Restoration of genetic diversity in the dry forest treeSwietenia macrophylla(Meliaceae) after pasture abandonment in Costa Rica

We studied the levels of genetic diversity of Swietenia macrophylla (big leaf mahogany) in five successional plots in the Santa Rosa National Park, Guanacaste, Costa Rica. We selected sites with different lengths of time since the last major disturbance (typically fire): 6, 9, 15 and 20 years. In addition, we also included a patch of mature forest that had experienced selective logging and other human activity in the past 100 years. Genetic diversity was assessed using five polymorphic DNA microsatellite loci. We found a total of 21 alleles in the five loci examined, in which the number of alleles present varied among the five sites studied. Allelic diversity varied between sites ranging from 20 to 14 alleles, and our data revealed that earlier successional sites have more alleles than older sites. There was significant heterogeneity in allele frequencies between sites; however, genetic differentiation between populations was low (FST = 0.063) indicating that most of the variation was found within sites and extensive gene flow between sites. In addition, our analysis also showed that genetic diversity of adult trees does not solely determine the diversity of seedlings and saplings found around them, also supporting the existence of extensive gene flow. The impact of these findings for the design of conservation strategies for tropical dry forests trees is discussed.

Peritonitis due to rupture of retroperitoneal teratoma: computed tomography diagnosis

Retroperitoneal benign cystic teratoma is relatively rare in adults. We report a case of traumatic rupture of primary retroperitoneal teratoma into peritoneum that produced chemical peritonitis. It was demonstrated by computed tomography, which showed fat-fluid levels in the peritoneum. We suggest that the demonstration of fat-fluid levels in the peritoneum could be a reliable sign of intraperitoneal rupture of abdominal teratoma and subsequent chemical peritonitis.

Chronic anisakiasis presenting as a mesenteric mass

Chronic anisakiasis is a rare entity, and its diagnosis is difficult. We report a case of chronic anisakiasis with multiple gastrointestinal manifestations presenting as a palpable mesenteric mass, diagnosed by specific serology and histologic findings. We describe the computed tomographic appearance of this mass and the pathologic correlations. To our knowledge, this is the first time this mesenteric location has been detected by imaging before surgery.

[Primary pneumonic plague with nosocomial transmission in La Libertad, Peru 2010]

Pneumonic plague is one of the clinical forms of plague, of low frequency and high mortality, transmitted by direct inhalation of Yersinia pestis coming from an animal or from person to person.

OBJECTIVE

To describe the clinical and epidemiological characteristics of the cases of primary pneumonic plague in an outbreak in the north of Peru.

MATERIALS AND METHODS

The clinical records of the confirmed cases of primary pneumonic plague presenting in an outbreak occurring in La Libertad, in July 2010, were reviewed, also the search and contact investigation was performed.

RESULTS

The index case was identified, as well as three additional cases, out of these, two were nosocomial infections related to the index case. The initial clinical presentation was characterized by sudden onset of fever, chills, myalgia and chest pain, which in less than 24 hours evolved to hypotension and cyanosis. The initiation of specific treatment varied from 2 to 12 days, and cases with prompt initiation of treatment had a better clinical outcome. The lethality was 50% (2/4).

CONCLUSION

Nosocomial transmission of pneumonic plague in Peru is evidenced, with severe clinical manifestations and high lethality.

Venezuelan equine encephalitis and upper gastrointestinal bleeding in child

Venezuelan equine encephalitis (VEE) is reemerging in Peru. VEE virus subtype ID in Peru has not been previously associated with severe disease manifestations. In 2006, VEE virus subtype ID was isolated from a boy with severe febrile disease and gastrointestinal bleeding; the strain contained 2 mutations within the PE2 region.

A foodborne outbreak of brucellosis at a police station cafeteria, Lima, Peru

Brucella melitensis is highly infectious for humans and can be transmitted to humans in a number of epidemiological contexts. Within the context of an ongoing brucellosis surveillance project, an outbreak at a Peruvian police officer cafeteria was discovered, which led to active surveillance (serology, blood culture) for additional cases among 49 police officers who had also eaten there. The cohort was followed up to 18 months regardless of treatment or symptoms. Active surveillance estimated the attack rate at 26.5% (13 of 49). Blood cultures from four cases were positive; these isolates were indistinguishable using multiple locus variable number tandem repeat analysis. This investigation indicates the importance of case tracking and active surveillance for brucellosis in the context of potential common source exposure. These results provide rationale for public health investigations of brucellosis index cases including the bioterrorism-related dissemination of Brucella.

[Genetic diversity of Peruvian isolates of Leptospira spp. through pulsed field gel electrophoresis]

OBJECTIVES

Determine the genetic diversity of Peruvian isolations of Leptospira spp. through Pulsed Field Gel Electrophoresis (PFGE).

MATERIALS AND METHODS

The PFGE methodology proposed by Galloway and Levett (2008) was standardized. A database including the PFGE profiles of 65 reference strains was prepared, and the technique was applied in 111 isolates of Leptospira spp. obtained in Peru between 2002 and 2010.

RESULTS

A great generic diversity of serovars of circulating Leptospira spp. was determined in our country. 57 serovars were identified, 47 out of 97 pathogen isolates. Most frequent serovars were Icterohaemorrhagiae/Copenhageni (n=24) and Canicola (n=7). The most frequent species were L. santarosai (49,5%) and L. interrogans (37,1%). The distribution of species, clusters and serovars changed according to the source of isolate, the environmental context and the origin.

CONCLUSIONS

There is great diversity of circulating serovars in Peru. There are genetic and epidemiological relations among isolates of different sources, and this is related to species, reservoir, environmental context and the origin of the isolate.