive for norovirus. The odds of detecting TD-associated pathogens in 231 matched cases and asymptomatic controls were 5.4 (95% CI: 3.6-8.1) and 2.0 (95% CI: 1.1-3.7) in 121 matched TD and loose stool cases (P < 0.05). Enteroaggregative E. coli was the most common pathogen detected in asymptomatic controls and loose stool cases. Detection of diarrhoeagenic E. coli, Shigella/enteroinvasive E. coli and Campylobacter spp. was significantly associated with TD. CONCLUSION: FTA Cards are a useful adjunct to traditional stool collection methods for evaluating the pathogen-specific epidemiology of TD in austere environments. Qualitative detection of pathogens was associated with TD. Measures to improve compliance and quality of FTA Card collection with decreased storage duration may further optimize detection.

Risk factors for acute mountain sickness in travellers to Cusco, Peru: coca leaves, obesity and sex.

BACKGROUND: Acute mountain sickness (AMS) may occur after rapid ascents to altitudes >2500 m. Cusco (3350 m) in Peru is a popular destination for altitude inexperienced travellers. This study aimed at evaluating the incidence and risk factors for AMS among a cohort of foreign Spanish language students in Cusco. METHODS: We performed a cohort study among young healthy foreign Spanish language students arriving to Cusco between 2012 and 2016. Consenting students answered an enrollment questionnaire on demographics, travel history and intended AMS preventive behaviour within 48 h of arrival. At 4-5 days after enrollment participants answered a second questionnaire about actual preventive behaviour before symptoms and the development of symptoms compatible with AMS during their first 48 h in Cusco. We used the 2018 Lake Louise Scoring System for AMS diagnosis. Participants with headache and a score ≥ 3 were considered to have AMS. RESULTS: We enrolled 142 language students, the median age was 21 years (interquartile range 20-25) and 57% were female. Participants decreased physical activity (38%), increased fluid intake (34%), drank coca leaf tea (34%), took acetazolamide (16%) and acclimatized at a lower altitude (6%) to prevent AMS. Thirty-nine percent had AMS. In the multivariate analysis, obesity [odds ratio (OR) 14.45 (2.33-89.6)] and female sex [OR 4.32 (1.81-10.28)] were associated with increased risk of AMS. Taking acetazolamide [OR 0.13 (0.03-0.56)] was associated with decreased AMS risk. Consumption of coca leaf tea was not associated with decreased risk of AMS. CONCLUSIONS: In our cohort, AMS affected two out of five travellers. Obesity and female sex were associated with increased risk. Drinking coca leaf tea for prevention did not decrease the risk of AMS. Acetazolamide prophylaxis was associated with decreased risk of AMS.

Validation of the T86I mutation in the gyrA gene as a highly reliable real time PCR target to detect Fluoroquinolone-resistant Campylobacter jejuni.

BACKGROUND: Campylobacter jejuni is a leading cause of bacterial diarrhea worldwide, and increasing rates of fluoroquinolone (FQ) resistance in C. jejuni are a major public health concern. The rapid detection and tracking of FQ resistance are critical needs in developing countries, as these antimicrobials are widely used against C. jejuni infections. Detection of point mutations at T86I in the gyrA gene by real-time polymerase chain reaction (RT-PCR) is a rapid detection tool that may improve FQ resistance tracking. METHODS: C. jejuni isolates obtained from children with diarrhea in Peru were tested by RT-PCR to detect point mutations at T86I in gyrA. Further confirmation was performed by sequencing of the gyrA gene. RESULTS: We detected point mutations at T86I in the gyrA gene in 100% (141/141) of C. jejuni clinical isolates that were previously confirmed as ciprofloxacin-resistant by E-test. No mutations were detected at T86I in gyrA in any ciprofloxacin-sensitive isolates. CONCLUSIONS: Detection of T86I mutations in C. jejuni is a rapid, sensitive, and specific method to identify fluoroquinolone resistance in Peru. This detection approach could be broadly employed in epidemiologic surveillance, therefore reducing time and cost in regions with limited resources.

