Human leptospirosis in The Federated States of Micronesia: a hospital-based febrile illness survey.

BACKGROUND: Human leptospirosis is an emerging infectious disease of global significance, and is endemic to several countries in the Pacific. Zoonotic transmission dynamics combined with diagnostic challenges lead to difficulties in prevention and identification of cases. The Federated States of Micronesia (FSM) lacks surveillance data for human leptospirosis. This hospital-based serologic survey sought to estimate the burden of leptospirosis, collect information relating to associated factors, and assess the leptospirosis point-of-care rapid diagnostic test (RDT) commonly used in FSM. METHODS: A four-month hospital-based survey was conducted in Pohnpei State, FSM in 2011. Patients with undifferentiated fevers presenting to hospital were referred for enrolment by physicians. Consenting participants provided paired blood specimens 10-30 days apart, and responded to interview questions regarding demographics, clinical symptoms, exposure to animals, and environmental exposure. Blood samples were subjected to immunochromatographic RDT and confirmed by microscopic agglutination test (MAT). RESULTS: Of 54 participants tested by MAT, 20.4% (95% confidence interval [CI] 10.1-30.6%) showed serologic evidence of acute infection. Occupation student (odds ratio [OR], 17.5; 95% CI: 1.9-161.1) and recreational gardening (OR, 8.6; 95% CI: 1.0-73.8), identified by univariate logistic regression, were associated with infection. The local rapid diagnostic test (RDT) performed with a sensitivity of 69.2 (42.3-89.3 CI) and specificity of 90.0 (81.6-95.6 CI) compared to MAT. CONCLUSIONS: This study demonstrated a high burden of leptospirosis in Pohnpei. Further work is warranted to identify additional risk factors and opportunities to control leptospirosis in Pohnpei and other Pacific settings.

Zika virus outbreak on Yap Island, Federated States of Micronesia.

BACKGROUND: In 2007, physicians on Yap Island reported an outbreak of illness characterized by rash, conjunctivitis, and arthralgia. Although serum from some patients had IgM antibody against dengue virus, the illness seemed clinically distinct from previously detected dengue. Subsequent testing with the use of consensus primers detected Zika virus RNA in the serum of the patients but no dengue virus or other arboviral RNA. No previous outbreaks and only 14 cases of Zika virus disease have been previously documented. METHODS: We obtained serum samples from patients and interviewed patients for information on clinical signs and symptoms. Zika virus disease was confirmed by a finding of Zika virus RNA or a specific neutralizing antibody response to Zika virus in the serum. Patients with IgM antibody against Zika virus who had a potentially cross-reactive neutralizing-antibody response were classified as having probable Zika virus disease. We conducted a household survey to estimate the proportion of Yap residents with IgM antibody against Zika virus and to identify possible mosquito vectors of Zika virus. RESULTS: We identified 49 confirmed and 59 probable cases of Zika virus disease. The patients resided in 9 of the 10 municipalities on Yap. Rash, fever, arthralgia, and conjunctivitis were common symptoms. No hospitalizations, hemorrhagic manifestations, or deaths due to Zika virus were reported. We estimated that 73% (95% confidence interval, 68 to 77) of Yap residents 3 years of age or older had been recently infected with Zika virus. Aedes hensilli was the predominant mosquito species identified. CONCLUSIONS: This outbreak of Zika virus illness in Micronesia represents transmission of Zika virus outside Africa and Asia. Although most patients had mild illness, clinicians and public health officials should be aware of the risk of further expansion of Zika virus transmission.

Protective effect of maritime quarantine in South Pacific jurisdictions, 1918-19 influenza pandemic.

We reviewed mortality data of the 1918-19 influenza pandemic for 11 South Pacific Island jurisdictions. Four of these appear to have successfully delayed or excluded the arrival of pandemic influenza by imposing strict maritime quarantine. They also experienced lower excess death rates than the other jurisdictions that did not apply quarantine measures.

Molecular strain typing of the yaws pathogen, Treponema pallidum subspecies pertenue.

