How to cite this article: Del Carpio-Orantes L. [Emerging Arboviroses in Mexico: chikunguña and zika]. Rev Med Inst Mex Seguro Soc. . 2016 May-Jun;54(3):278-9.
LETTERS TO THE EDITOR
Luis Del Carpio-Orantesa
aDepartamento de Medicina Interna, Hospital General de Zona 71, Instituto Mexicano del Seguro Social, Veracruz, México
Communication with: Luis Del Carpio-Orantes
Arboviruses are characterized by being transmitted from animals to humans through blood-sucking arthropod vectors (Aedes mosquitoes abound in our area, primarily Aedes aegypti and to a lesser extent A. albopictus). They have ample worldwide distribution, especially in tropical and subtropical regions of the world where they are considered endemic. We distinguish between 300 and 400 species, of which one third affect people and 40 of them cause defined clinical conditions and generate emergent diseases.1
Arboviruses can generate three well-established clinical syndromes, although they are not exclusive to one virus or another, and one of these alone can even cause the three conditions to a greater or lesser extent. These are:
We are currently seeing in both Europe and in Americas the emergence of arboviruses that were considered typical of Asia and Africa, probably favored by human migration; but climate change has also been a detonator, as change in climates that were initially cold or non-tropical, with global warming, heat waves, and the increasing polar temperatures, has led to reported cases of purely tropical and subtropical viral diseases, such as dengue, in circumpolar cities and countries. Such is the case of Uruguay and Argentina, which have had cases of this viral disease lately, which was considered rare and unusual, and which it has still not been able to defeat despite ample information on the waves in America during the late seventies and early eighties.1,2
Now, Latin America has been surprised by the advent of a new viral disease that was considered proper to Africa and Asia: the chikungunya virus, characterized by a febrile syndrome similar to dengue, but with greater predilection for polyarticular involvement, which, without prompt treatment, can lead to severe reactive arthritis and become chronic, with great functional limitation of the patient; however, unlike dengue, there is no greater hematologic or organic involvement.
The 2013 outbreak in the Islands of St. Martin in the Caribbean rocked all Latin America, since from that location it affected Central and South America, and is currently touring the southern border of North America; just in Chiapas, Mexico, there have been ten thousand suspected cases; however, through July 2015, only 524 cases had been confirmed. As it was an emerging viral disease and the pandemic was not anticipated, in many cases there is underreporting because the infrastructure necessary for serological diagnosis, which takes days to come back, is not there. However, given the clinical and biochemical features presented by this viral disease, there has been effort to differentiate it from dengue and give it treatment, although the chronicity of injuries and functional limitations this brings remain to be seen.3-5
On the other hand, another virus made its appearance in 2014, zika, which like chikungunya was considered endemic to regions of Oceania, Africa, and Asia. This virus was reported in one case in Chile and one in Brazil in 2015. Zika is a dengue-like viral disease, but with higher conjunctival and skin involvement, and despite registered cases of severe neurological involvement (cases of Guillain-Barré syndrome) during an outbreak in Micronesia, there have been no reported deaths from this cause, so this viral disease has a benign course with mild, self-limited involvement (Table I). It apparently will take the same path of spread as the chikungunya virus, favored by the abundance of local blood-sucking arthropods. However, through February 2016 and after the surge in South America, three confirmed deaths by zika have been reported in Colombia and one in Brazil.4,6
|Vector||Aedes aegypti Aedes albopictus||Aedes aegypti Aedes albopictus||Aedes aegypti Aedes hensilii Aedes polynesiensis|
|Virus||Arbovirus (flavivirus) DEN-1, DEN-2, DEN-3, DEN-4||Arbovirus (alphavirus) Chikungunya virus (CHIK)||Arbovirus (flavivirus) Zika virus|
|Origin (first world outbreak, global expansion, and first outbreak in America)||Australia (cases of hemorrhagic fever in Queensland, 1898) First outbreak (Greece, 1928; Manila, 1953) Spread to Europe, Asia, Oceania, and America (Jamaica and Puerto Rico), 1977-1978; Cuba, 1980)||Africa (Tanzania, 1952) Spread to Asia America (Island of St. Martin in the Caribbean, 2013)||Africa (Uganda, 1967) Spread to Oceania and Asia America (Chile, 2014; Brazil, 2015)|
|Clinical and biochemical signs||Acute febrile syndrome, Myalgia, arthralgia, rash (in addition to leukopenia), lymphopenia, thrombocytopenia, Hemorrhagic syndrome with multiple organ damage (renal, hepatic, hematological, (pulmonary, etc)||Acute febrile syndrome, Myalgia, arthralgia, rash. Frequent leukopenia or lymphopenia, rarely thrombocytopenia. Hemorrhagic syndrome with multiple organ damage (rare)||Acute febrile syndrome, Myalgia, arthralgia, rash. Frequent leukopenia or lymphopenia, rarely thrombocytopenia Rare neurological involvement|
|Most characteristic data||Headache Myalgia, arthralgia Cutaneous rash||-Polyarthralgia -Severe reactive arthritis, can be chronic and simulate Rheumatoid arthritis||-Non-purulent conjunctivitis -Severe skin rash (maculopapular)|
|Diagnosis||-NS1 -IgM and IgG - Viral RT-PCR||-Viral culture (1-3 days) -IgM and IgG (3-5 weeks) - Viral RT-PCR (first 3 days)||-IgM and IgG (5-6 days) - Viral RT-PCR (first 3 days)|
|Treatment||No specific treatment, only symptomatic, can require intensive care No effective vaccine so far||No specific treatment, only symptomatic NSAIDs, FARMES, steroids for reactive arthritis have been used No effective vaccine so far||No specific treatment, only symptomatic No effective vaccine so far|
|Prognosis||Variable, depending on the severity of signs||Variable, depending on the severity of signs||Variable, depending on the severity of signs|
Given the above, it is important for the medical community to be aware of the appearance of new viral diseases, and not underestimate the incidence of cases, attempting at all times to document the diagnosis for a reliable statistic that helps to generate protocols for timely diagnosis and treatment and limit the damage (secondary and tertiary prevention).
Similarly, we must encourage health authorities to improve health infrastructure for these epidemiological threats as they are emerging pandemics that often leave no time for proper planning, and all health systems must be prepared to face them. At present, the southern region of Mexico does not have the equipment for rapid diagnosis, and it usually takes between seven and 10 days, as it is referred to state and national public health laboratories belonging to the Instituto de Diagnóstico y Referencia Epidemiológicos, whose catalog currently only does chikungunya detection by real-time quantitative polymerase chain reaction (RT-qPCR). This is also not available for the entire population, and one must say that some private sector hospitals only do IgM antibody detection. There is no diagnostic method for zika virus in Mexico, probably because the possibility of a pandemic in this region is remote; however, as has been widely reported, arboviruses have the virulence, infectivity, and pathogenicity necessary to cause pandemics quickly, so it would be good to begin planning rapid diagnostic protocols for better contingency and treatment planning.7