Fecal Contamination of Drinking Water Was Associated with Diarrheal Pathogen Carriage among Children Younger than 5 Years in Three Peruvian Rural Communities.

Drinking water contamination is a frequent problem in developing countries and could be associated with bacterial pathogen carriage in feces. We evaluated the association between the risk of drinking water and bacterial carrier status in children younger than 5 years in a cross-sectional study conducted in 199 households from three Peruvian rural communities. Fecal samples from children were screened for pathogenic Aeromonas, Campylobacter, and Vibrio species, as well as for Enterobacteriaceae, including pathogenic Escherichia coli. The drinking water risk was determined using E. coli as an indicator of contamination. Nineteen (9.5%) children were colonized with pathogens and classified as carriers, all without diarrhea symptoms. Of 199 drinking water samples, 38 (19.1%) were classified as very high risk because of high fecal contamination (> 100 E. coli/100 mL). Shared-use water sources, daily washing of containers, and washing using only water were associated with higher prevalence of bacterial carriage, whereas there was no association between households reporting boiling and chlorination of water and carrier status. The prevalence of carriage in children exposed to very high-risk water was 2.82 (95% CI: 1.21-6.59) times the prevalence of those who consumed less contaminated water, adjusted by the water source and daily washing. Our results suggest that household drinking water plays an important role in the generation of carriers with diarrheal pathogens. Our findings also highlight the importance of interventions to ensure the safety of drinking water. Further studies are needed to validate the observed association and determine its significance with respect to diarrhea in the community.

Extensively drug-resistant (XDR) Pseudomonas aeruginosa identified in Lima, Peru co-expressing a VIM-2 metallo-ß-lactamase, OXA-1 ß-lactamase and GES-1 extended-spectrum ß-lactamase.

INTRODUCTION: Pseudomonas aeruginosa has the ability to acquire plasmids and other mobile genetic elements that confer resistance to antibiotics. Bacterial genes encoding different ß-lactamases (bla), such as metallo-ß-lactamases (MBLs) and extended-spectrum ß-lactamases (ESBL), can confer resistance to multiple classes of ß-lactam antibiotics. CASE PRESENTATION: An 83 year old female was admitted in 2012 to the Peruvian Naval Hospital, Centro Médico Naval 'Cirujano Mayor Santiago Távara' (CEMENA), in Lima, Peru. A midstream urine sample was collected and sent to the local CEMENA laboratory for routine urine culture. P. aeruginosa was isolated and initial antibiotic susceptibility testing showed it to be sensitive to imipenem. The clinicians started a course of meropenem, but the patient did not improve. After 5 days, a second urine culture was performed and a P. aeruginosa was isolated again, but this time the strain showed resistance to imipenem. The treatment course was changed to fosfomycin and the patient improved. Phenotypic and molecular laboratory testing to characterize the antibiotic resistance were performed, demonstrating the presence of both MBL and ESBL genes. CONCLUSION: To our knowledge, this is the first report of a P. aeruginosa XDR clinical isolate that co-expresses an MBL (VIM-2), OXA-1 beta-lactamase and the ESBL (GES-1) in Peru. It is also the first report of a VIM carbapenemase in Peru.

An Improved Enzyme-Linked Immunoassay for the Detection of Leptospira-Specific Antibodies.

Leptospirosis is a neglected zoonotic disease with worldwide endemicity and continues to be a significant public health burden on resource-limited populations. Previously, we produced three highly purified recombinant antigens (rLipL32, rLipL41, and rLigA-Rep) and evaluated their performance of detecting Leptospira-specific antibodies in enzyme-linked immunosorbent assay (ELISA) as compared with the microscopic agglutination test (MAT). The overall sensitivity of this assay approached 90%. Recently, another recombinant antigen (rLigB-Rep) was prepared. We tested each individual antigen and a 1:1:1:1 mixture of these four antigens for the detection of Leptospira-specific antibodies in ELISA. The performance of these recombinant antigens was evaluated with a much larger febrile patient panel (337 MAT-confirmed positive sera and 92 MAT-negative sera from febrile patients). Combining the detection results of immunoglobulin M and immunoglobulin G from these four individual antigens, the overall sensitivity was close to 90% but the specificity was only 66%, based on the MAT reference method. The overall sensitivity and specificity of the four-antigen mixture were 82% and 86%, respectively. The mixture of four antigens also exhibited a broader reactivity with MAT-positive samples of 18 serovars from six major pathogenic Leptospira species. Given the limitations of MAT, the data were further analyzed by Bayesian latent class model, showing that ELISA using a 1:1:1:1 mixture still maintained high sensitivity (79%) and specificity (88%) as compared with the sensitivity (90%) and specificity (83%) of MAT. Therefore, ELISA using a mixture of these four antigens could be a very useful test for seroprevalence studies.