Yaws is a neglected tropical disease caused by the bacterium Treponema pallidum subspecies pertenue. The disease primarily affects children under 15 years of age living in low socioeconomic conditions in tropical areas. As a result of a renewed focus on the disease owing to a recent eradication effort initiated by the World Health Organization, we have evaluated a typing method, adapted from and based on the enhanced Centers for Disease Control and Prevention typing method for T. pallidum subsp. pallidum, for possible use in epidemiological studies. Thirty DNA samples from yaws cases in Vanuatu and Ghana, 11 DNA samples extracted from laboratory strains, and 3 published genomic sequences were fully typed by PCR/RFLP analysis of the tpr E, G, and J genes and by determining the number of 60-bp repeats within the arp gene. Subtyping was performed by sequencing a homonucleotide "G" tandem repeat immediately upstream of the rpsA gene and an 84-bp region of tp0548. A total of 22 complete strain types were identified; two strain types in clinical samples from Vanuatu (5q11/ak and 5q12/ak), nine strain types in clinical samples from Ghana (3q12/ah, 4r12/ah, 4q10/j, 4q11/ah, 4q12/ah, 4q12/v, 4q13/ah, 6q10/aj, and 9q10/ai), and twelve strain types in laboratory strains and published genomes (2q11/ae, 3r12/ad, 4q11/ad, 4q12/ad, 4q12/ag, 4q12/v, 5r12/ad, 6r12/x, 6q11/af, 10q9/r, 10q12/r, and 12r12/w). The tpr RFLP patterns and arp repeat sizes were subsequently verified by sequencing analysis of the respective PCR amplicons. This study demonstrates that the typing method for subsp. pallidum can be applied to subsp. pertenue strains and should prove useful for molecular epidemiological studies on yaws.

Risk of person-to-person transmission of pneumonic plague.

Plague has received much attention because it may be used as a weapon by terrorists. Intentionally released aerosols of Yersinia pestis would cause pneumonic plague. In order to prepare for such an event, it is important, particularly for medical personnel and first responders, to form a realistic idea of the risk of person-to-person spread of infection. Historical accounts and contemporary experience show that pneumonic plague is not as contagious as it is commonly believed to be. Persons with plague usually only transmit the infection when the disease is in the endstage, when infected persons cough copious amounts of bloody sputum, and only by means of close contact. Before antibiotics were available for postexposure prophylaxis for contacts, simple protective measures, such as wearing masks and avoiding close contact, were sufficient to interrupt transmission during pneumonic plague outbreaks. In this article, I review the historical literature and anecdotal evidence regarding the risk of transmission, and I discuss possible protective measures.

Molecular differentiation of Treponema pallidum subspecies in skin ulceration clinically suspected as yaws in Vanuatu using real-time multiplex PCR and serological methods.

We developed a TaqMan-based real-time quadriplex polymerase chain reaction (PCR) to simultaneously detect Treponema pallidum subspecies pallidum, T. pallidum subsp. pertenue, and T. pallidum subsp. endemicum, the causative agents of venereal syphilis, yaws, and bejel, respectively. The PCR assay was applied to samples from skin ulcerations of clinically presumptive yaws cases among children on Tanna Island, Vanuatu. Another real-time triplex PCR was used to screen for the point mutations in the 23S rRNA genes that have previously been associated with azithromycin resistance in T. pallidum subsp. pallidum strains. Seropositivity by the classical syphilis serological tests was 35.5% among children with skin ulcerations clinically suspected with yaws, whereas the presence of T. pallidum subsp. pertenue DNA was only found in lesions from 15.5% of children. No evidence of T. pallidum subsp. pertenue infection, by either PCR or serology was found in ∼59% of cases indicating alternative causes of yaws-like lesions in this endemic area.

Risk of hospital-acquired legionnaires' disease in cities using monochloramine versus other water disinfectants.

OBJECTIVE: To measure the association between the disinfection of municipal drinking water with monochloramine and the occurrence of hospital-acquired legionnaires' disease (LD). SETTING: One hundred sixty-six U.S. hospitals. DESIGN: Survey of 459 members of the Society for Healthcare Epidemiology of America (SHEA) for hospital features; endemic- and outbreak-related, hospital-acquired LD; the source of the hospital water supply; and the methods of disinfection used by the hospitals and municipal water treatment plants. RESULTS: SHEA members representing 166 (36%) of 459 hospitals responded; 33 (20%) reported one or more episodes of hospital-acquired LD during the period from 1994 to 1998 and 23 (14%) reported an outbreak of hospital-acquired LD during the period from 1989 to 1998. Hospitals with an occurrence of hospital-acquired LD had a higher census (median, 319 vs 221; P = .03), more acute care beds (median, 500 vs 376; P = .04), and more intensive care unit beds (median, 42 vs 24; P = .009) than did other hospitals. They were also more likely to have a transplant service (74% vs 42%; P = .001) and to perform surveillance for hospital-acquired disease (92% vs 61%; P = .001). After adjustment for the presence of a transplant program and surveillance for legionnaires' disease, hospitals supplied with drinking water disinfected with monochloramine by municipal plants were less likely to have sporadic cases or outbreaks of hospital-acquired LD (odds ratio, 0.20; 95% confidence interval, 0.07 to 0.56) than were other hospitals. CONCLUSION: Water disinfection with monochloramine by municipal water treatment plants significantly reduces the risk of hospital-acquired LD.

