Rice and Sutter Journal of Medical Case Reports 2010, 4:353 http://www.jmedicalcasereports.com/content/4/1/353 the spleen, as well as the unique infectious risks that our military personnel face while on deployment. The World Health Organization estimates that 300 to 500 million humans worldwide have malaria each year, with an estimated 2% occurrence rate of splenic rupture and up to 80% mortality of these cases [3,8,9]. Rupture is most commonly seen with Plasmodium vivax infec- tion; however, all four Plasmodium species have been implicated. Some theories propose that splenic conges- tion results from infiltration of red pulp by parasitized RBCs, pigment-laden macrophages and other WBCs; others cite the pooling of platelets as a causal factor [8]. However, with splenomegaly occurring in up to 90% of patients, typically within four days of symptom onset, most theories agree that rupture results from acute, rapid splenic congestion [9,10]. Regardless of species, the majority of ruptures occur with primary infection in nonimmune individuals, with lower rates among inhabi- tants of malarial endemic areas. This is thought to result from the gradual splenic enlargement and fibrosis seen in these populations, which likely protects from future rupture. In contrast, nonimmune patients, travelers in particular, have been shown to have significantly higher rates of splenic rupture with infection [8,10]. This point is of particular importance for our military personnel, who are often deployed in regions endemic for malaria and other pathogenic causes of splenic rupture and rarely with the protection of immunity. Despite having a clinical presentation consistent with an infectious cause, our patient’s microbiologic and his- topathologic investigations did not reveal an infectious source, including Plasmodium spp. Based on the infor- mation at hand, he did meet the proposed criteria for spontaneous splenic rupture (Appendix 1). In retrospect, however, there were some variations in sampling meth- ods and additional tests that may have helped identify a particular agent. If stool samples had been obtained at the time of the patient’s diarrhea, it is likely that cul- tures would have been more revealing because the chances of growing out Salmonella, Campylobacter, Shi- gella and Yersinia spp. decrease rather quickly as diar- rhea subsides, with culture yield markedly reduced after three days [12]. If bone marrow biopsy had been per- formed, in addition to excluding lymphoproliferative and neoplastic processes, it may have provided a med- ium for difficult-to-culture organisms (i.e., Brucella, Leishmania, Mycobacteria and Histoplasma spp. as well as Salmonella typhi, for which bone marrow cultures have been specifically recommended [13]). Additionally, culture of fresh splenic tissue may have proven useful in identifying a particular organism as a more sensitive alternative to special staining. However, in this case, the resected sample was delivered from the operating room in formalin, eliminating that possibility. Page 4 of 5 Although no infectious source was identified in this Marine and the cause of his splenic rupture was ulti- mately undetermined, the case does serve as a reminder of the infectious causes that pose a threat to deployed military personnel. Particularly as the U.S. and joint military focus shifts from operations in Iraq to Afghani- stan and the United States Central Command’s area of responsibility continues to broaden, it is increasingly vital to consider the infectious risks facing our troops. Of the infectious diseases known to cause pathologic splenic rupture, many are endemic to the Middle East and South-Central Asia (Table 2). Military members receive vaccinations for several of these pathogens, and some are common causes of respiratory and diarrheal illness at home and abroad. However, others are not as routinely encountered in everyday practice and thus may not be given sufficient consideration to make a timely diagnosis. Of particular concern, based on preva- lence in the region, are malaria, visceral leishmaniasis and tuberculosis [14-17]. Realizing that our military per- sonnel have significant exposure to these infectious causes of splenic rupture, physicians caring for them abroad and at home must consider their transmission, as well as this potentially fatal clinical entity. Conclusion Spontaneous splenic rupture is a rare event that, if unrecognized, may lead to life-threatening hemorrhage. Although the cause of our patient’s rupture was not determined, the case serves to remind of the infectious causes of this condition that are faced by our deployed troops. Physicians caring for military personnel must be alert to these infectious risks and their association with splenic rupture because a high index of suspicion is required to promptly diagnose and treat this serious complication. Consent Written informed consent was obtained from the patient for publication of this case report. A copy of the written Table 2 Some Infectious Causes of Pathologic Splenic Rupture that are Endemic to and of Particular Concern in the Middle East and South-Central Asia [14-17] Bacterial Viral Other Staphylococci Clostridium spp. Salmonella spp. Campylobacter spp. Haemophilus spp. Brucellosis Tuberculosis Mumps Hepatitis A Dengue Rubella Influenza HIV Malaria Leishmaniasis (visceral) Typhus Leptospirosis Q fever Relapsing fever Echinococcus spp.