Case-Case Analysis Using 7 Years of Travelers' Diarrhea Surveillance Data: Preventive and Travel Medicine Applications in Cusco, Peru.

AbstractIn Cusco, Peru, and South America in general, there is a dearth of travelers' diarrhea (TD) data concerning the clinical features associated with enteropathogen-specific infections and destination-specific risk behaviors. Understanding these factors would allow travel medicine providers to tailor interventions to patients' risk profiles and travel destination. To characterize TD etiology, evaluate region-specific TD risk factors, and examine relationships between preventive recommendations and risk-taking behaviors among medium- to long-term travelers' from high-income countries, we conducted this case-case analysis using 7 years of prospective surveillance data from adult travelers' presenting with TD to a physician in Cusco. At the time of enrollment, participants provided a stool sample and answered survey questions about demographics, risk behaviors, and the clinical features of illness. Stool samples were tested for norovirus (NV), bacteria, and parasites using conventional methods. Data obtained were then analyzed using case-case methods. NV (14%), enterotoxigenic Escherichia coli (11%), and Campylobacter (9%), notably ciprofloxacin-resistant Campylobacter, were the most frequently identified pathogens among adults with TD. Coinfection with multiple enteropathogens occurred in 5% of cases. NV caused severe disease relative to other TD-associated pathogens identified, confining over 90% of infected individuals to bed. Destination-specific risk factors include consumption of the local beverage "chicha," which was associated with Cryptosporidium infection. Preventive interventions, such as vaccines, directed against these pathogens could significantly reduce the burden of TD.

"Improved" But Not Necessarily Safe: An Assessment of Fecal Contamination of Household Drinking Water in Rural Peru.

The indicator used to measure progress toward the Millennium Development Goal (MDG) for water is access to an improved water supply. However, improved supplies are frequently fecally contaminated in developing countries. We examined factors associated with Escherichia coli contamination of improved water supplies in rural Pisco province, Peru. A random sample of 207 households with at least one child less than 5 years old was surveyed, and water samples from the source and storage container were tested for E. coli contamination. Although over 90% of households used an improved water source, 47% of source and 43% of stored water samples were contaminated with E. coli. Pouring or using a spigot to obtain water from the storage container instead of dipping a hand or object was associated with decreased risk of contamination of stored water (adjusted prevalence ratio [aPR] = 0.58, 95% confidence interval [CI] = 0.42, 0.80). Container cleanliness (aPR = 0.67, 95% CI = 0.45, 1.00) and correct handwashing technique (aPR = 0.62, 95% CI = 0.42, 0.90) were also associated with decreased contamination risk. These findings highlighted the limitations of improved water supplies as an indicator of safe water access. To ensure water safety in the home, household water treatment and improved hygiene, water handling, and storage practices should be promoted.

Epidemiology and Genetic Characterization of Noroviruses among Adults in an Endemic Setting, Peruvian Amazon Basin, 2004-2011.