An outbreak of diarrhea in a neonatal medium care unit caused by a novel strain of rotavirus: investigation using both epidemiologic and microbiological methods.

OBJECTIVE: In December 1999, an outbreak of diarrhea was reported in a general hospital neonatal medium care unit (NMCU) caused by a novel strain of rotavirus with genotype P[6], G9. An investigation was conducted to determine risk factors for illness among neonates. DESIGN: Rotavirus diagnosis was by latex agglutination and typing by reverse transcriptase polymerase chain reaction. A case-control study was performed using data collected from medical records on exposures in a 3-day period before illness (cases) or a random 3-day period (controls). Environmental swabs were tested for rotavirus. Antenatal blood samples from mothers and blood samples provided by hospital staff were analyzed for rotavirus antibodies. RESULTS: Fifty-six cases of rotaviral illness were confirmed by latex agglutination. Forty-seven of these were among 118 neonates exposed to the NMCU (attack rate, 40%). There was a 4-week period with no clinical cases in the course of the outbreak. Increased frequency (> or = 15 times in 3 days) of ungloved nasogastric feeding was a significant risk factor (adjusted odds ratio, 8.79), controlling for birth weight and gestational age. Environmental sampling showed persistence of the virus on ward surfaces despite cleaning. None of 24 NMCU staff members had high levels of antibodies against P[6], G9. Three (8%) of 38 mothers had high antibody levels; 2 had infants who became ill. The outbreak ended with a 7-day ward closure, disinfection, and introduction of gloved nasogastric feeding. CONCLUSIONS: Case-control studies can be successful in identiffying risk factors for nosocomial outbreaks of diarrhea. High levels of rotavirus antibodies in mothers may not protect infants. The environment may be the most important reservoir of rotavirus during outbreaks.

Impact of a targeted typhoid vaccination campaign following cyclone Tomas, Republic of Fiji, 2010.

After a category 4 cyclone that caused extensive population displacement and damage to water and sanitation infrastructure in Fiji in March 2010, a typhoid vaccination campaign was conducted as part of the post-disaster response. During June-December 2010, 64,015 doses of typhoid Vi polysaccharide vaccine were administered to persons ≥ 2 years of age, primarily in cyclone-affected areas that were typhoid endemic. Annual typhoid fever incidence decreased during the post-campaign year (2011) relative to preceding years (2008-2009) in three subdivisions where a large proportion of the population was vaccinated (incidence rate ratios and 95% confidence intervals: 0.23, 0.13-0.41; 0.24, 0.14-0.41; 0.58, 0.40-0.86), and increased or remained unchanged in 12 subdivisions where little to no vaccination occurred. Vaccination played a role in reducing typhoid fever incidence in high-incidence areas after a disaster and should be considered in endemic settings, along with comprehensive control measures, as recommended by the World Health Organization.

Influenza antiviral resistance in the Asia-Pacific region during 2011.

Despite greater than 99% of influenza A viruses circulating in the Asia-Pacific region being resistant to the adamantane antiviral drugs in 2011, the large majority of influenza A (>97%) and B strains (∼99%) remained susceptible to the neuraminidase inhibitors oseltamivir and zanamivir. However, compared to the first year of the 2009 pandemic, cases of oseltamivir-resistant A(H1N1)pdm09 viruses with the H275Y neuraminidase mutation increased in 2011, primarily due to an outbreak of oseltamivir-resistant viruses that occurred in Newcastle, as reported in Hurt et al. (2011c, 2012a), where the majority of the resistant viruses were from community patients not being treated with oseltamivir. A small number of influenza B viruses with reduced oseltamivir or zanamivir susceptibility were also detected. The increased detection of neuraminidase inhibitor resistant strains circulating in the community and the detection of novel variants with reduced susceptibility are reminders that monitoring of influenza viruses is important to ensure that antiviral treatment guidelines remain appropriate.

Pacific-wide simplified syndromic surveillance for early warning of outbreaks.

