The Zika virus con­tinues to spread, with WHO pre­dicting that as many as 4 mil­lion people could be infected by the end of the year. As of Feb. 10, there were 52 cases in the U.S. asso­ci­ated with travel abroad, according to the Cen­ters for Dis­ease Con­trol and Pre­ven­tion. Sus­pected to be asso­ci­ated with the birth defect micro­cephaly and the par­a­lyzing Guillain-​​Barré Syn­drome, Zika remains a con­stant in the news as gov­ern­ments scramble to warn their cit­i­zens about the risks.

In this in-​​depth Q&A, Richard Wamai, assis­tant pro­fessor in the Depart­ment of African Amer­ican Studies and an expert in inter­na­tional global health and devel­op­ment, talks about the Zika virus’s his­tory, puz­zling tra­jec­tory, and public health inter­ven­tions that could stem its spread.


Both Drs. Wilson Savino, director of a top Brazilian health­care insti­tu­tion, and Anthony Fauci, director of the National Insti­tutes of Health, have com­pared the Zika virus crisis to the HIV/​AIDS crisis of the 1980s, regarding the speed of the spread and the lack of sci­en­tific knowl­edge about the dis­ease. What sim­i­lar­i­ties and dis­sim­i­lar­i­ties do you see between the two, and how might we use our expe­ri­ence with HIV/​AIDS to inform our response to Zika?

My per­spec­tive is that there is a greater lack of knowl­edge about Zika virus than HIV both within the sci­en­tific com­mu­nity and the gen­eral pop­u­la­tion. HIV was first reported in the U.S. in a 1981 article by the CDC, but sci­en­tists now date the emer­gence to the 1940s and date the period of igni­tion and cir­cu­la­tion in sub-​​Saharan Africa to between the 1880s and 1950s. It then left Africa in the 1960s through Haiti. Sci­en­tific debate about HIV crys­tal­ized in the 1980s, after which gen­er­al­ized knowl­edge about it spread like fire around the world.

In con­trast, most people’s knowl­edge about Zika virus is prob­ably just about a month old. The Zika virus was dis­cov­ered in a cap­tive monkey in Uganda in 1947 during studies spon­sored by the Rock­e­feller Foun­da­tion on yellow fever, and the first human cases were reported in 1952 in Uganda and Tan­zania. While there have been out­breaks in Africa and else­where, it is only now that the world is learning about Zika virus.

There are more dif­fer­ences than sim­i­lar­i­ties between these two diseases.


Zika virus has been linked to micro­cephaly, a birth defect wherein a baby’s head is smaller than expected when com­pared to babies of the same sex and age. Babies with micro­cephaly often have smaller, under­de­vel­oped brains. Image by the Cen­ters for Dis­ease Con­trol and Prevention

For starters, the genetic makeup of HIV and Zika virus are dif­ferent, and thus the dis­eases they cause follow dif­ferent tra­jec­to­ries. HIV takes a long time to pro­duce dis­ease and, if not treated, has severe symp­toms over time including wasting and death from AIDS. Zika virus has mild symp­toms, and deaths due to it are very rare. Zika has been sus­pected of causing micro­cephaly and Guillain-​​Barré syn­drome, but there is no defin­i­tive proof yet, according to WHO’s latest report. It is puz­zling that micro­cephaly was not a widely asso­ci­ated out­come in past Zika virus out­breaks in Africa or else­where. A WHO bul­letin being con­sid­ered for peer-​​reviewed pub­li­ca­tion sup­ports ear­lier research sug­gesting that the char­acter of the virus in the cur­rent out­break in South America has changed from the African and Asian types.

The mode of trans­mis­sion of HIV and Zika virus is also dif­ferent. Unlike HIV, Zika virus is trans­mitted pri­marily by an infected mos­quito, the Aedes aegypti. HIV is trans­mitted pri­marily through blood and unpro­tected sex; a couple of cases of Zika have been found to be trans­mitted that way, but they are atypical.

The world has changed so much since the emer­gence of the HIV epi­demic in the 1980s. At that time there was denial and stigma at both the public and gov­ern­mental levels. Pol­i­cy­makers’ ini­tial reac­tion to HIV was a dis­aster in the U.S. and abroad. For example, it took decades, from 1981 to 2000, for suf­fi­cient funds to be mobi­lized for testing and treat­ment pro­grams in sub-​​Saharan Africa when mil­lions were dying.

There is no doubt that cli­mate change con­tributes to the spread of mosquito-​​borne dis­eases.
— Richard Wamai, assis­tant pro­fessor

For the Zika virus, in con­trast, there has been no denial, though stigma for chil­dren with micro­cephaly and their mothers is no doubt a con­cern. WHO and the inter­na­tional com­mu­nity reacted strongly to Zika, including des­ig­nating it an inter­na­tional public health emer­gency in record time. This may have been an over­re­ac­tion, with WHO trying to com­pen­sate for its slow des­ig­na­tion of Ebola as an emer­gency after wide­spread crit­i­cism in the media and sci­en­tific journals.

As for the lesson that stands out from our expe­ri­ence with HIV/​AIDS and Ebola: Given that out­breaks may be more common in the future, we need a global health infra­struc­ture capable of a more ver­sa­tile rapid response than has been the case. This requires invest­ments in out­break and emerging/​emergent dis­ease sur­veil­lance, early warning sys­tems, and pre­pared­ness programs.