BACKGROUND: Successful vaccination strategies against norovirus will require understanding the burden of disease and relevant genotypes in populations. However, few data are available from cohort studies of adults living in low- and middle-income countries (LMIC). MATERIALS AND METHODS: We conducted a nested case-control study within a Peruvian military cohort to characterize the burden of norovirus infection, predominant genotypes, and associated symptoms from 2004 through 2011. Randomly selected case and control stools were tested for norovirus, bacteria, and parasites. The odds ratio of the association between norovirus infection and diarrhea was estimated using multiple logistic regression and co-infection adjusted attributable fractions were calculated. RESULTS: Of the 3,818 cohort study participants, 624 developed diarrhea. Overall and norovirus-associated diarrhea incidence rates were 42.3 and 6.0 per 100 person-years, respectively. The most prevalent norovirus genogroup was GII (72.5%, 29/40), which was associated with diarrhea (AOR 3.4, 95% CI: 1.3-8.7, P = 0.012). The co-infection adjusted GII attributable fraction was 6.4%. DISCUSSION: Norovirus was a frequent cause of diarrhea in an adult population followed longitudinally in an LMIC setting. Vaccine strategies should consider targeting adults in endemic settings and special populations that could serve as community transmission sources.

Virulence factors and mechanisms of antimicrobial resistance in Shigella strains from periurban areas of Lima (Peru).

The study was aimed to describe the serotype, mechanisms of antimicrobial resistance, and virulence determinants in Shigella spp. isolated from Peruvian children. Eighty three Shigella spp. were serogrouped and serotyped being established the antibiotic susceptibility. The presence of 12 virulence factors (VF) and integrase 1 and 2, along with commonly found antibiotic resistance genes was established by PCR. S. flexneri was the most relevant serogroup (55 isolates, 66%), with serotype 2a most frequently detected (27 of 55, 49%), followed by S. boydii and S. sonnei at 12 isolates each (14%) and S. dysenteriae (four isolates, 5%). Fifty isolates (60%) were multi-drug resistant (MDR) including 100% of S. sonnei and 64% of S. flexneri. Resistance levels were high to trimethoprim-sulfamethoxazole (86%), tetracycline (74%), ampicillin (67%), and chloramphenicol (65%). Six isolates showed decreased azithromycin susceptibility. No isolate was resistant to nalidixic acid, ciprofloxacin, nitrofurantoin, or ceftriaxone. The most frequent resistance genes were sul2 (95%), tet(B) (92%), cat (80%), dfrA1 (47%), blaOXA-1like (40%), with intl1 and intl2 detected in 51 and 52% of the isolates, respectively. Thirty-one different VF profiles were observed, being the ipaH (100%), sen (77%), virA and icsA (75%) genes the most frequently found. Differences in the prevalence of VF were observed between species with S. flexneri isolates, particularly serotype 2a, possessing high numbers of VF. In conclusion, this study highlights the high heterogeneity of Shigella VF and resistance genes, and prevalence of MDR organisms within this geographic region.

Detection of Campylobacter in stool and determination of significance by culture, enzyme immunoassay, and PCR in developing countries.

Campylobacter is a common bacterial enteropathogen that can be detected in stool by culture, enzyme immunoassay (EIA), or PCR. We compared culture for C. jejuni/C. coli, EIA (ProSpecT), and duplex PCR to distinguish Campylobacter jejuni/C. coli and non-jejuni/coli Campylobacter on 432 diarrheal and matched control stool samples from infants in a multisite longitudinal study of enteric infections in Tanzania, Bangladesh, and Peru. The sensitivity and specificity of culture were 8.5% and 97.6%, respectively, compared with the results of EIA and 8.7% and 98.0%, respectively, compared with the results of PCR for C. jejuni/C. coli. Most (71.6%) EIA-positive samples were positive by PCR for C. jejuni/C. coli, but 27.6% were positive for non-jejuni/coli Campylobacter species. Sequencing of 16S rRNA from 53 of these non-jejuni/coli Campylobacter samples showed that it most closely matched the 16S rRNA of C. hyointestinalis subsp. lawsonii (56%), C. troglodytis (33%), C. upsaliensis (7.7%), and C. jejuni/C. coli (2.6%). Campylobacter-negative stool spiked with each of the above-mentioned Campylobacter species revealed reactivity with EIA. PCR detection of Campylobacter species was strongly associated with diarrhea in Peru (odds ratio [OR] = 3.66, P < 0.001) but not in Tanzania (OR = 1.56, P = 0.24) or Bangladesh (OR = 1.13, P = 0.75). According to PCR, Campylobacter jejuni/C. coli infections represented less than half of all infections with Campylobacter species. In sum, in infants in developing country settings, the ProSpecT EIA and PCR for Campylobacter reveal extremely high rates of positivity. We propose the use of PCR because it retains high sensitivity, can ascertain burden, and can distinguish between Campylobacter infections at the species level.

