Eyal Meltzer

Schistosomiasis among travelers: new aspects of an old disease.

Schistosomiasis is increasingly encountered among travelers returning from the tropics; signs and symptoms of travelers may differ from those of local populations. During 1993–2005, schistosomiasis was diagnosed in 137 Israeli travelers, most of whom were infected while in sub-Saharan Africa. Clinical findings compatible with acute schistosomiasis were recorded for 75 (66.4%) patients and included fever (71.3%), respiratory symptoms (42.9%), and cutaneous symptoms (45.2%). At time of physical examination, 42 patients (37.1%) still had symptoms of acute schistosomiasis, chronic schistosomiasis had developed in 23 (20.4%), and 48 (42.5%) were asymptomatic. Of patients who were initially asymptomatic, chronic schistosomiasis developed in 26%. Diagnosis was confirmed by serologic testing for 87.6% of patients, but schistosome ova were found in only 25.6%. We conclude that acute schistosomiasis is a major clinical problem among travelers, diagnostic and therapeutic options for acute schistosomiasis are limited, and asymptomatic travelers returning from schistosomiasis-endemic areas should be screened and treated.

Enteric fever: a travel medicine oriented view.

Purpose of review Enteric fever continues to be an important infection among populations in endemic countries and among travelers to these areas. This review aims to describe recent epidemiological trends and developments in diagnosis, treatment and prevention. Recent findings Data indicate that the burden of enteric fever is declining in many middle-income countries, whereas the bulk of cases occur in the Indian subcontinent and in south-east Asia. In these regions, Salmonella Paratyphi A is increasingly seen and sometimes surpasses Salmonella Typhi as the main pathogen. Enteric fever caused by S. Paratyphi A is indistinguishable from that caused by S. Typhi. In addition, drug resistance, including nalidixic acid/quinolone resistance now occurs in the majority of clinical isolates of S. Typhi and S. Paratyphi A in Asia. Currently, third generation cephalosporins and azythromycin are the only reasonable therapeutic options for most cases of travel-related enteric fever. Summary The ongoing emergence of S. Paratyphi A results in partial benefit from current typhoid vaccines in the prevention of enteric fever in travelers. Increasing antimicrobial resistance complicates therapy for travel-related enteric fever. New vaccines, offering protection against both agents of enteric fever, are urgently needed; however, none of the current vaccine candidates is likely to be available for several years.

Travel-related Schistosomiasis Acquired in Laos

Twelve Israeli travelers acquired schistosomiasis in Laos during 2002–2008, and 7 of them had acute schistosomiasis. The patients were probably exposed to Schistosoma mekongi in southern Laos, an area known to be endemic for schistosomiasis. Four possibly were infected in northern Laos, where reports of schistosomiasis are rare.

Sexually transmitted brucellosis in humans.

Sexual transmission of brucellosis has rarely been reported in humans. We describe 2 cases of probable sexual transmission of Brucella from husband to wife. In 1 case, orchidoepididimitis existed, whereas in the other case, the presence of Brucella in the semen in the absence of genital symptoms was demonstrated by polymerase chain reaction.

Schistosomiasis: Current Epidemiology and Management in Travelers

Schistosomiasis is increasingly encountered among travelers returning from the tropics, mainly from Africa. Schistosoma-infected travelers have served as sentinels for the existence of unknown foci of transmission even outside Africa. Acute schistosomiasis (also termed Katayama syndrome) is the common manifestation among travelers and may follow exposure to any of the Schistosoma species. Neuroschistosomiasis is a rare complication but may result in severe disability. Diagnosis in travelers is hampered by the poor sensitivity of microscopy in urine and stool, especially during acute infections, while seroconversion may be delayed for a period of weeks. During acute schistosomiasis, symptomatic treatment is the only available therapy, while for chronic schistosomiasis, praziquantel is the only drug available, despite reports of emerging resistance to it. Since the potential for exposure to Schistosoma through travel will probably continue to increase, it is clear that new, sensitive diagnostic methods and drugs affecting the parasite in all its stages are needed.

