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Monthly Archive for "June 2019"

Asymptomatic &Burden &Dengue &Diagnosis &Ebola &Elimination &Epidemiology &Health Systems &ITNs &MDA &Mosquitoes &NTDs &Schistosomiasis &Schools &Vector Control &Zoonoses Bill Brieger | 30 Jun 2019

The Weekly Tropical Health News 2019-06-29

Below we highlight some of the news we have shared on our Facebook Tropical Health Group page during the past week.

Polio Persists

If all it took to eradicate a disease was a well proven drug, vaccine or technology, we would not be still reporting on polio, measles and guinea worm, to name a few. In the past week Afghanistan reported 2 wild poliovirus type 1 (WPV1) cases, and Pakistan had 3 WPV1 cases. Circulating vaccine-derived poliovirus type 2 (cVDPV2) was reported in Nigeria (1), DRC (4) and Ethiopia (3) from healthy community contacts.

Continued Ebola Challenges

In the seven days from Saturday to Friday (June 28) there were 71 newly confirmed Ebola Cases and 56 deaths reported by the Democratic Republic of Congo’s Ministry of Health. As Ebola cases continue to pile up in the Democratic Republic of the Congo (DRC), with 12 more confirmed Thursday and 7 more Friday, a USAID official said four major donors have jump-started a new strategic plan for coordinating response efforts. To underscore the heavy toll the outbreak has caused, among its 2,284 cases, as noted on the World Health Organization Ebola dashboard today, are 125 infected healthcare workers, including 2 new ones, DRC officials said.

Pacific Standard explained the differences in Ebola outbreaks between DRC today and the West Africa outbreak of 2014-16. On the positive side are new drugs used in organized trials for the current outbreak. The most important factor is safe, effective vaccine that has been tested in 2014-16, but is now a standard intervention in the DRC. While both Liberia and Sierra Leone had health systems and political weaknesses as post-conflict countries, DRC’s North Kivu and Ituri provinces are currently a war zone, effectively so for the past generation. Ebola treatment centers and response teams are being attacked. There are even cultural complications, a refusal to believe that Ebola exists. So even with widespread availability of improved technologies, teams may not be able to reach those in need.

To further complicate matters in the DRC, Doctors Without Borders (MSF) “highlighted ‘unprecedented’ multiple crises in the outbreak region in northeastern DRC. Ebola is coursing through a region that is also seeing the forced migration of thousands of people fleeing regional violence and is dealing with another epidemic. Moussa Ousman, MSF head of mission in the DRC, said, ‘This time we are seeing not only mass displacement due to violence but also a rapidly spreading measles outbreak and an Ebola epidemic that shows no signs of slowing down, all at the same time.’”

NIPAH and Bats

Like Ebola, NIPAH is zoonotic, and also involves bats, but the viruses differ. CDC explains that, “Nipah virus (NiV) is a member of the family Paramyxoviridae, genus Henipavirus. NiV was initially isolated and identified in 1999 during an outbreak of encephalitis and respiratory illness among pig farmers and people with close contact with pigs in Malaysia and Singapore. Its name originated from Sungai Nipah, a village in the Malaysian Peninsula where pig farmers became ill with encephalitis.

A recent human outbreak in southern India has been followed up with a study of local bats. In a report shared by ProMED, out of 36 Pteropus species bats tested for Nipah, 12 (33%) were found to be positive for anti-Nipah bat IgG antibodies. Unlike Ebola there are currently no experimental drugs or vaccines.

Climate Change and Dengue

Climate change is expected to heighten the threat of many neglected tropical diseases, especially arboviral infections. For example, the New York Times reports that increases in the geographical spread of dengue fever. Annually “there are 100 million cases of dengue infections severe enough to cause symptoms, which may include fever, debilitating joint pain and internal bleeding,” and an estimated 10,000 deaths. Dengue is transmitted by Aedes mosquitoes that also spread Zika and chikungunya. A study, published Monday in the journal Nature Microbiology, found that in a warming world there is a strong likelihood for significant expansion of dengue in the southeastern United States, coastal areas of China and Japan, as well as to inland regions of Australia. “Globally, the study estimated that more than two billion additional people could be at risk for dengue in 2080 compared with 2015 under a warming scenario.”