The International Health Regulations require timely detection and response to outbreaks. Many attempts to set up an outbreak early warning system in Pacific island countries and territories (PICTs) have failed. Most were modelled on systems from large countries; large amounts of data often overwhelmed small public health teams. Many conditions required overseas laboratory confirmation, further reducing timeliness and completeness. To improve timeliness and reduce the data burden, simplified surveillance was proposed, with case definitions based on clinical signs and symptoms without the need for laboratory confirmation or information on symptoms, location, sex and age. After trials in three PICTs, this system was implemented throughout the Pacific. Enthusiastic adoption by public health staff resulted in 20 of 22 PICTs reporting weekly to the World Health Organization within 12 months of starting to use the system. In the first year, the system has detected many infectious disease outbreaks and facilitated timely implementation of control measures. For several Pacific countries and territories, this is the first functional and timely infectious disease surveillance system. When outbreak detection is the principal objective, simplification of surveillance should be a priority in countries with a limited public health system capacity.

Sustaining surveillance: evaluating syndromic surveillance in the Pacific.

Prior to the 2009 H1N1 pandemic, the Pacific Island Countries and Territories (PICTs) had agreed to develop a standardised, simple syndromic surveillance system to ensure compliance with International Health Regulations requirements (rapid outbreak detection, information sharing and response to outbreaks). In October 2010, the new system was introduced and over the next 12 months implemented in 20 of 22 PICTs. An evaluation was conducted to identify strengths and weaknesses of the system, ease of use and possible points for improvement. An in-country quantitative and qualitative evaluation in five PICTs identified that the most important determinants of the system's success were: simplicity of the system; support from all levels of government; clearly defined roles and responsibilities; feedback to those who collect the data; harmonisation of case definitions; integration of data collection tools into existing health information systems; and availability of clinical and epidemiological advice from external agencies such as the World Health Organization and the Secretariat of the Pacific Community. Regional reporting of alerts, outbreaks and outbreak updates has dramatically increased since implementation of the system. This syndromic system will assist PICTs to detect future influenza pandemics and other emerging infectious diseases and to rapidly contain outbreaks in the Pacific.

Use of serum and blood samples on filter paper to improve the surveillance of Dengue in Pacific Island Countries.

BACKGROUND: In Pacific Island Countries (PICs) the epidemiology of dengue is characterized by long-term transmission of a single dengue virus (DENV) serotype. The emergence of a new serotype in one island country often indicates major outbreaks with this serotype will follow in other PICs. OBJECTIVES: Filter paper (FP) cards on which whole blood or serum from dengue suspected patients had been dried was evaluated as a method for transportation of this material by standard mail delivery throughout the Pacific. STUDY DESIGN: Twenty-two FP-dried whole blood samples collected from patients in New Caledonia and Wallis & Futuna Islands, during DENV-1 and DENV-4 transmission, and 76 FP-dried sera collected from patients in Yap State, Majuro (Republic of Marshall Islands), Tonga and Fiji, before and during outbreaks of DENV-2 in Yap State and DENV-4 in Majuro, were tested for the presence of DENV RNA, by serotype specific RT-PCR, at the Institut Louis Malardé in French Polynesia. RESULTS: The serotype of DENV could be determined, by a variety of RT-PCR procedures, in the FP-dried samples after more than three weeks of transport at ambient temperatures. In most cases, the sequencing of the envelope gene to genotype the viruses also was possible. CONCLUSIONS: The serotype and genotype of DENV can be determined from FP-dried serum or whole blood samples transported over thousands of kilometers at ambient, tropical, temperatures. This simple and low-cost approach to virus identification should be evaluated in isolated and resource poor settings for surveillance for a range of significant viral diseases.

A standardized process for developing a national notifiable diseases list in a pacific island setting.

The authors describe an adapted method, originally developed for infectious disease resource allocation, for prioritizing infectious diseases for inclusion in a Pacific island nation's National Notifiable Diseases List. Using a process that was systematic, transparent, objective, and addressed multiple criteria, a panel of stakeholders judged candidate diseases against 12 objective criteria and arrived at weighted scores for the diseases, which were then ranked. The result was the successful creation of a list of 22 urgently notifiable conditions. However, the process was only incrementally more useful than the use of consensus, and certain anomalies necessitated a reality check and adjustment of the final results. The process described herein may be more useful in settings where there is wide disagreement among stakeholders; it also appears more useful for its original purpose-prioritizing public health resource allocation for infectious disease control. The modifications discussed may make it more relevant to notifiable disease selection.

Investigation and control of an outbreak of Enterobacter aerogenes bloodstream infection in a neonatal intensive care unit in Fiji.