Trop­ical dis­eases such as Zika and dengue are migrating north­ward, including to the United States, as a result of cli­mate change and cheaper, more fre­quent travel. How do these fac­tors con­tribute to the spread of these dis­eases, and what can we do to pre­vent it?
There is no doubt that cli­mate change con­tributes to the spread of mosquito-​​borne dis­eases. Warming weather expands the geo­graphic range of dis­ease car­riers that thrive pre­dom­i­nantly in the tropics. It also means longer breeding cycles and increased rates of insect sur­vival. A. aegypti had been elim­i­nated in the U.S. in ear­lier cam­paigns to erad­i­cate yellow fever in the South; how­ever, a recent report described the per­sis­tence of those mos­qui­toes through low winter tem­per­a­tures in the neigh­bor­hoods of Wash­ington, D.C. A U.N. report notes that the cur­rent El Niño event may be con­tributing to the spread of the Zika virus.

Zika has, once again, brought to the fore the urgent need for WHO, gov­ern­ments, and insti­tu­tions including uni­ver­si­ties to invest in research on the basic sci­ences, epi­demi­ology, and health sys­tems.
— Richard Wamai, assis­tant pro­fessor

Regarding travel, most cer­tainly yes: it is a huge factor. The world has become small, with rapid air– and ground-​​transportation sys­tems. The cases Zika trans­mitted through sexual con­tact and blood trans­fu­sion, how­ever, point up the risks of travel for those not even vis­iting endemic areas. There are a few cases of what is known as Odyssean Malaria, where mos­qui­toes infected with malaria have been imported from endemic areas; that could happen with Zika-​​carrying mos­quitos as well.

But those are anom­alies. The bigger problem is at-​​risk people trav­eling to endemic areas. While coun­tries may advise their cit­i­zens to avoid cer­tain coun­tries or areas—as the CDC has done—to pre­vent cir­cu­la­tion and migra­tion of dis­ease, sur­veil­lance sys­tems, both domestic and global, are needed. Ebola taught us the impor­tance of insti­tuting screening for all travelers—not just for those coming from endemic coun­tries. I remember under­going screening with thermal tech­nolo­gies that detect high fever when I entered Kenya in the summer of 2015. There was, how­ever, no such screening on my return to Boston.

Why do sci­en­tists and the med­ical com­mu­nity know so little about the Zika virus? Why were we all so unprepared?

Zika has, once again, brought to the fore the urgent need for WHO, gov­ern­ments, and insti­tu­tions including uni­ver­si­ties to invest in research on the basic sci­ences, epi­demi­ology, and health sys­tems, and the value of studies in global health, including sur­veil­lance, given the rapidity with which dis­eases can now travel. Clearly, even after the pre-​​colonial Zika cases in sub-​​Saharan Africa and the spread to Micronesia, South Asia, and ulti­mately the southern part of the Western Hemi­sphere, not much was ever done.

October 30, 2014 - Assistant Professor of Public Health Richard Wamai researches health systems, HIV/AIDS and neglected tropical diseases (NTDs).

Richard Wamai, assis­tant pro­fessor in the Depart­ment of African Amer­ican Studies, is an expert in inter­na­tional global health and devel­op­ment. Photo by Brooks Canaday/​Northeastern University

For many years now, WHO and the CDC have sup­ported a pro­gram called Inte­grated Dis­ease Sur­veil­lance and Response in Africa. Unfor­tu­nately, many coun­tries with weak health sys­tems in sub-​​Saharan Africa still do not have robust IDSRs. It is promising that the CDC has signed a mem­o­randum with the African Union to sup­port an African Cen­tres for Dis­ease Con­trol and Pre­ven­tion. WHO should strengthen its Global Out­break Alert and Response Net­work, and African coun­tries should build the Africa Field Epi­demi­ology Net­work. Aca­d­emic insti­tu­tions should increase the avail­able tech­nical exper­tise by training stu­dents in areas like epi­demi­ology; it is notable that many African coun­tries have fewer epi­demi­ol­o­gists than are needed for main­taining effec­tive dis­ease vigilance.

From a public health per­spec­tive, what rec­om­men­da­tions should author­i­ties make regarding the 2016 Summer Olympics in Rio de Janeiro?

These games should go on. Since the symp­toms and most out­comes from the Zika virus are mild, the main worry is micro­cephaly in chil­dren and Guillain–Barré syn­drome. It is note­worthy that the WHO emer­gency dec­la­ra­tion sprang from sus­pi­cion of these two out­comes rather than the Zika-​​virus infec­tion itself. There are no known severe dan­gers to the gen­eral adult pop­u­la­tion. Brazil has already deployed about a quarter-​​million sol­diers to help track cases and con­trol the mos­quito pop­u­la­tion. Classic public health mea­sures like these should be con­tinued. Those mea­sures, as well as pro­tecting preg­nant women, are the most urgent. The com­mu­ni­ties affected must be a crit­ical part of the cam­paign against Zika. A third mea­sure is also cru­cial but will take time: devel­oping treat­ments and, better yet, a vac­cine. A race is already on regarding both. A ded­i­cated response to Ebola, from basic research to the imple­men­ta­tion of sur­veil­lance pro­grams, has shown that it is pos­sible to con­tain, con­trol, and ulti­mately elim­i­nate a disease.

Infec­tious dis­eases like these are a matter of global secu­rity, as the Global Health Risk Frame­work, pub­lished by the National Academy of Med­i­cine last month, shows. We are indeed living in inter­esting times regarding pan­demics; it is expected we will see major infectious-​​disease out­breaks more often. In this, global health is a matter of graver human secu­rity con­cern than nuclear war­fare. So it is encour­aging to see efforts like the No More Epi­demics Cam­paign emerge. Zika is yet another wake-​​up call.