Schistosomiasis – MDA Is Not Enough, and Neither Are Supplementary Interventions

Schistosomiasis is one of the five neglected tropical diseases (NTDs) that are being controlled and potentially eliminated through mass drug administration (MDA) of preventive chemotherapy (PCT), in this case praziquantel. In The Lancet Knopp et al. reported that biannual MDA substantially reduced Schistosomiasis haematobium prevalence and infection intensity but was insufficient to interrupt transmission in Zanzibar. In addition, neither supplementary snail control or behaviour change activities did not significantly boost the effect of MDA. Most MDA programs focus on school aged children, and so other groups in the community who have regular water contact would not be reached. Water and sanitation activities also have limitations. This raises the question about whether control is acceptable for public health, or if there needs to be a broader intervention to reach elimination?

Trachoma on the Way to Elimination

Speaking of elimination, WHO has announced major “sustained progress” on trachoma efforts. “The number of people at risk of trachoma – the world’s leading infectious cause of blindness – has fallen from 1.5 billion in 2002 to just over 142 million in 2019, a reduction of 91%.” Trachoma is another NTD that uses the MDA strategy.

The news about NTDs from Dengue to Schistosomiasis to Trachoma is complicated and demonstrates that putting diseases together in a category does not result in an easy choice of strategies. Do we control or eliminate or simply manage illness? Can our health systems handle the needs for disease elimination? Is the public ready to get on board?

Malaria Updates

And concerning being complicated, malaria this week again shows many facets of challenges ranging from how to recognize and deal with asymptomatic infection to preventing reintroduction of the disease once elimination has been achieved. Several reports this week showed the particular needs for malaria intervention ranging from high burden areas to low transmission verging on elimination to preventing re-introduction in areas declared free from the disease.

In South West, Nigeria Dokunmu et al. studied 535 individuals aged from 6 months were screened during the epidemiological survey evaluating asymptomatic transmission. Parasite prevalence was determined by histidine-rich protein II rapid detection kit (RDT) in healthy individuals. They found that, “malaria parasites were detected by RDT in 204 (38.1%) individuals. Asymptomatic infection was detected in 117 (57.3%) and symptomatic malaria confirmed in 87 individuals (42.6%).

Overall, detectable malaria by RDT was significantly higher in individuals with symptoms (87 of 197/44.2%), than asymptomatic persons (117 of 338/34.6%)., p = 0.02. In a sub-set of 75 isolates, 18(24%) and 14 (18.6%) individuals had Pfmdr1 86Y and 1246Y mutations. Presence of mutations on Pfmdr1 did not differ by group. It would be useful for future study to look at the effect of interventions such as bednet coverage. While Southwest Nigeria is a high burden area, the problem of asymptomatic malaria will become an even bigger challenge as prevalence reduces and elimination is in sight.

Sri Lanka provides a completely different challenge from high burden areas. There has been no local transmission of malaria in Sri Lanka for 6 years following elimination of the disease in 2012. Karunasena et al. report the first case of introduced vivax malaria in the country by diagnosing malaria based on microscopy and rapid diagnostic tests. “The imported vivax malaria case was detected in a foreign migrant followed by a Plasmodium vivax infection in a Sri Lankan national who visited the residence of the former. The link between the two cases was established by tracing the occurrence of events and by demonstrating genetic identity between the parasite isolates. Effective surveillance was conducted, and a prompt response was mounted by the Anti Malaria Campaign. No further transmission occurred as a result.”

Bangladesh has few but focused areas of malaria transmission and hopes to achieve elimination of local transmission by 2030. A particular group for targeting interventions is the population of slash and burn cultivators in the Rangamati District. Respondents in this area had general knowledge about malaria transmission and modes of prevention and treatment was good according to Saha and the other authors. “However, there were some gaps regarding knowledge about specific aspects of malaria transmission and in particular about the increased risk associated with their occupation. Despite a much-reduced incidence of malaria in the study area, the respondents perceived the disease as life-threatening and knew that it needs rapid attention from a health worker. Moreover, the specific services offered by the local community health workers for malaria diagnosis and treatment were highly appreciated. Finally, the use of insecticide-treated mosquito nets (ITN) was considered as important and this intervention was uniformly stated as the main malaria prevention method.”

Kenya offers some lessons about low transmission areas but also areas where transmission may increase due to climate change. A matched case–control study undertaken in the Western Kenya highlands. Essendi et al. recruited clinical malaria cases from health facilities and matched to asymptomatic individuals from the community who served as controls in order to identify epidemiological risk factors for clinical malaria infection in the highlands of Western Kenya.