Ten neonates developed blood stream infection with extended-spectrum beta-lactamase-producing Enterobacter aerogenes in a neonatal intensive care unit in Fiji. The source of the outbreak was traced to a bag of contaminated normal saline in the ward, which was used for multiple patients. All isolates recovered from patients were indistinguishable from the bacteria recovered from the normal saline by pulsed-field gel electrophoresis. The outbreak was controlled using simple infection control practices such as reinforcement of strict hand hygiene policy, provision of single use vials of normal saline, and strict aseptic technique for injections.

Pneumonic plague cluster, Uganda, 2004.

The public and clinicians have long-held beliefs that pneumonic plague is highly contagious; inappropriate alarm and panic have occurred during outbreaks. We investigated communicability in a naturally occurring pneumonic plague cluster. We defined a probable pneumonic plague case as an acute-onset respiratory illness with bloody sputum during December 2004 in Kango Subcounty, Uganda. A definite case was a probable case with laboratory evidence of Yersinia pestis infection. The cluster (1 definite and 3 probable cases) consisted of 2 concurrent index patient-caregiver pairs. Direct fluorescent antibody microscopy and polymerase chain reaction testing on the only surviving patient's sputum verified plague infection. Both index patients transmitted pneumonic plague to only 1 caregiver each, despite 23 additional untreated close contacts (attack rate 8%). Person-to-person transmission was compatible with transmission by respiratory droplets, rather than aerosols, and only a few close contacts, all within droplet range, became ill.

Isolated case of bioterrorism-related inhalational anthrax, New York City, 2001.

On October 31, 2001, in New York City, a 61-year-old female hospital employee who had acquired inhalational anthrax died after a 6-day illness. To determine sources of exposure and identify additional persons at risk, the New York City Department of Health, Centers for Disease Control and Prevention, and law enforcement authorities conducted an extensive investigation, which included interviewing contacts, examining personal effects, summarizing patient's use of mass transit, conducting active case finding and surveillance near her residence and at her workplace, and collecting samples from co-workers and the environment. We cultured all specimens for Bacillus anthracis. We found no additional cases of cutaneous or inhalational anthrax. The route of exposure remains unknown. All environmental samples were negative for B. anthracis. This first case of inhalational anthrax during the 2001 outbreak with no apparent direct link to contaminated mail emphasizes the need for close coordination between public health and law enforcement agencies during bioterrorism-related investigations.

A European study on the relationship between antimicrobial use and antimicrobial resistance.

In Europe, antimicrobial resistance has been monitored since 1998 by the European Antimicrobial Resistance Surveillance System (EARSS). We examined the relationship between penicillin nonsusceptibility of invasive isolates of Streptococcus pneumoniae and antibiotic sales. Information was collected on 1998-99 resistance data for invasive isolates of S. pneumoniae to penicillin, based on surveillance data from EARSS and on outpatient sales during 1997 for beta-lactam antibiotics and macrolides. Our results show that in Europe antimicrobial resistance of S. pneumoniae to penicillin is correlated with use of beta-lactam antibiotics and macrolides.

Laboratory analysis of tularemia in wild-trapped, commercially traded prairie dogs, Texas, 2002.

Oropharyngeal tularemia was identified as the cause of a die-off in captured wild prairie dogs at a commercial exotic animal facility in Texas. From this point source, Francisella tularensis-infected prairie dogs were traced to animals distributed to the Czech Republic and to a Texas pet shop. F. tularensis culture isolates were recovered tissue specimens from 63 prairie dogs, including one each from the secondary distribution sites. Molecular and biochemical subtyping indicated that all isolates were F. tularensis subsp. holarctica (Type B). Microagglutination assays detected antibodies against F. tularensis, with titers as great as 1:4,096 in some live animals. All seropositive animals remained culture positive, suggesting that prairie dogs may act as chronic carriers of F. tularensis. These findings demonstrate the need for additional studies of tularemia in prairie dogs, given the seriousness of the resulting disease, the fact that prairie dogs are sold commercially as pets, and the risk for pet-to-human transmission.

First reported prairie dog-to-human tularemia transmission, Texas, 2002.

A tularemia outbreak, caused by Francisella tularensis type B, occurred among wild-caught, commercially traded prairie dogs. F. tularensis microagglutination titers in one exposed person indicated recent infection. These findings represent the first evidence for prairie-dog-to-human tularemia transmission and demonstrate potential human health risks of the exotic pet trade.