A travel medicine view of dengue and dengue hemorrhagic fever

Dengue fever is the most prevalent arboviral infection worldwide, with up to 40% of the world population living in endemic regions. Among travelers to tropical countries, dengue infection is increasingly reported, and it is now a leading cause of post-travel fever. Outbreaks of dengue-like illness were already described since the 18th century, but it is only in the last half century that a severe form of the disease - dengue hemorrhagic fever (DHF) has been described. Although the cause of DHF is not established, the prevailing theory attributes the disease to antibody-dependent enhancement of viral replication, in the presence of a secondary dengue infection. Comparative studies of primary vs. secondary infection are difficult to perform in endemic countries because of the rarity of primary infection except during early infancy. Travelers on the other hand are usually diagnosed with primary infection and are therefore a better study population. Data on dengue and DHF among travelers appears to suggest that severe dengue and DHF occur in similar rates among cases with primary and with secondary infections. Epidemiological and physiological data from travelers suggest that the prevailing theory on the causes of DHF needs to be reconsidered.

Arboviruses and viral hemorrhagic fevers (VHF).

The viral hemorrhagic fever (VHF) syndrome is a potentially life-threatening infection typified by a combination of a capillary leak syndrome and bleeding diathesis. Most but not all agents causing VHF are arboviruses, with transmission to humans resulting from an arthropod bite. Agents of VHF affect humans on all continents. Population growth, urbanization, human activities, and even climate change all contribute to a continual flux in the epidemiology of many arboviruses. This review provides an overview of the epidemiology of arboviral infections and VHF, the main clinical syndromes, and their diagnosis and treatment.

The Clinical Spectrum of Zika Virus in Returning Travelers

INTRODUCTION The clinical spectrum of Zika virus had, to date, been described in small series from endemic/epidemic countries and is not well established. METHODS We describe the clinical manifestations of laboratory-proven Zika virus infection in Israeli travelers during December 2015-February 2016, and review all published cases of travel-related Zika virus. RESULTS During the study period, 8 returning Israeli travelers were diagnosed with Zika virus infection. In addition, 41 published cases were included, mostly from Latin America to Europe and North America. Overall, 65.3% were diagnosed by polymerase chain reaction. Rash was the most frequent symptom, present in 95.7% of cases, followed by fever and arthralgia. Conjunctivitis was present in 53.1%; however, only 40.3% presented with a triad of conjunctivitis, fever, and rash. Less frequent symptoms included dysgeusia and nightmares, which, together with arthralgia, persisted for several weeks in some travelers. CONCLUSIONS Zika virus clinical picture in travelers is diverse. Prolonged symptoms may occur.

Zika Virus Disease in Traveler Returning from Vietnam to Israel.

To the Editor: On February 1, 2016, the World Health Organization designated the Zika virus disease outbreak in Latin America as a Public Health Emergency of International Concern (1). Genetic and epidemiological data suggest that Zika virus had been present in Southeast Asia since the 1940s (2); however, the disease burden and geographic extent of Zika virus disease in Asia are not clear. Occasional cases in some Asian countries, mostly in returning travelers, have recently been documented (3–5); however, as of February 2016, none were in Vietnam.

Capillary Leakage in Travelers with Dengue Infection: Implications for Pathogenesis

Dengue hemorrhagic fever is characterized by the presence of a capillary leak syndrome. Its pathogenesis is presumed to differ from that of classical dengue fever (DF) and to be associated with secondary dengue infection. Returning travelers given a diagnosis of DF were evaluated for capillary leakage with abdominal sonography. Data were compared between travelers with primary/secondary infection defined by epidemiologic and serologic parameters. A total of 12 (34.3%) of 35 patients had sonographic signs of capillary leakage. Most (85%) patients with capillary leakage had classical DF. Capillary leak was diagnosed in 32% of primary dengue cases and in 40% of secondary dengue cases (P = 0.69). The two patients given a diagnosis of dengue hemorrhagic fever had primary infections. The high prevalence of capillary leakage among travelers, most of them with primary exposure to dengue, calls into question the importance of secondary infection in causing capillary leakage in dengue infection.