“A greater percentage of people in the control group without malaria (64.6%) used insecticide-treated bed nets (ITNs) compared to the families of malaria cases (48.3%). Low income was the most important factor associated with higher malaria infections (adj. OR 4.70). Houses with open eaves was an important malaria risk factor (adj OR 1.72).” Other socio-demographic factors were examined. The authors stress the need to use local malaria epidemiology to more effectively targeted use of malaria control measures.

The key lesson arising from the forgoing studies and news is that disease control needs strong global partnerships but also local community investment and adaptation of strategies to community characteristics and culture.

Borders &Diagnosis &Ebola &Elimination &Eradication &Health Systems &Measles &Surveillance &Vaccine &Yaws Bill Brieger | 22 Jun 2019

The Weekly Tropical Health News Update 2019-06-22

For almost 20 years we have been maintaining an email list where current news and articles have been shared with those interested in tropical health and malaria. The listserve host we have been using is changing to a paid model. While there are still some free listserve options, these are cumbersome to produce. Since we are already maintaining this blog, we thought it best to provide a weekly summary of key news events through this medium.

Mapping Plasmodium Vivax

The Malaria Atlas Project has published in The Lancet a global burden of Plasmodium Vivax mapping study. The authors describe the contribution of this study as: “Our study highlights important spatial and temporal patterns in the clinical burden and prevalence of P vivax. Amid substantial progress worldwide, plateauing gains and areas of increased burden signal the potential for challenges that are greater than expected on the road to malaria elimination. These results support global monitoring systems and can inform the optimisation of diagnosis and treatment where P vivax has most impact.”

Ebola Spread from DRC to Uganda

Since the major ongoing outbreak of Ebola Virus Disease in North Kivu and Ituri Provinces of the Democratic Republic of Congo (DRC) started nearly a year ago, there has been concern that the disease might spread to neighboring countries like Uganda, Rwanda, South Sudan and the Central African Republic. This fear same true recently when a family affected by Ebola crossed from DRC into Uganda to connect with relatives in Kasese District Uganda. Uganda has had many years’ experience dealing with Ebola and was able to contain the situation.

A press release this week noted that, “As of today (21 June 2019), Uganda has not registered any new confirmed Ebola Virus Disease (EVD) case in Kasese District or any other part of Uganda since the last registered case one week ago. There are no new suspect cases under admission. Currently, 110 contacts to the confirmed Ebola cases in Kagando and Bwera are being followed up daily. A total of 456 individuals have been vaccinated against EVD using the Ebola-rVSV vaccine in Kasese District, Western Uganda.”

Although many people expected that the meeting of the “International Health Regulations (2005) Emergency Committee} for Ebola virus disease in the Democratic Republic of the Congo would finally declare the current outbreak a Public Health Emergency of International Concern (PHEIC) because it crossed a border, the result was noting that the challenge was still an emergency only for DRC. WHO did note that there were serious funding gaps and support from other countries for the DRC’s predicament. Ironically, such gaps make it more likely that Ebola can spread more widely.

As of 21 June 2019, the DRC reported a total of 2,211 cases since the start of the epidemic last year, of which 2,117 have been confirmed and 94 are probable. There have been 1,489 deaths. To date 139,027 persons have been vaccine with the Merck rVSV-ZEBOV vaccine.

Progress toward Eliminating Malaria – the E-2020 Countries

The process of eliminating malaria from the world needs to start in a step-by-step fashion. WHO explained that, “Creating a malaria-free world is a bold and important public health and sustainable development goal. It is also the vision of the Global technical strategy for malaria 2016-2030, which calls for the elimination of malaria in at least 10 countries by the year 2020.”

Actually, WHO identified 21 countries, spanning 5 regions, that could defeat malaria by 2020. The progress report charts the effort. During the recent World Health Assembly two countries received recognition for being certified malaria-free, Argentina and Algeria. This week WHO also announced that 5 more countries have not had malaria cases in the past year. There was also release of a downloadable report on progress toward the 2020 target for selected countries.

Reconsidering Yaws Eradication

In the 1950s and 1960s the world focused on the possibility of eradicating Yaws through screening and treatment interventions. Like the early malaria eradication programs from the same period, the Yaws effort slowed, stopped and experienced a resurgence. The Telegraph reported that, “Between 1952 and 1964, Unicef and the WHO screened some 300 million people for the illness, in a coordinated programme which treated more than 50 million cases. Yaws was on the brink of being wiped out and reports of the disease dropped by 95 per cent.” WHO continues to work on treatment strategies with azithromycin and for resistant cases, benzathine benzylpenicillin injection.