Detection of Leptospira-specific antibodies using a recombinant antigen-based enzyme-linked immunosorbent assay.

We produced three highly purified recombinant antigens rLipL32, rLipL41, and rLigA-Rep (leptospiral immunoglobulin-like A repeat region) for the detection of Leptospira-specific antibodies in an enzyme-linked immunosorbent assay (ELISA). The performance of these recombinant antigens was evaluated using 121 human sera. Among them, 63 sera were microscopic agglutination test (MAT)-confirmed positive sera from febrile patients in Peru, 22 sera were indigenous MAT-negative febrile patient sera, and 36 sera were from patients with other febrile diseases from Southeast Asia, where leptospirosis is also endemic. Combining the results of immunoglobulin M (IgM) and IgG detection from these three antigens, the overall sensitivity is close to 90% based on the MAT. These results suggest that an ELISA using multiple recombinant antigens may be used as an alternative method for the detection of Leptospira-specific antibodies.

Outbreak of Group A beta hemolytic Streptococcus pharyngitis in a Peruvian military facility, April 2012.

Group A Streptococcus (GAS), or Streptococcus pyogenes, is a common cause of acute pharyngitis as well as other diseases. Closed populations such as those living on military bases, nursing homes, and prisons are particularly vulnerable to GAS outbreaks due to crowding that facilitates person-to-person transmission. This report details a large outbreak of GAS pharyngitis at a Peruvian military training facility near Lima, Peru, in April 2012. Initial findings showed 145 cases. However, as the investigation continued it was revealed that some trainees may have concealed their illness to avoid real or perceived negative consequences of seeking medical care. A subsequent anonymous survey of all trainees revealed at least 383 cases of pharyngitis among the facility's 1,549 trainees and an attack rate of 34 percent among the 1,137 respondents. The epidemic curve revealed a pattern consistent with routine person-to-person transmission, although a point-source initiating event could not be excluded. Laboratory results showed GAS emm type 80.1 to be the culprit pathogen, an organism not commonly implicated in outbreaks of GAS in the Americas. Barious unique and illustrative features of outbreak investigation in military facilities and populations are discussed.

The U.S. military's Neisseria gonorrhoeae resistance surveillance initiatives in selected populations of five countries.

Multi-drug resistant Neisseria gonorrhoeae (GC) threatens the successful treatment of gonorrhea. This report presents preliminary findings with regard to the prevalence of laboratory-confirmed GC and the extent of drug-resistance among sample populations in five countries. Between October 2010 and January 2013, 1,694 subjects (54% male; 45% female; 1% unknown) were enrolled and screened for the presence of laboratory-confirmed GC in the United States, Djibouti, Ghana, Kenya, and Peru. Overall, 108 (6%) of enrolled subjects tested positive for GC. Antimicrobial susceptibility testing results were available for 66 GC isolates. Resistance to at least three antibiotics was observed at each overseas site. All isolates tested in Ghana (n=6) were resistant to ciprofloxacin, penicillin, and tetracycline. In Djibouti, preliminary results suggested resistance to penicillin, tetracycline, ciprofloxacin, cefepime, and ceftriaxone. The small sample size and missing data prevent comparative analysis and limit the generalizability of these preliminary findings.

Streptococcus equi subsp. zooepidemicus meningitis in Peru.

A 59-year-old man with a history of fever, unsteadiness, hemiparesis, motor aphasia and consciousness disturbance was hospitalized for Streptococcus equi subsp. zooepidemicus meningitis. He denied contact with farm animals, but had a practice of consuming unpasteurized goats' cheese from an uncertain source.