WHO noted that there were 80,472 cases reported in 2018, although this figure is likely to be much higher in actuality. The challenge of case detection exists but may be overcome, according to the Telegraph with a new molecular rapid diagnostic test which detects yaws within 30 minutes, and thus could allow on-the-spot diagnosis in remote regions.

Measles Cases Continue to Increase

The problem of measles in the DRC may not be receiving much attention because of the Ebola epidemic. Ironically, Outbreak News Today reports that, “In a follow-up on the measles outbreak in the Democratic Republic of the Congo (DRC), UN health officials report an additional 7500 suspect cases in the past 2 weeks, bringing the total cases since the beginning of the year to 106,870. The death toll due to the measles outbreak has reached 1815 deaths (case fatality ratio 1.7%).”

Vaccine coverage challenges in the DRC result from health systems weaknesses. Unfortunately, a global study has shown that increasing cases in the Global North are not due to weak systems, but ‘vaccine hesitancy.’ The Guardian reports that a global survey has revealed the scale of the crisis of confidence in vaccines in Europe, “showing that only 59% of people in western Europe and 50% in the east think vaccines are safe, compared with 79% worldwide.” The Guardian observes that, “In spite of good healthcare and education systems, in parts of Europe there is low trust in vaccines. France has the highest levels of distrust, at 33%.”

For more news and daily updates check our other services, a closed/private Facebook Group and a Twitter feed. For those who do not use social media, please check here each weekend to find a summary of some of the stories we have shared during the week.

Migration &Refugee Bill Brieger | 20 Jun 2019

Refugees and Malaria

The 2019 Theme of World Refugee Day is #StepWithRefugees – Take A Step on World Refugee Day. Taking steps in solidarity with refugees ensures that one recognizes that refugees experience several health problems, with malaria being especially devastating. Refugees may come from a malaria endemic area and move to one where there is no malaria and health workers may not recognize and treat it correctly. In contrast they may move from a non-endemic area into one with malaria transmission. Even if refugees move from one malarious area to another, the conditions of the camps where they shelter may lead to increased malaria morbidity and mortality.

In fact, Jamie Anderson and colleagues observe that, “Almost two-thirds of refugees, internally displaced persons, returnees and other persons affected by humanitarian emergencies live in malaria endemic regions. Malaria remains a significant threat to the health of these populations.” They found that, “an average of 1.18 million refugees resided in 60 refugee sites within nine countries with at least 50 cases of malaria per 1000 refugees during the study period 2008-2009,” a major disease burden. According to the authors, groups like UNHCR and the UN Foundation’s Nothing But Nets aim to increase LLIN coverage of vulnerable groups in emergency situations.

The US Centers for Disease Control and Prevention offers guidance to health staff in the United States who may encounter refugees coming from a malaria endemic country. These guidelines look at appropriate treatment regimens for either pre-travel or on arrival presumptive treatment. They address the challenges of sub-clinical disease, as well as testing and treatment for people with symptoms. Likewise, the Refugee Technical Assistance Center stresses the need for, “All refugees from malaria endemic areas, including those who have been presumptively treated for P. falciparum, should be tested for malaria if they develop clinical signs or symptoms of the disease.” Stefan Collinet-Adler et al. found that “Overseas presumptive therapy has greater cost-benefits than U.S. based screening and treatment strategies.”

The challenge of refugees moving from one endemic country, such as Burundi, to another was highlighted by MSF staff in Tanzania. Saschveen Singh reported that she, “was well versed in the emergency management of these cases from my previous training and from reading all the MSF clinical guidelines. But it was quite overwhelming to see how many admissions we had on the wards, and to see the outpatient area absolutely overflowing with patients with malarious fevers, and the number of our Burundian staff succumbing to the disease. With malaria, the worst of the worst cases are sadly always children.”

A few years ago, the US President’s Malaria Initiative in Kenya contributed to indoor residual spraying at a refugee camp. “Malaria has also been a recurrent problem in Kakuma Refugee Camp, particularly following large-scale population influxes from South Sudan, where malaria is endemic. Both ITNs and IRS have been used historically for malaria prevention in the camp along with prompt, effective case management for persons diagnosed with malaria. With the pyrethroid donation from PMI-Kenya, NRC implemented a successful IRS program,” covering an estimated 143,000 people.

It is encouraging to note that many agencies, international and domestic, and not just those specializing in refugee needs, lend a hand guaranteeing that refugees have a right to basic malaria prevention and treatment.